Functionalization of soya press cake (okara) by ultrasonication for enhancement of submerged fermentation with Lactobacillus paracasei LUHS244 for wheat bread production
This study was dedicated to the functionalization of soya press cake (SPC) by ultrasonication and fermentation to produce wheat bread enriched with okara nutrients. Different frequencies (18 & 850 kHz) ultrasound (US) was used for the treatment of SPC. The application of low-frequency US resulted in 80.64 and 58.06% higher contents of soluble proteins (SP) and soluble dietary fibre (SDF), respectively. The content of SP with high-frequency US treatment was increased by 64.51% and a significant increase in SDF content was found. The application of soya meal and SPC treated with low-frequency ultrasound as fermentation media resulted in a higher lactic acid bacteria (LAB) cell number and enhanced production of l-lactic acid. By adding 5% of sonicated and fermented SPC for wheat bread production, a higher porosity of bread crumb and specific volume was achieved, compared to breads with other soya ingredients. Novel method - emotional response to the products was applied in order to evaluate acceptability of final breads. Comparing breads enriched with okara, highest acceptability score (7.2) was achieved using 5% of sonicated and fermented SPC. The results of this study showed potential improvement in functionality of wheat bread supplemented with okara dietary fibre.