USE OF CHITOSAN TO EXTEND THE SHELF LIFE OF FERMENTED MILK PRODUCTS WITH LACTOBACILLUS DELBRUECKIISUBSP. BULGARICUS

In this article was stydied the influence of the shelf life of kefir for baby food on their quality, estimated by the titrated acidity and intensity of lipid peroxidation process. The last was determined by the change in the concentration of compounds reacting with thiobarbituric acid. Were researched Children's kefir of brands "Adventures of Jovi", "For kids", "Agusha", fat content of 2.5% and 3.2% manufacturers of JSC "lactis", JSC "Zelenodolsk milk processing combine" and LLC "Wimm bill Dann". For these samples of fermented milk products for baby food is characterized by different declared shelf life, equal to 6, 15, 9 and 15 days, respectively, which serves as indirect evidence of differences in the methods of their production. The control period of research took into account both the shelf life of the product, declared by the manufacturer, and the period of time a week after its end. This allows, in our opinion, both to assess the impact of the conditions of production of commodity products on its, and it is possible to assess the level of safety of the analyzed kefir in the declared shelf life and, thus, to identify the best brand. The results were compared with data on the integrated antioxidant activity of the studied fermented milk products. Their values were obtained earlier by coulometric titration with electrogenated bromine, which allows to cover the largest number of antioxidants present in the control products at the time of the research. As a result of the comparative analysis it is shown, that children's kefir, the brand " for kids” in the declared shelf life of the manufacturer, is characterized by a lower content of secondary products of lipid peroxidation, causing rancidity of kefirs, while its antioxidant activity is the highest among the studied samples of kefirs for baby food. The results suggest that the technology for producing baby kefir of this brand is optimal, providing high quality, which is very important for the growing up body.

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Efficacy of Antimicrobials in Fermented Milk Storage

Food Processing Techniques and Technology ◽

10.21603/2074-9414-2018-3-65-71 ◽

2019 ◽

Vol 48 (3) ◽

pp. 65-71

Author(s):

Станислав Сухих ◽

Stanislav Sukhikh ◽

Андрей Лукин ◽

Andrey Lukin ◽

Юлия Голубцова ◽

...

Keyword(s):

Shelf Life ◽

Mass Fraction ◽

Pathogenic Bacteria ◽

Dairy Product ◽

Control Sample ◽

Fermented Milk ◽

Cottage Cheese ◽

Experimental Conditions ◽

Milk Products ◽

Fermented Milk Products

The existing methods of disinfection of containers for fermented milk products proved to be ineffective. The present research featured an antimicrobial preparation based on silver, copper, and zinc nanoparticles as a disinfectant solution. The authors studied the properties of the antimicrobial in order to prove its effectiveness in processing containers to increase the shelf-life of fermented milk products. The size of the silver nanoparticles ranged from 1 to 10 nm. The nanoscale particles of copper were obtained by the method of electric explosion. It was established that the mass fraction of the active substance (active metals) in the antimicrobial was 50.1%; the mass fraction of water was 11.2%; the mass fraction of hydrogen peroxide was 1.0%. To assess the ability of the antimicrobial to increase shelf-life of fermented milk products, the authors analyzed the microbiological properties of cottage cheese. The 50-gram samples were packed in pre-treated polyethylene containers that had been cleaned with the antimicrobial. After that the samples were left for storage at minus 4 ± 1°C. The quality and the microbiological state of the cottage cheese was evaluated on days 3, 5, 7, 9, 11, and 13, which was justified by the experimental conditions and regulatory documentation. Eventually, it was established that the product contained no pathogenic bacteria, such as L. monocytogenes, Salmonella, E. coli, staphylococci, yeast, molds or any viable microbial cells. It was proved that the test sample retained its consumer properties for 13 days, while the control sample was found unusable by day 7. Thus, by using the antimicrobial, it was possible to increase the shelf life of the dairy product by more than 5 days.

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