Effects of Type of Starter Culture, Increase of Dry Matter and Microbial Transglutaminase on the Texture and Consumer Acceptability of Fermented Camel Milk

Abstract

Camel milk has been found to be difficult to process into different dairy products due to slower rate of acidification and other factors related to its composition. Hence, this study was aimed to evaluate effects of two different mesophilic starter cultures, addition of camel milk powder (CMP) and the use of microbial transglutaminase (MTGase) on the texture, viscosity, sensory and physicochemical properties of fermented camel milk. The two mesophilic starter cultures used were R-707 (Lactococcus lactis) and CHN-22 (contain multiple strains of Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. lactis biovar diacetylactis, Leuconostoc mesenteroides and Leuconostoc pseudomesenteroides). All milk samples were heat treated (90 oC, 10 min), cooled to inoculation and incubation temperature (27 oC) of starter cultures and incubated until pH reaches 4.6. Use of a single strain starter culture (R-707) resulted in fermented milk which was significantly (P<0.05) higher in cohesiveness and adhesiveness than a multi-strain (CHN-22) starter culture. But addition of CMP significantly (P<0.05) decreased the firmness, cohesiveness and adhesiveness of the fermented camel milk. Use of MTGase has improved the textural attributes of fermented camel milk samples and the effect depended on the starter culture used. The cohesiveness of the fermented camel milk was significantly (P<0.05) higher when made using R-707 starter culture with MTGase compared to using CHN-22 starter culture. Fermented camel milk produced using CHN-22 starter culture with MTGase was significantly (P<0.05) lower in titratable acidity as compared to that produced using CHN-22 starter culture without MTGase. Therefore, R-707 starter culture was found to be more preferable to improve the textural attributes of fermented camel milk samples, and MTGase can be used by dairy industries and smallholder farmers to improve the textural attributes of fermented camel milk.