Health-consciousness & increased awareness driving soy growth in India

Introduction
Processed food industry is the fifth largest industry in India in terms of production, consumption and exports and is considered as a sunrise industry.  It accounts for almost one-third of the country’s total food market and plays a vital role in the Indian economic growth as it is a crucial link between agriculture and industry.

The Indian food processing industry is growing at more than 10% CAGR for the last five years and continues to grow. Growing urbanisation, growing middle class, increasing disposable income, emerging organised food retail, and changing lifestyles and food consumption patterns are the drivers of this growth. In fact, rapid transformation in the lifestyle of Indians has resulted in increase in the demand for processed and convenience food.

Increasing health-consciousness among consumers is the leading cause for demand for health foods.  This situation is leading to introduction of ingredients, which have food processing function and provide health benefits (functional food). Health foods are one of the fastest moving processed food products in the world in the last five years. Consumers are more proactive about their health and spurred the global retail market for functional foods and beverages. Consumers are re-evaluating their health, nutrition, and lifestyle choices adopted years ago and are considering the role of functional foods and beverages that could or should play in diets in order to prevent or help treat all kinds of health conditions. Soy protein is a unique ingredient that offers both these functions to a food processor to meet the consumer demand.

Adoption of advanced technologies and good handling practices can go a long way in marketing value added soy protein products to their full potential which is not happening in India due to commodity market attitude of the processors. Defatted Soy Flour (DSF) is the fine powder of deoiled white flakes a basic value product from solvent extraction process. This is used as a raw material for a number of value-added protein products and quality of DSF is of utmost importance. Based on the quality and the extent of heat treatment, there are a number of varieties of soy flour products available.


Full fat soy flour is the product obtained from grinding dehulled soybeans before solvent extraction process. It has about 20% fat, 40% protein and usually has low shelf life unless specially packaged and stored. Enzyme active full fat soy flour contains lipoxygenase that acts on fatty acids in the dough, generating fatty acid hydroperoxides that bleach the yellow carotenoid pigments found in wheat flour, giving a whiter crumb and also interact with gluten during mixing, increasing dough strength.

Types of soy flours made from solvent extraction process

Product	PDI	Functionality	Applications
Full fat enzyme active soy flour	~90+	Bleaching	Bread, fermentation, protein isolates
Full fat enzyme inactive soy flour	10-25	Nutritional supplement	Feeding programmes
Untoasted DSF	65-85	Controlled water absorption, less oil absorption	Bakery products, doughnut mixes; baby foods, meat products, breakfast cereals, protein isolates
Lecithinated soy flour	65-85	Egg white and yolk	Eggless recipes
Slightly toasted DSF	45-65	Slight water absorption and texturisation	TSP
Toasted DSF	30-45	Nutritional supplement	Meat products
Toasted DSF	10-25	Nutritional supplement	Baby foods, gravies, hydrolysed vegetable proteins, feeding programmes

Value-added soy flour products
Production of white flakes allows the manufacturer to produce a number of functionally superior protein products. Some of these products are 1.    High PDI DSF; 2.     Lecithinated soy flour; 3. Textured soy protein (TSP); 4.    Soy protein concentrates ; and 5. Soy protein isolates.

High PDI soy flour
Native soy protein has a unique arrangement of amino acids, which provide certain functional properties in food processing such as, low fat binding capacity (FBC), high water absorption capacity (WAC), emulsification property, whipping characteristics and so on. This varying FBC and WAC is due to the arrangement of polar (outside) and non-polar amino acids (inside) in the native structure of protein. Soy ingredients when added provide a number of functional benefits to bakery products such as water binding, dough conditioning, emulsification, shortening (tenderising) and crust coloration.  Because of water-binding capacity of soy there is increased water absorption by dough or batter (and increased yield of product) and the finished product also has increased moisture content. This slows the rate of starch retrogradation (staling) and results in a longer shelf life. Water binding is a function of both the protein and the fibre present in soy flour.

Soy flour contains good amount of non-fermentable sugars, which undergo browning reaction to give characteristic appealing colour to the products during baking. In general, soy flour can be added up to 3% without changing formulation except water. In bakery products, three types of soy flour can be used based on the product. Currently a number of bakers are using full fat or defatted enzyme active soy flour up to 1% as bread improver. In case of bread and biscuits, high PDI soy flour (low heat treated) can be used as an alternate to non-fat dry milk to reduce the cost of raw material. Addition of soy flour improves the nutritional quality, increases water absorption, helps in emulsification of fats and other ingredients.

