title: Microbial cell-free extracts as sources of enzyme activities to be used for enhancement flavor development of ewe milk cheese.
abstract: Freeze-dried cell-free extracts (CFE) from Lactobacillus casei LC01, Weissella cibaria 1XF5, Hafnia alvei Moller ATCC 51815, and Debaryomyces hansenii LCF-558 were used as sources of enzyme activities for conditioning the ripening of ewe milk cheese. Compared with control cheese (CC), CFE did not affect the gross composition and the growth of the main microbial groups of the cheeses. As shown through urea-PAGE electrophoresis of the pH 4.6-soluble nitrogen fraction and the analysis of free AA, the secondary proteolysis of the cheeses with CFE added was markedly differed from that of the CC. Compared with CC, several enzyme activities were higher in the water-soluble extracts from cheeses made with CFE. In agreement, the levels of 49 volatile compounds significantly differentiated CC from the cheeses made with CFE. The level of some alcohols, ketones, sulfur compounds, and furans were the lowest in the CC, whereas most aldehydes were the highest. Each CFE seemed to affect a specific class of chemical compounds (e.g., the CFE from H. alvei ATCC 51815 mainly influenced the synthesis of sulfur compounds). Apart from the microbial source used, the cheeses with the addition of CFE showed higher score for acceptability than the control cheese. Cheese ripening was accelerated or conditioned using CFE as sources of tailored enzyme activities.
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, 70126 Bari, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Calasso
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, 70126 Bari, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Mancini
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, 70126 Bari, Italy. Electronic address: raffaella.dicagno@uniba.it.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Di Cagno
authors.affiliation: Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Cardinali
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, 70126 Bari, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbetti
mesh_terms: D000328:Adult; D000438:Alcohols / Q000032:analysis; D000447:Aldehydes / Q000032:analysis; D000818:Animals; D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D005260:Female; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D005663:Furans / Q000032:analysis; D020611:Hafnia alvei / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007659:Ketones / Q000032:analysis; D007780:Lacticaseibacillus casei / Q000378:metabolism; D008297:Male; D008892:Milk / Q000737:chemistry* / Q000382:microbiology*; D009584:Nitrogen / Q000032:analysis; D012756:Sheep; D012903:Smell; D013457:Sulfur Compounds / Q000032:analysis; D013649:Taste; D055549:Volatile Organic Compounds / Q000032:analysis; D058836:Weissella / Q000378:metabolism; D055815:Young Adult
chemical_list: D000438:Alcohols; D000447:Aldehydes; D005663:Furans; D007659:Ketones; D013457:Sulfur Compounds; D055549:Volatile Organic Compounds; D009584:Nitrogen
keywords: ewe milk cheese; microbial cell-free extract; ripening