Soil properties and enzymatic characterization of jackfruit (Artocarpus heterophyllus) varieties in Kerala

Table of contents

Table of figures

Table of tables

List of abbreviations

Chapter 1 General introduction
1. Introduction
2. Research objectives and hypothesis
3. Conclusions
References

Chapter 2
Effect of soil properties on the nutritional quality of jackfruit (Artocarpus heterophyllus) varieties in Southern parts of Kerala
Abstract
2.1. Introduction
2.1.1Taxonomical classification
2.2. Review of literature
2.3. Hypothesis
2.4. Materials and Methods
2.4.1 Collection of samples
2.4.2 Estimation of Organic Carbon (Walkley- Black method)
2.4.3 Estimation of Available Phosphorous (Ascorbic acid blue color method)
2.4.4 Estimation of Available Potassium
2.4.5 Estimation of Exchangeable Magnesium and Calcium
2.4.6 Estimation of Zinc, Copper and Manganese
2.4.7 Estimation of Electrical Conductance
2.4.8 Estimation of pH
2.4.9 Estimation of Bulk density
2.4.10 Estimation of starch by Anthrone Method
2.4.11 Estimation of reducing sugars by DNSA method
2.4.12 Proximate nutritional compositional analysis
2.4.13 Statistical analysis
2.5. Results and discussion
2.5.1 General soil characteristics
2.5.2 Proximate nutritional composition
2.6. Conclusions
Acknowledgements
References

Chapter 3 Analysis of factors affecting the sweetness among jackfruit (Artocarpus heterophyllus) varieties in Kerala: a brief overview
Abstract
3.1. Introduction
3.1.1Taxonomical classification
3.2. Review of literature
3.3. Hypothesis
3.4. Materials and Methods
3.4.1 Study area
3.4.2 Data and sample collection
3.4.3 Preparation of crude extract
3.4.4 Soil analysis
3.4.5 Determination of reducing sugar concentration before and after ripening of jackfruit
3.4.6 Determination of starch concentration before and after ripening of jackfruit
3.4.7 Determination of activity of crude enzyme (Amylase) extracted from different jack fruit at pH 5.2
3.4.8 Determination of activity of crude enzyme (Amylase) extracted from different jack fruit at room temperature
3.4.9 Pxoximate analysis
3.4.10 Statistical analysis
3.5. Results and discussion
3.5.1 Estimation of Dry matter & moisture content
3.5.2 Estimation of crude protein
3.5.3 Estimation of crude fat
3.5.4 Estimation of crude ash
3.5.5 Estimation of crude fibre
3.6. Conclusions
Acknowledgements
References

Chapter 4 General discussion and conclusions

4.1. General overview of the study approch

4.2. General conclusions

References

ACKNOWLEDGEMENTS

Firstly we thank God Almighty whose blessing were always with us and helped us to complete this project work successfully.

We wish to thank our beloved Manager Rev. Fr. Dr. George Njarakunnel, Respected Principal Dr. Joseph V.J, Vice Principal Fr. Joseph Allencheril, Bursar Shaji Augustine and the Management for providing all the necessary facilities in carrying out the study. We express our sincere thanks to Mr. Binoy A Mulanthra (lab in charge, Department of Biotechnology) for the support. This research work will not be possible with the co-operation of many farmers.

We are gratefully indebted to our teachers, parents, siblings and friends who were there always for helping us in this project.

Prem Jose Vazhacharickal*, Sajeshkumar N.K and Jiby John Mathew

*Address for correspondence

Assistant Professor

Department of Biotechnology

Mar Augusthinsoe College

Ramapuram-686576

Kerala, India

premjosev@gmail.com

Table of figures

Figure 2.1. Mean monthly rainfall (mm), maximum and minimum temperatures (°C) in Kerala, India (1871-2005; Krishnakumar et al., 2009).

Figure 2.2. Introduced and indigenous regions of Artocarpus heterophyllus around the world (Modified after; Haq, 2006).

Figure 2.3. Map of Kerala showing the various sample collection points (JK1 to JK7). JK8 and JK9 were not included in the map.

Figure 2.4. Morphological characters of jackfruit (Artocarpus heterophyllus Lam.).

Figure 2.5. Jackfruit trees a) jackfruit with varying sizes; b) different stages of fruiting; c) tree bearing fruits; d) fruits plucked; e) small type of jack fruit; f) jackfruit cut opened; g) jackfruit seeds; h) opened jackfruit flakes; i) flakes unopened.

Figure 2.6. Sample JK1 description a) jackfruit, b) spines c) stalk d) fruit stalk leaf, branch leaf, flake and seeds, e) vertical section of jackfruit, f) flakes, seed and spines, g) flake, seed and chakini.

Figure 2.7. Sample JK2 description a) jackfruit tree, b) flakes c) cross section of jackfruit d) fruit stalk leaf, branch leaf, flake and seeds, e) spines, f) flakes, seed and spines, g) seeds.

Figure 2.8. Sample JK3 description a) jackfruit, b) half opened portion of jackfruit, c) leaf, flake and spines, d) spines, flake and seeds, e) flake, f) seed and chakini.

Figure 2.9. Sample JK4 description a) jackfruit, b) fruit stalk, c) vertical section of jackfruit, d) & e) spines, f) fruit stock leaf, branch leaf, flake, seeds, chakini and spine, g) flake and seed.

Figure 2.10. Sample JK5 description a) jackfruit, b) spines, c) fruit stalk, d) leaf, flake with seed and spine, e) flake.

Figure 2.11. Sample JK6 description a) jackfruit, b) & c) spines d) vertical section of jackfruit, e) fruit stalk leaf, branch leaf, flake, seeds and spine, f) flake.

Figure 2.12. Sample JK7 description a) jackfruit, b) vertical section of jackfruit, c) pith d) fruit stalk leaf, branch leaf, flake, seeds and spine, e) leaf apex shape.

Figure 2.13. Sample JK8 description a) jackfruits, b) longitudinal section of jackfruit, c) flake, d) fruit stalk leaf, branch leaf, flake, seeds and spine, e) pith, f) intermediate spines.

Figure 2.14. Sample JK9 description a) jackfruit tree, b) branch contain jackfruits, c) jackfruit and its stalk, d) jackfruits, e) longitudinal section of Jack fruit, f) fruit stalk leaf, branch leaf, flake, seeds and spine, g) pith, h) flake.

Figure 3.15. Mean monthly rainfall (mm), maximum and minimum temperatures (°C) in Kerala, India (1871-2005; Krishnakumar et al., 2009).

Figure 3.16. Map of Kerala showing the various sample collection points (JK1 to JK7).

Figure 3.17. Sample JK1 description a) jackfruit, b) spines c) stalk d) fruit stalk leaf, branch leaf, flake and seeds, e) vertical section of jackfruit, f) flakes, seed and spines, g) flake, seed and chakini.

Figure 3.18. Sample JK2 description a) jackfruit tree, b) flakes c) cross section of jackfruit d) fruit stalk leaf, branch leaf, flake and seeds, e) spines, f) flakes, seed and spines, g) seeds.

Figure 3.19. Sample JK3 description a) jackfruit, b) half opened portion of jackfruit, c) leaf, flake and spines, d) spines, flake and seeds, e) flake, f) seed and chakini.

Figure 3.20. Sample JK4 description a) jackfruit, b) fruit stalk, c) vertical section of jackfruit, d) & e) spines, f) fruit stock leaf, branch leaf, flake, seeds, chakini and spine, g) flake and seed.

Figure 3.21. Sample JK5 description a) jackfruit, b) spines, c) fruit stalk, d) leaf, flake with seed and spine, e) flake.

Figure 3.22. Sample JK6 description a) jackfruit, b) & c) spines d) vertical section of jackfruit, e) fruit stalk leaf, branch leaf, flake, seeds and spine, f) flake.

Figure 3.23. Sample JK7 description a) jackfruit, b) vertical section of jackfruit, c) pith d) fruit stalk leaf, branch leaf, flake, seeds and spine, e) leaf apex shape.

Figure 3.24. Activity of crude enzyme (Amylase) extracted from different jackfruit (initial, before ripening) at room temperature and their corresponding pH.

