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Free tocopherols and tocotrienols in 82 plant species’ oil: Chemotaxonomic relation as demonstrated by PCA and HCA
Black Cumin Essential Oil as an Active Stabilization Component of Rapeseed Oil During Deep-Fat Model Heating
The aim of this study was to evaluate the potential of black cumin essential oils to reduce the degradation of rapeseed oil during heating. Rapeseed oil was heated without addition and with the addition of black cumin essential oil (200 ppm, 500 ppm, and 1000 ppm), and with synthetic antioxidant TBHQ (200 ppm). The heating was carried out at 170 °C ± 10 °C for 6 h, in a deep-fat heating model. In all samples, changes in fatty acid profile, lipid-nutritional quality indices (PUFA/SFA ratio, atherogenicity index, thrombogenicity index, and hypocholesterolemic/hypercholesterolemic ratio), tocopherol and phytosterol content, total polar compound content, and triacylglycerol polymers were determined. The heating process led to oil degradation, which depended on the amount and type of additive used. The greatest changes were observed in the control sample (without additives). The addition of TBHQ or 200 ppm of black cumin essential oil reduced the adverse transformations to a similar level. Higher additions of black cumin essential oil led to a significant improvement in the quality of heated oils. The best results were obtained with the addition of 1000 ppm of black cumin essential oil.
Assessment of Chemical Composition and Oxidative Stability in Cold-pressed Date Kernel Oil from Phoenix dactylifera L.: Implications for Food Quality and Sustainability
Water content, critical micelle concentration of phospholipids and formation of association colloids as factors influencing autoxidation of rapeseed oil
AbstractBACKGROUNDThe exact mechanism of lipid autoxidation in vegetable oils, taking into account physical aspects of this phenomenon, including the role of association colloids, is still not fully understood. The purpose of this study was to consider changes in moisture content and DOPC phospholipid (1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine) critical micelle concentration (CMC) in rapeseed oil during autoxidation as well as to find the relationship between these parameters and the accumulation of primary and secondary lipid oxidation products.RESULTSThe experiments were performed at initial oil humidity 220 ppm and 700 ppm, with DOPC below and above CMC. The increase in water concentration was favored by the presence of phospholipids above CMC and, at the same time, high initial water level, which favored oxidation processes and the creation of amphiphilic autoxidation products. At relatively high water level and low amphiphilic DOPC concentration, the growth of water content does not affect the concentration of oxidation products.CONCLUSIONAmphiphilic substances play a significant role in increasing the water content of oil. Autoxidation products may reduce CMC of DOPC, but water is able to compensate for the CMC‐reducing effect of oxidation products. The presence of association colloids and initial water content play a crucial role in the oxidation process of rapeseed oil. The increase in water concentration does not cause a sufficiently large increase in the number of micelles or sufficiently significant changes in their structure to effect an increase in the level of oxidation products. The formation of micelles requires an appropriate content of both water and amphiphilic substances derived from seeds (phospholipids). © 2021 Society of Chemical Industry.
The effect of the genotype-environment interaction on the concentration of carotenoids, tocochromanol, and phenolic compounds in seeds of Lupinus angustifolius breeding lines
Unravelling the importance of seed roasting for oil quality by the non-targeted volatilomics and targeted metabolomics of cold-pressed false flax (Camelina sativa L.) oil and press cakes
Effect of refining and fractionation processes on minor components, fatty acids, antioxidant and antimicrobial activities of shea butter
Shea butter is becoming increasingly popular in foods, cosmetics and pharmaceutical products. This work aims to study the effect of the refining process on the quality and stability of fractionated and mixed shea butters. Crude shea butter, refined shea stearin, olein and their mixture (1:1 w/w) were analyzed for fatty acids, triacylglycerol composition, peroxide value (PV), free fatty acids (FFA), phenolic (TPC), flavonoid (TFC), unsaponifiable matter (USM), tocopherol and phytosterol content. Additionally, the oxidative stability, radical scavenging activity (RSA), antibacterial and antifungal activities were evaluated. The two main fatty acids in the shea butter samples were stearic and oleic. The refined shea stearin showed lower PV, FFA, USM, TPC, TFC, RSA, tocopherol and sterol content than crude shea butter. A higher EC50 was observed, but antibacterial activity was much lower. The refined olein fraction was characterized by lower PV, FFA and TFC in comparison with crude shea butter, but USM, TPC, RSA, EC50, tocopherol and sterol content was unchanged. The antibacterial activity was higher, but the antifungal activity was lower than those of crude shea butter. When both fractions were mixed, their fatty acid and triacylglycerol composition were similar to those of crude shea butter, but other parameters were different.
