Wednesday, 18 July 2018

Polyphasic approach to study physico-chemical, microbiological and sensorial characteristics of artisanal Nicastrese goat's cheese

Food Microbiol. 2018 Apr;70:143-154. doi: 10.1016/ Epub 2017 Sep 13. . Pino A1, Liotta L2, Randazzo CL3, Todaro A4, Mazzaglia A1, De Nardo F5, Chiofalo V2, Caggia C1. Author information 1 Department of Agricultural, Food and Environment, University of Catania, Italy. 2 Department of Veterinary Sciences, University of Messina, Italy. 3 Department of Agricultural, Food and Environment, University of Catania, Italy. Electronic address: 4 Department of Agricultural and Forest Science, University of Palermo, Italy. 5 Italian Rare Breed Association (RARE), Lamezia Terme, Italy. Abstract Nicastrese goat's cheese is produced in the South of Italy under traditional procedures, from raw goat milk without any starter cultures addition. Samples from milk to ripened cheese provided by 4 different farms were subjected to a polyphasic approach to study their physico-chemical, microbiological and sensorial characteristics. In addition, volatile organic compounds formation in the final products was studied. Overall, gross composition and microbiological data revealed a significant variability among samples, which was confirmed by both the volatile organic compounds generated in the final products and by the sensorial data. Conventional technique allowed us to identify 720 isolates, mainly belonging to Lactococcus lactis, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus brevis, Leuconostoc mesenteroides, and Enterococcus faecalis. Culture-independent methods revealed shifts in the microbial community structure, with an increase in biodiversity of metabolically active bacterial species, from milk to cheese samples. Analysis of volatile organic compounds (VOCs) allowed the identification of 36 compounds; free fatty acids and ketones represented the main detected, followed by alcohols and esters. Moreover, statistical analysis was performed in order to correlate VOCs to bacterial species. Data showed that ester compounds as well as alcohol and aldehydes were positively correlated to NSLAB, indicating that the occurrence of L. casei, L. plantarum and L. brevis species is relevant for the VOCs formation in the final product. KEYWORDS: Chemical characteristics; LAB isolates; Microbiota; Raw goat milk cheese; VOCs PMID: 29173621 DOI: 10.1016/