Roman Sobolev

Для корреляции новых стандартизированных методов определения индукционного периода (ИП) масел и жиров с ранее известными методами исследованы популярные на рынке растительные масла с существенным различием в жирнокислотном составе – подсолнечное и пальмовое. ИП указанных масел определяли в образцах без добавок и с внесением термоустойчивого природного антиокислителя – экстракта розмарина на приборах: «Ранцимат» (Metrohm, Швейцария) по ГОСТ 31758–2012 (масса навески 4 г, температура анализа 90–140°С с шагом 10°С для всех приборов); «Окситест» (Velp Scientifica, Италия) по ГОСТ 34815–2021 (масса навески 4 г, температура анализа 90–120°С, давление кислорода 6 МПа); «RapidOxi» (Anton Paar, Германия) в соответствии с ГОСТ 34815–2021 (масса навески 4 г, температура анализа 90–140°С). Показано, что зависимость между температурой анализа и значениями ИП для всех приборов может быть описана уравнением Аррениуса. На основе логарифмированных форм уравнений, полученных для каждого вида масла, были построены прогностические математические модели и рассчитан срок годности масел. Спрогнозировано, что экстракт розмарина (80 мг/кг) увеличит сроки годности масел: подсолнечного в 1,09–2,56, пальмового в 1,11–1,26 раза в зависимости от типа прибора, применяемого для определения ИП. При проведении сравнительного анализа результатов исследований, выполненных на разных приборах, максимальную линейную корреляцию показали значения, полученные на приборах «Окситест» и «RapidOxi». Анализ ИП на этих приборах можно использовать для прогнозирования сроков годности растительных масел, в т. ч. с антиокислителями, по методу ГОСТ 34815–2021. To correlate new standardized methods for determining the induction period (IP) of oils and fats with previously known methods, popular vegetable oils on the market with significant differences in fatty acid composition – sunflower and palm – were studied. IP of these oils was determined in samples without additives and with the addition of a heat-stable natural antioxidant – rosemary extract – using the following devices: Rancimat (Metrohm, Switzerland) according to GOST 31758–2012 (sample weight 4 g, analysis temperature 90–140°C with a step of 10°C for all devices); Oxitest (Velp Scientifica, Italy) according to GOST 34815–2021 (sample weight 4 g, analysis temperature 90–120°C, oxygen pressure 6 MPa); RapidOxi (Anton Paar, Germany) in accordance with GOST 34815–2021 (sample weight 4 g, analysis temperature 90–140°C). It was shown that the relationship between the analysis temperature and the shelf life values for all devices can be described by the Arrhenius equation. Based on the logarithmic forms of the equations obtained for each type of oil, predictive mathematical models were constructed and the shelf life of the oils was calculated. Rosemary extract (80 mg/kg) has been found to increase the shelf life of sunflower oils by 1,09–2,56 times, and palm oil by 1,11–1,26 times, depending on the type of device used to determine the shelf life. When conducting a comparative analysis of the results of studies performed on different devices, the values obtained on the Oxitest and RapidOxi devices demonstrated the highest linear correlation. IP analysis on these devices can be used to predict the shelf life of vegetable oils, including those with antioxidants, using the GOST 34815–2021 method.

Flaxseed (Linum usitatissimum) is one of the most important crops worldwide due to its nutritional and functional properties. Given the diversity of flax and its processed products, this review aimed to systematize and analyze data on their antioxidant properties, oxidative stability, and content of biologically active substances. The literature search was conducted using the following databases: Scopus and The Lens. This review examines the approaches to studying the antioxidant properties, oxidative stability, and content of biologically active substances of flax and its processed products, which are used in the food industry, highlighting the advantages and limitations of the methods employed. For the analysis of AOA and OS in flaxseeds and their processing products, the most common approach is the in vitro model. For AOA assessment, non-standardized methods such as DPPH^•, FRAP, and ABTS^•+ are most frequently used, while standard methods for determining OS (PV, AV, p-AnV, CDs, CTs, TBARSs, OSI) are employed. However, these parameters are integral and cannot fully explain the underlying processes. In our opinion, the most promising directions for further research are the standardization of methods for analyzing the antioxidant activity (AOA) of flaxseed and its processing products. Furthermore, expanding the methodological framework will lead to a better understanding of the mechanisms of oxidative processes and how to inhibit them. An expanded set of AOA assessment methods will allow researchers not only to study the action of antioxidants but also to predict it. This is particularly relevant since the same antioxidant can exhibit both antioxidant and pro-oxidant effects.

