Inhibition of apple polyphenol oxidase activity by sodium chlorite.
نویسندگان
چکیده
Sodium chlorite (SC) was shown to have strong efficacy both as a sanitizer to reduce microbial growth on produce and as a browning inhibitor on fresh-cut apples in previous experiments. This study was undertaken to investigate the inhibitory effect of SC on polyphenol oxidase (PPO) and the associated mechanisms. The experiment showed that SC had a strong inhibition of apple PPO. The extent of inhibition was influenced by SC concentration and pH. Inhibition was most prominent at pH 4.5, at which approximately 30% of enzyme activity was lost in the presence of 10 mM SC, followed closely by that at pH 4.0 with a 26% reduction in PPO activity. The inhibition mode was determined using Dixon and Lineweaver-Burk plots, which established SC to be a mixed inhibitor of apple PPO for the oxidation of catechol. Preincubation of PPO with 8 mM SC for 8 min caused a maximum of 46% activity reduction compared to noninhibited control. However, preincubation of SC with catechol for 8 min resulted in no additional loss of PPO activity. These findings provide further evidence that the inhibition of PPO activity by SC is due to the inhibition of the enzyme itself rather than removal of the substrate.
منابع مشابه
Effect of Sodium Dodecyl Sulphate on Partial Purified Polyphenol Oxidase Activity in Red and Green Tomatoes (Solanum Lycopersicum)
In order to better understand how to prevent enzymatic greenning, it is important to understand kinetic properties of polyphenol oxidase. we investigated the effect of SDS on the rate of catechol oxidation by small cherry tomato partial purified PPO. PPO activity increased with increasing SDS concentration. The most effective concentration of SDS was 0.8, 1 and 1.25 mM in according to pH and ...
متن کاملEffect of Sodium Dodecyl Sulphate on Partial Purified Polyphenol Oxidase Activity in Red and Green Tomatoes (Solanum Lycopersicum)
In order to better understand how to prevent enzymatic greenning, it is important to understand kinetic properties of polyphenol oxidase. we investigated the effect of SDS on the rate of catechol oxidation by small cherry tomato partial purified PPO. PPO activity increased with increasing SDS concentration. The most effective concentration of SDS was 0.8, 1 and 1.25 mM in according to pH and ...
متن کاملPartial Purification and Characterisation of Polyphenol Oxidase from Tomatoes (Solanum Lycopersicum)
Polyphenol oxidase (PPO) from tomatoes was extracted and partially purified through (NH4)2SO4 precipitation, dialysis and ion exchange chromatography. The activity of polyphenol oxidase was investigated in solanum lycopersicum. Spectrophotometric method was used to assay the enzyme activity and the kinetic constants - maximum enzyme velocity (Vmax) and Michealis - Menten constant (Km). Of the ...
متن کاملElucidation of the mechanism of enzymatic browning inhibition by sodium chlorite.
Sodium chlorite (SC) is a well known anti-microbial agent and its strong inhibitory effect on enzymatic browning of fresh-cut produce has recently been identified. We investigated the effect of SC on polyphenol oxidase (PPO) and its substrate, chlorogenic acid (CA), as it relates to the mechanisms of browning inhibition by SC. Results indicate that the browning reaction of CA (1.0mM) catalyzed ...
متن کاملPartial Purification and Characterisation of Polyphenol Oxidase from Tomatoes (Solanum Lycopersicum)
Polyphenol oxidase (PPO) from tomatoes was extracted and partially purified through (NH4)2SO4 precipitation, dialysis and ion exchange chromatography. The activity of polyphenol oxidase was investigated in solanum lycopersicum. Spectrophotometric method was used to assay the enzyme activity and the kinetic constants - maximum enzyme velocity (Vmax) and Michealis - Menten constant (Km). Of the ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of agricultural and food chemistry
دوره 54 10 شماره
صفحات -
تاریخ انتشار 2006