Valorization of soursop flowers (Annona muricata L.) as potent source of natural antioxidants for stabilization of palm olein during accelerated storage

Abstract

This study investigates the effect of soursop flowers methanolic extract on the physicochemical characteristics of palm olein during accelerated storage. After analysis of the extract by determining its total phenolic content by colorimetry and identification of some of its phenolic antioxidants by HPLC‐DAD(Diode Array Detector), preliminary antioxidants tests have been done. After that, the extract was added in palm olein at concentrations 200–1800 ppm. BHT, at 200 ppm served as standard besides the Control. Induction time, peroxide, p‐anisidine, Total oxidation (TOTOX), thiobarbituric acid and iodine values, as well as changes in linoleic acid profile Gas Chromatography/Flamme Ionization Detector (GC/FID) of oil during the storage were evaluated. Results showed soursop flower extract to be rich in phenolic antioxidants and to be efficient, at all concentrations, in delaying palm olein oxidation on Rancimat and accelerated Schaal oven test of 30 days at 70°C. Soursop flowers might be used as potent source of antioxidants for the stabilization of palm olein.

Polyphenol antioxidants from cocoa pods: Extraction optimization, effect of the optimized extract, and storage time on the stability of palm olein during thermoxidation

“…In fact, hydroperoxides are thermolabile molecules, which easily breakdown into secondary oxidation products at high temperature. These results are in agreement with the studies of Womeni, Tonfack, Iruku, et al (), which found that soursop extract delay the formation of malonaldehyde in oils. On the basis of the quality standards for oils with respect to TBA value (≤1 ppm according to Patton & Kurtz, ), it would be advisable to heat at 180 °C, palm olein enriched with cocoa pods extracts at 2,000 ppm for 1–8 days in order to preserve its quality.…”

Optimization of the extraction of natural antioxidants from Coffea robusta leaves and evaluation of their ability to preserve palm olein from oxidation during accelerated storage

“…Similar results were obtained by Womeni, Tonfack, Iruku, et al. () who demonstrated that extracts of tea leaves significantly retard the total oxidation of palm olein during an accelerated storage of 30 days at 70°C. On the basis of the quality standards for oils with respect to TOTOX value (≤26 according to Codex Alimentarius ()), it would be advisable to store at 70°C, palm olein supplemented with coffee leaves extract at 2000 ppm during 32 days in order to preserve its quality.…”

Effect of sunlight on the physicochemical properties of refined bleached and deodorized palm olein

“…After the 90 day storage in the dark at room temperature, the value increased up to 5.19 and 7.13 ppm for palm olein supplemented with BHT and that without antioxidant respectively, and was still in the accepted range. The difference between these two samples might FULL PAPER be attributed to the presence of antioxidants which have retarded the peroxide formation in oil by giving their hydrogen atoms, as reported by Womeni et al (2016).…”

“…Palm olein is generally prone to have a good oxidative stability. Its auto-oxidation during storage in the oven and ambient temperature has already been reported (Pimpa et al, 2009;Womeni et al, 2016), but no report is available on the effect of sunlight on the quality and oxidative stability of this oil. In Cameroon and other developing countries where palm oil and its derivatives (case of palm olein) are the most produced and consumed refined oil, the exposition of oil out from the shops for advertising purpose is highly applied.…”