马泡瓜籽油理化特性、组成分析及氧化稳定性

Physicochemical Characteristics,Composition and Oxidative Stability of Cucumis bisexualis Seed Oil

在民间有利用马泡瓜籽制油的传统,为促进马泡瓜这一野生植物资源的开发利用,本实验对马泡瓜籽油的理化特性和营养组分进行了分析,并通过热分析技术对其氧化稳定性及热特性进行测定。结果表明,马泡瓜籽千粒质量6 g,出油率25%,马泡瓜籽油的酸值(0.37 mg/g)、过氧化值(0.17 g/100 g)均符合国家标准,不饱和脂肪酸相对含量达86.27%,其中亚油酸为最主要的脂肪酸,相对含量达67.1%,还含有少量γ-亚麻酸;此外马泡瓜籽油富含β-谷甾醇(186.18 mg/100 g)、生育酚等活性成分,γ-生育酚含量高达1614.21μg/g,具有良好的抗氧化性。通过差示扫描量热仪分析确定了马泡瓜籽油的初始氧化温度为221.6℃,在110、120℃和140℃条件下的氧化诱导时间分别为263.91、133.64 min和26.50 min,其氧化稳定性优于菜籽油,通过热重分析测得其烟点在300~350℃之间,质量开始损失时的温度为300℃,热稳定性良好,具有作为烹饪油的潜质。

There is a folk tradition of producing oil from Cucumis bisexualis seeds.In order to promote the development and utilization of this wild plant resource,in this study,the physicochemical and thermal characteristics of the oil pressed from Cucumis bisexualis seeds were investigated.The results showed that thousand-grain mass(TGM)of Cucumis bisexualis seeds was 6 g with an oil yield of 25%.The acid value(0.37 mg/g)and peroxide value(0.17 g/100 g)of the oil met the national standard for the quality of edible oils.The relative content of unsaturated fatty acids(UFAs)was 86.27%and linoleic acid was the most predominant fatty acid(67.1%of total fatty acids)along with a lesser amount ofγ-linolenic acid.Notably,the oil contained high contents ofγ-tocopherol(1614.21μg/g)andβ-sitosterol(186.18 mg/100 g)and consequently had high oxidative stability.At an initial oxidation temperature of 221.6℃(measured by differential scanning calorimetry(DSC)),the oxidative induction time(OIT)of the oil was 263.91,133.64 and 26.50 min in an oxygen atmosphere under isothermal conditions at 110,120 and 140℃,respectively.The oxidative stability was superior to that of rapeseed oil.Thermogravimetric(TG)analysis indicated that the smoking point of Cucumis bisexualis seed oil was 300–350℃,and mass loss began to occur at 300℃.It had excellent thermal stability and could be utilized as a potential cooking oil.