The effect of savoury plants, fermented with lactic acid bacteria, on the microbiological contamination, quality, and acceptability of unripened curd cheese

Abstract

Five bacteriocins producing lactic acid bacteria (LAB) strains were selected to carry out the fermentation of the plants called Satureja montana L. (Sm) and Rhaponticum carthamoides (CD.) Iljin (Rc). The bioproducts obtained were applied in the production of unripened curd cheese. The total amount of LAB in plant bioproducts ranged from 7.46 to 9.42 log10 CFU/g and depended on the LAB strain and the plant species used. To reduce the possibility of biased evaluation, the acceptability of the products was assessed by using Face Reader software. Pediococcus pentosaceus KTU05-8 strain was more adaptable in the media of both plants (Sm and Rc) under both fermentation conditions: traditional submerged fermentation and solid state fermentation. The fermentation of Sm and Rc plants with LAB significantly reduced the amount of spores of mesophilic bacteria, enterobacteria, yeast and fungi. The addition of these bioproducts to unripened curd cheese reduced pH and increased the total titratable acidity, the content of volatile compounds (thymol, carvacrol, p-cymene) and the acceptability of the cheese. In comparison to the results obtained after the addition of non-fermented Sm, Lactobacillus sakei fermented bioproducts decreased the content of biogenic amines in cheese.