The other major application for soy flour in bakery could be use of lecithinated soy flour as an alternate to whole eggs. High PDI soy flour with 6-15 % of lecithin can be used in cakes and doughnuts to replace eggs. A study conducted at American Institute of Baking suggested lecithinated soy flour as an alternative to egg by which the raw material cost could cut by almost 25%. Studies conducted across the globe suggest that addition of as low as 3% functional soy flour (high PDI) can provide a number of economic benefits to the bakers. These benefits are due to combination of various functions soy flour exhibits such as increasing water absorption, increasing water retention during dough development, reducing water evaporation during baking and increasing shelf life of the final products.

Textured Soy Protein
Textured Soy Protein (TSP) usually refers to products made from soy flour, soy protein concentrates and soy protein isolates. TSP can contain between 50% and 90% protein, depending on the starting material used. TSP is most commonly used as a meat extender or analog and can be added to meat to increase its protein content. TSP has a texture similar to ground meat and must be rehydrated with boiling water before use. TSP is made by running any of the three raw materials through an extrusion cooker, which allows for many forms and sizes. The dietary fibre and soluble carbohydrates content in TSP also varies based on the raw material. When hydrated, it has a chewy texture and is widely used as a meat extender.

Soy Protein Concentrates
Soy Protein Concentrate (SPC) is made by removing a portion of the carbohydrates from defatted soy flour. SPC retains most of the fibre of the original soybean. SPC is widely used as functional or nutritional ingredient in a wide variety of food products, mainly in baked foods, breakfast cereals and in some meat products. SPC is used in meat and poultry products to increase water retention, and to improve nutritional value (more protein, less fat). SPC should contain at least 65% protein on a moisture-free basis. The protein has different solubility characteristics, depending on the extraction method for example alcohol method results in low solubility. Some applications, such as beverages, require a highly soluble protein. SPC can be found in different forms - granules, flour and spray dried.

Soy Protein Isolates: They are isolated from defatted flakes and are most highly refined soy protein form, containing 90 per cent protein, possessing the greatest amount of protein of all soy products. They are a highly digestible source of amino acids and because of the bland taste can be added to foods without jeopardising flavour and taste. Isolates are used to add juiciness, cohesiveness, viscosity to a variety of meat, seafood, and poultry products. Isolates are used to enhance nutritional quality and sensory attributes of whole meat products. Isolates are commonly used in dairy products such as beverages, frozen desserts and imitation cheeses. They can also be used as an ingredient to supplement or replace milk powder. In India, SPI has been extensively used in dry blended protein supplements.

In addition to the above, soy can be processed into developed specialty ingredients like soy flakes, specific peptides, and dairy analogues.

Functionality of soy protein products
Soy was used mostly for its nutritional and functional properties before the revelation of the health benefits. Based on the unique protein structure and arrangement of amino acids, soy protein provides certain functional properties in food processing. The presence of both hydrophilic and hydrophobic groups in the same polymer chain facilitates association of the protein with both fat and water. The protein may adhere to solid particles and act as a binder or, in solution, as a dispersing and suspending agent. Protein films may adhere to surfaces, and solids may be distributed and cemented together within the protein film. Such properties usually require a protein with a relatively high degree of water dispersibility, soluble proteins are easier to incorporate into moist foods. In a relatively insoluble protein product, these properties are present to a limited degree. These products are nutritionally valuable but they may contribute only slightly to viscosity, gel formation, emulsification, binding, adhesion, or to the stabilisation of emulsions and suspensions. When soy protein is heated, protein gets denatured and these functional benefits are lost. The following tables give a clear picture of how soy protein acts in different food systems.
Functional properties of soy protein products in food

Functional property	Mode of action	Food system used	Product*
Solubility	Protein solvation, pH dependent	Beverages	F, C, I, H
Water absorption and binding	Hydrogen-bonding of water, entrapment water (no drip)	Meats, sausages, breads, cakes	F, C
Viscosity	Thickening, water binding	Soups, gravies	F, C, I
Gelation	Protein matrix formation and setting	Meats, curds, cheeses	C, I
Cohesion- adhesion	Protein acts as an adhesive	Meats, sausages, baked goods, pasta products	F.C.I
Elasticity	Disulfide links in deformable gels	Meats, bakery items	I
Emulsification	Formation and stabilisation of fat emulsions	Sausages, bologna, soups, cakes	F, C. I
Fat absorption	Binding of free fat	Meats, sausages, doughnuts	F, C, I
Flavour-binding	Adsoprtion, entrapment	Simulated meats, bakery items	C, I, H
Foaming	Forms film to entrap gas	Whipped toppings, chiffon desserts, angel cakes	I, W, H
Colour control	Bleaching (lipoxygenase)	Breads	F

*: F, C, I, H, and W denote soy flour, concentrate, isolate, hydrolysate, and soy whey, respectively.

