All-Russian Scientific Research Institute of Canned Food Technology

Special features of the protopectin complex structure of plant tissue suggest the necessity of performing point destruction of certain glycoside bonds in the structure of rhamnogalacturonan polymer chains for industrial production of pectin. These chains include homogalacturonan sites and branching zones. As the homogalacturonan fragments of the protopectin complex carry the main functional load, glycoside bonds between residues of rhamnose and galacturonic acid are targeted bonds. For their directional destruction, it is most expedient to use enzymes of lyase and hydrolase action. The aim of this review is to systemize notions of molecular specific features of enzymes of lyase and hydrolase action that catalyze the process of enzymatic destruction of the rhamnogalacturonan main chain. The paper examines systematics of lyase and hydrolase enzymes by mechanism of destruction of glycoside bonds and by molecular structure. It is shown that the classification data intercross, as a result, each family can include one or several enzyme groups. The review shows the main structural difference of enzymes of lyase and hydrolase action that consists in the obligatory presence of Ca2+ cations in the composition of lyase enzymes. These cations take part in stabilization of conformation of the enzyme molecule and in the catalytic process per se blocking the residue of galacturonic acid. Ca2+ cations are absent in the composition of targeted hydrolase enzymes. Molecular specific features of lyase enzymes determine sensitivity of their catalytic activity to the presence of Ca2+ cations in the system. Exceeding certain concentration can lead to the antagonistic effect. There is no unambiguous idea of this regarding hydrolase enzymes. The review demonstrates the necessity of studying approaches to assessment of expediency of preliminary partial removal of cations from the substrate.

Aspartame and acesulfame potassium are among the best known food sweeteners. Despite numerous studies showing the safety of these supplements, in recent years the attention of researchers has been focused on the negative side effects of their exposure, which can lead to the development of non-communicable diseases. The aim of this investigation was to study the nature of the impact (reversible or irreversible) of aspartame and acesulfame potassium on weight gain, as well as cytological, cytogenetic and metabolic parameters of onion roots. Roots were pre-treated with 0.5 and 1 g/l aqueous solutions of sweeteners, and then they were transferred to water for the purpose of further regenerative germination. The consequences of the toxic effect of aspartame on the weight gain of onion roots were minimal compared to the control. This indicator significantly and dose-dependently decreased to 38% in the samples with acesulfame potassium, which shows the presence of a delayed effect after exposure to this sweetener. In the experimental groups with the maximum content of sweeteners, a lower mitotic index (p≤0.05) in the meristem cells was also maintained compared to the control. The results obtained indicated an irreversible mitotoxic effect of these compounds. However, an increase in the frequency of mitosis pathologies found in the experimental samples due to pre-treatment with sweeteners was completely leveled after regenerative germination. Therefore, these genotoxic disorders were reversible. To assess the processes of lipid oxidation of root tissues, the concentration of malondialdehyde was measured. The effect of reducing the level of this indicator in all experimental samples compared with the control turned out to be irreversible, although not dose-dependent. The results obtained can be used in the development of formulations for adding food sweeteners to food products to reduce the risk of delayed toxic effects.

A demand for canned vegetables and fruit depend, first of all, on their consumer characteristics. These products should correspond to high requirements regarding their nutritional and biological value, as well as sensory properties. The aim of the work was to study the microstructural changes in the cells of green peas in the products of their processing. Fresh, frozen and canned peas made from fresh and rehydrated raw materials were used as objects of the research. Components such as chlorophyll and starch were characterized in the cells of the hypodermis and parenchyma, respectively, using light microscopy. It was found that plastids with chlorophyll stained in the bright green color were present only in cells of the hypodermis of frozen peas. Moreover, the same color of the pigment was also recorded in the samples of fresh peas. Appearance of brown hues in these cells was observed in the canned product from fresh peas, which was associated with transformation of chlorophylls into pheophytins and pyrophephytins. The hypodermis in the samples of canned peas from rehydrated raw materials was represented by almost colorless cells. When analyzing the preparations of the parenchymal cells of the indicated processed products stained with iodine, it was shown that starch grains in the samples of frozen and canned green peas from fresh raw materials maintained their concentric shape, while swelling of starch grains was observed in the stained preparations of the parenchyma of canned peas from rehydrated raw materials. The comparative microstructural analysis of processed products from green peas showed that maximum quality had the frozen product from fresh raw materials as the studied indicators (chlorophyll and starch grains) showed.

