How to Produce Gluten-Free Biscuits. Production-Challenges and Potential Solutions

TABLE OF CONTENTS

DEDICATION

ACKNOWLEDGEMENTS
CHAPTER ONE: INTRODUCTION
1.1 OBJECTIVE OF THE STUDY

CHAPTER TWO LITERATURE REVIEW
2.1 Gluten
2.2 Celiac Disease
2.2.1 Symptoms of CD
2.2.2 Diagnosis of CD
2.3 Gluten Free Food
2.2.1 Major examples of Gluten Free foods
2.4 Problems Associated with Production
2.4.1 Weak structure
2.4.2 Molding Problem
2.4.4 The production costs
2.4.5 Low nutrition in certain ingredient
2.5 Solutions to the problems related with the production of GF baked foods
2.5.1 Weak Structure
2.5.2 Low nutrition in certain ingredient
2.5.3 Production Costs Problem
2.5.4 Low nutrition in certain ingredient
2.5 Other novel technologies approach for improving gluten free baked product
2.5.1 Extrusion-cooking processes
2.5.2 Temperature control
2.5.3 Bioprocessing fermentation

CHAPTER THREE: Conclusion and Recommendation
3.1 Conclusion
3.2 Recommendation

References

DEDICATION

I dedicate this piece of work to my family member friends and course mate.

ACKNOWLEDGEMENTS

With colossal gratitude to God’s hands of provision, preservation and protection upon my studies. Nothing could have been achieved without his grace and providence.

I would like to thank those that have contributed in various ways to ensure the success of this work during the defense.

The same greetings go to the head of department and entire lecturers in Food Science for impacting knowledge and criticism.

Finally I thank Dr. Akubor P.I for taking much of his time to through this work in order to give it a better look.

CHAPTER ONE: INTRODUCTION

The production of traditional bakery products involves four steps of which ingredient mixing, dough kneading, fermentation and baking are involved. Gluten plays an important role in all of these procedures (Ziobro et al., 2016). Gluten is a general name given to the protein class that gives elastic properties to wheat. It is also a property that allows bread and other risen bakery products to be processed (Arendt & Moore, 2006). The gluten conveys structure that allows flour to rise and hold its shape when baked. Gluten exists not only in wheat but to a lesser degree, in relatives of wheat such as rye, spelt, triticale, barley and kamut.

However, for people born with certain health conditions, the gluten in wheat can cause problems (Armstrong et al., 2012; Aronsson et al., 2015; Furlán & Chen, 2017). There are three main forms that human reacts towards gluten intake. These are allergic (wheat allergy), autoimmune (celiac disease, dermatitis herpetiformis and gluten ataxia) and immune-mediated (gluten sensitivity) (Therdthai et al., 2016).

About 2% of the global population suffers from Celiac disease and the gluten intolerance is extremely restrictive. The only treatment is applying a healthy food and avoiding any food which contains gluten. An increasing demand of gluten-free (GF) products is caused by a growing number of diagnosed celiac diseases and a consumption trend to eliminate allergenic proteins from diet.

Attempts are thus, made to adopt methods that could produce cereal based gluten-free products with technological properties comparable to their gluten containing counterparts and minimum compromises with quality (Alvarez et al., 2010). GF bakery products are often less desirable in terms of their appearance, taste, aroma and texture. The simplest way to improve the structure of GF products is by adding other functional ingredients and additives (e.g. starches, protein, gum, hydrocolloids, emulsifiers, dietary fibre) to the wheat flour substitutes (e.g. rice, maize, sorghum, buckwheat, amaranth, quinoa, corn, chickpea) as reported by numerous authors (Arendt & Moore, 2006; Różyło et al., 2015; Rocha et al., 2015a; Akesowan, 2016).

1.1 OBJECTIVE OF THE STUDY

To highlight the challenges associated with the production of gluten free baked products.

CHAPTER TWO LITERATURE REVIEW

2.1 Gluten

The name gluten is derived from this glue-like property of wet dough. Gluten is a mixture of two proteins present in cereal grains, especially wheat, which is responsible for the elastic texture of dough. (Arendt and Moore, 2006). When flour is mixed with water, the gluten proteins form a sticky network that has a glue-like consistency. This glue-like property makes the dough elastic, and gives bakery product the ability to rise when baked. It also provides a chewy, satisfying texture. Gluten is one of the most commonly used proteins in the food industry. Its characteristic properties make it an important ingredient for the production of high quality dough, hence its popularity in the food (baking) industry (Zilic, 2013).

