含壳率对油茶籽油品质特性的影响

为了探究螺旋压榨过程中含壳率对油茶籽油品质特性的影响规律，论文考察了含壳率对螺旋压榨油茶籽油的出油率、理化指标、生物活性物质、脂肪酸组成、氧化诱导时间以及挥发性风味成分等品质特性的影响。结果表明，螺旋压榨出油率随着含壳率的增加而提高，到20％时趋于稳定，最高出油率为26.29％。且当含壳率为20%时，油茶籽油的酸价、过氧化值、水分及挥发物含量均最低，分别为0.82 mg/g、0.37 mmol/kg和0.07％，氧化诱导时间最长，为22.62 h，同时其色度值和磷脂含量均处较低水平。当含壳率为30％~40％时，油茶籽油中多酚含量最高，为67.48 mg/kg，且油茶籽油的色泽相对较深。含壳率对油茶籽油的甾醇、角鲨烯、维生素E含量以及脂肪酸组成无显著影响。通过电子鼻和GC-IMS对不同含壳率油茶籽油中挥发性风味成分进行分析，结果表明，油茶籽油中主要挥发性化合物为醛类、醇类、酯类、酮类和杂环类物质等，且含壳率较高的油茶籽油和含壳率较低的油茶籽油中的挥发性成分有显著差异，当含壳率低于20％时，油茶籽油中挥发性成分含量较多，其香味较为浓郁，随着含壳率的增加，油茶籽油中挥发性物质含量也随之减少。综合油茶籽油的理化指标、生物活性物质含量、氧化稳定性及挥发性成分含量，螺旋压榨油茶籽油时的物料理想含壳率为20％。

Effects of shell content on the quality characteristics of Camellia seed oil

In order to explore the effect of shell content on the quality characteristics of camellia seed oil during the screw pressing process, this paper investigated the effect of shell content on the oil yield, physicochemical index, bioactive substances, fatty acid composition, oxidation induction time, and volatile flavour components of screw pressed Camellia seed oil. The results indicated that as the shell content increased, the oil yield of the screw press increased and stabilized at 20% shell content, with the highest oil yield reaching 26.29%. In addition, when the shell content was 20%, Camellia seed oil showed the lowest acid value, peroxide value, and moisture and volatile matter content, which were 0.82 mg/g, 0.37 mmol/kg, and 0.07%, respectively; Camellia seed oil showed the longest oxidation induction time of 22.62 h. Meanwhile, its colour value and phospholipid content were at a low level. The highest polyphenol content of 67.48 mg/kg was found when the shell content was 30%-40%, and the colour of the oil was relatively dark. There was no significant effect of shell content on the sterols content, squalene content, vitamin E content, and fatty acid composition of Camellia seed oil. Electronic nose and GC-IMS were used to analyze the volatile flavour components in the oil. The results showed that the main volatile compounds in the oil were aldehydes, alcohols, esters, ketones, and heterocyclic substances, and there were significant differences between the volatile components in the oil with higher shell content rates and those with lower shell content rates. When the shell content was less than 20%, the oil contained more volatile components and had a stronger aroma, and as the shell content increased, the volatile content in the oil decreased. Considering the combined effect of shell content on the physicochemical index, bioactive substance content, and volatile component content of Camellia seed oil, the ideal shell content rate for screw pressing of Camellia seed oil was 20%.