Figure 3.25. Activity of crude enzyme (Amylase) extracted from different jackfruit (final, after ripening) at room temperature and their corresponding pH.

Figure 3.26. Activity of crude enzyme (Amylase) extracted from different jackfruit (final, after ripening) at 37 °C.

Table of tables

Table 2.1. Phenolic, flavinoid content and antioxidant activity of araticum, papaya and jackfruit in undigested and digested extracts (Modified after; Pavan et al., 2011).

Table 2.2. Biochemical difference in various jackfruit varieties in South India (Chrips et al., 2008).

Table 2.3. Uses of different jackfruit parts (Chrips et al., 2008).

Table 2.4. Uses of different lectins from jackfruit parts (Chrips et al., 2008).

Table 2.5. Different vernacular names of Artocarpus heterophyllus in India (Modified after; Baliga et al., 2011).

Table 2.6. Common names, uses and distribution of major Artocarpus species (Modified after; Jagtap and Bapat, 2010).

Table 2.7. Chemical composition of jackfruit (Modified after; Jagtap and Bapat, 2010).

Table 2.8. General description of the selected jackfruit varieties).

Table 2.9. Description of the jackfruit samples (JK1 to JK7#) and their special features.

Table 2.10. General features of jackfruit samples (JK1 to JK7#).

Table 2.11. Starch and sugar concentrations of jackfruit samples (JK1 to JK9).

Table 2.12. Soil properties and fruit features of jackfruit varieties (JK1 to JK9) in Kerala.

Table 3.13. Phenolic, flavinoid content and antioxidant activity of araticum, papaya and jackfruit in undigested and digested extracts (Modified after; Pavan et al., 2011).

Table 3.14. Biochemical difference various jackfruit varieties in South India (Chrips et al., 2008).

Table 3.15. Uses of different jackfruit parts (Chrips et al., 2008).

Table 3.16. Different vernacular names of Artocarpus heterophyllus in India (Modified after; Baliga et al., 2011).

Table 3.17. Common names, uses and distribution of major Artocarpus species (Modified after; Jagtap and Bapat, 2010).

Table 3.18. Chemical composition of jackfruit (Modified after; Jagtap and Bapat, 2010).

Table 3.19. Description of the jackfruit variety samples (JK1 to JK7) and their special features.

Table 3.20. General features of jackfruit variety samples (JK1 to JK7).

Table 3.21. Proximate composition of jackfruit variety samples on as such basis (JK1 to JK7).

Table 3.22. Proximate composition of jackfruit variety samples on dry matter basis (JK1 to JK7).

Table 3.23. Soil chemical composition of jackfruit variety samples on dry matter basis (JK1 to JK6).

Table 3.24. Starch, reducing sugar and enzyme activity of jackfruit variety samples (JK1 to JK6).

List of abbreviations

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Chapter 1 General introduction

1. Introduction

Artocarpus heterophyllus belong to the Moraceae family, colloquially jackfruit in English is native to India and seen abundant in Western Ghats (Jagadeesh et al., 2007a; Baliga et al., 2011; Reddy et al., 2014; Jagadeesh et al., 2007b; Prakash et al., 2009; Wangchu et al., 2013). Artocarpus heterophyllus belong to the Moraceae family, colloquially jack fruit in English is native to India and seen abundant in Western Ghats (Jagadeesh et al., 2007a; Baliga et al., 2011; Reddy et al., 2004; Jagadeesh et al., 2007b; Prakash et al., 2009; Wangchu et al., 2013). Besides India, jackfruit is commonly grown in home gardens of tropical and sub-tropical countries especially Sri Lanka; Bangladesh, Burma, Philippines, Indonesia, Thailand, Malaysia and Brazil (Jagadeesh et al., 2007b; Baliga et al., 2011; Dutta et al., 2011; Siti Balqis and Rosma, 2011; Lin et al., 2009; Saxena et al., 2009a Maia et al., 2004; Hameed, 2009). In India, it widely distributed in the states of Assam, West Bengal, Uttar Pradesh, Maharashtra, Kerala, Tamil Nadu and Karnataka (Wangchu et., 2013) and considered to be the ‘Poor man’s food’ (Jagadeesh et al., 2007a; Prakash et al., 2009). In Malayalam (regional language in Kerala, India) jackfruit is called as “Chakka” while the ancient Indian language Sanskrit refers as Atibruhatphala (Baliga et al., 2011; Haq, 2006; Prakash et al., 2009). The morphology of the tree varies with 10-30 m tall; with long tap root and desne crown (Wangchu et al., 2013) producing the largest tree born fruit in the world (Baliga et al., 2011; Prakash et al., 2009). The fruit weight up to 50 kg, but average weigh is considered to be 10 kg, while only 30-35% of the bulb is edible (Jagadeesh et al., 2007a; Baliga et al., 2011; Saxena et al., 2009b; Hameed, 2009; Swami et al., 2012; Selvaraj and Pal,1989).

Jackfruit is considered as national fruit in Bangladesh and highly appreciated in India due to cheap and availability in summer seasons were food is scarce (Muralidharan et al., 1997; Morton, 1987; Schnell et al., 2001). The fruit provide 2 MJ per kg/wet weight of ripe perianth and contain high levels of carbohydrates, protein, starch, calcium and vitamins (Swami et al., 2012; Ahmed et al., 1986; Burkill, 1997; Saxena et al., 2009a). Boiled and cooked jackfruit seeds are included in the diets which have 77% starch content, which is exploited as a potent source of starch (Bobbio et al., 1978; Tulyathan et al., 2002; Mukprasirt and Sajjaanantakul, 2004; Odoemelam, 2005). Jackfruit is widely used in culinary preparation, baking, candid jackfruit, baby food, jams, jellies, juice, chips, deserts and the advances in food processing technologies further expanded the possibilities (Burkill, 1997; Swami et al., 2012; Selvaraj and Pal, 1989; Narasimham, 1990; Roy and Joshi, 1995; Haq, 2006). Jackfruit is widely accepted by consumers, researchers and food industries due to the presence of bioactive compounds and diversity products made out of it (Swami et al., 2012; Saxena et al., 2009a; Dutta et al., 2011; Lin et al., 2009; Devalaraja et al., 2011). Various parts of jackfruit tree have been used for medicine and the hard wood used for construction (Roy and Joshi, 1995; Alagiapillai et al., 1996). The aim of this review paper was to improve the current knowledge, medicinal and industrial application properties of jackfruit.

Artocarpus species (15 edible fruits) are known to occupy various niches and habitats, comprise mainly bread fruit and jackfruit (Jagtap and Bapat, 2010; Wangchu et al., 2013). Jackfruit is monecious and pollinated flowers develop several months to develop into ripe fruit, depending on climatic and soil conditions (Morton, 1987; Baliga et al., 2011). According to Prakash et al (2009) jackfruit consist of lower fleshy edible region (bulb), middle fused region (syncarp) and out spiney region (spike). When ripe the fruit get fleshy, outer spines widened and flesh get soft and yellow (Saxena et al., 2009). Except the thorny outer bark and axis are not edible (Baliga et al., 2011).

The jackfruits were classified based on their phonotypical and organoleptic characteristics with variation in bulb colour as well as shape, size, odour, flake size, flake colour and period of maturity (Haq, 2006; Prakash et al., 2009; Jagadeesh et al., 2007b; Jagadeesh et al., 2007a). Two types of ecotypes are recognised flake characteristics, one with soft and spongy while other with firm carpels which called different in regional languages (Baliga et al., 2011; Amma et al., 2011; Shyamalamma et al., 2008; Muralidharan et al., 1997; Odoemelam, 2005).

2. Research objectives and hypothesis

The objectives of this study were (1) to provide a comprehensive overview of the soil chemical characterization around the differnt of jackfruit varieties and their nutritional variations; (2) to identify and characterize the enzymatic activity (amylase) of different jackfruit varities across Kerala.

The study is based on the following hypotheses:

(1) Soil chemical properties may differ around different jackfruit varities in Kerala.
(2) Soil chemical properties may influence the nutrional properties of jackfruit varieties in Kerala
(3) Amylase activity and ripening process affect the sweetness among jackfruit varieties

3. Conclusions

Being one of the underutilized fruits in India, Artocarpus heterophyllus Lam. has promising leads to further scientific researches and livelihood strategies. The tree indigenous to the Western Ghats is an important source of nutritious food during summer season.

