Antioxidant capacity is a surrogate measure of the quality and stability of vegetable oils

Abstract

Total antioxidant capacity (TAC) may be a comprehensive oil quality index because of its potential association with chemical composition, oxidative stability, and fresh oil quality. We aimed to investigate the chemical determinants of the oxidative stability and TAC of oils using multivariate statistical analyses and the use of the TAC assay as a predictor of oil stability. Fatty acids, tocols, phenolic compounds, peroxide value, acid value, induction period (by the Rancimat test) and TAC (by the TEAC assay) were determined in refined canola, corn, soybean, and sunflower oils as well as cold-pressed nut oils. Principal component analysis was used for data reduction and variable extraction. Generalized linear models successfully estimated the TAC (R 2 ¼ 90.3%, p < 0.005) and oxidative stability (R 2 ¼ 91.6%, p < 0.001) of the oils, and g-tocopherol was the most important predictor in both of the models. The peroxide value and induction period were linearly associated with antioxidant capacity (R 2 ¼ 0.65, p < 0.01 and R 2 ¼ 0.70, p < 0.01, respectively), allowing the prediction of the initial quality and oxidative stability of the oils by the TEAC assay. Additionally, the proposed minimum TAC value for good quality refined oils was 2.2 mmol TE/kg.Practical Applications: Lipid oxidation is one of the major causes of vegetable oil degradation, affecting its global quality and limiting its shelf life. Therefore, a quality index applicable for estimating oxidative stability and initial quality of refined and cold-pressed vegetable oils might be an important tool for quality control of oils in the food industry. We show that the TEAC assay, a simple and rapid spectrophotometric assay of antioxidant capacity, may be a useful tool for the determination of the global quality of oils due to its significant associations with the induction period and peroxide value. A minimum TAC value is advisable for good quality refined plant oils, especially when the initial quality and the shelf life are of concern.

Characterization of pecan nut expeller cake and effect of storage on its microbiological and oxidative quality

“…Synergistic antioxidant activities have been reported between tocopherols and nitrogen-containing phospholipids such as phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine, all of which are present in tree nut oils and their minor component extracts and may help explain the high antioxidant activities observed for these products. Antioxidant capacity has been previously used as an indicator of the overall quality and oxidative stability of oils with good accuracy (Castelo-Branco et al, 2016). In the present paper we found similar trends in TBARS and antioxidants assays.…”

Chemical composition and oxidative stability of jussara (<em>Euterpe edulis</em> M.) oil extracted by cold and hot mechanical pressing

“…This value was lower than those observed for cold pressed oils from almond (3.19), Brazil nut (1.11), hazelnut (1.29) and pecan (2.11) (Castelo-Branco et al, 2016). However, it was higher than the value calculated for açai oil (0.41), based on the composition reported by Rufino et al (2011).…”

“…Compared to other vegetable oils extracted by cold pressing such as almond, Brazil nut, hazelnut and macadamia (Castelo-Branco et al, 2016), jussara oil showed higher oxidative stability, with longer induction periods. This can be related to the lower PUFA/SFA ratio in jussara oil as compared to the above-mentioned ones.…”

Seed Oils of Five Black Tartary Buckwheat Cultivars with Biochemical Characterization and Antioxidant Properties

“…1 (1156.19 ± 16.32 mg/kg), while Yulin-6-21 had the lowest value (704.66 ± 2.53 mg/kg), which is still higher than that in rapeseed oil, a promising anti-aging oil (555-690 mg/kg) [30]. Moreover, the range of the total tocopherols in our study is much higher than that of extra virgin oleaster oil with a value ranging from 87 to 182 mg/ kg [15]; it is also higher than that in the refined oils of corn (11.05-15.27 mg/kg), soybean (15.81-18.45 mg/kg), sunflower (9.78-11.74 mg/kg) and canola (9.11-10.43 mg/ kg) [31]. Compared with the other common vegetable oils, BTBOs can be considered a good source of total tocopherols.…”