Oil Quality Indicators Research Articles

IMPROVEMENT OF OIL STORAGE TECHNOLOGY

The paper evaluates the possibility of using nanomaterials in the manufacture of containers intended for storing vegetable oils for various purposes. The oxidative resistance of oils under various conditions was studied. The main content of the study is the analysis of changes in the qualitative characteristics of vegetable oil depending on the type of container and the time of exposure to external UV radiation. The article presents the results of research on the main indicators of oil quality. The authors concluded that the proposed storage option is promising and research will continue.

INVESTIGATION OF THE EFFECT OF FERMENTED MILK STARTER CULTURE ON BUTTER QUALITY INDICATORS

Butter production in Kazakhstan is gaining growth, the food market is represented by a diverse range of sweet and creamy butters, butters with fillers, which are produced by oil processing enterprises. This article presents research on the development of sour-cream butter with functional properties, studies have been conducted on the influence of fermented milk crops on oil quality indicators during storage. Standard methods were used in three-fold repetition to conduct the research. Various types of fermented milk starter cultures were studied, and models of butter recipes with starter cultures were compiled. Fermented milk ferments were introduced into the butter layer during thermomechanical processing. The results of the study showed that it is recommended to use the bacterial starter culture of EM Kurungа for the production of butter. The butter quality indicators were studied using this starter culture. The introduction of a starter culture in an amount of 3% allows you to get a product with the best characteristics, the value of the acid number is within the normal range for sour cream butter and allows you to maintain the quality of the product for 60 days. The finished product had positive organoleptic properties, shelf life and can be recommended for functional nutrition.

The Effect of Salinity and Drought on the Essential Oil Yield and Quality of Various Plant Species of the Lamiaceae Family (Mentha spicata L., Origanum dictamnus L., Origanum onites L.)

Mentha spicata L., Origanum dictamnus L., and Origanum onites L. are aromatic plants that produce very important essential oils. They are considered model plants with beneficial health properties due to their antioxidant content. Enhancing the yield while maintaining the quality of essential oil is of significant commercial importance. Salinization and drought cause various effects on the yield and quality of the bioactive constituents in essential oil. By assessing the response of these plants and their secondary metabolites accumulation to different salt stress and irrigation levels, this study aims to gain insights into how plants adapt to and cope with salinity and drought. A pot experiment was conducted in the spring of 2020 to assess the effect of salinity and drought stress on the growth and essential oils content of the three aromatic plant species mentioned above. The soil mixture used was perlite and peat in a ratio of 1:1:6, while four salinity treatments (25, 50, 100, and 150 mΜ NaCl) and two levels of irrigation were applied (100% and 50%). Salinity significantly affects total chlorophyll concentration especially in higher concentrations (100 and 150 mM) in M. spicata plants, especially under 50% soil water irrigation. Under the same conditions, M. spicata contained the higher proline concentration, which was significantly greater than that in O. dictamnus and O. onites. Similar variations of malondialdehyde and hydrogen hyperoxide were revealed among the three species, with significantly higher values in M. spicata when subjected to both excess salinity and drought conditions. The major compounds identified in M. spicata were carvone, in O. dictamnus carvacrol, and p-cymene and in O. onites carvacrol. It is important to highlight that O. onites had the highest concentration of essential oil, and that the concentration increased with the increase of NaCl. This suggests that the presence of NaCl in the soil may have a stimulating effect on the production of essential oil in O. onites. However, it is plausible that the stress caused by NaCl triggers a physiological response in O. onites, leading to increased production of essential oil. This could be a protective mechanism to enhance the plant’s resistance to the stressor. Overall, O. onites and O. dictamnus appeared to be more resistant to these stress conditions than M. spicata, since they maintained their growth and essential oil quality indicators at higher levels. These two species possess mechanisms that prevent or minimize lipid peroxidation, thus protecting their cell membranes and maintaining their ultrastructure integrity.

