scholarly journals Effect of Novel Bacteriocinogenic Lactobacillus fermentum BZ532 on Microbiological Shelf-Life and Physicochemical and Organoleptic Properties of Fresh Home-Made Bozai

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2120
Author(s):  
Hafiz Abdul Rasheed ◽  
Tuhanguli Tuoheti ◽  
Zhiyu Li ◽  
Mekonen Tekliye ◽  
Yongzhu Zhang ◽  
...  

Bacteriocinogenic Lactobacillus fermentum BZ532 with novel bacteriocin LF-BZ532 was originally isolated from Chinese cereal fermented drink, showing an antimicrobial characteristic during fermentation. This study aimed to explore the in situ antimicrobial activities of L. fermentum BZ532 and co-culturing investigation against key food pathogens, i.e., Staphylococcus aureus and Escherichia coli K-12, was conducted during fresh bozai production. The growth of spoilage bacteria was suppressed and bacterial count was reduced to a significantly low level during 48 h of co-cultures. In situ production of antimicrobial compounds expressed positive activity against S. aureus and E. coli K-12, but negative acitivity against Salmonella sp. D104. The total viable count of bozai BZ-Lf (bozai fermented with BZ532 strain) had a comparatively lower viable count than bozai BZ-C (bozai as an experimental control without BZ532) during storage of 7 days. Titratable acidity of bozai treatments (BZ-C, BZ-Lf) was increased, while pH declined accordingly during storage of 7 days. The organoleptic quality of bozai BZ-C had low sensorial scores as compared with BZ-Lf during storage. In comparison with naturally fermented bozai (BZ-C), L. fermentum BZ532 (BZ-Lf) could significantly reduce the microbial spoilage and extend the shelf-life based on microbiological examination. Conclusively, L. fermentum BZ532 can be used as a bio-protective culture for improving the safety of bozai.

2012 ◽  
Vol 30 (No. 6) ◽  
pp. 512-519 ◽  
Author(s):  
R. Kamleh ◽  
I. Toufeili ◽  
R. Ajib ◽  
B. Kanso ◽  
J. Haddad

Halloumi cheese blocks, packaged in vacuum polyamide/polyethylene laminate bags, were stored at 5, 15, and 25&deg;C. The changes in total bacterial count, lactic acid bacteria, total anaerobic bacteria, yeasts and molds, pH, and titratable acidity were monitored during the storage. The appearance of the packaged Halloumi cheese exhibited significant correlations with the counts of the different microbial populations inhabiting the cheese. The shelf-life of the stored Halloumi cheese was determined using survival analysis and considering consumer rejection as a failure index. The nominal shelf-lives of Halloumi cheese were 79.6, 37.8, and 2.6 days when stored at 5, 15, and 25&deg;C, respectively. The Q<sub>10</sub> values (shelf-life at T &deg;C/shelf-life at T + 10&deg;C) at 5&deg;C and 15&deg;C were 2.1 and 14.5, respectively. The increase in the counts of different microbial populations during storage highlights the need for adherence to good manufacturing practices and maintenance of low temperatures during the storage and distribution of the packaged Halloumi cheese.


2021 ◽  
Vol 10 (2) ◽  
pp. 383-397
Author(s):  
Saleem Ehsan ◽  
Zahir Al-Attabi ◽  
Nasser Al-Habsi ◽  
Michel R. G. Claereboudt ◽  
Mohammad Shafiur Rahman

Pasteurized fresh milk requires an accurate estimation of shelf life under various conditions to minimize the risk of spoilage and product losses. Milk samples were stored for 56 h in an oven at 25°C and for 15 days in a refrigerator at 4°C. Samples were analyzed using an electronic nose (e-nose), total bacterial count, titratable acidity and pH to determine the quality of milk. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were used to analyze e-nose data of milk stored at 25°C, and 4°C. A clear shift in quality was identified by the e-nose, which also appeared in the total bacterial count after 24 h and 12 days for storage at 25 and 4°C, respectively. On the other hand, titratable acidity exceeded the normal limits of 0.14 % - 0.21 % after 24 h for storage at 25°C (0.247 ± 0.006 %) and after 15 days for storage at 4°C (0.25 ± 0.01 %). If pH was a good indicator of quality for samples stored at 25°C, it showed no clear trends for samples stored at 4°C. Based on the microbial count data and e-nose output, the milk had a shelf life of 0.3 day (i.e. 8 h) when stored at 25°C. Shelf life was extended to 9 days when stored at 4°C.


2018 ◽  
Vol 6 (2) ◽  
pp. 509-519
Author(s):  
Herve Mwizerwa ◽  
George Ooko Abong ◽  
Samuel Kuria Mbugua ◽  
Michael Wandayi Okoth ◽  
Patrick Gacheru ◽  
...  