References

Ahmed, K., Malek, M., Jahan, K. & Salamatullah, K. (1986). Nutritive value of food stuff. 3rd ed. Institute of Nutrition and Food Science. Bangladesh: University of Dhaka.

Alagiapillai, O.A., Kuttalam, P.S., Subramanian, V. & Jayasekhar, M. (1996). PPI-I jack: A new high yielding, regular bearing jack variety for Tamil Nadu. Madras Agricultural Journal, 83(1), 310-312.

Amma, S.P., Kumaran, K., Valavi, S.G., Peter, K.V. & Thottappilly, G. (2011). Jackfruit in South India. The jackfruit, Studium Press LLC, Houston, USA.

Baliga, M.S., Shivashankara, A.R., Haniadka, R., Dsouza, J. & Bhat, H.P. (2011). Phytochemistry, nutritional and pharmacological properties of Artocarpus heterophyllus Lam (jackfruit): A review. Food Research International, 44(7), 1800-1811.

Bobbio, F.O., el Dash, A.A., Bobbio, P.A. & Rodrigues, L.R. (1978). Isolation and characterization of the physicochemical properties of the starch of jackfruit seeds (Artocarpus heterophyllus). Cereal Chemistry, 55(4), 505-511.

Burkill, H.M. (1997). The useful plants of west tropical Africa. Vol. 4, 2nd Ed. Royal Botanic Gardens: Kew, UK.

Devalaraja, S., Jain, S. & Yadav, H. (2011). Exotic fruits as therapeutic complements for diabetes, obesity and metabolic syndrome. Food Research International, 44(7), 1856-1865.

Dutta, H., Paul, S.K., Kalita, D. & Mahanta, C.L. (2011). Effect of acid concentration and treatment time on acid-alcohol modified jackfruit seed starch properties. Food Chemistry, 128(2), 284-291.

Hameed, B.H. (2009). Removal of cationic dye from aqueous solution using jackfruit peel as non-conventional low-cost adsorbent. Journal of Hazardous Materials, 162(1), 344-350.

Haq, N. (2006). Jackfruit (Artocarpus heterophyllus). In J. T. Williams, R. W. Smith, & Z. Dunsiger (Eds.), Tropical fruit trees. Southampton, UK: Southampton Centre for Underutilised Crops, University of Southampton.

Jagadeesh S.L., Reddy, B.S., Basavaraj, N., Swamy, G.S.K., Gorbal, K., Hegde, L., Raghavan, G.S.V. & Kajjidoni, S.T. (2007a). Inter tree variability for fruit quality in jackfruit selections of Western Ghats of India. Scientia Horticulturae, 112(4), 382-387.

Jagadeesh, S.L., Reddy, B.S., Swamy, G.S.K., Gorbal, K., Hegde, L. & Raghavan, G.S.V. (2007b). Chemical composition of jackfruit (Artocarpus heterophyllus Lam.) selections of Western Ghats of India. Food Chemistry, 102(1), 361-365.

Jagtap, U.B. and Bapat, V.A. (2010). Artocarpus: A review of its traditional uses, phytochemistry and pharmacology. Journal of Ethnopharmacology, 129(2), 142-166.

Lin, K.W., Liu, C.H., Tu, H.Y., Ko, H.H. & Wei, B.L. (2009). Antioxidant prenylflavonoids from Artocarpus communis and Artocarpus elasticus. Food Chemistry, 115(2), 558-562.

Maia, J.G.S., Andrade, E.H.A. & Zoghbi, M.D.G.B. (2004). Aroma volatiles from two fruit varieties of jackfruit (Artocarpus heterophyllus Lam.). Food Chemistry, 85(2), 195-197.

Morton, J.F. (1987). Fruits of warm climates, Creative Resources Systems, Inc., Winterville, USA.

Mukprasirt, A. & Sajjaanantakul, K. (2004). Physico-chemical properties of flour and starch from jackfruit seeds (Artocarpus heterophyllus Lam.) compared with modified starches. International Journal of food science & technology, 39(3), 271-276.

Muralidharan, V.K., Ganapathy, M.M., Velayudhan, K.C. & Amalraj, V.A. (1997). Collecting jackfruit germplasm in Western Ghats. Indian Journal of Plant Genetic Resources, 10(2), 227-231.

Narasimham, P. (1990). Breadfruit and jackfruit. In: Nagy S, Shaw PE, Wardowski WF, editors, Fruits of tropical and subtropical origin Lake Alfred, FL: Florida Science Source. p 193–259.

Odoemelam, S.A. (2005). Functional properties of raw and heat processed jackfruit (Artocarpus heterophyllus) flour. Pakistan Journal of Nutrition, 4(6), 366-370.

Prakash, O., Kumar, R., Mishra, A. & Gupta, R. (2009). Artocarpus heterophyllus (Jackfruit): an overview. Pharmacognosy Reviews, 3(6), 353-358.

Roy, S.K. & Joshi, G.D. (1995). Minor fruits-tropical. In: Salunkhe DK, editor. Handbook of fruit science and technology. Marcel Dekker, Inc., New York, USA.

Saxena, A. Bawa, A.S. & Raju, P.S. (2009). Optimization of a multitarget preservation technique for jackfruit (Artocarpus heterophyllus L.) bulbs. Journal of Food Engineering, 91(1), 18-28.

Schnell, R.J., Olano, C.T., Campbell, R.J. & Brown, J.S. (2001). AFLP analysis of genetic diversity within a jackfruit germplasm collection. Scientia Horticulturae, 91(3), 261-274.

Selvaraj, Y. & Pal, D.K. (1989). Biochemical changes during the ripening of jackfruit (Artocarpus heterophyllus L.). Journal of Food Science Techolonlogy, 26(6), 304-307.

Shyamalamma, S., Chandra, S.B.C., Hegde, M. & Naryanswamy, P. (2008). Evaluation of genetic diversity in jackfruit (Artocarpus heterophyllus Lam.) based on amplified fragment length polymorphism markers. Genetics and Molecular Research, 7(3) 645-656.

Siti Balqis, Z. & Rosma, A. (2011). Artocarpus integer leaf protease: Purification and characterisation. Food Chemistry, 129(4), 1523-1529.

Swami, S.B., Thakor, N.J., Haldankar, P.M. & Kalse, S.B. (2012). Jackfruit and its many functional components as related to human health: a review. Comprehensive Reviews in Food Science and Food Safety, 11(6), 565-576.

Tulyathan, V., Tananuwong, K., Songjinda, P. & Jaiboon, N. (2002). Some physicochemical properties of jackfruit (Artocarpus heterophyllus Lam) seed flour and starch. Science Asia, 28(2002), 37-41.

Wangchu, L., Singh, D. & Mitra, S.K. (2013). Studies on the diversity and selection of superior types in jackfruit (Artocarpus heterophyllus Lam.). Genetic Resources and Crop Evolution, 60(5), 1749-1762.

Chapter 2 Effect of soil properties on the nutritional quality of jackfruit (Artocarpus heterophyllus) varieties in Southern parts of Kerala

Effect of soil properties on the nutritional quality of jackfruit (Artocarpus heterophyllus) varieties in Southern parts of Kerala

Prem Jose Vazhacharickal1*, Sajeshkumar N.K1, Jiby John Mathew1 and Deenamol Thomson1

* premjosev@gmail.com

1 Department of Biotechnology, Mar Augusthinose College, Ramapuram, Kerala, India-686576

Abstract

Jackfruit (Artocarpus heterophyllus) is commonly grown in home gardens of tropical and sub-tropical countries. The fruit which contain high levels of carbohydrates, protein, starch, calcium and vitamins. The Artocarpus heterophyllus is believed indigenous to the Western Ghats of India. It is adapted only to the humid tropical and near tropical climate. The tree flourishes in rich deep soil of medium or open texture, sometimes on deep gravelly or laterite soil. In India they say that the tree grows tall and thin on sand, short thick on sandy land. Here the physical and chemical properties of soil from surrounding plots of different varieties of Arthocarpus heterophyllus has been analysed by using different technical methods and evaluate the effects of soil property on jackfruit nutritional quality. It was observed that there was a considerable difference in case of some minerals likes phosphorous, potassium, magnesium, zinc and manganese. Change in the soil pH also noticed. The pH also plays a major role in the sweetness of the jackfruit. The optimum pH of the amylase inside the jackfruit was found to be 6.2 to 6.8. The result shows that the soils have higher pH have more sweet flakes. Proximate nutritional composition of the flake reveals the presence of protein, fat and fibre in a greater amount in some flake and these flakes were sweeter than the others. There was a much difference in the sugar level also. Increased protein, fat and fibre content found in flake of the trees that were growing in soil that have higher concentration of minerals. Further studies such as molecular studies, enzymatic studies should conduct to identify the whole variation among jackfruit in Kerala. Encouragements should be done to the marketing as well as value added food products from this underutilized fruit tree.

