Abstract
Camembert cheese is a surface white mould ripened cheese; when full ripe the casein becomes liquefy as the intensive degradation occurs by proteinases from surface flora and results over-ripening and off flavor. To control this, partial purified bacteriocin like substances (PPBLS) from newly lactic acid bacterial isolate (LAB100) exhibited antifungal activity against Penicillium candidum (in vitro) were used. Inhibition (%) of P. candidum by PPBLS at concentrations of 2, 4, 8, 16 and 32 mg/ml was 34, 50, 79, 80 and 85%, respectively. Based on their superior antifungal potential activity; isolate LAB100 was phenotypically and genotypically characterized as newly Lactobacillus sp. For delaying the Camembert cheese over-ripening (in vivo), bacteriocin producing isolate LAB100 and its PPBLS were incorporated and applied in different camembert cheese treatments. Three treatments beside control were conducted; after brining all cheese treatments stored at 12±2°C to ripen for 12 days and then at 5±2°C for more 30 days to complete ripening. Organoleptic properties, pH values and nitrogen distribution were determined during ripening period. In addition, the proteolysis of treated Camembert cheese was monitored by gel electrophoresis. The cheese treatment (T2) made with bacteriocin producer isolate LAB 100 added as co-culture to main starter recorded the highest total score, followed by T3 and the lowest one was recorded for control (T1). The highest WSN/TN% was in T1; 5.4, 22.87, 34.41 and 57.65% at 3, 10, 20, and 40 days after brining, respectively, while the lowest WSN/TN% was recorded for treatment that made with both bacteriocin producer strain LAB100 and sprayed by PPBLS solution after 3 days of brining (T3), where it was 5.05, 9.85, 13.82, and 31.74% at the same previous ages, respectively. These results were confirmed by gel electrophoresis, indicating that bacteriocin producer LAB100 and or its bacteriocin controlled the protein degradation. These results suggest that both bacteriocin producer strain and its PPBLS minimize the growth of P. candidum as a consequence the rate of proteolysis was controlled and hence extending the shelf life of Camembert cheese is occurred.
Highlights
Cheese ripening is a time-consuming process; involving complex and well-balanced reactions between glycolysis, proteolysis and lipolysis of the milk components [1]
120 Lactic acid bacterial isolates were isolated from local fermented dairy products and screened for bacteriocin production in the term of antifungal activity against P. candidum using agar-well diffusion method
The antifungal activity of the neutralized, catalase treated, and partial purified bacteriocin in this study indicated that the major antibacterial activity was most likely due to their antimicrobial peptides not to organic acids or hydrogen peroxide produced by Lactic Acid Bacteria (LAB) strains
Summary
Cheese ripening is a time-consuming process; involving complex and well-balanced reactions between glycolysis, proteolysis and lipolysis of the milk components [1]. The texture becomes soft and smooth only during ripening as a result of extensive proteolysis and an increase in pH [4]; the mould gives the cheese it's characterized of organoleptic properties by the end of ripening [6]. This type of cheese ripens very quickly because of the rapid growth of surface flora, and cannot be ripened for extended periods and must be marketed in a rather short time because it contains high moisture content which reduces the shelf life [7]. It contributes directly to flavour and to off-flavour (e.g. bitterness) of cheese through the formation of peptides and free amino acids [8, 9]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Nutrition and Food Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
