Miniature Cheddar-type cheeses were produced using microbial rennet from Bacillus amyloliquefaciens (milk-clotting enzyme [MCE]) or calf rennet (CAR). With the exception of pH, there were no significant differences in gross composition between MCE-cheese (MCE-C) and CAR-cheese (CAR-C). The pH value of CAR-C was significantly higher than that of MCE-C at 40 and 60 d of ripening. The total nitrogen content of the pH 4.6-soluble fraction obtained from MCE-C was higher than that obtained from CAR-C. However, nitrogen content of the 12% TCA-soluble fraction was similar between CAR-C and MCE-C. The extent of α(s1)-casein and β-casein hydrolysis, measured by urea-PAGE, was similar in both cheese samples. The hydrolysis of β-casein was lower than that of α(s1)-casein. Different reverse phase-high-performance liquid chromatography peptide profiles of ethanol-soluble and ethanol-insoluble fractions were obtained from CAR-C and MCE-C. The peptide content in the 2 cheese samples increased throughout ripening; the ratio of hydrophobic to hydrophilic peptides was lower in MCE-C than in CAR-C. Compared with CAR-C, MCE-C was softer as a result of higher protein hydrolysis. Microbial rennet from B. amyloliquefaciens contributed to higher proteolytic rates, which reduced ripening time.
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http://dx.doi.org/10.1111/1750-3841.12340 | DOI Listing |
Microbiome
December 2024
Department of Food Biosciences, Teagasc Food Research Centre, Teagasc-The Irish Agriculture and Food Development Authority, Moorepark, Fermoy, Co., Cork, P61 C996, Ireland.
Foods
October 2024
Department of Dairy Science and Quality Management, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, Oczapowskiego 7, 10-719 Olsztyn, Poland.
This study investigated the production of rennet gels from β-casein-depleted retentates obtained through cold microfiltration (MF) of skim milk (SM) that was treated beforehand to ensure microbial safety. The treatments included thermization (65 °C, 20 s), pasteurization (72 °C, 15 s), and microfiltration (50 °C; 1.4 μm pore size).
View Article and Find Full Text PDFInt J Biol Macromol
October 2024
Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil. Electronic address:
Thermolysin (TLN) is a microbial highly-priced thermostable metallo-endoprotease with complementary substrate specificity to those of proteases widely used in science and industry for protein digestion and milk-clotting. This study is the first to immobilize TLN on aminated superparamagnetic nanoparticles (FeO@silica-NH) aiming for higher stability, recoverability, reusability, and applicability in proteolysis and as a microbial rennet-like milk-clotting enzyme. The nanobiocatalyst developed (FeO@silica-TLN) displays hydrolytic activity on a synthetic TLN substrate and, apparently, was fully recovered from reaction media by magnetic decantation.
View Article and Find Full Text PDFFoods
March 2024
Departamento de Producción Animal, Universidad de Córdoba, 14071 Córdoba, Spain.
This study conducted a seasonal analysis of bulk tank milk from 77 sheep farms to establish relationships between the concentration of major microbial groups and milk coagulation properties. The investigated milk traits included composition (pH, fat, casein, lactose), coagulation properties (curd firmness: A-, rennet clotting time: RCT-, curd firming time: k-, curd yield: CY-), and somatic cell score (SCS). The main microbial groups analyzed were total mesophilic bacteria (SPC), thermodurics (THERMO), psychrotrophs (PSYCHRO), spp.
View Article and Find Full Text PDFProbiotics Antimicrob Proteins
March 2024
Department of Food Science and Technology, Ionian University, 28100, Argostoli, Kefalonia, Greece.
Autochthonous dairy lactic acid bacteria (LAB) isolates encompass a natural source of starter, adjunct, or probiotic candidates. In this context, traditionally manufactured, using exclusively animal rennet, Feta-type cheeses were collected from five farms located in different regions of Kefalonia island (Greece). The primary objective of this study was to isolate and characterize novel LAB, thereby exploring the unmapped microbial communities of Kefalonian Feta-type cheese and identifying new potential probiotics.
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