油茶籽油加工过程中理化性质和营养品质的变化

本研究通过测定精炼过程不同阶段油茶籽油的理化指标和营养成分的变化，研究精炼工艺对油茶籽油品质的影响。结果表明，毛茶油的酸值最高，为0.746 mg/g，碱炼油的酸值最低，仅为0.037 mg/g，碱炼过程酸值降低最多达95.04%。水洗脱水油的过氧化值最高，达5.81 meq/kg，脱臭油的过氧化值最低，仅2.22 meq/kg，整个过程过氧化值降低率为61.79%。从毛茶油到精炼油的加工过程中，茶多酚、α-生育酚和角鲨烯含量变化均呈递减趋势。毛茶油茶多酚、α-生育酚和角鲨烯的含量分别为54.698 5 μg/g、251.337 0、136.680 0 mg/kg，而脱臭油含量分别为25.134 1 μg/g、101.301 0、89.140 0 mg/kg。在精炼过程中脂肪酸种类和比例都有一定的变化，单不饱和脂肪酸比例降低0.188%，而饱和脂肪酸和反式脂肪酸比例分别增加0.029%和0.089%。精炼可降低酸值和过氧化值使油茶籽油达到食用油国家标准，但同时也造成茶多酚、α-生育酚和角鲨烯等活性成分的损失。因此应该提倡适度精炼以达到安全与营养的平衡。

Physical-Chemical Properties and Nutrients of Oil-Tea Camellia Seed Oil in Different Refining Stages

The main physical-chemical properties of oil-tea camellia seed oil during the refining process were measured
and the changes of nutritional components were analyzed in order to explore the effect of the refining process on the quality
of oil-tea camellia seed oil. The results showed that the crude oil had the highest acid value, which was 0.746 mg/g. The
alkalized oil had the lowest acid value of only 0.037 mg/g. The acid value during alkali refining revealed a significant
decrease by 95.04%. The dehydrated oil had the highest peroxide value of 5.81 meq/kg. On the contrary, the deodorized oil
had the lowest peroxide value of only 2.22 meq/kg. The peroxide value throughout the whole refining process was decrease
by 61.79%. From crude oil to deodorized oil, the contents of tea polyphenols, α-tocopherol and squalene gradually decreased
from 54.698 5 μg/g, 251.337 0 mg/kg and 136.680 0 mg/kg to 25.134 1 μg/g, 101.301 0 mg/kg and 89.140 0 mg/kg,
respectively. Some changes were also observed in fatty acid composition and contents. Monounsaturated fatty acids were
decreased by 0.188%, while saturated fatty acids and trans fatty acids were increased by 0.029% and 0.089%, respectively.
The refining process of oil-tea camellia seed oil can reduce acid value and peroxide value to the national standards for edible
oil. At the same time, there are losses in tea polyphenols, α-tocopherol and squalene during the refining process. So it is very
important to choose appropriate refining conditions to achieve a balance between safety and nutrition.