Quality and nutritional characteristics of traditional curd cheese enriched with thermo-coagulated acid whey protein and indigenous Lactococcus lactis strain

Abstract

Today’s production of dairy products is far from sustainable. In EasternEurope, during the production of curd cheese, large quantities of acid whey are by-produced, however,its food applications are limited.Moreover, wild-type, indigenous lactic acid bacteria (LAB) isolated from various local sources are being extensively investigated as possible starters, protective cultures, nutraceuticals, probiotics, and flavour enhancers. Considering these aspects, the objectives of this study were to manufacture thermo-coagulated protein (TAWP matrix) from fresh acid whey and to use it as support for protective and flavour enhancing indigenous Lactococcus lactis strain. Obtained matrix was used to produce an enriched traditional curd cheese. This study aimed to evaluate the effects of this supplementation on the nutritional, physicochemical, microbiological, and sensory parameters of curd cheeses during their refrigerated storage. The replacement of fresh curd cheese with 25% (w/w) of TAWP was technically viable, allowing by-product value aggregation, and contributing to a more sustainable (circular) production.The supplementation of curd cheese with TAWP led to 8-10% higher contents of moisture, 23-31% of lactose, 12-13% of unsaturated, 5-6% of monounsaturated, 63% of polyunsaturated, and 3-4% of long-chain fatty acids. Lipid quality indices – TI, AI, h/H, and Omega 6/3 among others, were also significantly better than those of control cheese. The addition of indigenous Lactococcus lactis strainenhanced the flavour of cheese samples, decreased the counts of yeast and mold up to 1 log cfu g⁻¹ after ten days of storage. The replacement of curd with TAWP resulted in novel cheese with overall sensory perception above 77 points and added nutritional and functional value, however, body and texture parameters of modified cheese samples require an improvement.