REUSE OF KEFIR WHEY IN THE FERMENTATION OF SAUERKRAUT: MICROBIOLOGICAL, PHYSICOCHEMICAL, SHELF-LIFE AND SENSORIAL CHARACTERIZATION

This study investigates the use of kefir whey, a byproduct of kefir cheese production,as a resource for food preservation and functional food development. Due to itsprobiotic content and low pH, whey can be used to reduce pH, a key factor in foodpreservation, especially in fermentation processes. The environmental impact ofwhey disposal is highlighted, emphasizing the need for sustainable utilization. Theresearch proposes integrating kefir whey into sauerkraut production to enhance itsprobiotic and functional properties. The development of red cabbage sauerkraut withkefir whey as a starter culture was carried out, monitoring pH, titratable acidity, andpopulations of lactic acid bacteria, fungi, and yeasts. Bacterial taxonomy wasassessed by 16S rRNA genetic sequencing, and antioxidant properties wereanalyzed through DPPH, anthocyanin, and phenolic compound tests. Compared tothe control, "kefirkraut" (KT) achieved the ideal pH (<4.1) and >1% acidity in 7 days,while the control took 27 days. KT maintained the concentration of lactic acidbacteria and yeasts similar to kefir, indicating preserved probiotic potential, with apredominance of microorganisms such as *Acetobacter spp.*, *Lentilactobacillusspp.*, and *Leuconostoc spp.*. The use of kefir whey reduces fermentation time,innovates the process, and adds probiotic potential to the sauerkraut.