This research is aimed at conducting a comparative analysis of the dehydration process of lactose-containing ingredients and sucrose. Differential scanning calorimetry (DSC) and thermogravimetry (TG) methods were used to investigate the moisture bond types and the process of thermal degradation in native whey, dried skimmed milk, dried whole milk, dried milk whey demineralized, purified lactose, and sucrose. There were several peaks on the DSC and TG curves for lactose-containing ingredients. They determine the loss of the physically absorbed water on surfaces, physically occluded water and hydrate-forming water (up to 180°C), anomerization of lactose (160–220°C), and melting followed by decomposition (above 230°C). The multiple peaks on the dDSC curves from 135 to 170°C indicate the course of the Maillard reaction in the mix with proteins. For the native whey, the amount of chemically bound water was %; for the dried whole milk, it was %; for the milk whey demineralized, it was %; and for the dried skimmed milk, it was %. The results are presented as ( ) and were considered statistically significant when . The similar to some extent form of the DSC and TG curves to lactose-containing ingredients and granulated sugar confirms the possibility of using them as the component of bakery and confectionery product formulas to reduce the glycemic index and improve organoleptic properties of products as well as correct their mineral compositions. Considering the constant changing of technologies for obtaining various dairy ingredients as well as the occurrence of their new kinds, such studies contribute to the expansion of existing knowledge and reference data.
27 October 2016 in Indian Journal of Science and Technology
Milk and dairy products are included in the list of the Food Security Doctrine and are of paramount importance in the diet of the human population. At the same time, the presence of many macro- and microcomponents in milk, as available sources of carbon and energy, as well as the high activity of water, cause the rapid development of native and pathogen microorganisms in it. The goal of the work was to assess the possibility of using an array of gas chemical sensors based on piezoquartz microbalances with polycomposite coatings to assess the microbiological indicators of milk quality and to compare the microflora of milk samples. Piezosensors with polycomposite coatings with high sensitivity to volatile compounds were obtained. The gas phase of raw milk was analyzed using the sensors; in parallel, the physicochemical and microbiological parameters were determined for these samples, and species identification of the microorganisms was carried out for the isolated microorganisms in milk. The most informative output data of the sensor array for the assessment of microbiological indicators were established. Regression models were constructed to predict the quantity of microorganisms in milk samples based on the informative sensors’ data with an error of no more than 17%. The limit of determination of QMAFAnM in milk was 243 ± 174 CFU/cm3. Ways to improve the accuracy and specificity of the determination of microorganisms in milk samples were proposed.
Whey proteins has the highest biological value among all proteins, but the main disadvantage of their use in food technologies is the presence of antigenic epitopes in the molecules that can cause allergic reactions in the human body. The most efficient way to reduce the allergenicity of whey proteins is their enzymatic hydrolysis, which leads to the destruction of antigenic sites and the release of biologically active peptides, including those with antioxidant effects. The purpose of the research is the determination of the whey proteins hydrolysis efficiency in an ultrafiltration concentrate (UF-concentrate) of cheese whey to reduce its allergenicity, as well as to establish the antioxidant activity of the obtained hydrolysate. The experimental studies were carried out at the Core Facilities Centre "Structural and Functional Research of Proteins and RNA" at the FSBSI "Institute of Protein of the Russian Academy of Sciences", as well as "Control and Management of Energy-efficient Projects" at FSBEI HE VSUET. Evaluation of the effectiveness of exposure to whey proteins in the UF-concentrate of cheese whey was carried out by the molecular weight distribution, length and charge of hydrolysis products. ?-lactoglobulin’s derivatives containing from 5 to 17 amino acid residues with a molecular weight of 561 to 1943 Da were found in the finishing hydrolysate. At the same time, hydrolysis made it possible to increase the mass fraction of short-chain peptides, including those with antioxidant properties. As a result of the whey proteins proteolysis in the UF-concentrate of cheese whey, its antioxidant activity increased by 2 times. The degree of hydrolysis of the main allergenic protein, ?-lactoglobulin, was 90-91%. The obtained hydrolysate of whey proteins can be recommended for use in the technology of various assortment groups of dairy products for dietary food with reduced allergenicity and antioxidant effect.