Pashukevich Motor oil performance analysis due to water and coolant contamination

Introduction. During the operation of heavy-duty diesel equipment in areas with a low-temperature climate, engine oils are contaminated by coolant and water. The ingress of these substances into the lubricant leads to a deterioration in its quality indicators, which subsequently leads to problems in the nodes of the internal combustion engine.Relevance. The deterioration of the values of engine oil quality indicators is directly related to the presence of water and coolant in it. It is not always possible to objectively track the ways of leakage of these pollutants, and this, in turn, leads to serious consequences in the form of wear of the contacting surfaces of engine parts, corrosion. It is also important to evaluate the resource of lubricant additive packages due to its dilution with water and antifreeze.Materials and methods. This paper presents the results of a literature review aimed at studying the ways of coolant and water ingress during the operation of diesel engines, their influence on the physical and chemical properties of motor oils. The brief information about the composition of the coolant is indicated.Conclusions. The ingress of water and coolant into the engine oil leads to an increase in the kinematic viscosity of the lubricant, as well as to the formation of deposits on the surfaces of the engine friction pairs. In addition, spherical compounds appear in the crankcase of the engine, which are a combination of destroyed additive packages and glycol. Oil change intervals must be monitored at an increased rate of water and coolant entering the engine oil.Scope of the study / possibility. This type of study will help to determine the causes of penetration of water and coolant into the crankcase space, to understand the consequences of using engine oil contaminated with water and coolant.Originality / value. The conducted research can be the basis for the development of recommendations for improving the maintenance of internal combustion engines for enterprises that have at their disposal cars with diesel engines in order to increase the resource of power units and reduce operating costs.

Design of an Artificial Intelligence of Things-Based Sesame Oil Evaluator for Quality Assessment Using Gas Sensors and Deep Learning Mechanisms.

Traditional oil quality measurement is mostly based on chemical indicators such as acid value, peroxide value, and p-anisidine value. This process requires specialized knowledge and involves complex steps. Hence, this study designs and proposes a Sesame Oil Quality Assessment Service Platform, which is composed of an Intelligent Sesame Oil Evaluator (ISO Evaluator) and a Cloud Service Platform. Users can quickly assess the quality of sesame oil using this platform. The ISO Evaluator employs Artificial Intelligence of Things (AIoT) sensors to detect changes in volatile gases and the color of the oil during storage. It utilizes deep learning mechanisms, including Artificial Neural Network (ANN), Convolutional Neural Network (CNN), and Long Short-Term Memory (LSTM) to determine and evaluate the quality of the sesame oil. Evaluation results demonstrate that the linear discriminant analysis (LDA) value is 95.13. The MQ2, MQ3, MQ4, MQ7, and MQ8 sensors have a positive correlation. The CNN combined with an ANN model achieves a Mean Absolute Percentage Error (MAPE) of 8.1820% for predicting oil quality, while the LSTM model predicts future variations in oil quality indicators with a MAPE of 0.44%. Finally, the designed Sesame Oil Quality Assessment Service Platform effectively addresses issues related to digitization, quality measurement, supply quality observation, and scalability.

High-oleic rapeseed oil quality indicators and endogenous antioxidant substances under different processing methods.

This study exposed high-oleic rapeseed oil (HORO) to different pretreatment (microwave or roasting) and processing methods to investigate (cold pressing, hexane extraction, subcritical butane extraction, and aqueous enzymatic extraction) the effects of processing technologies on HORO parameters associated with its physicochemical properties, endogenous antioxidant substances, and antioxidant capacity. The oil yield of various processing technologies was between 35.4% and 59.7%, and the fatty acid composition did not significantly differ. Hierarchical clustering and principal component analyses were used for evaluation. The results revealed that the microwave pretreatment-hexane extraction (M-HE) method resulted in significantly higher levels of tocopherols (688.4mg/kg), polyphenols (1007.76mg/kg), and phytosterols (1810.6mg/kg) in HORO, implying strong free radical scavenging capacity (DPPH-oil: 79.63, DPPH-nonpolar: 71.42, DPPH-polar: 6.65, FRAP: 55.4, ABTS: 3043.7μmol TE/kg). Hence, M-HE is a promising method for producing HORO with a higher stability and nutritional value.

