牡丹籽油优势抗氧化剂研究

Preponderant antioxidant of peony seed oil

对牡丹籽油及其他5种植物油的基本理化指标进行了测定比较。牡丹籽油酸值(KOH)(2.034 mg/g)、过氧化值(0.286 mmol/kg)均在国标限值以内,碘值(I)185.8 g/100 g,说明其为干性油,皂化值(KOH)(188.1 mg/g)符合国家规定注射用油标准,较其他5种植物油品质好。选用迷迭香提取物、α-生育酚、TBHQ 3种抗氧化剂,并选择柠檬酸作为抗氧化增效剂,以不同比例组合加入牡丹籽油中,采用Rancimat法测定其氧化诱导时间(OSI)以确定优势抗氧化剂,结合温度外推法推测牡丹籽油货架期。最终遴选0.02%TBHQ+0.01%柠檬酸为优势抗氧化剂,推得20℃下添加此抗氧化剂的牡丹籽油货架期为3 737 h,约是未加抗氧化剂牡丹籽油的27倍,显著提高了牡丹籽油的耐贮藏性。

The basic physicochemical indexes of peony seed oil and other five kinds of vegetable oils were determined and compared. The results showed that both the acid value（ 2. 034 mg KOH / g） and peroxide value（ 0. 286 mmol / kg） of peony seed oil were within the limit of national standard; the iodine value of peony seed oil was 185. 8 g I /100 g,indicating that peony seed oil was drying oil; the saponification value（ 188. 1 mg KOH/g） was in accord with injection oil of national standard,therefore the quality of peony seed oil was better than that of the other five kinds of vegetable oils. Selecting rosemary extract,α- tocopherol and TBHQ as antioxidants,citric acid as synergist,the oxidative stability index（ OSI） of peony seed oils added with antioxidants respectively blended in different ratios were determined by Rancimat method to screen preponderant antioxidant,then the shelf life of peony seed oil was inferred by the method of temperature extrapolation. Finally 0. 02% TBHQ matched with 0. 01% citric acid was selected as the preponderant antioxidant,and the shelf life of peony seed oil added with the selected preponderant antioxidant was 3 737 h,which was 27 times as long as that of peony seed oil without antioxidant,thus the storage characteristics of peony seed oil improved.