Abstract

Soy food has been consumed for more than a thousand years, but only in the last 15 years they have made way for Western cultures and diets. Soymilk is a cheap, decent protein source that does not contain lactose. It replaces bovine milk as well. Though, soy milk protein is less digestible and more anti-nutrient than milk protein, it resolves the lactose intolerance problem and acts as a vegan milk supply. Soy milk is typically divided into two categories: fermented and unfermented.

In comparison with unfermented one, fermented soy milk is less favorable. But there are also some inconveniences, such as low stability, shorter shelf-life and anti-nutritional causes. Different technology should overcome all these disadvantages such as Ultra high temperature, Microwave processing, Ultra-high pressure homogenization, Pulsed electric field and High pressure processing. Besides both of these soy milk, bioactive compounds like isoflavones, genistein, daidzein, and glycitein can also be minimized by thermal processing. (Aarushi Saini and Sonia Morya)

Three different heat treatments, their impact on the sensory, nutritional and anti-nutritional properties have been discussed in this piece of work.

CHAPTER ONE

INTRODUCTION

1.1 Background Of Soybean.

Soybean, (Glycine max), annual legume of the pea family (Fabaceae) and its edible seed. The soybean is economically the most important bean in the world, providing vegetable protein for millions of people and ingredients for hundreds of chemical products. The soybean is an erect branching plant and can reach more than 2 metres (6.5 feet) in height. The self-fertilizing flowers are white or a shade of purple. Seeds can be yellow, green, brown, black, or bicoloured, though most commercial varieties have brown or tan seeds, with one to four seeds per pod.  The origins of the soybean plant are obscure, but many botanists believe it was first domesticated in central China as early as 7000 BCE. An ancient crop, the soybean has been used in China, Japan, and Korea for thousands of years as a food and a component of medicines. Soybeans were introduced into the United States in 1804 and became particularly important in the South and Midwest in the mid-20th century.

Brazil and Argentina are also major producers. In the United States the majority of soybean crops are genetically modified for resistance to the herbicide glyphosate. The soybean may be cultivated in most types of soil, but it thrives in warm, fertile, well-drained, sandy loam. The crop is planted after all danger of frost is past. Soybeans are usually harvested mechanically, after the leaves have fallen off the plant and the moisture content of the seed has dropped to 13 percent, permitting safe storage. Like other legumes, the plant adds nitrogen to the soil by means of nitrogen-fixing bacteria and historically has been an important soil-enriching crop, though this practice is not common in most industrial agriculture systems..(Aarushi Saini and Sonia Morya)

Soybeans are mainly composed of protein but also contain good amounts of carbs and fat. The nutrition facts for 3.5 ounces (100 grams) of boiled soybeans are; Calories: 172, Water: 63%, Protein: 18.2 grams, Carbs: 8.4 grams, Sugar: 3 grams, Fiber: 6 grams, Fat: 9 grams, Saturated: 1.3 grams, Monounsaturated: 1.98 grams, and Polyunsaturated: 5.06 grams Soybeans are among the best sources of plant-based protein. The protein content of soybeans is 36–56% of the dry weight .One cup (172 grams) of boiled soybeans boasts around 31 grams of protein. The nutritional value of soy protein is very good, although the quality is not quite as high as some animal proteins. The main types of protein in soybeans are glycinin and conglycinin, which make up approximately 80% of the total protein content. These proteins may trigger allergic reactions in some people. Consumption of soy protein has been linked with a modest decrease in cholesterol levels. Soybeans are classified as oilseeds and used to make soybean oil. The fat content is approximately 18% of the dry weight — mainly polyunsaturated and monounsaturated fatty acids, with small amounts of saturated fat (11Trusted Source).The predominant type of fat in soybeans is linoleic acid, accounting for approximately 50% of the total fat content.

Being low in carbs, whole soybeans are very low on the glycemic index (GI), which is a measure of how foods affect the rise in blood sugar after a meal. This low GI makes soybeans suitable for people with diabetes. Soybeans contain a fair amount of both soluble and insoluble fiber. The insoluble fibers are mainly alpha-galactosides, which may cause flatulence and diarrhea in sensitive individuals. Alpha-galactosides belong to a class of fibers called FODMAPs, which may exacerbate the symptoms of irritable bowel syndrome (IBS).Despite causing unpleasant side effects in some people, soluble fibers in soybeans are generally considered healthy.