2.1.1 The Role of Gluten in Baked product

Wheat flour's unique properties in yeast‐leavened baked goods are due to gluten. it is composed of 2 main protein fractions, gliadins, which contribute essentially to the viscosity of the dough and glutenins, responsible for dough elasticity (Steffolani, 2014). Gluten becomes apparent when wheat flour is hydrated and subjected to the energy of mixing, even by hand. It is a viscoelastic mass that has the ability to form thin gas‐retaining films that trap gases, allowing dough to expand to become a softer, lighter and palatable food after baking (Costantini et al., 2014).

In baked goods, gluten is a key functional component. It provides extensibility, mixing tolerance and gas-holding ability to the dough, all of which influence product structure and volume. Gluten contains the protein fractions glutenin and gliadin. The former is a rough, rubbery mass when fully hydrated, while gliadin produces a viscous, fluid mass on hydration. Gluten, therefore, exhibits cohesive, elastic and viscous properties that combine the extremes of the two components. The gluten matrix is a major determinant of the properties of dough (extensibility, resistance to stretch, mixing tolerance, gas holding ability), enclosing the starch granules and fibre fragments. A significant challenge to eliminating gluten from a traditional bread dough system is the change from plastic dough to a liquid batter. Resulting products are very different in appearance, texture, and eating quality (Steffolani et al., 2014).

2.2 Celiac Disease

Celiac Disease is a disease in which the small intestine is hypersensitive to gluten, leading to difficulty in digesting food. When people with celiac disease eat gluten, their body mounts an immune response that attacks the small intestine. These attacks lead to damage on the villi, small fingerlike projections that line the small intestine, that promote nutrient absorption. When the villi get damaged, nutrients cannot be absorbed properly into the body (Newnham, 2017).

More so, in the cases of celiac disease, the immune system mistakes substances found inside gluten as a threat to the body and attack them. This damages the surface of the small bowel (intestines), disrupting the body’s ability to absorb nutrients from food. Exactly what causes the immune system to act in this way is still not entirely clear, although a combination of a person's genetic make-up and the environment appear to play a part (Leffler et al., 2015).

Epidemiological studies estimate a worldwide prevalence of CD of approximately 1:100 individuals, with a considerable proportion of patients remaining undiagnosed and untreated (Flande et al., 2011). The ingestion of gluten in genetically predisposed individuals carrying alleles can arouse a T-cell mediated immune reaction against tissue transglutaminase, an enzyme of the extracellular matrix, leading to mucosal damage and eventually to intestinal villous atrophy (Clerici et al., 2009). Gliadins are supposed to be the active fractions of gluten. They contain the immunogenic peptides (especially the 33mer) and are able to exert a direct cytotoxic effect on the cell (Shepherd et al., 2014). The clinical manifestations of CD are heterogeneous and range from the so-called “classical” syndrome with diarrhea, weight loss and malnutrition, to selective malabsorption of micronutrients (iron, vitamin B12, and calcium), (Elli et al., 2015).

2.2.1 Symptoms of CD

The symptoms usually involve the digestive system and cause abdominal discomfort, bloating, nausea and loose bowel movements. However, there is a wide spectrum of symptoms that may occur. The intestine becomes inflamed. It may also lose its ability to absorb nutrients from the diet, leading to other associated illnesses. Treatment of celiac disease is following a strict gluten free diet (Leffler et al., 2013).

2.2.2 Diagnosis of CD

The diagnosis of CD is classically based on a combination of findings from a patient’s clinical history, serologic testing and gastroscopy by means of duodenal biopsies. Even in the absence of clinical symptoms, the screening for CD should be considered among the first-degree relatives of celiac patients, patients with type-I diabetes mellitus and patients with Down’s syndrome, given the high prevalence of CD in these and other at risk groups (Volta et al., 2014).

2.3 Gluten Free Food

Gluten free food is food which does not contain composite of storage proteins termed prolamins and glutelins stored together with starch in the endosperm of various cereal grains (Moreira et al., 2012). GFDs have several short comings such as adversely altered intestinal flora and an elevated risk of micronutrient deficiencies in patients with CD. Some of the risks and drawbacks that go with gluten free diet include limited variety of healthy food choices, increased intake of necessary nutrients such as carbohydrates, protein, fiber, folate, iron, vitamin B-3, calcium and increased food cost (Miñarro et al., 2012).

