Optimizing the extraction of phenolics and antioxidants from feijoa (Feijoa sellowiana, Myrtaceae)

This study was aimed to optimize the extraction of phenolic compounds and antioxidants in feijoa fruit by investigating the variables of solvent to sample ratio, type of solvent, extraction time and temperature with respect to the extraction efficiency. The selected optimum conditions (60 : 1 as solvent to sample ratio, 40 A degrees C temperature and 3 h extraction time) for extraction were used to extract feijoas with different solvent systems. Acetone : water (80 : 20) was chosen as the most effective solvent for extraction. Utilizing the optimum extraction conditions, total phenolic content and antioxidant activity were measured as 18.56 and 32.47 mg gallic acid equivalents per g dry weight; 165 and 465.7 milimolar Trolox equivalents per g dry weight, in flesh and the peel, respectively. Besides, syringic, ferulic, o - coumaric and trans - cinnamic acids were determined in feijoa fruit. Due to the very strong antioxidant activity found in especially feijoa peel; the extracts have the potential of being utilized in various food matrices to prevent deteriorations originated from oxidation.