Hinokitiol Inhibits Polyphenol Oxidase and Enzymatic Browning

Abstract

We screened for inhibitors of enzymatic browning among fermented broths of lactic acid bacteria (58 strains), extracts of spices (7 samples), and food additives (34 samples) from the standpoint of practical use. We found that hinokitiol, a preservative, definitely inhibited the browning of apple sections. An apple section sprayed with a 0.02% hinokitiol solution did not turn brown for 2 h at room temperature. Hinokitiol competitively inhibited apple polyphenol oxidase (PPO). The Ki value of hinokitiol against apple PPO was 5.5 μM, while the Km value of chlorogenic acid was 2.5 mM. Furthermore hinokitiol non-competitively inhibited tyrosinase and the discoloration of shrimp caused by tyrosinase during cold storage.

Influence of Artificial Inoculation with <i>Pseudomonas fluorescens</i> on Enzymatic Browning Reactions of Fresh-cut Potatoes

“…For PPO assay, the reaction mixture consisted of 50 μL enzyme extract, 200 μL of 10 mM L-β-(3,4-Dihydroxyphenyl) alanine (L-DOPA) , and 750 μL of diluted Macilvain buffer (pH 4.5) . PPO activity was measured by increase in absorbance at 475 nm according to a modified method of Okumura et al (2011) and determined as change in absorbance at 475 nm/min/g fresh weight.…”

The Biological Activities of Troponoids and Their Use in Agriculture A Review

“…Broothaerts et al (2000) showed that polyphenol oxidase reaction in transgenic apple and tobacco leaves was strongly inhibited by tropolone, a Cu competitor, and restored by the addition of Cu 2+ . Okumura et al (2011) found that hinokitiol (ß-thujaplicin) and tropolone definitely inhibited polyphenol oxidase and browning of apple sections and inhibited browning of shrimps (Penaeus indicus). For darkening or discoloration of shrimps during cold storage, tyrosinase is mainly responsible.…”

Effect of hinokitiol impregnated sheets on shelf life and quality of “KEK‐1” tomatoes during storage

“…Hinokitiol fresh sheets and hinokitiol dissolved in ethanol were used to prevent the decay of commercially harvested peaches, in which hinokitiol fresh sheets were more effective than hinokitiol dissolved in ethanol, and 41.1% of the untreated fruit developed brown rot . Hinokitiol used as an inhibitor for enzymatic browning of apples, apple sections sprayed with a 0.02% hinokitiol solution completely inhibited polyphenol oxidase and prevented browning . Hinokitiol inhibits ethylene production through suppression of ACC synthase and ACC oxidase in wounded winter squash mesocarps, apple fruit plugs, and peach seeds .…”

“…12 Hinokitiol used as an inhibitor for enzymatic browning of apples, apple sections sprayed with a 0.02% hinokitiol solution completely inhibited polyphenol oxidase and prevented browning. 13 Hinokitiol inhibits ethylene production through suppression of ACC synthase and ACC oxidase in wounded winter squash mesocarps, apple fruit plugs, and peach seeds. [14][15][16] Hence, the objective of the present investigation was to compare the effect of hinokitiol impregnated into nonwoven rayon on quality and shelf life extension of "KEK-1" tomatoes at two different temperatures (15°C and 25°C) under MAP and non-MAP conditions.…”