Faculty Publications
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Item Use of antioxidants for enhancing oxidative stability of bulk edible oils: a review(Blackwell Publishing Ltd, 2021) Mishra, S.K.; Belur, P.D.; Iyyaswami, R.Edible oils industry is using synthetic and natural antioxidants to enhance the oxidative stability of bulk edible oils. Due to safety concerns of BHA, BHT and TBHQ, there is an ongoing effort to find an effective and safe replacement. Finding a safe antioxidant or its synergistic mixture, which delays, retard or prevent the oxidation of bulk oil without changing the colour or flavour upon addition is a challenge. In this review, a brief account of chemical basis of oxidative deterioration of the stored oil is given. The effectiveness of most widely experimented antioxidants such as tocopherols, carotenoids, ascorbic acid and its derivatives, lignan compounds, flavonoids, polyphenols and phenolic acids in various edible oils have been reviewed. Further, the synergistic and antagonistic combination of these antioxidants in controlling oxidative degradation of edible oils has been discussed. © 2020 Institute of Food, Science and Technology (IFSTTF)Item Effects of different cooking methods on chemical compositions, in vitro starch digestibility and antioxidant activity of taro (Colocasia esculenta) corms(John Wiley and Sons Inc, 2022) Kapcum, C.; Pasada, K.; Kantiwong, P.; Sroysang, B.; Phiwtawee, J.; Suphantharika, M.; Belur, P.D.; Agoo, E.M.G.; Janairo, J.I.B.; Wongsagonsup, R.The impacts of different cooking methods (boiling, steaming, baking, microwaving and frying) on chemical compositions, starch digestibility and antioxidant activity of taro corms were investigated. Compared with raw taro, boiling and frying reduced crude protein and ash contents. Frying significantly increased crude fat and fibre contents but decreased carbohydrate content. All cooking methods reduced oxalate content, especially frying. Among the cooked products, the boiled taro had the highest rapidly digestible starch (RDS) but the lowest resistant starch (RS) contents. In contrast, the fried taro provided the lowest RDS but the highest RS contents. All cooking methods reduced the total phenolic content and antioxidant activity of taro. The boiled taro had the lowest antioxidant activity but the fired taro provided the highest. Frying was able to retain most of the health-promoting compounds with the lowest oxalate content; however, the high consumption of high-fat fried taro may adversely affect human health. © 2022 Institute of Food Science and Technology.Item Probing the synergistic effects of rutin and rutin ester on the oxidative stability of sardine oil(Springer, 2022) Chandrasekar, V.; Arunachalam, S.S.; Hari, H.; Shinkar, A.; Belur, P.D.; Iyyaswami, R.Multicomponent antioxidant mixture is proved to be highly effective in imparting oxidative stability to the edible oil. It is believed that the high efficacy of those mixtures is due to the synergistic effect exhibited by two or more components. The current study aims to analyse the synergistic effect of a flavonoid and its corresponding ester in improving the oxidative stability of n-3 PUFA rich sardine oil. The oxidative stability of rutin, esterified rutin and their combinations at three different concentrations was studied in sardine oil stored at 37 ºC for 12 days in contact with air under darkness. The combination of rutin and rutin ester showed maximum reduction of 54.2% in oxidation at 100 mg/kg and 150 mg/kg. Perhaps this is the first report on the synergistic effect of a flavonoid and its lipophilized ester for improving the oxidative stability of n-3 PUFA rich oil. © 2022, Association of Food Scientists & Technologists (India).Item Comparison of efficacy of various natural and synthetic antioxidants in stabilizing the fish oil(John Wiley and Sons Inc, 2022) Mishra, S.K.; Belur, P.D.; Iyyaswami, R.Use of antioxidants (natural and synthetic) can retard oxidative degradation of fish oil having n-3 PUFA. The performance of each antioxidant is found to be affected by the composition of the oil, presence of impurities and storage condition. Hence an attempt was made to find the efficacy of catechin, resveratrol, β-carotene, caffeic acid, sinapic acid, ellagic acid, ferulic acid, vanillic acid, quercetin, rutin, TBHQ, BHA, and BHT at a concentration of 0.9 mM in the bulk fish oil, stored for 50 days exposed to air at 25°C under darkness. The extent of primary and secondary oxidation of the stored oil was determined every 5 days and were compared. The efficacy of TBHQ followed by BHA and BHT was found to be highest among all the antioxidants studied. Among the natural antioxidants, resveratrol and catechin were found to exhibit superior efficacy, whereas β-carotene was found to exhibit proxidant behavior. Novelty impact statement: This is the first comprehensive study carried out to find the most effective antioxidant involving ten natural and three synthetic antioxidants in n-3 PUFA containing fish oil. TBHQ exhibited superior efficacy among all the antioxidants tested and at a concentration of 0.9 mM, the change in TOTOX value by the end of 40 days of storage was about 80%. None of the other antioxidants studied here, exhibited such superior stability. Among the natural antioxidants, resveratrol and catechin were found to be superior. © 2022 Wiley Periodicals LLC.Item Synthesis and characterization of 3,4-dihydroxyphenyl acetic acid esters and study of their efficacy in bulk fish oil(Elsevier Ltd, 2024) Arunachalam, S.S.; Chandrasekar, V.; Belur, P.D.Lipophilization of natural antioxidants is a proven strategy to enhance the solubility in bulk oil systems, thereby increasing their efficacy against oxidative degradation. This study aims to synthesize esters of 3,4-dihydroxyphenylacetic acid (3,4-DHPA) using Amberlyst-15 and to study the application of these esters in refined fish oil. Lipophilic esters were synthesized by esterification and transesterification of 3,4-DHPA in various solvent systems. Esters of methanol, butanol and hexanol were obtained with percent conversion of 81.1, 69.3 and 78.8 respectively, and were subjected to molecular characterization and in vitro oxidant assays. The 3,4-DHPA and its methyl ester showed 36% reduction in the TOTOX value over 30 days of storage. The length of the acyl chain in the ester was found to exert a high influence on its efficacy and lipophilicity. This is the first report of 3,4-DHPA and its lipophilic esters studied for enhancing the oxidative stability of fish oil. © 2024 Elsevier Ltd