Korus (2015) found out that on average, gluten-free products are about 160% more expensive than regular products. Other problems include decreased number and variety of beneficial bacterial in the gut, which may make the immune system less effective, increased intake of wheat replacement that, have higher glycemic indexes and lower fiber and protein levels than wheat ,decrease fiber intake, which can cause constipation and other digestive issues increased intake of fat, sodium, and calories. Fat and sugars are often used as replacement in gluten-free products.

2.2.1 Major examples of Gluten Free foods

The following grains and other starch-containing foods are naturally gluten-free food: Rice, Cassava, Corn (maize), Soy, Potato, Tapioca, Beans, Sorghum, Fruits, Vegetables, Meat, and poultry, Fish and seafood, Dairy, Beans, gumes, and nuts, Millet Buckwheat, groats (also known as kasha) Arrowroot Amaranth and Chia Gluten-free oats Nut flours Many items that usually contain gluten have gluten-free alternatives that are widely available in most grocery stores, and make living gluten-free much easier.

2.4 Problems Associated with Production

Working with non-wheat flours has a number of challenges which include weak structure, molding problem, inferior sensory and nutritional quality, high production costs and low nutrition in certain ingredient,

2.4.1 Weak structure

When wheat flour is removed or reduced in a formulation, so are the two proteins, glutenin and gliadin, responsible for forming gluten also go missing. When glutenin and gliadin are mixed with water, they connect and cross-connect to form elastic strands of gluten, which then capture and retain leavening gasses and provide structure to baked foods. Gluten also aids in binding water, a key factor in freshness (What’s, 2016).

2.4.2 Molding Problem

With gluten-free bread, there is no single gluten-free flour that is a direct substitute for wheat flour. So, often you use twice as many ingredients, with a mix of different flours and starches, to get a similar texture and flavor. Low-gluten and gluten-free systems tend to resemble liquid batters and, therefore, can present challenges with production equipment,” “In terms of shelf life, many gluten-free formulations contain more bound water than their wheat-based counterpart, which can create a molding problem. Traditional gluten-free flours and starches have very little inherent nutritional value, which is why gluten-free systems are primes for fortification (Witczak, 2016).

2.4.3 Inferior sensory and nutritional Quality

In the past, gluten-free baked products have been described as being less cohesive and elastic than wheat dough’s, difficult to handle and have poor gas holding retention. The products these breads and dough’s create have been portrayed as having inferior sensory and nutritional quality compared to wheat products, as it usually presents crumbly texture, low volume, poor crust color, taste and aroma, short shelf-life, high glycemic index, and low protein and high fat content (Giuberti et al., 2015; Arendt et al., 2009; Minarro et al., 2012).

2.4.4 The production costs

The production costs for manufacturers have also proven to be problematic, as bakery equipment needs to be guaranteed gluten free, ingredients tend to be costly, and distribution can be difficult due to the higher rate of staling of the products.

2.4.5 Low nutrition in certain ingredient

Despite the advances been made in this area practically by focusing on reviewed and new ingredients as processing methods, maize, potato, rice flour and starches are currently utilized in gluten free flours. These are used as base flours due to their bland flavor and neutral effects on baked products. These flours and starches usually tend to be low in nutrition and have very minimal structure-building potential (Norah et al., 2015).

2.5 Solutions to the problems related with the production of GF baked foods

In other to address the problems related to the production of GF baked food, listed above. The following solutions are necessary in solving them.

2.5.1 Weak Structure

Specific contribution of gluten to texture relates to the strength of the dough, the size and uniformity of the air cells within the dough, and the presence of a heterogeneous matrix within the dough. Weaker dough yields larger and less uniformly sized air cells. Weaker dough also exhibits greater heterogeneity and yields a longer, chewy texture. Stronger dough has smaller and more uniformly sized air cells and exhibits a less heterogeneous appearance. The strength of the gluten replacement system is critical to mimic of the targeted bread product. The physical space that the gluten occupies within the dough in a whole wheat bread also requires compensating adjustments. An effective replacement method must ensure that the volume and weight contributed by the gluten protein are replaced with a gluten-free alternative ingredient.

For poor structure (inability to retain CO2, appearance of a dense crumb grain) and the lack of nutritional content, some ingredients such as flour oil and olive oil has been used to aid the process. These two oils have been used in chestnut dough as a possible means to improve the rheological properties of chestnut flour-based doughs. Adding these oils to the flour decreased the water absorption of the resulting doughs, while decreasing the stability of the dough. These oils decreased the apparent viscosity and storage modulus of the chestnut doughs (Rafiq et al., 2017). You have not given any strong solution to weak structure formation.