Oilseed flax (Linum usitatissimum L.) is a valuable crop characterized by a high content of fats, dietary fiber, protein and various biologically active substances, in particular cyclopeptides. Cyclic peptides are a group of cyclic hydrophobic peptides consisting of eight to ten amino acids with a molecular weight in the range of 950–2300 Da. Flax oil and seeds contain from 0.1 to 0.3% cyclopeptides, which can exhibit antioxidant, anti-inflammatory, immunosuppressive, antihypertensive and antitumor activity. The aim of this review was to systematize and summarize the available literature data on methods of extraction, separation and identification of cyclopeptides from flaxseed oil. It was found that the main methods for obtaining cyclopeptides are solid-liquid, liquid-liquid or solid-phase extraction. Commonly used solvents include methanol, hexane, ethyl acetate, dichloromethane, acetonitrile and deionized water. Preparative flash chromatography on silica gel or polymer adsorbents is used to purify and concentrate cyclopeptides, and high-performance liquid chromatography (HPLC) is used to obtain individual standards. The most commonly used stationary phases are non-polar modified sorbents — octadecyl (C18) and phenylhexyl functional groups. Identification is carried out using instrumental methods of analysis: IR spectroscopy, NMR, HPLC with a diode array detector (HPLC-PDA/DAD), high-resolution tandem mass spectrometry with electrospray ionization (ESI-HR-MS/MS). For the qualitative and quantitative determination of cyclopeptides, the HPLC with a diode array detector at a wavelength of 214 nm is sufficient. In turn, mass spectral methods, including tandem mass spectrometry, make it possible to confirm the qualitative composition and establish the amino acid sequence of cyclic peptides.

One of the research directions of oleogels is to study the possibility of their practical application in the food industry as an alternative to solid fats. In this work, the possibility of replacing solid fat in margarine (fat content 82.5%) with oleogels was evaluated. The oleogel content varied from 10 to 50% of the fat phase. The concentration of gelator for which beeswax or wax components (9:1 combination of beeswax and hydrocarbons) were used represented 3% in oleogels. The fatty acid composition of the fat components used, their textural characteristics, and their color were studied. The following physicochemical and rheological properties of margarines were determined: color values, textural and thermal characteristics, and sensory properties. The data obtained were processed using principal component analysis (PCA). Oleogels were characterized by lower textural properties compared to commercial fat (CF), but a lower content of saturated fatty acids. When using oleogels, the color characteristics of the margarines changed insignificantly. A decrease in textural and organoleptic properties was shown when using more than 30% oleogel in the composition of margarines. It was found that an increase in the proportion of oleogel leads to a decrease in the melting enthalpy of margarines. The margarines, depending on the ratio of oleogel in the fat phase, were characterized by a content of saturated fatty acids reduced by 7–35% and increased by a 18–92% level of polyunsaturated fatty acids. Thus, the application of oleogels in margarine technology makes it possible to adjust the fatty acid composition while improving the physicochemical properties.

