• Food Science of Animal Resources
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• v.43 no.2
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• pp.319-330
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• 2023

Some preservatives are naturally contained in raw food materials, while in some cases may have been introduced in food by careless handling or fermentation. However, it is difficult to distinguish between intentionally added preservatives and the preservatives naturally produced in food. The objective of this study was to evaluate the minimum inhibitory concentration (MIC) of propionic acid, sorbic acid, and benzoic acid for inhibiting food spoilage microorganisms in animal products, which can be useful in determining if the preservatives are natural or not. The broth microdilution method was used to determine the MIC of preservatives for 57 microorganisms. Five bacteria that were the most sensitive to propionic acid, benzoic acid, and sorbic acid were inoculated in unprocessed and processed animal products. A hundred microliters of the preservatives were then spiked in samples. After storage, the cells were counted to determine the MIC of the preservatives. The MIC of the preservatives in animal products ranged from 100 to 1,500 ppm for propionic acid, from 100 to >1,500 ppm for benzoic acid, and from 100 to >1,200 ppm for sorbic acid. Thus, if the concentrations of preservatives are below the MIC, the preservatives may not be added intentionally. Therefore, the MIC result will be useful in determining if preservatives are added intentionally in food.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1405-1412
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• 2014

Lysozyme is a protein found in egg white, tears, saliva, and other secretions. As a marketable natural alternative to preservatives, lysozyme can act as a natural antibiotic. In this study, we have isolated Bacillus licheniformis TIB320 from soil, which contains a lysozyme gene with various features. We have cloned and expressed the lysozyme in E. coli. The antimicrobial activity of the lysozyme showed that it had a broad antimicrobial spectrum against several standard strains. The lysozyme could maintain efficient activities in a pH range between 3 and 9 and from $20^{\circ}C$ to $60^{\circ}C$, respectively. The lysozyme was resistant to pepsin and trypsin to some extent at $40^{\circ}C$. Production of the lysozyme was optimized by using various expression strategies in B. subtilis WB800. The lysozyme from B. licheniformis TIB320 will be promising as a food or feed additive.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1994.06a
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• pp.17-22
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• 1994

Food additives are minor components which are used to enhance nutritive or sensory values, and to improve shelf life of foods. In foods, natural additives are preferred over artificial or synthetic materials because of concern on food safety. Many biotechnological techniques have been applied to the production of food additives since the biotechnology has been utilized to prodyce many flavor components such as glutamate, 5'-nucleotides, esters, 2,3-bytadione, pyrazines, terpenes, and lactones. Natural flavors, fragrances, sweetners, and colorants can be produced by plant cell culture. Many lactic acid bacteria produce bacteriocins such as nisin or diplococcin. These bacteriocins are used as safe preservatives in foods and many researches on the improvenment of bacteriocin productivity by genetic engineering are in progress.

• Food Science of Animal Resources
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• v.42 no.2
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• pp.280-294
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• 2022

This study aimed to evaluate the effectiveness of propolis extract as a natural preservative for livestock products in term of chemical and microbiological characteristics by meta-analysis. The stages carried out in this study were identification, selection, checking suitability, and the resulting selected articles were used in the meta-analysis. The selection results obtained a total of 22 selected journal articles consisting of 9 articles for analysis of the antimicrobial activity of propolis extract and 13 articles for analysis of the chemical and mirobiological characteristics of livestock products. The articles were obtained from electronic databases, namely Science Direct and Google Scholar. The model used in this study is the random-effect model involving two groups, control and experimental. Heterogeneity and effect size values were carried out in this study using Hedge's obtained through openMEE software. Forest plot tests and data validation on publication bias was obtained using Kendall's test throught JASP 0.14.1 software. The results showed that there is a significant relationship between propolis extract with the results of the antimicrobial activity (p<0.05). In addition, the results of the application of propolis extract on the livestock products for the test microbes and the value of thiobarbituric acid reactive substances (TBARs) showed significant results (p<0.05). Conclusion based on the random-effect model on the effectiveness of antimicrobial activity of propolis extract and their apllication as a natural preservative of the chemical and microbiological characteristics of livestock products is valid by Kendall's test (p>0.05). Propolis in this case effectively used as natural preservatives in livestock products.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.192-200
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• 2021

