Effect of domestic processing on the antioxidant activities of edible mushrooms

• Main Author: Woo, Candice Xin Ci
• Format: Academic Exercise
• Language: English
• Published: 2012
• Subjects: TX341-641 Nutrition. Foods and food supply
• Online Access: https://eprints.ums.edu.my/id/eprint/7761/1/ae0000001615.pdf; https://eprints.ums.edu.my/id/eprint/7761/

This study evaluated the effect of domestic cooking practices (boiling, steaming and pan-frying) on the antioxidant activities of Pleurotus sajor-caju (Grey oyster mushroom), Lentinus edodes (Shiitake) and Auricularia polytricha (Black jelly mushroom). Four different antioxidant assays, namely ABTS, DPPH, FRAP and ORAC were conducted to determine the antioxidant properties after cooking treatments. Colour change in Shiitake and black jelly mushroom was more marked as stated by higher ΔE values as compared to steamed samples. Interestingly, lightness (L * ), redness (a *) and yellow (b* ) of black jelly mushroom was markedly increased upon all cooking methods. Shiitake (15 minutes) had the highest Total Phenolic Content (TPC) among all the boiled samples whereas black jelly mushroom (5 minutes) had the highest after steaming. Boiling had detrimental effect on TPC of black jelly mushroom, which caused almost 100% lost. The losses of phenolics were associated to unexceptionally high phenolic content (34.08±0.19 mg GAE/g extract) that released into the cooking water. This had led to tremendous reduction of DPPH radical scavenging activity after boiled for 15 minutes. However, steamed grey oyster mushroom showed the FRAP and ORAC values increased 4 fold after steamed for 20 minutes. Phenolic compounds namely catechin, syringic acid, (-) Epicatechin, naringin, quercetin and kaempferol were present in all three mushroom species except catechin was found absent in grey oyster and Shiitake mushrooms. No phenolic compounds were detected in both mushroom species after pan-frying at 3 minutes. Black jelly mushroom is the only species that contained catechin. The principle component of grey oyster mushroom correlated well with FRAP, TPC, ORAC and moderately with ABTS whereas high inter-relationship among FRAP and ABTS was observed among Shiitake. Similarly, PCA of black jelly mushroom demonstrated phenolic content of mushroom extracts were highly related with DPPH radical scavenging activity. In conclusion, the present findings demonstrated that domestic cooking methods significantly affected antioxidant activities of the studied mushroom species. Steaming seems to be the best cooking methods for edible mushrooms, as it appeared to efficiently increase bio-accessibility of polyphenols while preserving or even enhancing antioxidant actions in edible mushrooms.