Relevance and methodology. Today, white cabbage is the most popular type of vegetable raw materials used for fermentation not only in Russia, but also in other countries. To obtain a variety of flavors and shades of flavor, various vegetables (carrots, sweet peppers), fruit (apples, cranberries) and spicy-aromatic additives (cumin, dill seed, etc.) are added to the cabbage during fermentation. During fermentation, the product contains not only the initial components of the raw material (vitamin C, macro-and micronutrients), but also significantly increases the number of lactic acid microorganisms – the main "participants" in the process.One of the main products of the metabolism of lactic acid microorganisms is lactic acid. At a concentration of 0.5%, it begins to inhibit the development of many microorganisms. When reaching a concentration of 1-2% microbiological enzymatic hydrolysis, as a rule, ceases. The accumulation of acetic acid allows us to judge the intensity of the heterofermentative stage of fermentation using strains of lactic acid microorganisms.Results. The L. plantarum + L. casei consortium has shown a synergistic interaction in the accumulation of lactic acid, since the amount of acid produced by the consortium significantly exceeds the amount of acid produced by each strain separately. This point is also noted for the accumulation of acetic acid. In the L. brevis + L. casei consortium, the opposite situation is observed: when using cultures separately, the accumulation of lactic acid occurs to a greater extent than when using two cultures simultaneously. There are no obvious differences between monocultures and the consortium in terms of acetic acid accumulation. In the case of the L. plantarum + L. brevis consortium, we observe a synergistic interaction, with the dominant role in this consortium played by L. plantarum, and the contribution of L. brevis to the accumulation of lactic acid is insignificant. At the same time, the total resulting accumulation of acetic acid is significantly less than the result of each strain separately, which may indicate a negative mutual effect of the participants in the process. Acid degradation of the polysaccharide matrix of cell walls does not occur during the entire fermentation process.

Inclusion of minor components in the formulation of homogeneous food systems should inevitably result in some shift of redox equilibrium under conditions of interaction as "all with all." Chemical nature of components combined with properties of elements of medium chemical composition should determine direction and expression of such displacement. But due to the multicomponence of the medium itself and the small initial expression of redox properties for the added components, predicting the resulting properties of the formed food system becomes difficult. The aim of the work was to study the regularities of the influence of neutral minor components on the change of redox properties of homogeneous canned products from vegetable raw materials. Puree-shaped single-component natural canning products (puree) from fruit (apples, plum) and vegetable (pumpkin, carrots) raw materials are taken as research objects. Table salt (NaCl), sucrose and apple pectin were used as minor components. In the obtained canned product, active acidity (pH) and redox potential (Eh) were determined, and the reducing power index (RH) value was calculated. The studies showed that there was no statistically significant effect of NaCl on the redox properties of the food systems studied. There was a statistically significant effect of sucrose on the reducing power index of homogeneous canned puree from plums (in the range up to 18%) and carrots (in the range up to 10%). It has been found that inclusion of pectin in the composition of fruit and vegetable puree does not have a statistically significant effect on the reducing capacity of the product, except for stone fruit puree, for which there was statistically significant single step increase of RH within a weight fraction value of the minor component as 0.61-0.62%. In order to determine the mechanism of such a response, it is necessary to carry out an additional set of targeted studies.

The process of processing and selling fresh vegetable and mushroom products is accompanied by a high risk of rapid bacteriological damage and, as a consequence, short shelf life. The search for methods of processing lightly damaged varieties of plant materials is an urgent problem of the food industry. Studies have been carried out to study the effect of relativistic electrons on a 10 MeV facility (Tekleor company) on the dynamics of inhibition of native microflora during storage of delicate types of plant materials. Fresh mushroom champignons and fresh spinach greens were chosen as objects of study. Product samples were Packed weighing 200 g in plastic bags brand RA / PE. Storage and transportation of samples was carried out at a temperature of 8–10 ° С. After processing the experimental data, a plateau zone was revealed during processing with a beam energy of 1 kGy with a further decrease in the number of microorganisms with an increase in dose to 2 kGy. Studies of changes in the dynamics of inhibition of the initial number of microorganisms in mushroom and green products showed that in the microflora of mushroom and green products, there are stable types of microorganisms that are characterized by the presence of a plateau zone. Processing spinach with a beam energy of 1 and 2 kGy allows extending the shelf life compared to control samples from 5 to 12 and 15 days. The treatment of champignon mushrooms with a beam energy of 2 kGy, despite the high initial level of seed contamination with native microflora, allowed us to maintain the upper limit of the norm (1 · 105 CFU / g) of microbiological seed for up to 5 days.

