冻融破乳方法对水代法提取油茶籽油的影响Effects of freeze-thaw demulsification methods on aqueous extraction of oil-tea camellia seed oil

Abstract

为提高水代法提取油茶籽油的提油率，将油茶籽经过脱壳、粉碎、过筛、加水过胶体磨、离心分离得到乳状液，经冻融破乳后离心分离得油茶籽油。以提油率为指标，探究了加热冻融、乙醇冻融、调pH冻融、加盐冻融等冻融破乳方法对水代法提取油茶籽油的影响，并通过共聚焦激光扫描显微镜对破乳前后乳状液的微观结构进行了观察。结果表明：乙醇冻融和加盐冻融使油茶籽的提油率降低；调pH可提高提油率，在pH为8时提油率为92.17%；加热冻融法是最佳的冻融破乳方法，在加热温度60 ℃、加热时间20 min条件下，提油率最高，达到92.57%；加热冻融处理后油滴聚集，粒径明显增大。采用加热冻融法对乳状液进行破乳可有效提高水代法提取油茶籽油的提油率。 In order to improve the oil extraction rate of oil-tea camellia seed oil by aqueous extraction method, the oil-tea camellia seed was treated by peeling, crushing, sieving, mixing with water through colloid mill and centrifugation to get the emulsion, and the oil-tea camellia seed oil was obtained by centrifugation after freeze-thaw demulsification. With the oil extraction rate as the index, the effects of freeze-thaw demulsification methods, such as heating freeze-thaw, ethanol freeze-thaw, pH adjustment freeze-thaw, salt freeze-thaw, on the extraction of oil-tea camellia seed oil by aqueous extraction method were studied. The microstructure of the emulsion before and after demulsification was observed by confocal laser scanning microscope. The results showed that ethanol freeze-thaw and salt freeze-thaw reduced the oil extraction rate. The oil extraction rate increased by adjusting pH, and it was 92.17% at pH 8. Heating freeze-thaw was the best method of freeze-thaw demulsification. Under heating temperature 60 ℃ and heating time 20 min, the oil extraction rate was the highest, reaching 92.57%. After heating freeze-thaw, the oil droplets gathered and its particle size increased significantly. Demulsification of emulsion by heating freeze-thaw method can effectively increase the oil extraction rate of oil-tea camellia seed oil by aqueous extraction method.

Keywords

• 油茶籽油；冻融破乳；加热；ph
• oil-tea camellia seed oil; freeze-thaw demulsification; heating; ph