Soy protein products such as flour, concentrates and isolates are used in food formulation because of their functionality, nutritional value and low cost. To obtain their optimal nutritive and functional properties as well as desirable flavor different treatments are used. Soybean proteins can be modified by physical, chemical and enzymatic treatments. Different thermal treatments are most commonly used, while the most appropriate way of modifying soy proteins from the standpoint of safety is their limited proteolysis. These treatments cause physical and chemical changes that affect their functional properties. This review discusses three principal methods used for modification of soy protein products, their effects on dominant soy protein properties and some biologically active compounds

Soybeans provide a source of low-cost protein with good nutritional and physico-chemical properties. Recently, soybean has received much attention because of its potential role in preventing and treating several diseases including cancer and other human chronic diseases. Health benefits of soy diet are attributed to the minor soybean constituents (calledphytochemicals). Soybean contains a variety of phytochemicals with demonstrated anticancer activity, including bioactive proteins andpolypeptides (trypsin inhibitors and the most recently discoveredpeptide lunasin), isofl avones, phytic acid, phytosterols and saponins. The present review provides an overview of recent knowledge about biologically active components of soybean

Kunitz inhibitor (KTI) and Bowman-Birk trypsin inhibitor (BBI) are inhibitors of digestive enzymes in raw soybeans. Due to their antinutritive properties in the active state, their inactivation by heat treatment is commonly used. Soymilk is a turbid and stable colloidal solution, obtained by thermal treatment of soybean. In this study soymilk was made on a pilot-plant scale from six soybean cultivars using hydrothermal cooking (HTC) as the production method. This procedure is significantly different from the traditional one. The aim of this investigation was to evaluate the impact of the HTC processing for soymilk production and different soybean genotypes on trypsin inhibitor content and activity. Obtained soymilk contained BBI in trace amounts, in the BBI-polymeric forms. The BBI monomeric forms were not detected. The soymilk of the investigated soybean genotypes had very similar KTI levels (2.34-2.99%). Results have suggested that the soybean genotype does not have substantial effects on the levels of KTI, as well as on the value of residual trypsin inhibitor activity (rTIA). The total content of TI and rTIA showed a strong dependence (r=0.91; p<0.05). HTC-soymilk rTIA was <20% (7.15-19.89%). These results have indicated that HTC processed soymilk is applicable for human consumption. [Projekat Ministarstva nauke Republike Srbije, br. TR 31022 i EU FP7 project Grant Agreement No. 316004 (REGPOT-AREA)]

To study the influence of the preparation mode, including mild alkali modification, of soy protein concentrate on soluble protein content and composition, some of its nutritive and functional properties were investigated. Soy protein concentrate prepared by aqueous alcohol leaching was modified in mild alkaline solutions (pH 8.0) at 40, 50 and 60° C for 60 minutes and compared with two principal types of commercial soy protein concentrate. Soluble protein content, composition and properties of soy protein concentrate, as well as their potential use are essentially determined by the preparation mode. Limited mild alkali hydrolysis increased protein solubility by 40-71%, while emulsion stability was increased by 18-56%. Major storage soybean proteins exhibited different stability to alcohol denaturation and mild alkali modification. The most susceptible were acidic -A3 - and -A5- subunits of glycinin