Effect of Accelerated Storage on Fatty Acids, Thermal Properties and Bioactive Compounds of Kenaf Seed Oil

Abstract

The effects of thermal oxidation at 65 °C for 24 days on oxidation indices, fatty acid positional distribution, thermal properties, vitamin E composition and sterol composition of kenaf seed oil are investigated. The results showed that total oxidation value (TOTOX) of the oil increased from initial 8.83 to 130.74 at the end of 24 days storage. Linoleic acid at sn‐1, 3 positon of kenaf seed oil was less stable than the one at sn‐2 positon. Oxidative degradation changed the melting profile of kenaf seed oil, the value of endothermic enthalpy reduced from 58.17 to 20.25 J/g after 24 days of storage. Moreover, the content of vitamin E and total sterol decreased by 84.26% and 38.47%, respectively. Tocotrienols were more stable than tocopherols during the accelerated storage. Correlation analysis indicated vitamin E content was significantly related to p‐anisidine value, while sterol content was significantly related to peroxide value. Practical Application Kenaf seed oil is rich in polyunsaturated fatty acids and bioactive compounds. Heating process and long‐term storage cause oil oxidation and bioactive compounds degradation. The oxidation process of kenaf seed oil is simulated with accelerated storage. The study evaluates fatty acid composition and distribution, vitamin E and sterol content, melting thermal characteristics of kenaf seed oil at different oxidation levels. The research shows the stability of fatty acid is related with its type and position in backbone of triacylglycerol molecule. There are good correlation among oxidation level, vitamin E and sterol content, and melting enthalpy value of kenaf seed oil.

Synthesis of acetyl ferulic 7‐hydroxyisoflavone ester and evaluating its antioxidant activity on improving fish oil thermal stability

“…In general, POV indicates the amount of primary oxidation products, while TBARS and pAV are indicators of formation of secondary oxidation products (Zhang et al ., 2019). The oxidative stability of the fish oil samples (with and without antioxidants) heated at 80 °C for 12 days was evaluated by measuring their POV, TBARS and pAV values.…”

Synthesis of lipoic acid ferulate and evaluation of its ability to preserve fish oil from oxidation during accelerated storage

“…In general, POV is a quantitative index of primary oxidation products, while TBARS and p AV reflect the amount of secondary oxidation products ( Zhang et al, 2019 ). The POV, TBARS and p AV values of the fish oil samples with and without antioxidants during the accelerated storage at 80 °C were shown in Fig.…”

Comparison of quality and oxidative stability of pumpkin seed (Cucurbita maxima) oil between conventional and enzymatic extraction methods

“…Other studies have reported similar results aer storage tests; the decrease in UFA (including PUFA and MUFA) content and the increase in SFA content could be associated with oil oxidation. 53,54 During the oil oxidation process, the PUFA is gradually oxidised to MUFA and subsequently to SFA. 26,53 In contrast, CPE extracted pumpkin seed oil had a higher PUFA loss rate than that extracted by SE and AEE, indicating that the former may be more oxidised.…”

“…53,54 During the oil oxidation process, the PUFA is gradually oxidised to MUFA and subsequently to SFA. 26,53 In contrast, CPE extracted pumpkin seed oil had a higher PUFA loss rate than that extracted by SE and AEE, indicating that the former may be more oxidised. Taking together, it was indicated that AEE and SE had relatively higher oxidative stability than CPE, with AEE performing the best.…”