Keywords: Anti-oxidant; Soil properties; Jackalin; Proximate analysis; Underutilized fruit.

2.1. Introduction

Jackfruit is a tropical fruit species found in tropical, high rainfall, coastal and humid areas of the world. It belongs to family Moraceae. Scientifically Artocarpus heterophyllus, it is the favourite fruit of many, owing to its sweetness. The jackfruit tree is widely cultivated in tropical regions of India, Bangladesh, Nepal, Sri Lanka, Vietnam, Thailand, Malaysia, Indonesia and the Philippines. However, India is considered to be the native of jack fruit (Jagadeesh et al., 2007a; Baliga et al., 2011; Reddy et al., 2014; Jagadeesh et al., 2007b; Prakash et al., 2009; Wangchu et al., 2013).

In our country, the trees are found distributed in southern states like Kerala, Tamil Nadu, Karnataka, Goa, coastal Maharashtra and other states like, Assam, Bihar, Tripura, Uttar Pradesh and foothills of Himalayas. The name originated from its Malayalam name Chakka. It is also called kathhal (Hindi and Urdu), pala (Tamil), halasina hannu (Kannada) panasa pandu (Telugu) and phanos (Marathi and Konkani). The fleshy carpel which is botanically the perianth is the edible portion ((Baliga et al., 2011; Haq, 2006; Prakash et al., 2009).

Apart from its use as a table fruit, jackfruit is a popular fruit for preparation of pickles, chips, jack leather and papad. The fruit has got good potential for value addition into several products like squash, jam, candy and halwa. The ripe bulbs can be preserved for one year in sugar syrup or in the form of sweetened pulp. The unripe mature bulbs can be blanched and dehydrated for further use throughout the year. Seed is a rich source of starch and a delicacy during season (Swami et al., 2012; Ahmed et al., 1986; Burkill, 1997; Saxena et al., 2009a; Bobbio et al., 1978; Tulyathan et al., 2002; Mukprasirt and Sajjaanantakul, 2004; Odoemelam, 2005; Burkill, 1997; Swami et al., 2012; Selvaraj and Pal, 1989; Narasimham, 1990; Roy and Joshi, 1995 Haq, 2006). The timber is highly valued for its strength and sought for construction and furniture. The dried leaves are stitched to make disposable plates.

Jackfruit is rich in several nutrients. It can act as source of complete nutrition to the consumers. The fruit is equivalent to Avocado and olive in terms of the healthier mix of nutrients for human dietary needs, almost having the exact nutrient equivalents of mother’s milk. It is rich in vitamin B and C, potassium (K), calcium (Ca), iron (Fe), proteins and high level of carbohydrates, affordable and readily available supplement to our staple food (Burkill, 1997; Swami et al., 2012; Selvaraj and Pal, 1989; Narasimham, 1990; Roy and Joshi, 1995 Haq, 2006).

Jackfruit occupies about 14000 hectares is in Assam, Kerala, Tamil Nadu and parts of Karnataka. Since this crop needs a warm humid climate and very good drainage Jack grows well and gives good yield in warm humid climate of hill slopes and hot humid climate of plains. The crop grows successfully from sea level up to an elevation of 1200 meters (m) at an optimum temperature range of 22-35oC. It cannot tolerate frost or drought. The yield and quality of fruits are medium under low humidity. The West coast plains with high humidity are found to be highly suitable. A deep rich alluvial or open textured loamy soil or red laterite soils with slightly acidic condition (pH 6.0 to 6.5) with good drainage is ideal for jackfruit, however, it can come up in variety of soils (Jagadeesh et al., 2007a; Prakash et al., 2009; Roy and Joshi, 1995).

The trees have a significant role in the preservation of the environment. They can be very effective in the amelioration of soils and prevention of soil erosion and are therefore an important component of sustainable development (Ghosh, 2000).

Plant growth is influenced by a number of factors including temperature, available water, light and available nutrients in the soil. Changes in the soil fertility influence on only the crop yield but also the crop quality also. Jackfruit trees are able to grow on different types of soil and climate. The objective of this study is to evaluate the effects of soil property on jackfruit nutritional quality.

2.1.1Taxonomical classification

Kingdom: Plantae-- planta, plantes, plants, vegetal

Subkingdom: Tracheobionta -- vascular plants

Division: Magnoliophyta -- angiosperms, flowering plants, phanerogames

Class: Magnoliopsida -- dicots, dicotyledones, dicotyledons

Subclass: Hamamelidae

Order: Urticales

Family: Moraceae - mulberries

Genus: Artocarpus - breadfruit

Species: Artocarpus heterophyllus Lam.

2.2. Review of literature

Arthocarpus heterophyllus belongs to the family of Moraceae (Bhattacherjee and Bose, 1985). It is widely distributed in many parts of India and Bangladesh. It grows wild in the Western Ghats of India (Reddy et al., 2014). The popularity of jackfruit as a commercial crop is very meager due to the wide variation in fruit quality, long gestation period of plants raised from seeds (Samaddar, 1985). It is also widely grown in Burma, Sri Lanka, Malaysia, and Indonesia, Philippines, Brazil and other countries. (Narasimham, 1990)

Arthocarpus heterophyllus is an evergreen latex producing tree. It can grow up to a height of 80 feet which has a straight stem. The tree has a long taproot. The flowers of this tree are borne on short shoots on the trunk and older branches. Average fruit size is about 35 pounds .It has about short blunt spines. It is thought to have originated in Southwest Asia, then to tropical Africa. It is also believed indigenous to the rainforests of the Western Ghats of India. Arthocarpus heterophylus is the longest tree borne fruit in the world (Coronel, 1983).

Arthocarpus heterophylus is to be found in the 16th century. The consumption of this fruit has several health benefits that includes it optimizes immune function, it is a high energy source, maintains blood pleasure and cardiovascular health, improves digestion, vitamin A for vision, skin health, asthma, bone health, anemia.

Arthocarpus heterophyllus have a distinctive sweet and fruity aroma. When a study was conducted in the flavor volatiles of five fruits it was detected that it contains ethyl isovalerate, propyl isovalerate, 3-methyl butyl acetate, isobutyl isovalerate, butyl isovalerate, 1-butanol and 2-methyl butanol (Ong et al., 2008). Jackfruit tree is monoecious and both male and female inflorescences are found on the same tree. (Bose, 1985; Morton, 1987).The fruit is considered as poor man’s food in India owing to the numerous culinary uses for the unripe, tender fruit. The value of its versatility is enhanced when the supply of other vegetables is low (Singh et al., 1963).

In South India the fruit is classified into two; soft fleshed (koozha) and firm fleshed (varikka). The soft fleshed have small fibrous soft mush, but very sweet carpals. The firm fleshed are crisp carpers of high quality. Another important variety recommended for Kerala is Mutton varikka and Singapore or Cylon jack (Morton, 1987).

The other distinct types in Kerala include; pottachakka, honey jack, Tamara Chaka, pathy varikka, thenthulli vrikka, valya mundan, cheriya mundane, kezhakombu mundan, kaatu varikka and vaali varikka (local names in Malayalam)

Arthocarpus heterophyllus mature after 3 to 8 months from flowering. After its maturation there is a change of fruit color from light green to yellow brown. After ripening they turn brown. The fruit flourishes in rich deep soil of medium or open texture. Planting on top of old compost is best for its growth. The tree cannot withstand wet feet and it needs the best drainage.

