Isolation, Characterization, and Influence of Native, Nonstarter Lactic Acid Bacteria on Cheddar Cheese Quality

Abstract

To determine whether adventitious nonstarter lactic acid bacteria (NSLAB) might affect cheese flavor and quality, we studied a population of NSLAB present in 30 premium quality Cheddar cheeses (3-mo ripened) produced at a commercial facility in the United States. DNA fingerprinting analysis with a sensitive strategy for arbitrary priming polymerase chain reaction showed that 75 isolates corresponded to at least 18 distinct nonstarter organisms. According to ribotype database comparisons of representatives from the 18 groups, 9 matched Lactobacillus (closest to paracasei species), 8 matched Streptococcus thermophilus, and 1 matched to a Lactococcus species. This finding indicated that among the 75 NSLAB isolates, Lactobacillus made up 64%, S. thermophilus 32%, and Lactococcus 4%. Isolates representing 11 NSLAB groups were characterized for protease, peptidase, and diacetyl production. Based on this phenotypic analysis, two Lactobacillus isolates were evaluated as adjuncts in Cheddar cheese. All of the NSLAB identified from the adjunct cheese at 3 mo by DNA fingerprinting consisted of the adjunct lactobacilli, showing that the adjunct strains predominated throughout the early stages of ripening. The impact of adjunct lactobacilli was evident after 6 mo when free amino acids significantly increased and sensory scores improved in adjunct cheese as compared with a control cheese. The largest impact was found in adjunct cheese containing a blend of both lactobacilli strains. These results show that certain adventitious NSLAB positively contribute to flavor development.

Effect of salt and fat reduction on the composition, lactose metabolism, water activity and microbiology of Cheddar cheese

“…Lactobacillus casei, Lactobacillus paracasei, Lactobacillus plantarum), which constitute the major NSLAB species in Cheddar cheese, have been found to metabolize lactose to compounds (e.g. acetate, galactose) which were not measured in the current study (Jordan and Cogan 1993;Swearingen et al 2001). However, even where lactose was utilized quickly (e.g.…”

Production of probiotic fresh white cheese using co-culture with Streptococcus thermophilus

“…Ong et al (2006) (Karimi et al, 2012b). Several adjunct cultures of strains of the species L. casei and L. plantarum have been claimed to increase peptidolysis and improve the sensory properties of cheese (Lynch et al, 1999;Menéndez et al, 2000;Swearingen et al, 2001;Irigoyen et al, 2007). Escobar et al (2012) reported that probiotic supplementation of Panela Cheese had no effect on perceived taste or appearance and the starchless cheese containing L. rhamnosus GG showed greater consumer acceptance in the compactness, hardness, moisture, and softness descriptors.…”

Microbiology of Cheddar cheese made with different fat contents using a Lactococcus lactis single-strain starter

“…At the same time, NSLAB (whose initial numbers are commonly below 10 2 cfu/g in cheese made under good sanitary conditions with high-quality pasteurized milk) begin to grow and eventually plateau at cell densities of 10 7 to 10 8 cfu/g after 3 to 9 mo of aging (Peterson and Marshall, 1990). Nonstarter LAB populations can be quite diverse, but are usually dominated by facultatively heterofermentative species of lactobacilli (Broome et al, 1990;Fitzsimons et al, 1999;Beresford et al, 2001;Crow et al, 2001;Swearingen et al, 2001;Broadbent et al, 2003).…”