INTRODUCTION
Protein Isolates are a purified form of protein that contains higher protein content and excellent digestive properties. Protein isolates can be added to less nutrient-dense food products to increase their nutritional value. There are plenty of food products available in the market that is attractive to consumers. However, these products do not contain any nutritional value in them. About 45 nutrients are considered to be essential and must be supplied through food or supplementation.
There are roughly about 13 vitamins, 21 minerals, water, glucose, two essential fatty acids, nine essential amino acids and others that must essentially be supplied through food or supplementation. They are classified into various categories such as carbohydrates, fats (lipids), protein, vitamins, minerals and water. All of these are essential for every cell in the body and for human life to exist. Since proteins are a fuel for muscle growth and development, highly active people may require higher than average proteins, carbohydrates, including the requirement for numerous vitamins and minerals.
Proteins are a major source of building materials for the blood, muscles, skin, hair, nails and glands, as well as for hormones enzymes and antibodies. The Recommended Dietary Allowances (RDA) that most of us are aware of represents the level of nutrients that are to be consumed daily by individuals, in order to meet all their nutritional requirements. Hence, RDAs help us plan balanced diets and they include a variety of foods derived from diverse food groups that help meet an individual’s nutrient requirements.
Owing to its many functional qualities, protein isolate is now a key source of affordable proteins, particularly for athletes, bodybuilders and vegetarians and it is widely used in a variety of beverages as well as in the Dairy Industry, including in infant meals.
How to Isolate Protein?
It is widely extracted after defatting legumes such as peanuts, cowpeas, soybeans, etc., including animal sources such as fish and milk by a combination of isoelectric and alkaline precipitation using H2SO4 and NaOH, followed by centrifugation to obtain the pure isolates, which can further be dried to powdered form of about 90% protein. The problem of anti-nutritional factors in legumes can be successfully reduced by these processing methods.
How adding Protein Isolates into various Food Products can improve their nutritional quality
Isolated protein can be incorporated into cakes, muffins, papads, cookies, including any other food product that is less nutritious. Gularteet et al. (2012) investigated the impact of incorporating different legumes (chickpea, pea, lentil and bean) on quality, chemical composition, in-vitro protein and starch digestibility of gluten-free layer cakes and suggested that the legume flours were useful for protein and fibre enrichment of gluten-free cakes. However, only few studies describing the effects of protein isolates from different legumes and amaranth on the characteristics of gluten-free muffins are available in the literature. (Rondaet al., 2011; Ziobroet al., 2013; Matos et al., 2014)
Pasta is a popular cereal food that comprises of spaghetti, noodles, vermicelli, etc. It is mostly made from durum wheat, since it maintains a desirable firm texture during cooking and has natural amber colour that is associated with good quality pasta. Various unconventional ingredients such as buckwheat, amaranth and lupin flours (Rayas-Duarte et al. 1996), finger millet flour (Devaraju et al. 2008; Shukla and Srivastava 2011) have been used to increase nutritional and functional quality of pasta and noodles. Shanthi et al. (2005) prepared composite pasta using refined wheat flour, whole wheat flour, soya flour and finger millet in different proportions and observed that nutritional quality of pasta could be enhanced using composite flour mixtures.
Sozer et al. (2009) studied the rheological properties of rice pasta dough supplemented with proteins and gums and observed that gums are an essential part of the formulations of non-wheat pasta. Similarly, several dairy ingredients have also been used in cereal products for nutritional and functional benefits in addition to flavour and texture enhancement. Prabhasankar et al. (2007) made vermicelli from durum wheat using whey protein concentrate, ascorbic acid and glycerol monostearate and observed that the product contained higher protein content, apart from having improved colour and texture.
References:
1. Gularte, M. A., Gómez, M., & Rosell, C. M. (2012). Impact of legume flours on quality and in vitro digestibility of starch and protein from gluten-free cakes. Food and Bioprocess Technology, 5(8), 3142-3150.
2. Ronda, F., Oliete, B., Gómez, M., Caballero, P. A., & Pando, V. (2011). Rheological study of layer cake batters made with soybean protein isolate and different starch sources. Journal of Food Engineering, 102(3), 272-277.
3. Ziobro, R., Witczak, T., Juszczak, L., & Korus, J. (2013). Supplementation of gluten-free bread with non-gluten proteins. Effect on dough rheological properties and bread characteristic. Food Hydrocolloids, 32(2), 213-220.
4. Matos, M. E., Sanz, T., & Rosell, C. M. (2014). Establishing the function of proteins on the rheological and quality properties of rice based gluten free muffins. Food Hydrocolloids, 35, 150-158.
5. Rayas-Duarte, P., Mock, C. M., & Satterlee, L. D. (1996). Quality of spaghetti containing buckwheat, amaranth, and lupin flours. Cereal Chemistry, 73(3), 381-387.
6. Devaraju, B., Begum, J. M., Begum, S., & Vidya, K. (2008). Finger millet pasta fortified with plant and animal protein and their sensory qualities. J Dairy Foods Home Sci, 27, 193-195.
7. Shukla, K., & Srivastava, S. (2011). Quality Characteristics of Finger Millet Based Baby Food Preparation as Affected by Its Varieties and Processing Tecniques.
8. Shanthi P, John Kennedy Z, Parvathi K, Malathi D, Thangavel K, Raghavan GSV (2005) Studies on wheat based composite flour for pasta products. Indian J Nutr Diet 42:503–506.
9. Sozer, N. (2009). Rheological properties of rice pasta dough supplemented with proteins and gums. Food Hydrocolloids, 23(3), 849-855.
10. Prabhasankar, P., Rajiv, J., Indrani, D., & Rao, G. V. (2007). Influence of whey protein concentrate, additives, their combinations on the quality and microstructure of vermicelli made from Indian T. Durum wheat variety. Journal of Food Engineering, 80(4), 1239-1245.