Arthocarpus heterophyllus seeds can be sprouted in the spring and it can be exposed to dappled sunlight. During their growth, they need strong light, so we should make them grow in a patio deck. They are susceptible to cold weather; they cannot withstand freezing weather.

The fruit is made of easily digestible flesh of about 100 g of raw fruit given about 95 calories and is a good source of the antioxidant vitamin C, providing about 13.7 g. They are also rich in vitamin B6, potassium (K), Calcium (Ca), and iron (Fe). Seeds of this fruit are recalcitrant. This fruit is very easy to grow. Seedlings will develop faster reaching 25 cm in height within 3-4 months. Seeds are cross pollinated. Propagation by vegetative means is also possible. This fruit can be planted on farms to prevent soil erosion.

The pulp of the young fruit can be cooked as a starchy food. The fruit is also pickled or canned in brine or curry. The ripe fruit is pressed into numerous dishes that include jam, jelly, and chutney. The pulp can also be used as flavoring in ice cream and drinks. The young leaves can be cooked and eaten as vegetable. The latex of the fruit can be used as chewing gum. The wood of the fruit can be used for building material, furniture, and even for musical instruments. Branches and trunk can be burned for fuel wood. The inner bark of the fruit can be made into cordage or cloth (Elevitch and Manner, 2006).

The marketing of Arthocarpus heterophyllus involves three groups: producers, traders and also includes sellers and retailers. The marketing part is a very complex process. In Kerala, a huge quantity of production of jackfruit occurs naturally but about 97% of its production is not being used due to the lack of processing units and marketing.

Soil is composed of several components like minerals, organic matter, water and air. The composition and proportion of these components influence soil properties that include texture, structure and porosity. The physical properties influence air and water movement in the soil. Chemical properties include mineralogical composition and the content of the type of mineral.

Soil occurs in nature as sand, gravel or any other single component. Usually they exist as mixtures with different amount of particles of different sizes. Each compound contributes its characteristics to the mixture. Soil represent more complex environment because they are an intimate mixture of the living and non living components and because they vary naturally in both space and time over a range of scales. Soil quality is somewhat choosing chemical, physical and biological indicators which represent particular constituents, processes or conditions.

A good indication of soil quality is the presence of several characteristics. Soil quality cannot be concluded by a single component, it must include many other indicators. It must contain factors such as pH, clay, and organic matter content and ion exchange capacity. All these parameters must be considered because they influence the bioavailability of the pollutant and also its persistence, movement and effect on selected processes.

There are several functions of soil. Some of them include; it supports growth of higher plants, it is a primary factor in controlling fate of water in hydrologic systems, it is nature’s recycling system for nutrients, habitat for organisms and also is an engineering medium. (Brady et al., 2008)

Soil is an important dynamic component of the environment. It is subjected to alteration, and can be either degraded or wisely managed. A thorough knowledge about the ecology of the soil ecosystem is an important part of designing and managing agro ecosystems in which long-term fertility and productive capacity of the soil is maintained or even improved.

A developed soil has a well defined profile. The layers in soil may vary in thickness and may be distinguished from morphological characteristics which include color, texture and structure. The profile consists of three main horizons; A, B and C. The A horizon are rich in organic matter. Horizon B is below A and has a dominance of clay, Fe, aluminium (Al) and humus alone or combination. The C horizon excludes the bedrock. (Ariyaratne, 2000).

The major soil types of India include:

- Red soil: They are wide in their spread. The red color is diffusion due to diffusion of iron.
- Laterite soil: Consists of a combination of hydrated oxides of aluminum and iron with small amounts of manganese oxide.
- Black soil: composed of a high amount of Ca and magnesium (Mg) carbonates.
- Alluvial soil: This is an agriculturally most important group of soils.
- Desert soils: They are found mostly in dry areas.
- Forest and hill soil which are high in organic matter.

Soil texture has a great importance on water holding capacity, water conducting ability and chemical soil properties. Since soils are of different sizes, they are differentiated using the so called soil texture triangle. Texture is a proportion of three mineral particles; sand, slit and clay. Particles over 2 mm in diameter is not considered in texture. Texture occurs as a result of weathering.

Soil structure is the arrangement of the different particles into soil aggregates. Roots move between these aggregates. A compact soil will resist root movement. The organic matter helps the soil aggregation process. Soil color changes from reddish to brownish color which shows well drained condition. The range of yellowness and mottling show poor drainage. Gray to dark color indicates the presence of organic matter. (Adepetu et al., 1984)

Soil consistence refers to cohesiveness of soil. Soil consistence and structure are interrelated. Consistence is described under wet, moist, or dry soil moisture conditions. When the soil is wet, consistence may be described by degrees of stickiness and plasticity. Consistence of soil under dry condition is characterized by degree of hardness, maximum resistance to pressure and inability of crushed material to cohere again when pressed together.

Bulk density is the weight of the soil in the given volume. A compact soil has a higher value while and organic soil has a lower value. It also affects water holding capacity of the soil solution. Soil pH measures the negative logarithm of the hydrogen activity of the soil solution. It is a measure of the soil acidity or alkalinity of a soil (Adepetu et al., 1984). The most important effect of pH in the soil is on ion solubility. In acid soils, hydrogen and aluminum are the dominant exchangeable cations. Parent material, climate and vegetation are the important factors that affect soil pH (Brady, 1991).

In the case of the blended jackfruit seed flour there was no appreciable change in the bulk density of blended jackfruit seed flour. When the raw jackfruit seed flour was compared with the flour having seed coat which has got high bulk density value which in accordance with its high ash content value. However when the blends are concerned, bulk density goes on increasing with the increase in blend percentage (Chawdhury et al., 1997; Chawdhury et al., 2012).

Soil electrical conductivity is an indirect measurement that correlates with soil physical and chemical properties. It is an ability of a material to conduct an electrical current and it is commonly expressed in units of millisiemens/meter. Since sands have low conductivity and clays have high conductivity, soil electrical conductivity correlates very strongly with particle size and soil texture. Soils exposed to drought and erosion will show difference in soil texture that can be delineated using soil electrical conductivity. The greatest difficulty with a measurement as inclusive as soil electrical conductivity is to conclude what is causing the variation in any given area.

Organic carbon is the most commonly analyzed soil constituents. Already in the nineteenth century chemists was routinely analyzing soil carbon (Lawes and Gilbert, 1885). Phosphorous (P) is the second most plant nutrient. The soil mineral apatite is the most common mineral source of phosphorous. While there is on average 1000lb of part available, more than half comes from the mineralization of organic matter (Brady et al., 1984).

The amount of K present in soil must be about 80,000lb/acre, of which only 150lb or 2% is required for plant growth. Common mineral sources of potassium include mica biotite and potassium feldspar. When it is solubilised, half of them will be held as exchangeable cations on clay and the other half is in the soil water solution. Potassium fixation takes place when soil dry and potassium is bonded between layers of clay (Retallack, 2008).

Calcium and Mg are secondary nutrients. Plants require them in large quantities similar to P. They are positively charged ions. They are held to the surface of clay and organic matter in the soil by electrostatic charge. Since Ca and Mg are only available to plants in the exchangeable form, soil tests. Calcium and Mg are also factors that affect soil pH. Plants take most of the Ca and Mg through mass flow rather than by root interception (Simson et al., 1979). Calcium is only less weight in soils. Therefore it is low in sandy and heavily leached soil (Donanae et al., 1977).

Calcium plays an important role in plant nutrition. Through calcium addition cell wall strength and thickness are increased. The quality of the fruit produced is strongly coupled to calcium availability (Easterwood, 2002).

Sulphur (S) is present in soil in many different form, both organic and inorganic, and it find its total amount it is important to change all the sulphur in these compounds into one form in which it can be subsequently estimated. For this purpose soil can be treated either with a strong oxidizing agent thus oxidizing all the sulphur to sulphate, with a reducing agent, whereby the sulphur is either driven off as hydrogen sulphide or left as a metallic sulphide which can be decomposed by dilute acid with the evolution of hydrogen sulphide.

The micronutrients that are important for plant growth include Fe, manganese (Mn), zinc (Zn), copper (Cu), boron (B), chlorine (Cl) and molybdenum (Mo). They are needed only in small amounts, they are very important for plant growth. They are generally available in the mineral component of the soil (Johnson et al., 1957).

