Anning Liu,Huijuan Jing,Xiaojing Du,Chaoyang Ma,Hongxin Wang
In this study, the recovery of pecan nut kernel oil (PNKO) obtained by mechanical pressing (MP) was compared with that obtained by ultrasonic-assisted aqueous enzymatic extraction (UAAEE). At the same time, contents of substances with proven bioactivity, fatty acid compositions, physicochemical properties and antioxidant activities of PNKO were also assessed. Obviously, the oil yield obtained by UAAEE (71.32%) was higher than that obtained by MP (56.81%). Therefore, Plackett-Burman design (PBD), as well as Box-Behnken design (BBD), further optimized the UAAEE process, and the highest oil yield of 78.83% was acquired under the following conditions: incubation time of 2 h, the mixed enzyme (cell ulase+hemicellulase+pectinase+neutrase, w/w/w/w=1/1/1/1) concentration of 2.9%, liquid-solid ratio of 4 mL/g, pH of 4, particle size of 300 μm, ultrasonic time of 20 min, ultrasonic power of 432 W and reaction temperature of 53°C. The PNKO obtained by the two methods possessed similar fatty acid composition, but that obtained by UAAEE had comparatively low acid value and peroxide value. Moreover, rich content of total phenolics, squalene and phytosterols, as well as strong scavenging activities against DPPH and ABTS+ free radicals, were also contained in the PNKO obtained by UAAEE. These results demonstrated that UAAEE was an efficient method to acquire pecan nut kernel oil with excellent quality and high recovery.
Lu Yuanchao,Hou Rongrong,Li Mengren,Yu Ningxiang,Huan Weiwei,Nie Xiaohua,Meng Xianghe
Camellia oleifera Abel is a traditional and high-quality oil source in China, characterized as polyphenols. This study evaluated how extraction methods impacted the phenolic profiles and antioxidant activities of Camellia oils. The contribution rates of phenolic profiles to antioxidant activities were investigated. HPLC and UPLC-Triple-TOF/MS demonstrated that phenolic content significantly varied with extraction methods while phenolic profiles were not. Herein, 15, 15, 17, 14, and 14 compounds were identified in mechanical pressing (MP), solvent extraction-hexane (SE-H), solvent extraction-ethanol (SE-E), aqueous enzymatic extraction (AEE), aqueous extraction (AE) oils, respectively. Results presented that SE-E oils were rich in phenolic acids (caffeic acid and p-hydroxybenzaldehyde), while AE oils were abundant in flavonoids (rutin and quercetin). Besides, the antioxidant activities of AEE and AE oils were significantly higher than other oils, originating from flavonoids (rutin and quercetin) and non-phenolics (rhododendron acid). Furthermore, Camellia oils from five extraction methods were remarkably classified by principal component analysis based on phenolic categories and antioxidant activities. It was assumed that low-polar and high-polar phenolic profiles were simultaneously transferred into SE-E oils, while only low-polar phenolic profiles (mainly flavonoids) were extracted into AE or AEE oils. The antioxidative origin of Camellia oils was ascribed to rutin, quercetin, and rhododendron acid. Our results provided an in-depth understanding of Camellia oils on phenolic profiles and the relationship between extraction methods and antioxidant activities.
危险品化学品经营许可证（带存储）