Utilising waste from soybean processing as raw materials for the production of preparations with antioxidant properties, serving as natural food preservatives - A pilot study

Abstract

Technologies for the production of protein hydrolysates from soybean bran, left over from the soy flour production process, have been designed. The influence of using various enzyme preparations on antioxidant activity and quality (zeta potential, free amino acid profile, sodium dodecyl sulfate polyacrylamide gel electrophoresis, total phenolic content) of soybean bran hydrolysates were assessed. It was found that regardless of the applied enzyme, the obtained hydrolysates were characterised by high antioxidant properties measured via the FRAP method and metal chelating activity (13.51–15.58 μM Trolox/mg and 93.5–95.15%), while the ability to scavenge free radicals, varies depending on the method of obtaining the hydrolysate. Hydrolysates acquired as a result of digestion with Alcalase were characterized by the highest content of protein and polyphenols, as well as high antioxidant properties. Therefore, they were used in further research as additives to minced meat. It has been stated that the protein hydrolysate produced from soybean bran, despite increasing the hardness of meat model products, cannot be used as an antioxidant agent, because it does not reduce lipid oxidation in meat. Careful analysis of its chemical structure and interactions with meat constituents is necessary to detect the exact cause of the pro-oxidative effect observed.