In the case of jackfruit there is a significant change in titrable acidity and color, but there are no significant changes in moisture and crude fiber content during ripening. The total soluble salts and total sugar content increases significantly throughout the process. It is also found that the total number of organic acids decrease from the early to later stages of ripening (Ong et al, 2006). There is a wide variety in the TSS content of jackfruit. And there is also a great difference in sugars, starch and carotenoid contents that was observed in the bulbs of jackfruit. (Jagadheesh et al., 2007b)

Jackfruit is rich in a wide variety of compounds that include thiamin, vitamin C, vitamin A, riboflavin, calcium, potassium, sodium, zinc, niacin. Jackfruit is low in calories. Jackfruit (100 g) contains only about 94 calories (Mukprasirt and Sajjaanantakul, 2004). Jackfruit is also rich in various phytonutrients such as lignans, isoflavones, and saponins. These phytonutrients are essential in preventing cancer, ulcer and aging. It also contains niacin which is an essential compound for energy metabolism. Jackfruit pulp (100 g) produces about 4 mg of niacin (Soobratte et al., 2005).

Jackfruit is a rich source of carbohydrates that includes mono, di and polysaccharides. Ripe jackfruit contain high amount of glucose, fructose, and sucrose (Chowdhurry et al., 1997) which provide sweetness to the fruit (Berry and Kalra, 1988).

According to Selvaraj and Pal (1989) when the fruit is ripened, the acidity will decrease and tannin content will increase and also sterol and fatty acid content. But the level of starch and alcohol insoluble solids decreases after the ripening of fruit.

Phytochemical composition varies with the varieties of jackfruit. Depending upon the variety of jackfruit carbohydrates and proteins in the seeds vary although they are from the same region. Chrips et al. (2008) evaluated the protein and carbohydrate concentration of different varieties of jackfruit seed. When compared with other tropical fruits jackfruit pulp and seed have relatively large amounts of Ca, Fe and protein. (Bhatia et al., 1955; Haq, 2006; Kumar et al., 1988).

The pH of unripe fruit decreased significantly during the early stage of ripening and it was slightly increased after harvest. The lower pH indicates that the fruit is sour (Ong et al., 2006).

The unripe jackfruit has a great importance as vegetable, while the ripe fruit is rich in various vitamins and minerals. The jackfruit latex was reported to possess bacteriolytic activity. The tree has an important role in protecting the environment (Elevitch and Manner, 2006).

In their ripening stages most fruits are rich in high percentages of glucose, fructose and sucrose but at the stage of immaturation they may remain absent or present in very small amounts Therefore, the gradual increase of these sugars with the maturity of jackfruit is quite consistent (Chan and Kwok, 1975; Moriguchi et al., 1990; Nahar et al., 1990; Rahman et al., 1999; Rahman et al., 1995; Wills et al., 1986).

Sucrose is the major sugar contributing to its sweetness followed by fructose and glucose. There was a significant increase in the sucrose content throughout the ripening process. There was a three-fold increase in sucrose concentration with a corresponding increase in the concentration of glucose and fructose which were six and five fold (Selvaraj and Pal, 1989).

Several studies has shown that the starch content of the perianth and seed of both the soft and firm fleshed varieties of jackfruit samples increased gradually with the increase of maturity. In the experiment of Rahman et al. (1991), the starch content of the ripened fruits decreased drastically compared to the immature samples. Here the ash content of perianth and seed decreased with the increase of maturity. The decrease in ash content may be due to the increase of relative percentages of dry matter content (Rahman et al., 1999).

Plant growth is influenced by a number of factors including temperature, available water, light and available nutrients in the soil. A German scientist Justus von Liebig in the mid 19th century was one of the first scientists to show that nutrients are essential for plant growth (Tucker, 1999). Studies show that there are over 100 chemical elements but research has determined 17 nutrients that are also called essential elements (Jones and Jacobsen, 2001).

It is reported that for an element to be classified as essential, it must meet the following criteria: it must be needed by a plant to complete its life cycle; its function cannot be replaced by another element; it is directly involved in plant growth and reproduction; and it must be needed by most plants (Foth and Ellis, 1988).

Out of the 17 essential elements carbon (C), hydrogen (H) and oxygen (O) are the nonmineral nutrients because they are derived from the air and water (Jones and Jacobsen, 2001). The remaining 14 mineral nutrients include six macronutrients: nitrogen (N), P, K, Ca, Mg, and S; and eight micronutrients: B, Cl, Cu, Fe, Mn, Mo, Ni and Zn (Tucker, 1999; Brady and Weil, 2008). Other nutrients that do not fall within the list of 17 essential elements but are needed in specific cases are referred to as beneficial elements (Jones and Jacobsen, 2001). Each of the nutrients is needed in different amounts and carries specific functions in the plant. Depending on the amount that is available for plant uptake, these nutrients influence crop yields and quality. (Havlin et al., 2005).

Some crop quality attributes influenced by the nutrients include; sugar and protein content, seed size, kernel size, fruit color, flavor, vitamin levels and grain hardness (Blumenthal et al., 2008). Nutrients obtained from crops and crop products, for example N, S, and P, are constituents of various types of proteins and protein enzymes, which are important for building plant tissues and activating various metabolic processes respectively (Soetan et al., 2010). Despite the many functions of the nutrient elements, in many countries especially in sub-Saharan Africa, there is concern about a low and an unbalanced use of fertilizers (Bationo et al., 2004).

Phosphorus is a very important macronutrient involved in most growth processes. It is an essential component of most organic compounds in the plant including nucleic acids, proteins, phospholipids, sugar phosphates, enzymes and energy-rich phosphate compounds, a common example being adenosine triphosphate (ATP) (Brady and Weil, 2004; Sylvia et al., 2005). Research has determined that P improves crop quality in a number of ways including: reduced grain moisture content, winter hardiness, and increased sugar content, increased protein content, increased P content, increasing proportion of marketable yields, better feed value, and improved drought and disease resistance in crops.

Potassium is an essential nutrient that is absorbed by plants in larger amounts than any other nutrient except N (Roy et al., 2006). Unlike N, P and most other nutrients, K is not incorporated into structures of organic compounds; instead potassium remains in ionic form (K+) in solution in the cell and acts as an activator of many cellular enzymes (Havlin et al., 2005). Therefore, it has many functions in plant nutrition and growth that influence both yield and quality of the crop. These include regulation of metabolic processes such as photosynthesis; activation of enzymes that metabolize carbohydrates for synthesis of amino acids and proteins; facilitation of cell division and growth by helping to move starches and sugars between plant parts. It is reported that among the many plant mineral nutrients, K stands out as a cation having the strongest influence on quality attributes that determine fruit marketability, consumer preference, and the concentration of critically important human-health associated phyto-nutrients or bioactive compounds (ascorbic acid and Beta carotene) (Jifon and Lester, 2009; Lester et al., 2010).

Calcium is used in large amounts by plants second only to N and K (Brady and Weil, 2008). It is a major component of the middle lamella (Ca-pectates) of the cell wall. It strengthens the cell walls and is involved in cell elongation and division, membrane permeability, and activation of several critical enzymes (Brady and Weil, 2008). It is important in N metabolism and protein formation by enhancing NO3- uptake and it is also important in translocation of carbohydrates and other nutrients (Havlin et al., 2005). In accordance with its functions, Ca influences crop and food quality. Calcium is less mobile such that its influence on crop quality is easily noted with foliar application.

Magnesium is another secondary nutrient element. It is important as a primary constituent of chlorophyll and as a structural component of ribosomes, it helps in their configuration for protein synthesis (Havlin et al., 2005). It is also required for maximum activity of almost all phosphorylating enzymes in carbohydrate metabolism.