Benefits of soy in traditional foods

Product	Replacement	Level of replacement	Benefits		Soy Component
			Functional	Economic
Traditional snacks	Pulses	20-30 %	Low oil absorption	Yes	Flour, Isolate
Papad	Black gram	40-50%	Low oil absorption, more diametric expansion	Yes	Flour
Roti	Wheat flour	10-15%	Increase in freshness		Flour
Cakes	Egg	60-100 %		Yes	Flour, lecithin
Bread	White flour	1-5 %	High yield, shelf life	Yes	Flour
Cookies	Milk powder	60-100 %		Yes	Flour, lecithin
Noodles	White flour / egg	10-15% / 60-100%	More yield, strong noodles, low breakage losses	Yes	Flour, lecithin

Opportunities in Indian food industry
Wheat-based Products
Wheat flour can be fortified with DSF maximum up to 10 per cent, which increases the protein content to about 16-17 per cent. This is about 25-30 per cent more compared to regular whole-wheat flour. Soy fortified wheat flour will improve the protein profile and functional characteristics of the end products by increasing moisture retention so that rotis will remain fresh for longer time while.

Bakery Products: In different bakery products wheat flour can be fortified with soy both for functional and nutritional reasons. Studies suggest that addition of as low as 3% soy flour will improve yield and shelf life in bread. In biscuits and cookies, soy flour with sweet dry whey powder can be used to replace expensive skimmed milk powder. In cakes, lecithinated soy flour can replace eggs completely.

Noodles and Vermicelli: Fortifying refined wheat flour, which is the basic raw material for noodles will improve the nutritional quality and give some functional benefits also. Addition of 10-12 % DSF to wheat flour will give a product with increased moisture retention in case of wet noodles and in fried noodles it will save oil during frying. Addition of 10 per cent soy flour reduces about 60 per cent usage of eggs in egg noodles. Soy flour reduces breakage losses by making the noodle stronger.

Legume-based Products
DSF has more than double the amount of protein compared to pulse flours. Approximately 20-40% of pulse flours can be replaced with DSF without affecting the organoleptic attributes. Twenty per cent substitution of pulse flours with DSF, results in increase in the protein content from 20 to 26% in the blend translating to an increase of 30% in protein content. The low-fat binding capacity of soy protein allows less oil absorption during deep-frying of products made with soy fortified gram flour. Addition of 20% soy flour to gram flour almost reduced 20% oil absorption during frying (besan, papad) giving consumer a healthier, low-fat product and reducing cost for the manufacturer. In case of papads, addition of soy flour was found to increase diametric expansion considerably after frying.

Protein Supplements
Protein supplements such as general health supplements, disease specific supplements, sports nutrition and weight management products are some of the fastest growing functional foods in India and across the globe. Soy protein products especially soy protein isolate is being used as the primary ingredient in these products due its proven health benefits.

Extruded Products
Extrusion cooking is one of the novel techniques of food processing with great versatility and a wide range of application, has great potential in the food industry in developing countries like India. In extrusion, soy is used widely as an ingredient to make good quality meat analogs, meat alternates, snacks and other products. Soy protein ingredients can be used in a number of other processed food products such as protein bars, confectionery products, processed meat products, diary analogues, breakfast cereals, beverages, soups, fruit juices, and meal replacement products.

Conclusion
Rapid transformation in the lifestyle of Indians has resulted in dramatic increase in the demand for processed and convenience food. Further, considerable increase in health-consciousness among Indian consumers also increased awareness of the health benefits of soybean. These two factors offer soy and soy ingredients immense potential in this predominantly vegetarian society. The Indian food industry should also take the advantage of functional properties of soy protein so that they can reduce the raw material/processing cost. At the same time, consumers will benefit from soy consumption and improve overall health. Soy protein is a highly versatile ingredient whose limitation to application in the food processing industry is only imagination.

(The author is a Ph D and is with NutriTech Consulting Services Pvt. Ltd, New Delhi. He can be contacted at sitapu@nutritechindia.com)