Effect of Blanching Pomegranate Seeds on Physicochemical Attributes, Bioactive Compounds and Antioxidant Activity of Extracted Oil.

Tafadzwa Kaseke,Umezuruike Linus Opara,Olaniyi Amos Fawole

doi:10.3390/molecules25112554

Tafadzwa Kaseke, Umezuruike Linus Opara + Show 1 more

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https://doi.org/10.3390/molecules25112554

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Abstract

This study investigated the effect of blanching pomegranate seeds (PS) on oil yield, refractive index (RI), yellowness index (YI), conjugated dienes (K232), conjugated trienes (K270), total carotenoid content (TCC), total phenolic compounds (TPC) and DPPH radical scavenging of the extracted oil. Furthermore, phytosterol and fatty acid compositions of the oil extracted under optimum blanching conditions were compared with those from the oil extracted from unblanched PS. Three different blanching temperature levels (80, 90, and 100 °C) were studied at a constant blanching time of 3 min. The blanching time was then increased to 5 min at the established optimum blanching temperature (90 °C). Blanching PS increased oil yield, K232, K270, stigmasterol, punicic acid, TPC and DPPH radical scavenging, whereas YI, β-sitosterol, palmitic acid and linoleic acid were decreased. The RI, TCC, brassicasterol, stearic acid, oleic acid and arachidic acid of the extracted oil were not significantly (p > 0.05) affected by blanching. Blanching PS at 90 °C for 3 to 5 min was associated with oil yield, TPC and DPPH. Blanching PS at 90 °C for 3 to 5 min will not only increase oil yield but could also improve functional properties such as antioxidant activity, which are desirable in the cosmetic, pharmaceutical, nutraceutical and food industries.

Highlights

Fruit processing generates huge amounts of waste in the form of compacted peels and seeds commonly referred to as pomace
Blanching Pomegranate seeds (PS) at 90 ◦ C for 3 min significantly increased the pomegranate seed oil (PSO) yield by 35%, which was the highest improvement in the oil yield when compared with the oil yield from seeds blanched at 80 and 100 ◦ C
Positive scores on F2 corresponded to oil from PS blanched at 90 ◦ C for 5 min, that were correlated with total phenolic compounds (TPC) and total carotenoid content (TCC)

Summary

Introduction

Fruit processing generates huge amounts of waste in the form of compacted peels and seeds commonly referred to as pomace. This byproduct presents a huge disposal problem to the agro-processing industry as it is regarded as waste. The global production and consumption of pomegranate fruit continue to increase due to its health-promoting effects [8]. This has generated more waste from the fruit between the preharvest and processing stages as sunburned, bruised, cracked and scalded fruit is rejected due to failure in meeting export market standards. Low quality grade fruit such as bruised fruit may be Molecules 2020, 25, 2554; doi:10.3390/molecules25112554 www.mdpi.com/journal/molecules

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