2.5.2 Low nutrition in certain ingredient

According to Catassi (2012), one can choose from a number of alternative ingredients. However through a method of “trial and error” one has to establish the most suitable recipe. What follows is a list of ingredients one can choose from.

- Rice flours, brown and white, to replace wheat flour
- Buckwheat flour and teff flour
- Almond flour
- Fibres (apple, psyllium, pea)
- Rice proteins, for water binding,
- Rice starch, instant or cook-up, for elasticity and adhesion,
- Tapioca starch, instant or cook-up, for elasticity and adhesion,
- Non-hydrogenated vegetable oils, for tenderizing,
- Xanthan gum or CMC (carboxymethylcellulose), for film forming and water binding,
- Guar gum, for film forming and water binding,
- Sugar, e.g., sucrose, for water binding
- Milk powder
- Egg powder

Sorghum or brown rice flour, presents itself as potential viable flour in the development of gluten-free products. It has been reported to contain good nutritive properties such as vitamins E and B, iron, folate, essential fatty acids, and dietary fiber (nutritional components which gluten-free products are usually lacking (Blanco et al., 2011).

Blanco and others (2011) investigated the effects of 4 additives (acetic acid, lactic acid, citric acid, and monosodium phosphate) in a rice flour and hydroxypropyl methylcellulose) HPMC-based bread formulation. It was found that the use of monosodium phosphate increased loaf volume significantly; it was also noted that the inclusion of this additive resulted in the largest cell area compared to the control. These positive effects may be a consequence of hydrogen bonding during the proofing stage between HPMC and monosodium phosphate, preventing the CO2 from escaping, thus resulting in larger loaf volumes.

Many researchers have been carried out to enhance the nutrition of gluten free product. Krupa-kozak and others (2011) used two types of calcium supplements (calcium caseinate [CAS] and calcium Citrate [CIT]) and investigated their addition on the baking characteristics of a gluten-free formulation. At 2% addition, CIT showed the most positive effect on bread characteristics. Its presence increased the specific volume from 2.29 cm[3]/g (control sample) to 3.34cm[3]/g. Inclusion of CIT was also found to increase bake loss; the authors suggested this was due to larger cell volume found in the crumb structure which would accelerate the loss of moisture.

Gomez and others (2013) investigated the effects of mixing speed, time; mixing attachment and proofing time on gluten free dough and batter (that contained 80% and 110% water). The authors found that higher water additions led to batter-like consistencies, and required mixing regimes similar to that of cakes, that is, lower mixing speed but longer mixing time, and using a whip wire mixing attachment to incorporate more air and bubbles into the batter. It was also observed that longer mixing times had a positive effect on the amount of CO2 produced. Two reasons for this were proposed; 1st, longer mixing times permits greater oxygenation which allows yeast to reproduce under its preferred aerobic conditions. Second, greater mixing times allow amylase to produce maltose, which is the reserved food source for yeast after sucrose has been consumed during proofing. A shorter mixing time would not allow for these 2 occurrences, therefore, fermentation would cease in the first 15 min of proofing leading to a reduction in CO2 production and a reduced final loaf volume. Longer proofing time (90 min) was required for the sample containing 110% water, compared to the sample which contained 80% moisture (50 min). The authors suggest that a fluid batter can retain more air and expand more easily during proofing. Beyond the optimal proofing time, the structure developed becomes too weak to support itself and collapses (Gomez and others 2013).

2.5.3 Production Costs Problem

Demirkesen and others (2011) compared infrared-microwave baking to conventional baking as a possible cost-saving method. The authors proposed that using microwave ovens offered advantages such as energy efficiency, faster heating, space saving and food which retained better nutritional quality.

Findings showed how microwave power and infrared power were 2 of the prominent factors effecting bake loss, firmness, and specific volume. When these 2 factors were at the maximum levels, a higher level of bake loss was attained, resulting in a drier crumb with a firmer texture. Infrared power particularly affected loaf specific volume. It increased the temperature of the crust more quickly than the crumb, thus reducing the ability of the crumb to develop, resulting in a reduced volume. The optimized baking conditions were calculated to be 40% infrared, 30% microwave power and a baking time of 9 min.

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