烘烤和微波预处理对植物油品质特性影响的研究

Effects of Oil-Bearing Materials Roasting and Microwave Pretreatment on Quality Characteristics of Oils Prepared by Screw Mechanical Pressing

选用亚麻籽、油菜籽、花生、葵花籽、芝麻5种油料,进行烘烤预处理和微波预处理,利用螺旋压榨制得5种植物油。研究2种预处理方法对5种植物油感官指标、理化指标、主体组分、挥发性组分和微量营养组分的影响。结果表明:烘烤预处理后5种植物油感官评价总分比微波预处理组高4.2~1.9分,说明烘烤预处理更有利于保持5种植物油的感官品质。预处理后5种植物油的酸价和过氧化值都有显著变化(P<0.05),其中,烘烤预处理后亚麻籽油、葵花籽油过氧化值分别增加了1.2倍和2.4倍,但均符合国家食品安全标准。2种热处理对脂肪酸和甘油三酯组成及含量无显著性影响(P<0.05),但微波预处理后,除了芝麻油,其他4种植物油UFA/SFA比例增加0.45~1.02 g/100 g。2种预处理对5种植物油挥发性物质含量也产生影响,尤其微波预处理后菜籽油和花生油中杂环类物质吡嗪类和呋喃类增加到10.25%和18.54%。2种预处理后都有利于提升5种植物油中总酚和VE含量,其中,微波预处理后芝麻油中总酚含量提升了1.7倍、葵花籽油中VE含量提升了1.5倍(1.08 g/kg)。烘烤预处理有利于提升这5种植物油感官品质,微波预预处理是制备浓香型植物油的理想工艺,同时,2种预处理都能提升植物油自身抗氧化性能。

Five types of oilseeds,flaxseed,rapeseed,peanut,sunflower and sesame,were selected for roasting pretreatment and microwave pre-treatment to produce five vegetable oils by screw press.The effects of the two pretreatment methods on the sensory,physicochemical,main components,volatile components and micronutrient fractions of the five vegetable oils were investigated.The results indicated that the total sensory evaluation scores of the five vegetable oils after baking pretreatment were 4.2~1.9 points higher than those of the microwave pretreatment group,indicating that the baking pretreatment was more beneficial to maintain the sensory quality of the five vegetable oils.The acid value and peroxide value of all five vegetable oils changed significantly after pretreatment(P<0.05),with the peroxide value of flaxseed oil and sunflower oil increasing by 1.2 and 2.4 times,respectively,after roasting pretreatment,but all met national food safety standards.The two heat treatments had no significant effect on fatty acid and triglyceride composition and content(P<0.05),but the microwave pretreatment increased the UFA/SFA ratio by 0.45 to 1.02 g/100 g for the four vegetable oils,except for sesame oil.The two pretreatments also affected the volatile content of the five vegetable oils,especially the heterocyclic substances pyrazines and furans increased to 10.25%and 18.54%in rapeseed and peanut oils after microwave pretreatment.Both pretreatments facilitated the improvement of total phenol and VE content in the five vegetable oils,with the microwave pretreatment increasing the total phenol content in sesame oil by 1.7 times and the VE content in sunflower oil by 1.5 times(1.08 g/kg).The analysis indicated that the baking pretreatment was beneficial to improve the sensory quality of these five vegetable oils,and the microwave pretreatment was an ideal process for the preparation of concentrated vegetable oils,meanwhile,both pretreatments could improve the antioxidant properties of vegetable oils themselves.