Effect of Adverse Storage Conditions on Oil Quality and Tocochromanol Content in Yellow‐Seeded Breeding Lines of Brassica napus L.
ABSTRACTThis study evaluated the contents of tocopherols and plastochromanol‐8, as well as the acid values, in oils extracted from yellow‐seeded Brassica napus L. lines stored under adverse post‐harvest conditions. Seeds were stored at temperatures of 25°C and 30°C, with adjusted seed moisture contents of 10.5%, 12.5%, and 15.5%, corresponding to relative humidity levels of 81%, 85%, and 91%, respectively. A statistically significant reduction in total tocopherol content—up to 22% (p < 0.05)—was observed in seeds with the highest moisture content (15.5%) stored at 30°C. In contrast, seeds with 12.5% moisture stored at 25°C exhibited a smaller but still significant decrease of 11%–14% (p < 0.05). The lowest tocopherol degradation (2%–5%) occurred in seeds with 10.5% moisture stored at 25°C. Additionally, degradation rates differed between tocopherol homologues: α‐tocopherol decreased more rapidly than γ‐tocopherol, as evidenced by a significant decline in the α‐T/γ‐T ratio under high‐moisture and high‐temperature conditions. The most pronounced reduction in this ratio was recorded in seeds stored with 15.5% moisture at 30°C. Plastochromanol‐8 was also highly sensitive to storage parameters, exhibiting an even more pronounced reduction than tocopherols under high‐moisture conditions (p < 0.05). A significant increase in acid value was also observed under high temperature and moisture conditions, exceeding the acceptable threshold of 3.0 mg KOH/g in some cases, indicating advanced lipid hydrolysis during storage.
Corrigendum to ‘Phytochemical content of roasted seeds of three white mustard (Sinapis alba L.) varieties differing in their glucosinolate and erucic acid content’ [Ind. Crops Prod. 220 (2024) 119207]
The effect of ultrasound-assisted maceration of selected cold-pressed oils with lyophilized mullein flowers (Verbascum thapsus L.) on their oxidative stability and chemical composition
Physicochemical characteristics of cold-pressed blackcurrant-, strawberry-, and raspberry seed oils during storage and its influence on thermo-oxidative stability
Assessment of the Quality, Bioactive Compounds, and Antimicrobial Activity of Egyptian, Ethiopian, and Syrian Black Cumin Oils
Background: The oils obtained from the seeds of Nigella sativa, also named black cumin, are rich in bioactive compounds that strengthen immunity and support human health. This study aimed to compare Nigella sativa oils pressed from Egyptian (Eg-NSSO), Ethiopian (Et-NSSO), and Syrian (Sy-NSSO) seeds. Methods: The analyzed oils were obtained from a local company. The content of phenolic compounds, tocochromanols, phytosterols, volatile compounds, triglycerides, and fatty acids composition was determined using chromatographic methods. The oxidative stability was determined by Rancimat technique as well as the determination of DPPH and ABTS scavenging activity. As an assessment of bioactivity, the antimicrobial and anti-aflatoxigenic properties of oils were evaluated. Results: Ethiopian oil had highest content of phenolic compounds, flavonoids, phytosterols, and tocochromanols and was characterized by the longest induction period (IP = 7.89 h). The share of thymoquinone was the highest in Ethiopian oil (34.84%), followed by Egyptian (27.36%), then Syrian (22.59%). Ethiopian oil recorded a high antibacterial activity, while Egyptian oil showed a unique antifungal activity against toxigenic fungi. Aflatoxins’ secretion into liquid medium containing NSSO was reduced, especially with Egyptian oil.
