Whole milk powder (WMP) is a universal raw material component that can overcome the problem of seasonality of raw milk. It can be used to provide high-nutritional products to remote areas experiencing a raw milk shortage. Its long shelf life depends on the conditions of storage and transportation, which are recommended to be carried out in a range from 0 to 10°C. At higher temperatures, the quality of WMP deteriorates because of a substantial increase in the degradation of fat and protein fractions. A range of low negative temperatures for storage have not been systematically investigated. Previous studies have shown that freezing WMP results in protein denaturation, crystallization of lactose, and extraction of free fat, all of which reduce the quality characteristics of the product, including deterioration of solubility, quick rancidification, and microbiological changes. However, these previous studies did not simulate the possible situations of transportation and storage of milk powder at low negative temperatures that occur in practice. Given the volume of transportation, distances and climatic characteristics of transportation routes play an important role in WMP preservation. In this study, we simulated storage and transport of WMP at -20°C. The samples were periodically thawed to 10 and 20°C and examined for physicochemical, functional-technological, thermodynamic, microbiological, and organoleptic parameters. Based on our results, storage of WMP at -20°C for 40 d did not have a significant effect on its qualitative characteristics. We observed some compaction of product structure and clustering or clumping, which was reversible by slight mechanical impact. Artificial contamination of the packaging surface with yeast and molds, followed by thawing of the samples, indicated the absence of the contaminants, which was explained by possible redistribution of moisture in the system.
The development of molecular genetic and bioinformatic systems for identifying the species of milk and the raw material composition of dairy products is of great scientific and practical importance with the purpose of introducing developments in the system for controlling the turnover of falsified products. The aim of the research is to develop a method of PCR-RFLP analysis for species identification of milk and dairy products from agricultural ruminant animals by the κ-casein gene (CSN3) with the possibility of qualitative and relative quantitative assessment of species-specific DNA of the tested biomaterial. The objects of research were samples of raw milk and milk powder, pasteurized cream, and hard and semi-hard cheeses. The developed method of species identification of milk and dairy products includes sample preparation of the studied samples, nucleic acid extraction, combined PCR-RFLP technique, detection of obtained results by the method of horizontal electrophoresis in agarose gel and their analysis, including using the developed mathematical algorithms and software. The synergistic effect established in combined operation of 2 restriction enzymes ensured their application in a mix with increased performance in an ergonomic way in the context of DNA authentication of cow, goat, and sheep milk and dairy products based on them. The specificity and sensitivity of the proposed method is potentially suitable for implementing the development of a system to control the turnover of falsified and counterfeit goods.
The development of food products implies ensuring the optimal composition and ratio of the basic components, as well as their technological compatibility. A priori, the quality of raw materials, the optimal formula of the product and the efficiency of the technological process determine the quality of products, including biological value. The use of whole-cell sensors such as infusoria Tetrahymena pyriformis is most productive for screening biological studies. At present, for a comprehensive assessment there are no data on the use of simplest technology of fermented dairy products and the design of their biological value. The purpose of this research is to develop a methodology for creating whole-milk products of optimal biological value using the express method of biotesting. The research object was yogurt with the ratio of the mass fraction of fat and protein in the range of 0.36 ÷ 1.5, sucrose in the range of 5 ÷ 10%. An express method for determining the relative biological value of fermented dairy products using test organisms and an original methodology for creating whole-milk products of optimal biological value have been developed. A software has been developed to calculate formula of the product optimized for the following indicators: the relative biological value of the product, the cost of raw material and basic materials. The methodology is a tool to assist industry organizations in improving production technologies and quality management systems.
DNA authentication of wines is a process of verifying their authenticity by genetic identification of the main plant component. The sample preparation of experimental and commercial wines was carried out by precipitation of wine debris by centrifugation with preliminary exposure with precipitators and co-precipitators, including developed macro- and micro-volume methods applicable to white or red wines, using polyvinylpyrrolidone as a co-precipitator. Addition of 2-mercaptoethanol and proteinase K to the lysing solution made it possible to adapt the technology for DNA extraction from the precipitated wine debris. The additionally tested technique of DNA extraction from wine debris by dimethyl sulfoxide (DMSO) lysis had fewer stages and, consequently, a lower risk of contamination. The results of further testing of one of the designed primer pairs (UFGT-F1 and UFGT-R1) in conjunction with the tested methods of wine material sample preparation and nucleic acid extraction, showed the advantage in the given set of oligonucleotides over previously used ones in terms of sensitivity, specificity and reproducibility. The developing strategy for genetic identification of grape varieties and DNA authentication of wines produced from them based on direct sequencing of polymerase chain reaction (PCR) products is implemented by interpreting the detected polymorphic positions of variable Vitis vinifera L. UFGT gene locus with distribution and split into 13 UFGT gene-associated groups.
The key trends driving the global dairy market are shelf-life extension and generating consumer demand for new products. Healthy diets and special foods meet the criteria based on the protein digestibility-corrected amino acid score, while other factors affecting the digestibility and actual biological value of the protein are not considered. Express biological evaluation tests are very important for choosing the optimal formulation and efficient manufacturing process in order to maximize the biological value (BV). Such tests adequately represent the food properties: safety, nutrition value, digestibility, health benefits, etc. This study deals with the procedures for the quick biological evaluation of dairy products using indicator organisms. We adapted the relative biological value evaluation procedure, involving Tetrahymena pyriformis, for curd (cottage cheese) and curd products. The experiments showed that the most significant parameters are the milk pasteurization temperature and the curd heating temperature. The full factorial experiment identified the optimal curd production conditions to maximize the relative biological value (RBV): 81 °C milk pasteurization temperature and 54 °C curd heating temperature using the acid method of curd production. With these parameters, the RBV is at least 282%. Biotesting confirmed the optimal curd product component ratio of 60% curd to 40% fermented dairy beverage.