| Abstract [eng] |
The aim of the project is to modernize the process of pea (Pisum sativum) processing by selecting technological solutions for the processing of by-products that are made during pea processing. The technological experiment was carried out under production conditions in two directions: fractionation of pea mills and the separation of by-products by using the dry separation process, secondly – production of whole grain pea flour (WGF). Possibilities of using low–temperature extrusion, solid-phase fermentation LAB (L. uvarum, L. brevis and L. paracasei) and ultrasound (850 kHz) for processing by-products of pea processing and whole-grain pea flour were examined. The effect that technological factors had on the quality of pea processing products (PPP) was examined based on the changes in proteinaceous substances, functional properties and anti-nutritional factors. The use of the dry fractionation process results in a high total protein content (22,9 g/100 g d.b.) in the by–products after the separation process of the control pea flour (CPF), while the protein content in pea shell products (PSP) were only up to 5,3 g/100 g d.b. Processing peas into WGF could be a technological alternative, which would allow the processing of peas on a sustainable basis and produce 22,0 g/100 g d.b. protein content products. The highest amount of soluble proteins was detected in ŽMK and WGF products. Pea processing by-products (PPBP) and PSP, which mainly consist of larger particles (64% and 58,7%, respectively), had higher water and fat absorption index. The highest levels of trypsin inhibitors and lower levels of digestibility at the in vitro stage were found in CPF and WGF products. A decrease in the amount of protein substances was detected while evaluating the effect that the extrusion process has on the composition of PPP. The effect that this process has on functional properties depends on the type of PPP: the analysis of the products (PSP–E3 and VGŽD–E4–E5) revealed 1,2 times higher water absorption than the control sample. The low-temperature extrusion process was determined to not reduce the activity of protease inhibitors in pea processing products. A decrease in protein content was detected in fermented pea processing products (2,7% on average). The process of fermentation had a negative effect on the functional properties of ŽPP: the water absorption capacity of fermented PPP had a lower level than the ability to absorb fat. The positive effect of fermentation was noticeable (regardless of the LAB strain) on protein uptake: by decreasing trypsin inhibitor activity (mean 50,4%) together with protease activity (68,2%) and increasing protein in vitro environment digestibility (0,8%). The ultrasound treatment of PPP increased the water uptake index (7,8% on average). In addition, the effect that the ultrasound process had on PPP correlated on the intensity at which it was used: at lower intensities (0,9 W and 1,3 W/cm3) an increase in protease activity was observed (1,7 and 1,4 times lover, respectively), while at the highest intensity (2 W/cm3) a decrease in protease activity (average 1,5 times) was noticeable. The largest change in protein content and a decrease in trypsin inhibitors were detected at the lowest intensity (0,9 W/cm3). |