Micronutrient elements such as Zn, Fe, Bo, Mo, Cu, Mn, Cl and nickel (Ni) are known to be essential for plant growth. Others such as selenium (Se) and Co, which are needed in specific cases are commonly referred to as beneficial elements. For instance, Co is required by bacteria that fix nitrogen in legumes. Zinc and Fe are some of the most important micronutrient essential for plant growth (Muthukumararaja and Sriramachandrasekharan, 2012). Zinc is a major metal component and activator of several enzymes involved in metabolic activities and biochemical pathways (Kabata-Pendias and Pendias, 2001; Grotz and Guerinot, 2002). It is a functional, structural or regulatory co-factor of a large number of enzymes (Grotz and Guerinot, 2002). It is required in a large number of enzymes and plays an essential role in DNA transcription (Sing et al., 2012). Other process of oxidation in plant cell and is vital for the transformation of carbohydrates; and influencing the formation of chlorophyll and auxins, the growth promoting compounds (Mamatha, 2007). On the other hand, Fe in a constituent of enzyme system which brings about oxidation-reduction reactions in the plant, it regulates respiration, photosynthesis, reduction of nitrates and sulphates (Mamatha, 2007). These reactions are essential to plant development and reproduction. Micronutrients Zn and Fe limit plant growth when they are present both in low concentrations and in excessive concentrations due to deficiency and toxicity respectively (Conolly and Guerinot, 2002; Alloway, 2008).

2.3. Hypothesis

The current research work is based on the following hypothesis

1) Jackfruit varieties in Kerala differ in nutrional features
2) Soil properties play a crucial role in sweetness among jackfruit varities
3) Nutrional variations are related to climatic and soil properties

2.4. Materials and Methods

2.4.1 Collection of samples

The soil samples were collected from the surrounding plot of different varieties (6 soft and 3 firm) of Arthocarpus heterophyllus. The GPS (global positioning system) positions were also recorded. Nine soil samples were collected from 6 inch soil depths and labeled VK1 to VK9. Soil samples were collected from four sides of a tree and later pooled into single. After the soils were reached the lab it was dried stored in a powdered form for further tests.

2.4.2 Estimation of Organic Carbon (Walkley- Black method)

The soil, ground up so as to pass through a 0.5 mm mesh sieve, was placed in a 500 ml Erlenmeyer flask. The amount of soil used in the determination was calculated based on initial information on the C concentration in the soil and ranged from 0.1 to 0.5 g. Ten ml of potassium dichromate (K2Cr2O7) and 20 ml of concentrated sulfuric acid (H2SO4) were added to the soil while stirring it to ensure good mixing of the soil with the reagents. After a 30 min rest, 200 ml of distilled water, 10 ml of concentrated phosphoric acid (H3PO4) and 1 ml of 0.16 % diphenylamine were added. The excess dichromate that was not reduced in the reaction was determined by volumetric titration using ammonium ferrous sulfate.

Table 2.1. Phenolic, flavinoid content and antioxidant activity of araticum, papaya and jackfruit in undigested and digested extracts (Modified after; Pavan et al., 2011).

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Numbers represent means ± one standard deviation (SD) of the mean

TEAC: Trolox Equivalent Antioxident Capacity; ORAC: Oxygen Radical Absorbence Capacity

Table 2.2. Biochemical difference in various jackfruit varieties in South India (Chrips et al., 2008).

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Numbers represent means ± one standard deviation (SD) of the mean.

2.4.3 Estimation of Available Phosphorous (Ascorbic acid blue color method)

Five gram of soil was taken in a 100 ml shaking bottle. 50 ml of Bray No. 1 Solution was added. It was shaken for five minutes and filtered through a Whatman No.42 filter paper. Transferred 50 ml filtrate into a 50 ml volumetric flask. The pH was adjusted to three with 4N sodium carbonate (Na2CO3) or 4 ammonium chloride (NH4Cl), 2, 4- dinitrophenol being used as an indicator. It became yellow as pH three is approached from the acid side. Added a few drops of indicator to solution and if yellow color was formed, 4N hydrocholoric acid (HCl) was added drop wise until it becomes colorless. If indicator gives a colorless solution indicating a solution pH below three then 4N Na2CO3 can be added drop wise just until a yellow color is developed, and finally 4N HCl was added and yellow becomes faint. Added 5 ml molybdate reagent, followed by 4ml freshly prepared ascorbic acid. Make up the volume. Mixed well and kept it for color development. Intensity of color was determined in a photo electric colorimeter or spectrophotometer at 730-840 nm.

2.4.4 Estimation of Available Potassium

Five gram of soil was taken in a shaking bottle and 50 ml neutral 1N ammonium acetate (NH4CH3CO2) solution was added. It was kept shaken for five minutes in a reciprocating shaker and after five minutes it was filtered through a Whatman No.42 filter paper. Pipette out ten ml of aliquot and make up the volume to 50 ml with distilled water. Reading was taken in a flame photometer using potassium filter. The equipment was standardized initially with distilled water to indicate a reading of zero in the meter dial of flame photometer. Then a 10 ppm potassium solution was used which is to be read as hundred in the meter.

2.4.5 Estimation of Exchangeable Magnesium and Calcium

Ammonium acetate extract was used for the analysis of Magnesium. First the Atomic Absorption Spectrophotometer (AAS) was standardized using ten ppm Mg solution and then the extract was read directly using the hollow cathode lamp specific for Mg. Dilute the sample if necessary while reading. For Ca also ammonium acetate extract was used. Flame photometer was the equipment used for the estimation of calcium. Calcium solution was used as standard. Then the samples were read in flame photometer.

2.4.6 Estimation of Zinc, Copper and Manganese

Two gram of soil was shaken with twenty ml of 0.1 M HCl for five minutes. It was filtered through Whatman No.42 filter paper. The filtrate was collected and the contents of Mn, Zn, and Cu were estimated using AAS.

2.4.7 Estimation of Electrical Conductance

The clear supernatant of 1:2.5 soil water suspensions prepared for pH measurement can be used for estimation of electrical conductivity. Conductivity meter was calibrated using potassium chloride solution and the cell content was determined. The conductivity of the supernatant liquid was determined.

2.4.8 Estimation of pH

The pH meter was calibrated using two buffer solutions, one was buffered with neutral pH and the other was buffered based on the range of calibrate pH in the soil. The buffer solution was taken in the beaker. The electrode was inserted alternately in the beakers containing two buffer solutions and adjusted the pH. The instrument indicating pH as per the buffers is used to test the samples. Ten gram of soil sample was taken in a 100 ml beaker and 20 ml of calcium chloride (CaCl2) solution was added. The soil was allowed to absorb calcium chloride solution without stirring. Then it was thoroughly stirred for ten seconds using a glass rod. The suspension was stirred for thirty minutes and the pH was recorded on the calibrated pH meter.

2.4.9 Estimation of Bulk density

Bulk density of soil is usually determined from a core sample which was taken by driving a metal corer into the soil at the desired depth and horizon. This gives a soil sample of known total volume. From this sample the wet bulk density and the dry bulk density can be determined.

2.4.10 Estimation of starch by Anthrone Method

The amount of total soluble sugars can be estimated using either anthrone or phenol-sulphuric acid method calorimetrically. Carbohydrates exit as free sugars and polysaccharides. The basic units of carbohydrates are the monosaccharide which cannot be split by hydrolysis into simpler sugars. The carbohydrate content can be measured by hydrolyzing the polysaccharides into simple sugars by acid hydrolysis and estimating the resultant monosaccharide.

The anthrone reaction is the basis of a rapid and convenient method for the determination of hexoses, aldopentoses and hexuronic acids either free or present in polysaccharides. Carbohydrates are dehydrated by concentrated H2SO4 to form furfural. Furfural condensed with anthrone to form a blue-green coloured complex which is measured calorimetrically at 630 nm.

2.4.11 Estimation of reducing sugars by DNSA method

0.5 ml of extract was taken in test tubes and three ml of water was added. To this three ml of dinitrosalicylics acid (DNSA) reagent was added. The contents were heated in a boiling water bath for five minutes. The tubes were cooled and the volume was made up to 20 ml. The percent transmittances of the standard and the sample against reagent blank were read at 540 nm.The reducing sugars were determined.

2.4.12 Proximate nutritional compositional analysis

The powered jackfruit samples were subjected various proximate analysis using standard protocols. The analysis includes estimation of dry matter and moisture content, determination of minerals using crude ash (CA) method, estimation of crude fat, fibre, crude protein and nitrogen free extract (NFE).