They are fermented by bacteria in your colon, leading to the formation of short-chain fatty acids (SCFAs), which may improve gut health and reduce your risk of colon cancer. Soybeans are a good source of various vitamins and minerals, including; Molybdenum, Vitamin K1, Folate, Copper, Manganese, Phosphorus, Thiamine also known vitamin B1, all of which plays an important role in many bodily functions. Soybeans are rich in various bioactive plant compounds, including; soflavones, a family of antioxidant polyphenols, isoflavones have a variety of health effects. The main types of isoflavones in soy are genistein (50%), daidzein (40%), and glycitein (10%). Phytic acid found in all plant seeds, phytic acid (phytate) impairs the absorption of minerals like zinc and iron. Levels of this acid can be reduced by boiling, sprouting, or fermenting the beans. Saponins, one of the main classes of plant compounds in soybeans, saponins have been found to reduce cholesterol in animals. .(Aarushi Saini and Sonia Morya)

Soybean may act as an antidiabetic agent and may help in reducing renal disorders. Soybeans may help in reducing the increased protein content by replacing animal proteins with soybean plant proteins. Soybean plant protein may help in renal hyper filtration and may reduce renal disease in diabetes type 2. Soybeans contain isoflavonoids and stigma sterol which may act as antidiabetic agents by targeting glucose transporters. Regular intake of soybeans as a part of a regular diet may reduce the risk of cancer. The constituent of soybean that may be responsible for its anti-cancer effect is an isoflavone. Soybean may be used for breast, prostate, and colon cancer due to its anti-proliferative property (property of inhibiting the growth of cancerous cells). The diseases that affect the heart and the blood vessels are cardiovascular diseases. Coronary heart disease, coronary artery disease and hypertension are a few examples of cardiovascular disease. Isoflavone and phytosterols, present in soybean may play a major role in cardiovascular diseases by lowering cholesterol levels.

Osteoporosis refers to weaker, brittle bones and joints, which generally happens in older women. Isoflavones in soybean may be used for osteoporosis as they may maintain bone mineral density. Soybean is a good source of protein and regular intake of soybean in your diet may help in taking less food in humans which, may help in lowering obesity. Studies in animals and humans have shown that soy proteins may reduce body weight and body fat mass. The high protein content of soybean may help maintain proper blood pressure. Soy protein is generally hypotensive; that is, it may help to reduce blood pressure. Isoflavones present in soybeans may help to improve overall skin health. Soybeans may increase collagen synthesis, a protein that may improve the skin elasticity, and water-holding capacity of the skin, reducing pigmentation, and wrinkles. Soybean may be beneficial in managing depression and Isoflavones present in soybean may have anti-depressant properties. Studies have shown that the consumption of soybean may reduce depressive symptoms. (Aarushi Saini and Sonia Morya)

Despite the numerous health benefits of soybeans some people still show allergic response to it and over consumption of it can lead to Constipation and diarrhea and may alter thyroid function in people with iodine deficiency. (Aarushi Saini and Sonia Morya)

1.2 Problem Statement.

The demand for milk is increasing day by day and fulfilling the future need will be a big challenge. About 55-58 percent of the human population has little or no ability to digest lactose after infancy because their bodies don’t produce enough of an enzyme called lactase (Facioni MS, Raspini B, Pivari F, Dogliotti E, Cena H.).

Lactase is like a key that unlocks lactose, a sugar found in milk. Without enough lactase, the lactose can’t be absorbed properly in the small intestine and ends up moving to the colon where it ferments, causing uncomfortable symptoms like bloating, gas, and diarrhea. That’s why there is need of a substitute which can replace the bovine milk. (Aarushi Saini and Sonia Morya)

Soy milk has been considered as an excellent economic dairy substitute. Soymilk is a cheaper source of high-quality protein with many other health-promoting properties (Achla Bharti.).  Soymilk contains all essential amino acids in high amount which exerts positive impacts on cardiovascular health. It is rich in potassium as well as calcium and contains very little saturated fat. Functional soymilk contains extra bio-active compounds and may enhance health or lower the risk of diseases. The products of soymilk are generally rich in omega fatty acids and phyto-antioxidant and thereby strengthen blood vessels completely. It also contains phytoestrogen that decreases the risk of prostate cancer. The presence of calcium and vitamin D makes it suitable solution to fight against osteoporosis.

The low glycemic index and high fiber content of soymilk makes it suitable for making healthy diets for diabetic patients. Soymilk has been an excellent source of high-quality proteins, isoflavones, and B complex vitamins. Soy milk is a good choice for lactose intolerant due to absence of lactose sugar. Galactose is not present in soymilk, which makes it completely safe for children with galactosemia. (Aarushi Saini and Sonia Morya)

However, soybeans have some disadvantages such as they contain anti-nutrients that can hinder digestion and nutrient absorption. Additionally, raw soybeans have an unpleasant beany smell and a short shelf life. Thus there’s a need to solve this problem so as to make soy milk more acceptable reason why this research is currently being carried out.

1.3 Objectives Of Study

1.3.1 Main Objective

The main Objective of this study is to access how each of this processing methods (roasting, boiling and dehydration, and blanching and dehydration) optimizes soybean for consumption ( by improving taste and reducing undesirable compounds.), Nutrition ( by maximizing the availability of beneficial nutrients.), And storage ( by increasing shelf life.).

1.3.2 Specific objectives

1. Effect of different processing methods on the sensory qualities of Soymilk.
2. Effect of different processing methods on the nutritional and anti-nutritional properties of Soymilk.
3. Effect of different processing methods on the shelf life of Soymilk.

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