Analysis of physicochemical properties, fatty acid composition and antioxidant activity of seed oil extracted from 12 citrus materials

Abstract

The massive citrus seed waste provides a new approach to the shortage of edible oils in China. In this study, the physicochemical properties, fatty acid composition and antioxidant activity of 12 citrus seed oils from China were determined, aiming to provide a theoretical basis for the development and utilisation of citrus seed oil. Results show most of the citrus seeds had a high oil content (28.3%-41.4%), with 2.6% in Zhi (Poncirus trifoliata). The crude oil extracted from the seeds of Dahongpao (Citrus reticulata) and Tongnanningmeng (Citrus limon) could directly meet the 'National Standard for Food Safety Vegetable Oil' (GB 2716(GB -2018. With total phenolic content (TPC) (62.1-2086.8 lg GAE g À1 DW), total flavonoid content (TFC) (59.6-2275.3 lg RE g À1 ) and total carotenoid content (TCC) (37.4-896.6 lg g À1 ), seed oil of Zhi had the highest content of bioactive substances and the strongest antioxidant capacity. The content of unsaturated fatty acids in citrus seed oil ranged from 72.4% to 82.2%, and the SFA: MUFA: PUFA ratio was closer to the recommended intake ratio of 1:1:1 by the Chinese Nutrition Society than other vegetable oils, which have higher nutritional value. Therefore, citrus seed oil is a potentially valuable oil source for healthy edible oil.