Meta-analysis of transcriptome reveals key genes relating to oil quality in olive

BackgroundOlive oil contains monounsaturated oleic acid up to 83% and phenolic compounds, making it an excellent source of fat. Due to its economic importance, the quantity and quality of olive oil should be improved in parallel with international standards. In this study, we analyzed the raw RNA-seq data with a meta-analysis approach to identify important genes and their metabolic pathways involved in olive oil quality.ResultsA deep search of RNA-seq published data shed light on thirty-nine experiments associated with the olive transcriptome, four of these proved to be ideal for meta-analysis. Meta-analysis confirmed the genes identified in previous studies and released new genes, which were not identified before. According to the IDR index, the meta-analysis had good power to identify new differentially expressed genes. The key genes were investigated in the metabolic pathways and were grouped into four classes based on the biosynthetic cycle of fatty acids and factors that affect oil quality. Galactose metabolism, glycolysis pathway, pyruvate metabolism, fatty acid biosynthesis, glycerolipid metabolism, and terpenoid backbone biosynthesis were the main pathways in olive oil quality. In galactose metabolism, raffinose is a suitable source of carbon along with other available sources for carbon in fruit development. The results showed that the biosynthesis of acetyl-CoA in glycolysis and pyruvate metabolism is a stable pathway to begin the biosynthesis of fatty acids. Key genes in oleic acid production as an indicator of oil quality and critical genes that played an important role in production of triacylglycerols were identified in different developmental stages. In the minor compound, the terpenoid backbone biosynthesis was investigated and important enzymes were identified as an interconnected network that produces important precursors for the synthesis of a monoterpene, diterpene, triterpene, tetraterpene, and sesquiterpene biosynthesis.ConclusionsThe results of the current investigation can produce functional data related to the quality of olive oil and would be a useful step in reducing the time of cultivar screening by developing gene specific markers in olive breeding programs, releasing also new genes that could be applied in the genome editing approach.

INFLUENCE OF CLIMATIC FACTORS AND SEED STORAGE PERIODS ON THE QUALITY OF LINSEED OIL

Purpose. The purpose of the research was to determine changes in the quality of oil flax seeds of different varieties on weather condition during cultivation and storage period. Methods. Laboratory and statical research methods used. The laboratory was used to determine the oil content of flax seeds and to establish the quality indicators of the oil obtained from flax seeds at different storage periods. Statistical for estimating the standard deviation in determining the oil content of seeds. Results. The article analyzes the weather conditions during the growing season of oilseed flax. It was determined that the amount of precipitation and air temperature during the research periods significantly deviated from the average longterm indicators, and the precipitation was characterized by unevenness of arrival. As a result of the conducted research, it was determined that the oil flax seeds grown in the agroclimatic conditions of Polissia of Ukraine have high quality and are suitable for use as food and technical raw materials. It was established that the Liryna variety had an oil content of 46.5–47.2 % on average over the years of experiments and was ahead of the Evryka variety by this indicator. Linseed oil had high quality indicators, its iodine value ranged from 178.4–184.2 gJ2/100g for the Eureka variety and 175.3–181.2 for the Liryna variety. A high iodine number determines a significant content of unsaturated fatty acids, which determines the oil as valuable when using it for food, pharmaceutical and technical purposes. The maximum oil content in seeds is set for the initial storage period – 38.8 and 44.5%, respectively, of the variety. At the end of the storage period, after 9 months, the oil content in the Evryka variety decreased by 4.1%, and in the Liryna variety by only 2.1%. A decrease in the iodine value was established depending on the storage period. This indicator of oil quality, depending on the shelf life, decreased from 182.1 to 179.6 (by 1.4%) for the Evryka variety and from 178.4 to 169.5 (by 5.0%) for the Liryna variety. At the end of the storage period, the acid numbers of linseed oils increased. Thus, at the end of the storage period, the content of free fatty acids in the oil obtained from the seeds of the Eureka variety increased by 1.7 times, for the Liryna variety, this indicator doubled. Conclusions. The climatic condition of Polissia ensure the production of high-quality oil, and the considered terms of storage of raw materials for its production, subject to the use of optimal regimes, ensure the quality regulated by state standard.

Контроль якості вбирної оливи для уловлювання бензольних вуглеводнів за показником виходу коксового залишку.

