Development and characterization of shelf stable cookies from soy bean residues (Okara)

Abstract

The production and consumption of soybeans and their products is increasing at a high rate. This is mainly attributed to the nutrition composition and health benefits associated with consumption of soy beans and their products in addition to economic benefits. Worldwide, soy bean is consumed in various forms including sauces, soups and fermented products. On the other hand, soy beans are processed to produce soy milk and tofu. During this process, large amounts of okara commonly known as soy bean residue a by-product is produced. Worldwide, 14 million tons of okara are being produced annually (Choi et al, 2015). Okara is underutilized by many food processing industries and they have resorted to feeding it to farm animals or disposing it into landfills which also cause environmental problems in addition to the lost opportunity of value addition. In this research, the major aim was to incorporate dried okara in a food product (cookies) to improve the nutrition of communities by utilizing locally available and relatively inexpensive raw materials such as soy bean residues. Okara from three different varieties of soy beans locally grown in Uganda was analyzed for nutrient composition. Three varieties of Mak soy 3N, 4N and 6N were used as these varieties are commonly grown in Uganda due to their high yields and resistance to diseases. Through proximate analysis, okara from all the three varieties contained a lot of essential nutrients especially fibers and proteins. Okara from Mak soy 6N had the highest percentages of all nutrients analyzed and therefore, was used in the development of cookies. It was added to other ingredients in varying percentage. The acceptability of cookies was then tested using a nine point hedonic scale. From the observations made, the degree of general acceptability of cookies reduced with an increase in composition of okara. An increase in okara composition caused no significant difference to the color and appearance. A significant difference was observed in the Aroma, flavor, taste and mouth feel of cookies with an increase in okara composition. It was concluded that although okara contains nutrients, panelists preferred cookies with the lowest amount of okara.