文章基本信息

标题：Effects of Extraction Conditions on Banana Peel Polyphenol Oxidase Activity and Insights into Inactivation Kinetics Using Thermal and Cold Plasma Treatment
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作者：Daria Wohlt ; Elena Schwarz ; Andreas Schieber 等
期刊名称：Foods
电子版ISSN：2304-8158
出版年度：2021
卷号：10
期号：5
页码：1022
DOI：10.3390/foods10051022
出版社：MDPI Publishing
摘要：The objective of this work was to characterize banana peel polyphenol oxidase (PPO) and to study the inactivation kinetics during thermal and cold atmospheric pressure plasma treatment. Since varietal differences in enzyme characteristics are a well-known phenomenon, ‘Prata’ banana peel PPO was characterized, and PPO activity and thermal stability of the peel PPO of the two dessert banana cultivars ‘Cavendish’ and ‘Prata’ were compared to identify the cultivar better suited for industrial food applications. A crude extract obtained from the peels of the Brazilian banana variety ‘Prata’ revealed highest PPO activities (46.0–55.2 nkat/mL) at 30–40 °C in a range of pH 6.0–6.5 after addition of 0.5 g/gsample polyvinylpyrrolidone and 0.5% (v/v) Triton X-100 during extraction. ‘Cavendish’ PPO activity was four times higher. Banana peel PPO exhibited the highest affinity towards dopamine (KM = 0.94 mM). Thermal inactivation of ‘Prata’ and ‘Cavendish’ PPO was achieved at 90 °C after 5 and 15 min, respectively, whereas cold plasma treatment did not decrease PPO activity below 46% of the initial enzyme activity. The inactivation behavior of PPO could successfully be described by a two-fraction model indicating at least two types of isoenzymes with different thermal stability. The overall high thermal stability was mainly attributed to membrane-bound PPO. The results may help to prevent enzymatic browning of banana peels and thereby facilitate their valorization as food ingredients.
关键词：enzyme characterization; Musa acuminata x M;balbisiana ; o -diphenoloxidase; cold atmospheric pressure plasma; membrane-bound PPO; soluble PPO enzyme characterization ; Musa acuminata x M;balbisiana ; o -diphenoloxidase ; cold atmospheric pressure plasma ; membrane-bound PPO ; soluble PPO