Oxidative stability assessment of industrial and laboratory-pressed fresh raspberry seed oil (Rubus idaeus L.) by differential scanning calorimetry
Metabolic Changes during Sprouting of Rapeseed and Their Consequences for the Volatilome of Cold‐Pressed Oil
AbstractAll the procedures before pressing seeds have a great influence on the flavor of cold‐pressed rapeseed oil. However, the studies on the modification of aroma caused by inappropriate storage leading to sprouting are scarce. Therefore, this study aims to determine the effects of sprouting on the metabolome and volatilome of rapeseed cold‐pressed oil and press cakes. The presence of 56 and 21 nonvolatile metabolites is detected in seeds/press cakes and oil, respectively. Sprouting significantly affects the total contents of all groups of compounds, except sugars. At the same time, 375 volatile organic compounds (VOCs) are detected. The abundance of VOCs in sprouted oil is almost threefold higher compared to control oil, with the biggest contribution of sulfur‐containing compounds (dimethyl sulfide), glucosinolate derivatives (4‐isothiocyanato‐1‐butene), and aldehydes (3‐methylbutanal). A similar tendency is observed in press cake. Moreover, sprouting results in the biggest number of VOCs detected only in this oil (61). The abundance of aroma‐active compounds is much higher in sprouted products compared to corresponding controls, which has a confirmation in sensory analysis. This study shows that simultaneous volatilomics and metabolomics can be used to track the changes in the oil quality caused by the inappropriate storage of seeds. Sprouting leads to metabolic changes in seeds, which intensify the formation of new VOCs and consequently aroma of oils.Practical applications: The results of this study will help to understand the formation of volatile organic compounds (VOCs) during the processing and production of cold‐pressed rapeseed oil. The combination of VOCs with nonvolatile precursors can help to understand the pathways involved in VOCs formation. Moreover, the oil obtained from sprouted seeds is characterized by many VOCs not present in control oil, which can potentially be used to develop tools for quick evaluation if the seeds used for pressing initiated sprouting, which can lead to changes in its sensory quality.
Comprehensive characteristic of lipid fraction as a distinguishing factor of three lupin seed species
Effect of the roasting level on the content of bioactive and aromatic compounds in Arabica coffee beans
Combining Targeted Metabolomics with Untargeted Volatilomics for Unraveling the Impact of Sprouting on the Volatiles and Aroma of False Flax (Camelina sativa) Cold-Pressed Oil
Assessment of Hemp Seed Oil Quality Pressed from Fresh and Stored Seeds of Henola Cultivar Using Differential Scanning Calorimetry
Cold-pressed hemp (Cannabis Sativa L.) seed oil has become very popular amongst consumers and researchers, due to its manifold application in food and medicine industry. In this study, oils pressed from stored and fresh hemp seeds of the Henola cultivar were analyzed. Determination of the acid value (AV) and color of oil (a* parameter) revealed significant differences between the two groups of oils (fresh and stored seeds) in contrast to the peroxide value (PV), p-anisidine value (p-AV), and fatty acid composition. On the other hand, isothermal and non-isothermal assessments of the thermo-oxidative stability by differential scanning calorimetry (DSC) showed no significant differences in oxidation induction time (OIT) as well as in onset temperature (Ton) between two groups of oils (p > 0.05). The DSC isothermal test (OIT 160) showed significant correlations with mono- and polyunsaturated fatty acids as well as with values of AV and a* (p ≤ 0.05), in contrast to the non-isothermal test, for which correlations were not significant (p > 0.05). However, the best distinction of both groups of oils was obtained analyzing all results together (DSC, fatty acid and tocochromanols composition, color, and oxidative stability results) by principal component analysis (PCA).
Comprehensive two-dimensional gas chromatography-time of flight mass spectrometry as a tool for tracking roasting-induced changes in the volatilome of cold-pressed rapeseed oil
AbstractThe aim of this study was to track changes in the volatilome of cold-pressed oil and press cakes obtained from roasted seeds and to combine it with the profile of non-volatile metabolites in a single study, in order to understand pathways of volatile organic compound (VOC) formation caused by thermal processing. Comprehensive two-dimensional gas chromatography-time of flight mass spectrometry was used for the analysis of VOCs in cold-pressed oils and corresponding press cakes obtained after roasting of seeds at 140 and 180 °C prior to pressing. Contents of primary metabolites (amino acids, saccharides, fatty acids) as well as selected secondary metabolites (glucosinolates, polyphenols) were determined, as many of them serve as precursors to volatile compounds formed especially in thermal reactions. After roasting, the formation of Maillard reaction products increased, which corresponded to the reduction of free amino acids and monosaccharides. Moreover, levels of the products of thermal oxidation of fatty acids, such as aldehydes and ketones, increased with the increasing temperature of roasting, although no significant changes were noted for fatty acids. Among sulphur-containing compounds, contents of the products and intermediates of methionine Strecker degradation increased significantly with the increasing temperature of roasting. Degradation of glucosinolates to nitriles occurred after thermal treatment. The results of this study confirmed that seed roasting before cold pressing has a significant effect on the volatiles, but also indicated roasting-induced changes in non-volatile metabolites of oil and press cake. Such an approach helps to understand metabolic changes occurring during rapeseed processing in cold-pressed oil production. Graphical Abstract
