Physico-chemical properties and lipid binding capacity of bacterial cellulose synthesized on whey

Bacterial cellulose (BC) has significant potential for applications in the food industry due to its ability to stabilize food dispersion systems. In this work, the efficiency of BC biosynthesis on dairy industry waste was investigated, and these process parameters were studied: amount of substrate, titratable acidity, mass of synthesized cellulose. The physico-chemical properties and lipid binding capacity of the obtained gel films and dehydrated polysaccharide samples were determined. Bacterial cellulose was obtained under static conditions, in a liquid nutrient medium – whey. Lactose from whey was preliminarily hydrolysed with the enzyme preparation LACTA FREE to a glucose content of 1.93%. The mass of cellulose produced under static conditions by the symbiotic consortium Medusomyces gisevii was 3.84 g/l over 21 days at T=31°C. A correlation was noted between low amounts of glucose in the culture fluid on the 6th day of biosynthesis and a decrease in titratable acidity. The degree of conversion of glucose from fermented whey to the mass of produced bacterial cellulose was 22.6%. The maximum biosynthesis rate of 0.181 gL-1×day-1 (dry weight) was established on the 15th day of the process. The water retention capacity of the synthesized bacterial cellulose gel films was determined to be 82.35 ± 0.63 g/g. Lyophilized samples of bacterial cellulose were characterized by a higher water absorption capacity (22.44 g/g) compared to samples dehydrated at T=50°C (5.42 g/g). It was found that rehydrated samples of lyophilized cellulose had a 3.43 times higher ratio of free and bound moisture compared to dried BC samples. The bulk density of disaggregated cellulose was determined: lyophilized - 20 kg/m3, thermally dried - 170 kg/m3. The work provides a comparative analysis of the lipid binding capacity of BC and chitosan. Microbiological parameters of disaggregated bacterial cellulose were determined.