Effect of Atmospheric-Pressure Plasma on Functional Compounds and Physiological Activities in Peanut Shells

Peanut (<i>Arachis hypogaea</i> L.) shell, an abundant by-product of peanut production, contains a complex combination of organic compounds, including flavonoids. Changes in the total phenolic content, flavonoid content, antioxidant capacities, and skin aging-related enzyme (tyrosinase,...

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Bibliographic Details
Published in:Antioxidants
Main Authors: Narae Han, Jinwoo Kim, Jin Hee Bae, Mihyang Kim, Jin Young Lee, Yu-Young Lee, Moon Seok Kang, Duksun Han, Sanghoo Park, Hyun-Joo Kim
Format: Article
Language:English
Published: MDPI AG 2022-11-01
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Online Access:https://www.mdpi.com/2076-3921/11/11/2214
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Summary:Peanut (<i>Arachis hypogaea</i> L.) shell, an abundant by-product of peanut production, contains a complex combination of organic compounds, including flavonoids. Changes in the total phenolic content, flavonoid content, antioxidant capacities, and skin aging-related enzyme (tyrosinase, elastase, and collagenase)-inhibitory activities of peanut shell were investigated after treatment in pressure swing reactors under controlled gas conditions using surface dielectric barrier discharge with different plasma (NO<sub>x</sub> and O<sub>3</sub>) and temperature (25 and 150 °C) treatments. Plasma treatment under ozone-rich conditions at 150 °C significantly affected the total phenolic (270.70 mg gallic acid equivalent (GAE)/g) and flavonoid (120.02 mg catechin equivalent (CE)/g) contents of peanut shell compared with the control (253.94 and 117.74 mg CE/g, respectively) (<i>p</i> < 0.05). In addition, with the same treatment, an increase in functional compound content clearly enhanced the antioxidant activities of components in peanut shell extracts. However, the NO<sub>x</sub>-rich treatment was significantly less effective than the O<sub>3</sub> treatment (<i>p</i> < 0.05) in terms of the total phenolic content, flavonoid content, and antioxidant activities. Similarly, peanut shells treated in the reactor under O<sub>3</sub>-rich plasma conditions at 150 ℃ had higher tyrosinase, elastase, and collagenase inhibition rates (55.72%, 85.69%, and 86.43%, respectively) compared to the control (35.81%, 80.78%, and 83.53%, respectively). Our findings revealed that a reactor operated with O<sub>3</sub>-rich plasma-activated gas at 150 °C was better-suited for producing functional industrial materials from the by-products of peanuts.
ISSN:2076-3921