Search

This study investigated the effect of different almond oil extraction techniques, namely, cold‐press extraction (CP), hydraulic press extraction (HP), and subcritical fluid extraction (SFE), on the fatty acid composition, physicochemical properties, bioactive substances, and thermal stability. The results showed that oleic acid and linoleic acid were the main unsaturated fatty acids in almond oil (AO). The overall physicochemical properties of the AO (SFE) had the better oil quality compared to cold‐press extraction and hydraulic press extraction in three kinds of varieties. Almond oil extracted from SFE contained the highest levels of total phenolics (9.58–11.75 mg/100 g), total phytosterols (92.86–244.21 mg/100 g), total tocopherols, and tocotrienols (48.03–55.74 mg/100 g). Meanwhile, the TG/DTG curves showed AO (SFE) were more thermally stable than AO (CP) and AO (HP) consistent with the result of oxidative induction time. Subcritical fluid extraction may be a useful extraction technology to produce high‐quality almond oils in the future.

The thermal stability of rapeseed oil fortified with 3 % sterol linolenate, sterol linoleate, and sterol oleate was investigated using the Rancimat accelerated oxidation method. The results indicated that the sterol ester content in fortified oil displayed positive correlations (P

Microwave treatment is a new method for rapeseed processing. To better understand the benefits of microwave pretreatment on rapeseed processing, qualitative and quantitative analysis of sinapic acid derivatives is needed. In this study, the effect of microwave treatment on the content of sinapic acid derivatives in rapeseed and the effect of cold-press and solvent extraction on the content of sinapic acid derivatives in rapeseed meal were evaluated using ultrahigh pressure liquid chromatography. It was found that during the microwave treatment, the content of sinapine and sinapic acid in the rapeseed increased slightly at the outset of treatment and significantly decreased thereafter. Following 7 min of microwave treatment, the content of sinapine in rapeseed exhibited its largest decrease of 16.7 %. By contrast, microwave heating of the rapeseed increased the canolol content significantly. We employed two sample paired t tests as a means to analyze the difference between meal and defatted cold-pressed cake. The results indicated that the content of sinapine and sinapic acid in defatted cake was significantly higher than that in meal, while the different extraction methods (solvent extraction and cold-press) did not appear to have a significant influence on the content of canolol in meal (p ≤ 0.05).

We analyzed and compared the difference in sinapine concentration in rapeseed meal between the filamentous fungus, Trametes sp 48424, and the yeast, Saccharomyces cerevisiae, in both liquid and solid-state fermentation. During liquid and solid-state fermentation by Trametes sp 48424, the sinapine concentration decreased significantly. In contrast, the liquid and solid-state fermentation process by Saccharomyces cerevisiae just slightly decreased the sinapine concentration (P ≤ 0.05). After the solid-state fermented samples were dried, the concentration of sinapine in rapeseed meal decreased significantly in Saccharomyces cerevisiae. Based on the measurement of laccase activity, we observed that laccase induced the decrease in the concentration of sinapine during fermentation with Trametes sp 48424. In order to eliminate the influence of microorganisms and the metabolites produced during fermentation, high moisture rapeseed meal and the original rapeseed meal were dried at 90 °C and 105 °C, respectively. During drying, the concentration of sinapine in high moisture rapeseed meal decreased rapidly and we obtained a high correlation coefficient between the concentration of sinapine and loss of moisture. Our results suggest that drying and enzymes, especially laccase that is produced during the solid-state fermentation process, may be the main factors that affect the concentration of sinapine in rapeseed meal.