Antioxidant Compounds for the Inhibition of Enzymatic Browning by Polyphenol Oxidases in the Fruiting Body Extract of the Edible Mushroom Hericium erinaceus

Author: mycolabadmin
2020-07-17
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Summary

This research investigated why lion’s mane mushroom extracts turn brown during processing and how to prevent this color change. The study found that specific enzymes cause the browning reaction, but the mushroom also contains natural antioxidants that can prevent this process. This finding has several practical implications: • Better preservation of mushroom-based food products by preventing unwanted color changes • Development of natural antioxidant ingredients for cosmetics and skincare products • Improved extraction methods for beneficial compounds from mushrooms • Potential new applications in natural food preservation • Creation of more stable mushroom-based nutritional supplements

Background

Mushrooms are attractive resources for novel enzymes and bioactive compounds, with many species historically used for food and medicine. However, mushrooms can spontaneously form brown pigments during food processing and extraction procedures. Hericium erinaceus (lion’s mane mushroom) is an edible and medicinal mushroom found in East Asia that has shown various biological activities including antitumor, antimicrobial, antioxidant and cytotoxic properties. The mushroom fruiting body is usually white initially but develops brown to black pigments during processing.

Objective

This study aimed to identify the cause of dark brown pigmentation in H. erinaceus extract via endogenous enzymatic reactions of the polyphenol oxidase (PPO) family, and to find ways to reduce this pigmentation. Additionally, the study sought to analyze putative PPO-coding genes and their transcripts in both fruiting body and mycelium, as well as conduct metabolite analysis to identify natural compounds that could serve as antioxidant substances or browning-reaction substrates.

Results

The study found that dark brown pigmentation was caused by PPO enzyme family oxidation of endogenous polyphenol compounds. Optimal detection wavelengths were identified at 380nm excitation and 444nm emission. Tyrosinase and laccase isoenzymes were highly expressed in the fruiting body. Metabolite profiling revealed potential enzymatic browning substances grouped into amino acids and derivatives, phenolic compounds, and purine/pyrimidine nucleobases. The mushroom contained high amounts of natural antioxidant compounds that could effectively decrease browning via PPO-inhibitory mechanisms.

Conclusion

The dark browning pigment in H. erinaceus extract was confirmed to be caused by polyphenol oxidases, particularly tyrosinases and laccases. The mushroom contains natural antioxidant compounds that can inhibit this enzymatic browning. These endogenous antioxidant substances could potentially be developed into nutrient substances for healthcare and cosmetic ingredients for nutricosmetics.

Published in:Foods,
Study Type:Laboratory Research,
Source: 10.3390/foods9070951