Kunun-zaki, produced by submerged fermentation of a combination of millet and sorghum, is a popular beverage in Northern Nigeria. Owing to the nature of the process involved in its production, kunun-zaki is highly susceptible to contamination by food spoilage microorganisms, leading to inconsistent quality and short shelf-life. In this study, we investigated various food spices, including cinnamon, garlic, and nutmeg, as potential preservatives that could be used to extend kunun-zaki shelf-life. Kunun-zaki varieties were fermented with each of these spices mentioned above and subjected to bacterial, nutritional, sensory, and quality maintenance assessments (using a twelve-member sensory panel to evaluate the organoleptic properties of kunun-zaki). Bacterial counts in the final products ranged between 10^5-7 CFU/ml. We identified two bacterial genera, Weissella and Enterococcus, based on partial 16S rRNA gene amplicon sequencing. Three amino acids, namely leucine, aspartate, and glutamate, were abundant in all kunun-zaki varieties, while the total essential amino acid content was above 39%, suggesting that kunun-zaki could potentially be considered as a protein-rich food source both for infants and adults. The kunun-zaki products were also rich in carbohydrates, crude proteins, ash, crude fiber, and fat, with contents estimated as 81-84, 8-11, 0.8-4.0, 2.9-3.58, and 5.1-6.3%, respectively. However, this nutritional content depreciated rapidly after 24 h of storage, except for kunun-zaki fermented with garlic, which its crude protein and fat content was maintained for up to 48 h. Our results revealed that organic spices increased the nutritional content of the kunun-zaki varieties and could be potentially be used as natural preservatives for enhancing the kunun-zaki shelf-life. However, garlic might be considered a better alternative based on our preliminary investigation. The presence of the isolated microorganisms in the analyzed kunun-zaki samples should be highlighted to raise awareness on the possible health hazards that could arise from poor handling and processing techniques.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.427-434
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• 2016

Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products.

• Journal of Life Science
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• v.30 no.12
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• pp.1128-1139
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• 2020

Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.75-81
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• 2012

Molds cause severe cheese deterioration, even though some white and blue molds are used for the manufacture of Camembert and Blue cheese, respectively. The species of Geotrichum, Moniliella, Aspergillus, Penicillium, Mucor, Fusarium, Phoma, and Cladosporium are the main fungi that affect contamination during cheese ripening. Once deteriorated by fungal spoilage, cheese becomes toxic and inedible. Fungal deterioration of cheese decreases the nutritional value, flavor profiles, physicochemical and organoleptic properties, and increases toxicity and infectious disease. Fungal contamination during cheese ripening is highly damaging to cheese production in Korean farmstead milk processing companies. Therefore, these companies hesitate to develop natural and ripened cheese varieties. This article discusses the recent and ongoing developments in the removal techniques of fungal contamination during cheese ripening. There are 2 categories of antifungal agents: chemical and natural. Major chemical agents are preservatives (propionic acid, sodium propionate, and calcium propionate) and ethanol. Among the natural agents, grapefruit seed extract, phytoncide, essential oils, and garlic have been investigated as natural antifungal agents. Additionally, some studies have shown that antibiotics such as natamycin and Delvocid$^{(R)}$, have antifungal activities for cheese contaminated with fungi. Microbial resources such as probiotic lactic acid bacteria, Propionibacterium, lactic acid bacteria from Kimchi, and bacteriocin are well known as antifungal agents. In addition, ozonization treatment has been reported to inhibit the growth activity of cheese-contaminating fungi.

• Journal of Dairy Science and Biotechnology
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• v.37 no.2
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• pp.83-93
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• 2019

Food spoilage by fungi is responsible for considerable food waste and economical losses. Among the food products, fermented dairy products are susceptible to deterioration due to the growth of fungi, which are resistant to low pH and can proliferate at low storage temperatures. For controlling fungal growth in dairy products, potassium sorbate and natamycin are the main preservatives used, and natamycin is approved by most countries for use in cheese surface treatment. However, a strong societal demand for less processed and preservative-free food has emerged. In the dairy products, lactic acid bacteria (LAB) are naturally present or used as cultures and play a key role in the fermentation process. Fermentation is a natural preservation technique that improves food safety, nutritional value, and specific organoleptic features. Production of organic acids is one of the main features of the LAB used for outcompeting organisms that cause spoilage, although other mechanisms such as antifungal peptides obtained from the cleavage of food proteins and competition for nutrients also play a role. More studies for better understanding these mechanisms are required to increase antifungal LAB available in the market.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.1-8
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• 2008

More safe and natural food was recently needed by consumers. Antimicrobials including sodium azide, penicillin, and vancomycin were used for therapeutic agents against pathogens such as Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 in dairy and meat industry. These antimicrobials and preservatives were prohibited in stock farm and food because they were caused resistant strain and side effects. Bacteriocins are proteinaceous compounds that may present antimicrobial activity towards important food-borne pathogens and spoilage-related microflora. Therefore, bacteriocins were reported as an alternative of antimicrobials. Due to these properties, bacteriocin-producing strains or purified bacteriocins have a great potential of use in biologically based food preservation systems. Despite the growing number of articles regarding on the isolation of bacteriocinogenic strains, genetic determinants for production, purification and biochemical characterization of these inhibitory substances, there are only limited reports of successful application of bacteriocins to dairy and meats. This review describes bacteriocins related to dairy and meat products for the further use.