Жиры и масла являются неотъемлемой частью рациона при сбалансированном питании. Однако в пищевой промышленности для придания желаемой текстуры пищевым продуктам на жировой основе традиционно используются гидрогенизированные масла, содержащие насыщенные и транс-изомерные жирные кислоты. Для замены масел, модифицированных химическими методами, в настоящее время рассматриваются структурированные пищевые масла (олеогели). При этом олеогели могут применяться не только как альтернатива твердым жирам и гидрогенизированным маслам, но и как носители биологически активных веществ. Цель исследования: сравнительный анализ свойств содержащих жирорастворимые витамины Д3 и К2 олеогелей, структурированных моноэфирами пчелиного воска, и олеогелей, структурированными исходным пчелиным воском, для получения обогащенных пищевых ингредиентов липидной природы - альтернативы твердым жировым продуктам, содержащим насыщенные и транс-изомерные жирные кислоты. В результате проведенных исследований показано влияние состава структурообразователя и жирорастворимых витаминов Д3 и К2 на свойства...

The use of oleogels as an alternative to solid fats to reduce the content of saturated and trans-isomeric fatty acids is a developing area of research. Studies devoted to the search for methods of obtaining oleogels with given properties are of current interest. Ultrasonic treatment as a method for modifying oleogel properties has been used to solve this problem. The number of publications on the study of the effect of ultrasonic treatment on oleogel properties is increasing. This review aimed to systematize and summarize existing data. It allowed us to identify the incompleteness of this data, assess the effect of ultrasonic treatment on oleogel properties, which depends on various factors, and identify the vector of this direction in the food industry. A more detailed description of the parameters of ultrasonic treatment is needed to compare the results between various publications. Ultrasonic treatment generally leads to a decrease in crystal size and an increase in oil-binding capacity, rheological properties, and hardness. The chemical composition of oleogels and the concentration of gelators, the amplitude and duration of sonication, the cooling rate, and the crystallization process stage at which the treatment occurs are shown to be the factors influencing the efficiency of the ultrasonic treatment.

The objective of this presentation is to highlight our research on the study of microstructure entropy as a parameter determining the textural properties of wax-based oleogels. This parameter was determined by analyzing microphotographs obtained by polarized light microscopy. The Gibbs entropy as a measure of the number of possible microscopic states of a system in thermodynamic equilibrium was thus calculated. We investigated oleogels based on beeswax and beeswax hydrocarbons. The effect of the cooling rate of oleogels from the melt on the crystal size and the yield strength of the oleogels was studied. Using the obtained data, the grain boundary energy, grain boundary energy per unit volume, and the temperature of microstructure as the energy required for the transition of the crystal system from one state to another under stress was also studied. Results allowed us to form a hypothesis defining the wax crystal orientation by {010} or {001} planes based on Gibbs free energy between the crystal boundaries and at the boundaries of the crystals and coverslip. Here we applied the Hall-Petch model to evaluate the relationship between the microstructure and textural properties of oleogels and showed its applicability to the study of waxy oleogels. We showed the inverse Hall-Petch effect for hydrocarbon-based oleogels, in contrast to beeswax-based oleogels. Based on the classical notions of grain boundary hardening within the framework of the Hall-Petch model, a possible explanation of the observed effect of hydrocarbon-based oleogels was proposed through a change in the probability for dislocation absorption by the grain boundary.This presentation will also show all steps for the microstructure entropy calculations straightforwardly for researchers to optimize the wax-based oleogel production technology.

This study aimed to find relationships between the properties of beeswax-based oleogels and the type of oil used. The influence of linseed, sunflower, olive, and fish oils was studied. For these oils, the fatty acid composition, the content of total polar components, and the iodine value were characterized. Textural and thermodynamic properties were determined for oleogels, the oil-binding capacity was estimated, and the morphology of crystals was studied. The concentration of beeswax in all oleogels was 6.0% w/w. It was shown that the type of oil has a significant influence on all characteristics of the oleogels. The use of different oils at the same technological treatment leads to the formation of crystals of diverse morphology—from platelets to spherulites. At the same time, it was revealed that some characteristics of oils have a varying contribution to the properties of oleogels. The content of total polar materials in oils is associated with a decrease in strength parameters (yield value and elastic modulus) and the oil-binding capacity of oleogels. In its turn, the iodine value of oils has a close positive correlation with the melting and crystallization temperatures of oleogels. The results obtained in this article indicate that the properties of beeswax-based oleogels can be directed by changing the oil composition.