Specific consumption of absorbent oil and its quality indicators are key characteristics of the benzene department, as they reflect the level of operating costs and determine the degree of equipment contamination with sediments. The thickening of coal tar absorbent oil during operation depends on the level of oil loss with crude benzene, the intensity of the oil polymerization and oxidation reaction, the degree of introduction of resinous and solid substances with coke oven gas, the intensity of coke formation under the influence of high temperatures, and the quality of the absorbent. Recently, little attention has been paid to such an integral indicator of absorbent oil quality as coke residue yield ("coking point"). Coking ability is associated with the viscosity, chemical composition and degree of oil purification, and is used mainly for petroleum oils operating at high temperatures. The relationship between the coke number and the physical and chemical properties of the feedstock can be traced by analyzing the dependence on the average boiling point of the tar fractions. An increase in the viscosity and density of the absorbent oil is reflected in an increase in the coke residue yield in a linear fashion, and a decrease in the content of lowboiling oil distillation in favor of high-boiling oil also increases the coke residue yield. The highest degree of correlation is observed in the exponential dependence of the coke number on the content of substances insoluble in toluene in the oil. The coking point of the absorbing oil is an indicator of the intensity of the oil oxidation and polymerization processes, the presence of corrosion and equipment wear products, the addition of tar and sulfurcontaining substances, and the presence of salts. The use of tar to initiate coke formation is an indicative and convenient way to comparatively assess the performance properties of fresh oil. This makes it possible to use the method of determining the yield of coke residue to assess the tendency of fresh oil to form sediments in equipment. Keywords: absorbent oil, coke residue yield, fractional composition, group composition, dependence, correlation degree. Corresponding author: A.L. Bannikov, e-mail: artiksmartik@gmail.com

Improvement of methods for controlling power oil of cooling tower recycling water supply units at Rivne nuclear power plant

The relevance of the study is conditioned upon the fact that at nuclear power plants, water pumping units using energy oils are operated in the heat exchange equipment of power units. The diagnostic criteria of oils allow identifying defects in the operation of technological equipment. The purpose of the work – to increase the reliability of the operation of oil-filled power equipment by improving the monitoring of the physical and chemical properties of power oil TP-30. The main attention is devoted to increasing the reliability of the operation of oil-filled power equipment by improving the monitoring of the physical and chemical properties of TP-30 power oil. Experimental studies were conducted by chromatography, and gas and liquid extraction using appropriate laboratory equipment. When exploring the content of chemical elements in the segments of the thrust bearing of the cooling tower pumping unit, which is based on Sn, an increase in the content of copper Cu and Sb was observed, which exceeded the standard by an average of 1.2 and 1.1 times, respectively. Most of the analysed physical indicators of oil quality (water content, kinematic viscosity, flash point, acid number) did not demonstrate deviations from the standard values. Only an increase in the mass fraction of mechanical impurities by 0.0026% relative to the standard was noted during the incoming inspection of TP-30 oil. The results of the operational control of the oil in terms of a set of physical indicators fully complied with the established technological standards. The highest content of soluble gases in the oil (0.56% by volume) was recorded for propylene (C3 H6 ). It is recommended to use the relative content of soluble gases in Tp-30 oil to C3 H6 when identifying degradation processes. The absence of residuals of circulating power oil TP-30 in the surface waters of the Styr River during the operational event was established. Generalisations have been generalised about the necessity of expanding the diagnostic criteria for the quality of TP-30 oil, in particular, expanding the list of its physical indicators. In practical terms, the results obtained can be useful for monitoring the quality of other brands of petroleum oils in the systems of turbine units of nuclear power plants, which is important in terms of the safe operation of heat exchange equipment

Properties of Winemaking By-products of Feteasca Neagra Grape Seeds

The composition of the lipophilic and hydrophilic extracts from the Feteasca Neagra ground seeds, grown in three different vineyards, was studied. The physicochemical indicators of the seeds, the oil quality indicators and the total content of polyphenols and flavonoids in the extracts were determined. Some phenolic and flavanol constituents were identified and quantified using reversed-phase HPLC by gradient-elution. The Trolox equivalent antioxidant capacity assay proved the increased antioxidant activity of the hydrophilic extracts, with the highest DPPH• scavenging effect of almost 91.70 and 93.81%, an equivalent of 281.66 and 288.27 µM/L Trolox. It was concluded that the seeds recovered from Feteasca Neagra by-products are a rich source of functional compounds, with significant antioxidant properties.