In most parts of Africa, the process of fermentation is not controlled and does not adhere to good manufacturing practices, therefore spoilage and pathogenic microorganisms can alter the quality of the end product and may cause foodborne illness.Traditional fermented products are mostly processed in an environment which creates a selection of microorganisms that produce the desired end product. In an attempt to find Lactobacilli which have probiotic properties and can be used in the development of starter culture for controlled fermentation of cereal products, the microbial populations of maize flour, overnight soaked dough, fermented cooked porridge, Mkarango and Busaawere enumerated and the inherent lactobacilli isolated. The microbial and biochemical profiles of the 6 days spontaneous Mkarangofermentation process were determined.The total viable count was 6.93 log cfu/g for fermented cooked porridge, 7.70 log cfu/g in Mkarango and 8.58 log cfu/g forBusaa. Lactobacillicounts were higher in maize flour with 7.43 log cfu/g whileEnterobactericeae were lower in Mkarango.The highest moulds and yeasts counts were observed forBusaa, 7.25 log cfu/g.The lactobacilli isolates from fermented maize based products from western Kenya were predominantly Lactobacillus fermentum andLactobacillus Plantarum.During fermentation time, Lactobacilliincreased from 6.62 to 12.46 log cfu/gafter 3 daysof fermentation. From day 4, an increase in moulds and yeast count was observed, varying from 8.42 to 10.53 log cfu/g. Enterobactericeae count decreased from 5.99 log cfu/g on day 1 to less than 1 log cfu/g on day 6.Titratable acidity increased from 0.32% to 0.73% on day 5. Inversely, the pH of Mkarangodecreased sharply from 6.64 to 3.64 on day 5 and slightly increased on the last day of fermentation. The microbial status of finished fermented maize based products is predominated by Lactobacilli and their isolates are predominantly Lactobacilli especially Lactobacillus fermentum andLactobacillus Plantarumthough further molecular tests are needed to confirm the species.


2022 ◽  
Vol 18 (1) ◽  
pp. 014-026
Author(s):  
Mercy M Umokaso ◽  
Bernard JO Efiuvwevwere ◽  
Francis S Ire

Cereal-porridge(‘ogi’) was produced by spontaneous fermentation using maize and sorghum substrates. The microbiological dynamics involved were monitored over a period of 48h fermentation. Bacteria, yeasts and moulds were isolated. Based on the morphological, cultural and biochemical test results, the aerobic bacterial isolates were identified as Proteus vulgaris, Proteus mirabilis, Klebsiella sp, Staphylococcus aureus, Lactobacillus sp, Pseudomonas sp, Citrobacter sp, Bacillus sp, Proteus sp, Shigella sp, and Escherichia coli. The Lactic acid bacteria were Lactococcus sp, Enterococcus sp, Lactobacillus fermentum, Lactobacillus sp. The yeast isolates were 2 strains of Saccharomyces cerevisiae, one other Saccharomyces sp and a Candida sp. The moulds were Aspergillus niger, Aspergillus flavus, Rhizopus sp and Penicillium sp. The lactic acid bacteria (LAB) isolated were 2 strains of Lactococcus lactis, 2 Enterobacter spp, 5 strains of Lactobacillus fermentum and 1 other Lactobacillus sp. The initial total viable aerobic bacterial count at 0h in maize, sorghum and maize-sorghum blend were 4.6 × 104, 7.3 × 104 and 2.4 × 105cfu/ml respectively. The growths rose to peaks of 6.5 × 107 and 3.9 × 107cfu/ml at 24h in maize and maize-sorghum blend, respectively. A Peak of 4.7 x 107cfu/ml was attained at 36h in sorghum. Coliform bacteria and moulds growths in the three samples attained peaks of growth at 12h and reduced till there was no growth by 48h. Lactic acid bacteria and yeasts increased in numbers till the end of fermentation. The initial pH value at 0h was lowest in maize-sorghum blend sample (5.43) and highest in maize (5.75). Final values at 48h were 3.76, 3.78 and 3.75 in maize, sorghum and maize-sorghum blend samples respectively. There were no significant differences between the microbial growth patterns, changes in pH, total titratable acidity (TTA) and amylase enzymatic activities in maize, sorghum and maize-sorghum blend samples during fermentation.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 985
Author(s):  
Ceferina Vieira ◽  
Ainhoa Sarmiento-García ◽  
Juan-José García ◽  
Begoña Rubio ◽  
Beatriz Martínez

The objective of the study was to evaluate the inclusion of a novel form of oleic acid and an organic-acid mix in the diet of Iberian pigs, and their effect on the quality and shelf-life of the pig meat. 200 castrated male Iberian pigs were randomly assigned to four groups. Diets included different fat sources: pig fat (G1), solid oleic acid (G2), oleic-high sunflower oil with solid oleic (G3); a diet of G3 supplemented with organic-acid mix (G4). Pigs were slaughtered at 182 days. Back fat and the longissimus thoracis et lumborum muscles were removed, and nutritive and sensory quality were analyzed. The shelf-life of meat packaged (70%O2/30CO2) during retail storage up to 21 days were studied. A higher percentage of oleic acid and MUFA, and lower SFA were observed in subcutaneous fat on a G2 diet. G2 resulted in the highest muscle fat content, and G4, the highest cooking losses. In sensory analysis, marbling, tenderness and chewiness were higher in the G2 samples. No differences were found in the bacterial count and sensorial analysis depending on storage time at the end of the experiment, but a lower total viable count was showed at the start of the study in the G4 samples. These results suggest a better assimilation of solid oleic acid. However, the organic-acid mix requires further studies.