The paper presents the experience of the operation of microwave drying plants for agricultural raw materials. The technology solutions concerning development and use of conveyor microwave ovens of drying installations for drying of vegetable raw materials are designated. The received parameters of energy consumption and dynamics of process of drying allow to define close to optimum border of transition from convective to microwave to a power supply. The optimum value of the transitional humidity (at the boundary of the microwave and convective modules) should be in the range from 120% to 140%. Application of a method of combined power supply when drying fruits and vegetables allows to reduce power consumption of process by 20-30%. Examples of successful introduction of the offered way of drying in the food industry are given.

The presence of the desirable alleles and genotypes of casein and whey protein genes in the genome of cows affects the milk protein content, quality and technological properties of their milk. Two important properties of milk its producibility is judged on are cheeseability and heat resistance. The present studies aimed at estimating the technological properties of milk of black-motley × Holstein and Kholmogorskaya breeds cows of the Tatarstan type with different kappa-casein (CSN3) and beta-lactoglobulin (BLG) genotypes. The study was carried out using a sampling of the first-calf cows of 5 cattle-breeding farms of the Republic of Tatarstan. In animals, the CSN3 and BLG genotypes have been determined by a PCR-RFLP analysis. The cheeseability, heat resistance and thermostability of milk have been estimated using standard methods. The studies have established that the CSN3 and BLG genotypes of cows affected the condition of a casein clot and duration of milk clotting time. The best cheese-making properties of milk were inherent in the animals with the BB and AB genotypes of the CSN3 and BLG genes. They were superior to the coevals with the AA genotype in terms of the highest yield of the desired dense casein clot and the shortest duration of milk clotting time. The first-calf cows, which are the carriers of an A allele of the CSN3 gene, were superior to the animals with the BB genotype of the CSN3 gene on the thermostability of milk including that on the proportion of animals with this milk characteristic. The BLG genotype of the studied animals did not significantly affect the thermostability of milk. Moreover, the highest thermostability of milk was characteristic of black-motley × Holstein cows with the AA genotype.

Existing approaches for evaluation of types of interactions between individual monocultures in consortiums allow obtaining only qualitative results (synergistic, antagonistic, additive interaction) as a whole, without regarding to changes in the cultivation process. Therefore, the development of a new approach for the quantitative determination of this indicator as a continuous function defined during the all period of cultivation is in need. In the course of the research a two-component consortium of lactic acid microorganisms cultivated on different mediums according to directed fermentation process in vegetable products was chosen to analyze types of interaction. As a result, the an original approach that was based on comparison of grow speed of biomass of microorganisms with calculated additive curve determined by results of dynamic analysis of titre of microorganism participating in consortium in monoculture during their cultivation has been elaborated. This approach is a convenient tool to identify complex regularity in changes of types of microorganism interaction in consortium represented by continuous function defined during all cultivation period.

<p>The objective of this study was to propose a multi-criteria optimization and decision-making technique to solve food engineering problems. This technique was demonstrated using experimental data obtained on osmotic dehydration of carrot cubes in a sodium chloride solution. The Aggregating Functions Approach, the Adaptive Random Search Algorithm, and the Penalty Functions Approach were used in this study to compute the initial set of non-dominated or Pareto-optimal solutions. Multiple non-linear regression analysis was performed on a set of experimental data in order to obtain particular multi-objective functions (responses), namely water loss, solute gain, rehydration ratio, three different colour criteria of rehydrated product, and sensory evaluation (organoleptic quality). Two multi-criteria decision-making approaches, the Analytic Hierarchy Process (AHP) and the Tabular Method (TM), were used simultaneously to choose the best alternative among the set of non-dominated solutions. The multi-criteria optimization and decision-making technique proposed in this study can facilitate the assessment of criteria weights, giving rise to a fairer, more consistent, and adequate final compromised solution or food process. This technique can be useful to food scientists in research and education, as well as to engineers involved in the improvement of a variety of food engineering processes.</p>