Relationship between polyphenol oxidase activity and phenolics degradation on ambient air-drying of herbal plants

Journal of Food Processing and PreservationVolume 42, Issue 7 e13672 ORIGINAL ARTICLE Relationship between polyphenol oxidase activity and phenolics degradation on ambient air-drying of herbal plants Zhi Hung Loh, Zhi Hung Loh School of Science, Monash University Malaysia, Bandar Sunway, Selangor, MalaysiaSearch for more papers by this authorHikari Kan Fu Oh, Hikari Kan Fu Oh School of Science, Monash University Malaysia, Bandar Sunway, Selangor, MalaysiaSearch for more papers by this authorYau Yan Lim, Corresponding Author Yau Yan Lim lim.yau.yan@monash.edu orcid.org/0000-0002-9508-6817 School of Science, Monash University Malaysia, Bandar Sunway, Selangor, MalaysiaCorrespondence Yau Yan Lim, School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia. Email: lim.yau.yan@monash.eduSearch for more papers by this author Zhi Hung Loh, Zhi Hung Loh School of Science, Monash University Malaysia, Bandar Sunway, Selangor, MalaysiaSearch for more papers by this authorHikari Kan Fu Oh, Hikari Kan Fu Oh School of Science, Monash University Malaysia, Bandar Sunway, Selangor, MalaysiaSearch for more papers by this authorYau Yan Lim, Corresponding Author Yau Yan Lim lim.yau.yan@monash.edu orcid.org/0000-0002-9508-6817 School of Science, Monash University Malaysia, Bandar Sunway, Selangor, MalaysiaCorrespondence Yau Yan Lim, School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia. Email: lim.yau.yan@monash.eduSearch for more papers by this author First published: 24 May 2018 https://doi.org/10.1111/jfpp.13672Citations: 2 Funding information: Monash University Malaysia; Ministry of Education, Malaysia (Fundamental Research Grant Scheme), Grant/Award Number: FRGS/2/2013/SG01/MUSM/02/1 Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Beneficial properties of herbal tea leaves can be affected by oxidase enzymes activity on harvesting, as these enzymes utilize phenolics as the main substrate. The purpose of this study was to investigate whether there is any correlation between the oxidase enzymes activity and the degree of phenolic degradation. Eight herbal tea leaves underwent ambient air-drying process and their total phenolic content change as well as polyphenol oxidase and peroxidase enzyme activity change for each fresh leaf were determined after ambient air-drying. Results showed that except for two plants, polyphenol oxidase activity had a positive linear correlation with total phenolic degradation (y = 1.929x + 21.082; R2 = 0.8909), but peroxidase activity showed no such relationship. Plants with rosmarinic acid as their main phenolics, showed a much better correlation. Practical applications The process of preserving herbal tea leaves for their bioactivities by drying is crucial for the purpose of commercialization. Herbal industries have been using, among others, air-drying method as a means of preservation because of its cost effectiveness. However, the presence of oxidase enzymes may lead to degradation of beneficial compounds. In our study, by identifying the correlation between oxidase enzyme activity for both polyphenol oxidase and peroxidase with that of total phenolic degradation, we are able to understand the actual effect of oxidase enzymes on phenolics degradation. Hence, through the correlation and solely based on its oxidase enzyme activity, mainly polyphenol oxidase, we could determine whether air-drying will be suitable for a particular herbal tea leaf. This will result in a much faster and efficient decision in choosing a preserving method for the herbal tea leaf. Citing Literature Volume42, Issue7July 2018e13672 RelatedInformation