2018 ◽  
Vol 6 (1) ◽  
pp. 106-112
Author(s):  
S. Susanti ◽  
B. E. Setiani ◽  
H. Rizqiati ◽  
D. R. Febriandi ◽  
V. P. Bintoro ◽  
...  

Microbial activities cause physical and functional alteration, which can decrease the quality and shelf life of meat. Inhibiting the bacterial growth becomes a crucial effort to prevent spoilage of meat. Previous studies reported that human pathogen bacterias could be inhibited by using cashew apple juice. It was interested to explore the utilization of cashew apple as marinade solution to suppress the meat bacteria. Current study was aimed to get more insight the effectiveness of cashew apple extract marinade (CAM) as growth inhibitor for spoilage bacteria on beefs and chickens. Results indicated that inhibition zone of 20% CAM were significant higher than 0% CAM on the medium of E. coli, and S. aureus. The pretty high polyphenols content in CAM was considered as an active compound responsible for antibacterial activity. Furthermore, total bacterial count assay showed that 10 to 30% CAM significantly reduced the beef total bacteria in comparison to 0% while 15 % CAM significantly decreased the chicken total bacteria. It was suggested the range of effective level of CAM to reduce the meats bacteria is 10 to 30%. Thus, cashew apple can be a promising natural food preservative in the future, especially for extending the shelf life of meat.


Author(s):  
Claude Elama ◽  
Mohanad Alayoubi ◽  
Mohannad Jazzar ◽  
Fuad Al-Rimawi .

Aims: The objective of this study is to use different essential oils (cinnamon, clove, rosemary, almond sweet, sesame, wheat germ, and cedar wood) in concentrated yoghurt as antimicrobial agents to increase shelf life of concentrated yoghurt. Place and Duration of Study: Department of Food Technology, Faculty of Science and Technology, Al-Quds University, Palestine, between January 2015 to August 2016. Methodology: Essential oils were added to concentrated yogurt at a concentration of 250 μl\kg. Antibacterial activity and properties of major borne bacteria such as total aerobic count bacteria, yeast, mold, Staphylococcus aureus, were evaluated by plate count method, (pouring plate method). All yogurt samples were sensory evaluated for flavor, body and texture, and appearance. Total solid content, and titratable acidity of different yogurt samples were also determined. Results: Total solids and pH of concentrated yogurt samples treated with essential oils were only slightly affected. The best three essential oils used in terms of influence on total bacterial viable count and mold count were found to be cinnamon, clove and rosemary. The most acceptable organoleptic properties of treated concentrated yogurt were those samples treated with sesame and rosemary oils. Conclusion: The addition of cinnamon, clove and rosemary essential oils could increase the shelf life of concentrated yogurt.


Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 490 ◽  
Author(s):  
Jun Mei ◽  
Xuan Ma ◽  
Jing Xie

Fish is extremely perishable as a result of rapid microbial growth naturally present in fish or from contamination. Synthetic preservatives are widely used in fish storage to extend shelf life and maintain quality and safety. However, consumer preferences for natural preservatives and concerns about the safety of synthetic preservatives have prompted the food industry to search natural preservatives. Natural preservatives from microorganisms, plants, and animals have been shown potential in replacing the chemical antimicrobials. Bacteriocins and organic acids from bacteria showed good antimicrobial activities against spoilage bacteria. Plant-derived antimicrobials could prolong fish shelf life and decrease lipid oxidation. Animal-derived antimicrobials also have good antimicrobial activities; however, their allergen risk should be paid attention. Moreover, some algae and mushroom species can also provide a potential source of new natural preservatives. Obviously, the natural preservatives could perform better in fish storage by combining with other hurdles such as non-thermal sterilization processing, modified atmosphere packaging, edible films and coatings.


Author(s):  
O. I. Dolmatova ◽  
V. S. Lemesheva ◽  
L. A. Zadneprovskaya

The authors proposed a milk-containing product with a substitute for milk fat, produced according to the technology of sour cream using a protective culture in order to prolong the shelf life. The use of protective starter cultures does not require additional equipment or changes in technological parameters. The protective culture is introduced along with the main sourdough and works according to the traditional principle of fermentation, as well as through competitive exclusion, i.e. taking up space and reducing the possibility for the growth of yeast, molds and BGKP. Two developments of a milk-containing product were carried out - the first using a protective culture (experimental sample), the second without using a protective culture (control sample). The products are stored for 40 days at a temperature of 4 ± 2 °C. In the control sample, on day 30, yeast growth, deterioration in organoleptic indices, increase in titratable acidity were observed, on day 40, the product was considered spoiled. In the experimental sample, organoleptic, physicochemical and microbiological parameters during storage were within normal limits. The shelf life of a milk-containing product with a milk fat substitute produced using the technology of sour cream is determined using a protective culture taking into account a safety factor of 30 days. An increase in the shelf life of the latter by 30% was established in comparison with the control sample.


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