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BACKGROUND: Factors such as variety, genetics, soil structure and plant diseases affect the oil amount and properties of flaxseed. By applying heat and various extraction treatments to flaxseed, the storage ability of the seed is increased by the removal of moisture, and the stability of phytochemicals in the seed against heat can be determined. RESULTS: Total carotenoid and phenol of flaxseeds changed from 0.13 (control) and 0.61 mg g−1 (120 °C) to 202.64 (control and 90 °C) and 225.69 mg 100 g−1 (120 °C), respectively. While total flavonoid of flaxseed roasted at different temperatures varied between 636.0 (90 °C) and 786.00 mg 100 g−1 (120 °C), antioxidant activity values for raw and roasted flaxseeds between 59.32% (control) and 68.64% (120 °C) were recorded. Oil content of seeds changed between 34.07 and 42.57% (P < 0.05). Viscosity of flaxseed oil extracted using different systems was between 31.95 (cold‐pressed; control) and 36.00 mPa s (ultrasonic; 120 °C). The dominant phenolics of flaxseeds were identified as isorhamnetin, resveratrol, quercetin, catechin, apigenin‐7‐glucoside and campherol. The oils of flaxseeds contained 55.27–58.23 linolenic, 17.40–18.91 oleic, 14.03–14.84 linoleic and 4.97–5.37 palmitic acids, depending on extraction method and roasting temperature. CONCLUSION: Roasting and oil extraction methods did not have a significant effect on free acidity, but was found to affect peroxide value. The predominant phenolic constituents of flaxseed samples were isorhamnetin, resveratrol, quercetin, catechin, apigenin‐7‐glucoside and campherol, respectively. The major fatty acids of flaxseed oil were determined as linolenic, oleic, linoleic and palmitic. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sunflower seeds are in the top five most abundant oilseeds in the world, as well as sunflower oil in the edible oils group. Recently, increasing attention has been paid to cold‐pressed sunflower oil because less processing is involved and no solvent is used. The present study was carried out to investigate dimensions (length, width, thickness), firmness, general (moisture content and hull content, mass of 1000 seeds), gravimetric (true and bulk density, porosity) and geometric characteristics (equivalent diameter, surface area, seed volume, sphericity) of 20 new sunflower hybrid seeds. Steps to determine most of these parameters are quite simple and easy since the process does not require long time or special equipment. RESULTS: Principal component analysis and cluster analysis confirmed differences in the mentioned characteristics between oily and confectionary sunflower hybrid seeds. One of the major differences between two groups of samples was in extraction oil yield. Mechanical extraction oil yield of the oily hybrid seeds was significantly (P ˂ 0.05) higher (from 68.72 ± 4.21% to 75.61 ± 1.99%) compared to confectionary hybrids (from 20.10 ± 2.82% to 39.91 ± 6.23%). Extraction oil yield values are known only after oil extraction. CONCLUSION: Knowledge of the extraction oil yield value before the mechanical extraction enables better management of the process. By application of the artificial neural network approach, an optimal neural network model was developed. The developed model showed a good generalization capability to predict the mechanical extraction oil yield of new sunflower hybrids based on the experimental data, which was a main goal of this paper. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, cold‐pressed oils have become more and more popular with consumers. However, their oxidative stability is low. Improving the oxidative stability of cold‐pressed oils will increase their shelf life. Maillard reaction products (MRPs) have been shown to promote the oxidative stability of lipids. In this study, products from the Maillard reaction of reducing sugars and sesame enzymatically hydrolyzed protein (SEHP) were added to cold‐pressed sesame oils to improve their oxidative stability. RESULTS: Three types of MRPs from reducing sugars (xylose, fructose, and glucose) and SEHP were prepared. Xylose–SEHP MRPs prepared under optimum conditions had the highest antioxidant activities among the three. The optimum conditions for xylose–SEHP were as follows: reaction temperature, 130 °C; reaction time, 180 min; pH, 6.5; and sugar/protein ratio, 10:1. The addition of xylose–SEHP MRPs at a level of 20 g kg−1 could significantly improve the oxidative stability of cold‐pressed sesame oil. Besides, the addition of MRPs reduced the loss of tocopherol. The interaction of MRPs with endogenous antioxidants in the sesame oil (sesamol and tocopherol) was proved by comparison with lard. There was a synergistic increase in antioxidant activity for the combination of MRPs and sesamol and the combination of MRPs and tocopherol. CONCLUSIONS: The results provide evidence that adding certain MRPs can improve the oxidative stability of cold‐pressed sesame oil. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]