The Usage of Fermented Milk By-Products in Cabbage Pickle Fermentation Through a Sustainable Food Production Approach

This study examined the physicochemical, microbiological, textural, organic acid, colour, and sensory aspects of cabbage pickles made with fermented dairy by-products as a brine medium. Yoghurt whey, whey, kefir whey, and buttermilk were used as brine media and compared with vinegar. Brine samples showed substantial changes in pH, Brix, colour, and rheology (p < 0.05). Yoghurt whey-based samples had the lowest brine pH (2.87) and Brix (10.04%), while buttermilk samples had the highest pH (3.26) and Brix (10.83%). Vinegar-based brine showed higher a* and b* values, whereas yoghurt whey-based brine had the highest L*. Yoghurt whey-based samples had lower consistency and a lower viscosity index. Pickle samples made with different brine types showed significant differences in physicochemical, microbiological, textural, and organic acid properties (p < 0.05). Pickle samples made with vinegar had the lowest pH (2.99), while samples made with buttermilk had the highest (3.31). Vinegar-based pickles had the highest dry matter (5.27%) and drained weight (64.15%). Yoghurt whey-based samples had the highest counts of Lactobacillus spp. (6.38 log CFU/g) and Lactococcus/Streptococcus (6.81 log CFU/g), while vinegar-based samples had the highest counts of acetic acid bacteria and total aerobic mesophilic bacteria. However, kefir whey-based samples had the highest yeast count (5.72 log CFU/g). The textural analysis showed that yoghurt whey-based samples had the highest hardness (471.72 N) and springiness, whereas buttermilk-based samples had higher adhesiveness and cohesiveness. Whey-based samples had the highest gumminess and chewiness. Yoghurt whey-based samples had the highest levels of lactic acid (14,569.39 mg/L) and citric acid, whereas vinegar-based samples had the highest levels of acetic acid (63,795.64 mg/L) and propionic acid. Kefir whey-based samples had the highest butyric acid content. Yoghurt whey-based pickles were the most popular with panellists, followed by whey and vinegar-based pickles. Buttermilk-based samples scored lowest in sensory rating. Finally, fermented dairy by-products can be used as a functional brine medium for cabbage pickle. Yoghurt whey has shown promise in improving microbiological quality, textural characteristics, and sensory acceptability. Using dairy industry by-products in pickle making is an innovative way to produce sustainable food and add value to by-products.