Determination of Maximum Oil Yield, Quality Indicators and Absorbance Spectra of Hulled Sunflower Seeds Oil Extraction under Axial Loading

The present study aims to estimate the maximum oil yield of hulled sunflower seed samples in a uniaxial process under a load of 40 kN and speed of 4 mm/min. The oil samples were assessed for their quality parameters and spectra curves within the wavelength range of 325–600 nm. The results show that heating temperatures in the range of 40 °C to 80 °C increased the oil output; however, a maximum oil yield of 48.869 ± 6.023% with a minimum energy of 533.709 ± 65.644 J at the fifth repeated pressing was obtained from the unheated sample compared to the heated samples. The peroxide values ranged from 6.898 ± 0.144 to 7.290 ± 0.507 meq O2/kg, acid values from 1.043 ± 0.166 to 1.998 ± 0.276 mg KOH/g oil and free fatty acid values from 0.521 ± 0.083 to 0.999 ± 0.138 mg KOH/g oil, which were within the recommended quality threshold. There were significant spectral differences among the oil samples. A single absorbance peak was observed at 350 nm for all oil samples, indicating low levels of pigment molecules in the oil. The study revealed the need for repeated pressings to recover the considerable residual oil remaining in the seedcake after the first pressing.

Understanding the early-stage release of volatile organic compounds from rapeseed oil during deep-frying of tubers by targeted and omics-inspired approaches using PTR-MS and gas chromatography

During deep-frying, a plethora of volatile products is emitted with the fumes. These compounds could act as oil quality indicators and change the indoor air composition leading to health risks for occupants. The presented experiments focus on deep-frying of different tubers in rapeseed oil at different frying temperatures. Here, two scenarios for real-time monitoring of volatile organic compounds (VOCs) using proton transfer reaction mass spectrometry (PTR-MS) were proposed. The first, targeted, involved the application of gas chromatography with a flame ionization detector (GC-FID). The second, omics-inspired, involved the use of solid-phase microextraction (SPME) along with gas chromatography-mass spectrometry (GC-MS) and molecular networking algorithm as a complementary tool to the PTR-MS analysis. In a targeted approach, it was shown that the emission profile of pentanal and hexanal depends on the frying temperature and as the temperature increases, a sudden release of these compounds can be observed in the first minutes of frying. Meanwhile, using an omics-inspired protocol enables finding the relation between 1,4-heptadienal and 2-heptanone, octanal and limonene emissions. Using both approaches it was possible to record real-time changes in emission profiles of various oils’ degradation products. It was also observed that the emission profiles of VOCs are strictly related to the frying temperature and the type of fried tuber.

The potential of wild olive leaves (Olea europaea L. subsp. oleaster) addition as a functional additive in olive oil production: the effects on bioactive and nutraceutical compounds using LC-ESI-QTOF/MS.

This study aims to investigate the influence of traditional maceration upon the enrichment of olive oil with oleaster leaves. The phenolic and tocopherolic compositions of control olive oil and enriched olive oils were determined. The influence of these oil preparation procedures on oil quality indicators was also investigated through spectrophotometric indices and fatty acid profiles. The total contents of bioactive compounds and pigments improved in oils obtained by maceration of fresh wild olive leaves, and were in statistically significant correlation with leaves proportions additions. The obtained results revealed that 15 phenolic compounds belonging to different phenolic types were characterized and quantified by an effective HPLC–DAD–ESI–MS/MS method. In all expected olive oils, the oleuropein aglycon (3,4-DHPEA-EA), and ligstroside aglycon (p-HPEAEA) derivatives were the most abundant compounds. Similarly, to phenolic compounds, tocopherols strongly increased with leaves addition during maceration process.The data obtained from this study suggested that the addition of olive leaf to oils allowed more functional olive oils with higher antioxidant contents. Thus, Extra Virgin Olive Oil (EVOO) extracted with 10% of olive leaves presented the highest amount of phenolic and tocopherol compounds.