2.4.12.1 Estimation dry matter and moisture

The dry matter (DM) is calculated using oven dry methods where fresh samples were kept hot air oven at 85°C for 48 hrs. The values are calculated based on the initial and final weight of the samples using the equation given below

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2.4.12.2 Estimation of crude ash and insoluble ash

The weight of clean dry empty silica crucible is determined as ‘W’ gms approximately 3 gms of the dried powdered sample is weighed noting the exact weight of crucible + sample as W1. Ignite it in the muffle furnace at 600°C for 3 hrs, allow to cool overnight. Take the weight of silica crucible + crude ash as W2. Digest the ash in the crucible with 25 ml of 5N HCl, boiling it for 10 minutes, cool, filter through Whatmann no 42 ashless filter paper and make paper and crucible acid free. Transfer the paper with residue to respective crucible. Dry in hot air oven and ignite in the muffle furnace at 600°C for 3 hrs. Cool overnight and take the weight of the crucible ‘W3’ gms, and acid insoluble ash is calculated as

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2.4.12.3 Estimation of crude fat

The crude fat is done using solvent extraction with petroleum ether. The extraction is done on soxtec fat analyser. Clean dry aluminium cups marked appropriately are weighed (W1).Dry powdered sample are weighed approximately 3 g of sample, noting exact sample weight, W in marked thimbles. The thimbles are attached in correct order on the adaptors of soxtec extractor. 60 ml of petroleum ether is taken in the aluminium cups and assembled seeing that markings of thimble, cup and sample numbers tally. Condenser water supply is switched on. The heating bench is turned on using the ‘power on’ button on control unit of soxtec unit and when the temperature reaches 100°C, the thimbles are dipped into boiling ether and boiling cycle is done for 15 minutes. The thimbles are raised and rinsed with condensed ether in the rinsing cycle for 30 minutes. This is followed by 10 minutes of recovery cycle where pure unsaturated ether is collected back and recovered. The fat containing cups with residual ether is then dried in hot air at 100°C for 1hr, cooled in desiccators and weighed, (W2) g. The crude fat is calculated as

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2.4.12.4 Estimation of crude fibre

The thimbles containing fat free extract from the forgoing estimation are dried in hot air oven at 50°C for overnight. Approximately 0.8 g of fat free sample is weighed exactly ‘W’ g into gooch crucibles provided with fibretec extraction assembly. They are set on the assembly and two digestions, (acid & alkali digestions) in 1.25% H2SO4 and 1.25% sodium hydroxide (NaOH) are done one after the other for 30 minutes. With draining of acid and alkali and flushing of hot distilled water done in between each digestion. The residue containing crucibles are removed, over dried at 60°C for overnight, weighed ‘W1’g.They are ashed at 600°C for 3 hrs in muffle furnace overnight, cooled and weighed ‘W2’ g.

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2.4.12.5 Estimation of crude protein

Estimation of crude protein consists of two parts: digestion and distillation. Weigh approximately 0.25 gm of dried powdered sample noting the exact weight,‘W’ g, into clean dry digestion tubes. Add approximately 1 g of digestion mixture (potassium sulphate & copper sulphate, 9:1 by weight) into each tube. Add 12ml of con.H2SO4 into each tube, place on the digester (Kjeltec) assembly and digest at 400°C for 11 to 12 hrs. Cool down to room temperature.

Place on distillation unit (Kjeltec) and set the program (water-70 ml, alkali-70 ml, receiver-30 ml, tube drain) and distil it with steam in the unit. The instrument estimates the crude protein on entering the weight of sample W as

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2.4.12.6 Estimation of nitrogen free extract

NFE or soluble carbohydrate is calculated based on difference

- NFE = Dry matter-(crude protein + crude fat+ crude ash + crude fibre)
- NFE = 100–(moisture + crude protein + crude fat + crude ash + crude fibre)

2.4.13 Statistical analysis

The survey results were analyzed and descriptive statistics were done using SPSS 12.0 (SPSS Inc., an IBM Company, Chicago, USA) and graphs were generated using Sigma Plot 7 (Systat Software Inc., Chicago, USA).

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Figure 2.1. Mean monthly rainfall (mm), maximum and minimum temperatures (°C) in Kerala, India (1871-2005; Krishnakumar et al., 2009).

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Figure 2.2. Introduced and indigenous regions of Artocarpus heterophyllus around the world (Modified after; Haq, 2006).

Table 2.3. Uses of different jackfruit parts (Chrips et al., 2008).

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Table 2.4. Uses of different lectins from jackfruit parts (Chrips et al., 2008).

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Figure 2.3. Map of Kerala showing the various sample collection points (JK1 to JK7). JK8 and JK9 were not included in the map.

Table 2.5. Different vernacular names of Artocarpus heterophyllus in India (Modified after; Baliga et al., 2011).

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Table 2.6. Common names, uses and distribution of major Artocarpus species (Modified after; Jagtap and Bapat, 2010).

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Table 2.7. Chemical composition of jackfruit (Modified after; Jagtap and Bapat, 2010).

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Figure 2.4. Morphological characters of jackfruit (Artocarpus heterophyllus Lam.).

Table 2.8. General description of the selected jackfruit varieties).

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*F: Firm variety; S: Soft variety

2.5. Results and discussion

Among the 9 samples there are 3 Varika (firm variety) and 6 Koozha (soft variety), from 45 to 100 m altitude, for data analysis the collected data were classified into two categories; soil general characteristics and proximate analysis.

2.5.1 General soil characteristics

The soil analysis shows that the concentration of P, K, Mg, Zn and Mn high in three samples (JK1, JK4 & JK7) compared with the others. Copper quantity was observed low in these samples and there is no much difference in case of calcium. Organic carbon also higher in the above mentioned samples. Electrical conductivity various in all samples and bulk density various marginally. The selected soil samples can be divided into two based on the pH level. Sample JK1, JK4 and JK7 with pH more than 6 and others have less than 6.

According to Brady and Weil (2008) phosphorous plays a major role in the protein and sugar concentration of the flakes and it also activate many enzymes. Potassium also functions as an activator of many cellular enzymes; therefore, it has many functions in plant nutrition and growth that influence both yield and quality of the crop (Jifon and Lester, 2009).

Havlin et al. (2005) says that magnesium plays a major role in protein synthesis and it was required for maximum activity of almost all phosphorylating enzymes in carbohydrate metabolism. Zinc was a major metal component and activator of several enzymes involved in metabolic activities and biochemical pathways (Kabata-Pendias and Pendias, 2001).

The pH also plays a major role in the sweetness of the jackfruit. The optimum pH of the amylase inside the jackfruit was found to be 6.2 to 6.8. The result shows that the soils have higher pH have more sweet flakes.

From the above information reveals that there was a relation between the jackfruit quality and the tree growing soil. This study shows that the sweetness variation may be due to the soil properties. Plants growing in high mineral soils have more sweetened flake than the others. This may be due to more enzymatic activities which enhanced by these mineral elements. The pH also plays a major role in the sweetness of the jackfruits flake. The results of the study are helpful for understanding the effect of variability of soil type in the nutritional quality of the jackfruit.

2.5.2 Proximate nutritional composition

Proximal nutritional composition of ripened jackfruit flake selected from corresponding areas shows differences in the presence of protein, fat, fibre and sugar level. High protein, fat, fibre and sugar level observed in samples collected from soil JK1, JK4 & JK7. Collection of samples was based on the sweetness of the ripened jackfruit and it was shown that the fruit collected from plants growing in sample JK1, JK4 & JK7 have more sweetness than the others. The rate of conversion of starch into sugar also observed high in these flake from these trees.

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Figure 2.5. Jackfruit trees a) jackfruit with varying sizes; b) different stages of fruiting; c) tree bearing fruits; d) fruits plucked; e) small type of jack fruit; f) jackfruit cut opened; g) jackfruit seeds; h) opened jackfruit flakes; i) flakes unopened.

Table 2.9. Description of the jackfruit samples (JK1 to JK7#) and their special features.

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* U: Urban; R: Rural; SU: Semi-urban

# JK8 and JK9 were not included

Table 2.10. General features of jackfruit samples (JK1 to JK7#).

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* V: Varika; K: Koozha

Numbers represent means ± one standard deviation (SD) of the mean

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