Effect of biogenic exopolysaccharides in characteristics and stability of a novel Requeson-type cheese

Whey is a by-product of the dairy industry with considerable nutritional value but tends to be discarded with industrial effluents. One of the alternatives for its use is the production of whey cheeses, although they need to add extra ingredients to raise the yields, which elevates production costs. A less expensive alternative is using exopolysaccharides (EPS), carbohydrate polymers microorganisms produce. This research aimed to formulate and evaluate the stability of a Requeson-type cheese employing whey that has EPS produced biogenically by in situ fermentation with lactic acid bacteria. Two EPS-producing strains, Lactobacillus delbrueckii subsp bulgaricus NCFB 2772 and Streptococcus thermophilus SY-102, were used separately and in coculture (1:1 ratio). We found that coculture had the highest EPS production (1.49 mg/mL of whey) compared to the monocultures. This influenced the yield of the processed Requeson-type cheese (5.56%), which was higher than the produced with unfermented whey (3.77%). Similarly, the physicochemical and sensory parameters of the developed product showed differences. Furthermore, none of the Requeson-type cheeses made with fermented whey showed microbial growth after 21 days of storage (4 °C). Therefore, EPS is a potential strategy for producing Requeson-type whey cheeses with a high yield and stability.