Rapid fatty acids detection of vegetable oils by Raman spectroscopy based on competitive adaptive reweighted sampling coupled with support vector regression

Abstract Objectives The composition and content of fatty acids are critical indicators of vegetable oil quality. To overcome the drawbacks of traditional detection methods, Raman spectroscopy was investigated for the fast determination of the fatty acids composition of oil. Materials and Methods Rapeseed and soybean oil at different depths of the oil tank at different storage times were collected and an eighth-degree polynomial function was used to fit the Raman spectrum. Then, the multivariate scattering correction, standard normal variable transformation (SNV), and Savitzky–Golay convolution smoothing methods were compared. Results Polynomial fitting combined with SNV was found to be the optimal pretreatment method. Characteristic wavelengths were selected by competitive adaptive reweighted sampling. For monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and saturated fatty acids (SFAs), 44, 75, and 92 characteristic wavelengths of rapeseed oil, and 60, 114, and 60 characteristic wavelengths of soybean oil were extracted. Support vector regression was used to establish the prediction model. The R2 values of the prediction results of MUFAs, PUFAs, and SFAs for rapeseed oil were 0.9670, 0.9568, and 0.9553, and the root mean square error (RMSE) values were 0.0273, 0.0326, and 0.0340, respectively. The R2 values of the prediction results of fatty acids for soybean oil were respectively 0.9414, 0.9562, and 0.9422, and RMSE values were 0.0460, 0.0378, and 0.0548, respectively. A good correlation coefficient and small RMSE value were obtained, indicating the results to be highly accurate and reliable. Conclusions Raman spectroscopy, based on competitive adaptive reweighted sampling coupled with support vector regression, can rapidly and accurately analyze the fatty acid composition of vegetable oil.

EFFECT OF TREPTOLEM ON MORPHOGENESIS, YIELD AND QUALITATIVE CHARACTERISTICS OF WHITE MUSTARD PLANTS

The influence of treptolem on morphogenesis, crop yield and qualitative characteristics of oil from white mustard cv. Oslav is studied. It is found that the treatment of white mustard plants with treptolem led to an increase in linear size, stem thickening, increasing the number and area of leaves.The formation of a powerful photosynthetic apparatus has caused enlarged yields of white mustard plants.It is established that the application of exogenous growth stimulant influenced the fruit formation, led to positive changes in the crop structure, increasing the number of pods on the plant. At the same time the mass of one thousand seeds and the number of seeds in the pod increased. It resulted in the increase in the productivity of white mustard culture. The use of treptolem led to an increase in the oil content in mustard seeds and improved its quality.Under the action of the preparation, the iodine number, saponification number, as well as the acid number decreased, which is an indicator of higher oil quality.

Blends of fresh olive oil and old olive oil: Characterization and quantification through chemical and sensory assessment

AbstractThe present research work undertakes the investigation of the effect of storage on the quality of olive oil from Chemlali cultivar harvested from the Sfax region. The comparison of fresh and old olive oils was conducted through several physico‐chemical methods (free fatty acids, peroxide value, UV‐spectrophotometry [K232, K270, and ΔK], moisture content, total ethyl esters content, pyropheophytin, 1,2‐diacylglycerol content, and sensory analysis). A trivial rise in quality parameter along with a minor impact on the sensory scores was observed. Not only did the pyropheophytin and 1,2‐diacyglycerol criteria prove excellent performance as indicators of overall olive oil quality and freshness, but also underlined any problems during oil storage. Besides, pyropheophytin increment (17%) and the 1,2‐diacylglycerols decreased (35%) at normal storage conditions over time. On the other hand, when blending fresh extra‐virgin olive oil with old extra‐virgin olive oil, no detectable modifications of the chemical composition were observed. This is revealed by the trivial alteration of the parameters which are usually deemed as quality indicators, namely peroxide value, K232, and sensory evaluation. In fact, the most reliable technique appears to be the identification of ethyl esters, pyropheophytin and 1,2‐diacyglycerol.

