Comparative Evaluation of Yogurt and Low‐Fat Cheddar Cheese as Delivery Media for Probiotic Lactobacillus casei

Abstract

This study used Lactobacillus casei 334e, an erythromycin-resistant derivative of ATCC 334, as a model to evaluate viability and acid resistance of probiotic L. casei in low-fat Cheddar cheese and yogurt. Cheese and yogurt were made by standard methods and the probiotic L. casei adjunct was added at approximately 10(7) CFU/g with the starter cultures. Low-fat cheese and yogurt samples were stored at 8 and 2 degrees C, respectively, and numbers of the L. casei adjunct were periodically determined by plating on MRS agar that contained 5 microg/mL of erythromycin. L. casei 334e counts in cheese and yogurt remained at 10(7) CFU/g over 3 mo and 3 wk, respectively, indicating good survival in both products. Acid challenge studies in 8.7 mM phosphoric acid (pH 2) at 37 degrees C showed numbers of L. casei 334e in yogurt dropped from 10(7) CFU/g to less than 10(1) CFU/g after 30 min, while counts in cheese samples dropped from 10(7) CFU/g to about 10(5) after 30 min, and remained near 10(4) CFU/g after 120 min. As a whole, these data showed that low-fat Cheddar cheese is a viable delivery food for probiotic L. casei because it allowed for good survival during storage and helped protect cells against the very low pH that will be encountered during stomach transit.

Survival of microencapsulated probiotic Lactobacillus paracasei LBC-1e during manufacture of Mozzarella cheese and simulated gastric digestion

“…To further test the effect of pH on bacterial survival and allow a greater increase in pH after adding the cheese, SGJ-3 was then made using 11 mM HCl. An additional acid digestion test (SGJ-4) was performed using 87 mM H 3 PO 4 (pH 2.0) instead of HCl as a comparison with the report of Sharp et al (2008) [Sharp et al (2008) incorrectly reported the strength of the H 3 PO 4 they used as 8.7 mM.] Before adding cheese, the SGJ were tempered to 37°C.…”

“…Various cheeses have been investigated, including Cheddar (Stanton et al, 1998;Phillips et al, 2006), low-fat Cheddar (Sharp et al, 2008), Gouda (Gomes et al, 1998), cottage cheese (Heller, 2001), Turkish white cheese (Kasimoglu et al, 2004), Argentinean cheese (Bergamini et al, 2006), and Ka ar (Ozer et al, 2008). Whether probiotic bacteria can survive in cheeses that are exposed to a severe heat treatment (such as the pasta filata process used during manufacture of Mozzarella cheese) has not been reported.…”

“…Yogurts and other fermented milks have been used as delivery systems for probiotic cultures, although cheese has been suggested as a better carrier because of better survival of the probiotic culture during storage and through the GI tract (Ong et al, 2006;Sharp et al, 2008). Various cheeses have been investigated, including Cheddar (Stanton et al, 1998;Phillips et al, 2006), low-fat Cheddar (Sharp et al, 2008), Gouda (Gomes et al, 1998), cottage cheese (Heller, 2001), Turkish white cheese (Kasimoglu et al, 2004), Argentinean cheese (Bergamini et al, 2006), and Ka ar (Ozer et al, 2008).…”

“…Whether probiotic bacteria can survive in cheeses that are exposed to a severe heat treatment (such as the pasta filata process used during manufacture of Mozzarella cheese) has not been reported. It is also difficult to properly enumerate probiotic bacteria in cheese by using selective media when high numbers of other lactic 6275 acid bacteria (LAB) are present (Oberg et al, 2011) unless the probiotic culture contains a biomarker that allows its specific enumeration (Sharp et al, 2008).…”

Viability of Bifidobacterium longum in cheddar cheese curd during manufacture and storage: effect of microencapsulation and point of inoculation

“…In cheddar cheese, many studies report severe declines in viable counts of probiotics during storage (Godward and Kailasapathy 2003;Lynch et al 1996;Sharp et al 2008), but some studies report more successful results (Daigle et al 1999;Stanton et al 1998). Viability losses seem to be mostly related to the probiotic strain (McBrearty et al 2001;Ong et al 2007).…”