Influence of temperature and beta-carotene on the processes of hydrolysis and oxidation of triacylglycerins in extra virgin olive oil during storage

The article presents the results of studies on the effect of antioxidant beta-carotene and storage temperature on hydrolytic and oxidative processes occurring during storage of extra virgin olive oil obtained from olives grown in the soil and climatic conditions of Syria. The aim is to study the effect of temperature and beta-carotene on the kinetics of reactions of hydrolysis of triacylglycerides (TAG) and oxidation of free fatty acids (FFA) of olive oil during storage. The object of the study was extra virgin olive oil obtained from olives grown in the soil and climatic conditions of Syria according to the generally accepted technology (harvest 2019). Control sample № 1 (without the addition of antioxidant) and experimental samples with the addition of beta-carotene in the amount of 400 (№ 2) and 600 mg/100 g (№ 3) were stored at a temperature of 18 °C for 7 months. Oil sample № 4 without the addition of antioxidants was stored at 4 °C. In the samples under study, the acid value was periodically determined by the titration method, according to the change in which the formation of free fatty acids during the hydrolysis of TAG, as well as the peroxide value characterizing the formation of FFA oxidation products, was estimated. The organoleptic assessment of the oil quality indicators according to the studied descriptors was 5 points. The rate constants of TAG hydrolysis and oxidation of FFA in olive oil have been calculated. It has been shown that during the storage of experimental oil samples the hydrolytic and oxidative processes of TAG significantly slow down with the addition of the antioxidant beta-carotene. It was found that minimal changes in the content of TAG hydrolysis products and FFA oxidation during storage of olive oil at a temperature of + 18 °C are characteristic for samples containing 400 mg/L of beta-carotene and for oil samples stored at a temperature of + 4 °C without the addition of an antioxidant. Expiration dates of olive oil are substantiated depending on the dose of beta-carotene and storage temperature

The i̇nfluence of water on the change i̇n engi̇ne oi̇l quali̇ty i̇ndi̇cators

Introduction. One of the main types of deposits in an internal combustion engine is an emulsion or sludge formed by water, decomposition of fuel residues and solid residues. The sludge usually settles on the colder surfaces of the engine, such as the bottom of the crankcase pan, valve chambers and upper boards. The main problem is that this type of deposits can be collected by the engine oil and transferred to areas such as the oil pump, intake valve or oil channels, where the sludge can interfere with the flow of oil and cause a failure of the lubrication mode. In addition to the disruption in the operation of the above-mentioned systems, the engine oil quality indicators are also undergoing changes for the worse.Materials and methods. To monitor the condition of the engine oil, it is necessary to determine the characteristics of its performance, such as: kinematic viscosity at 40 oC and at 100 oC, acid number, base number and determine the number of elements – indicators of additives and wear products contained in the engine oil. The viscosity was determined using a Stabinger SVM 3000 viscometer. It measures the dynamic viscosity and density of oils and fuels in accordance with ASTM D7042 and automatically calculates the kinematic viscosity, viscosity index and outputs the measurement results. The acid and base numbers were determined using an automatic titrator TitroLine alpha plus, and the presence of indicator elements in engine oil using an inductively coupled plasma optical emission spectrometer of the iCAP 7000 series, designed for analysis and determination of the number of indicator elements in liquid and solid samples.Results. The dynamics of changes in the performance characteristics of the Gazpromneft Diesel Ultra 10W-40 engine oil with an extended replacement interval, which is applicable for equipment operating in severe conditions, depending on the water content in the samples of this lubricant, was analyzed.Conclusion. The consequences that may occur due to water entering the engine oil are indicated.

Influence of the extraction conditions on chia oil quality and partially defatted flour antioxidant properties.

Partially defatted chia flour (PDCF) is a by-product of oil extraction from chia seeds (Salvia hispanica L.). It may be used as an ingredient to improve food products, especially due to its antioxidant properties. In this work, we studied the best screw press extraction conditions that allow preserving the antioxidant properties of PDCF. A central composite design was applied to perform a response surface analysis in order to optimize the oil extraction. The variables considered for optimization were seed moisture content and pressing temperature. Besides the oil quality indicators, the study was focused on the assessment of PDCF properties, including total polyphenol content and antioxidant capacity determined by chemical methods. Our results show that, within the range of screw press conditions evaluated, the chemical quality of the oil and the antioxidant properties of PDCF are both preserved. The best results (highest oil yield and stability) were obtained under a seed moisture content of 10.2% and a pressing temperature of 58.5°C. In general, our results indicate that screw press methodology can be applied to process chia seeds, using a wide range of conditions, to concurrently produce good quality oil and a PDCF with beneficial properties.