Insight of Polyphenol Oxidase Enzyme Inhibition and Total Polyphenol Recovery from Cocoa Beans

Abstract

A full factorial design (ascorbic acid/l-cysteine inhibitors, temperature, and time as factors) study was conducted to enhance inhibition of polyphenol oxidase (PPO) activity without decreasing cocoa polyphenol concentrations. The data obtained were modelled through a new equation, represented by Γ, which correlates both high polyphenol content with reduced specific PPO activity. At optimized values (70 mM inhibitory solution at 96 °C for 6.4 min, Γ = 11.6), 93.3% PPO inhibition and total polyphenol of 94.9 mg GAE/g were obtained. In addition, microscopy images confirmed the cell morphological changes measured as the fractal dimension and explained the possible cell lysis and denaturation as a result of heat treatment and chemical inhibitors. Results also showed that PPO enzyme was most suitable (higher vmax/Km ratio) for catechol, with a reduction in its affinity of 13.7-fold after the inhibition heat treatment. Overall, this work proposed a suitable and food-safe procedure for obtaining enriched polyphenol extract with low enzyme activity.

Bioactive compounds and techno-functional properties of high-fiber co-products of the cacao agro-industrial chain

“…At present, there are no studies on the optimal temperature, the type or the concentration of chemical inhibitors, the time of heat treatment to decrease the enzymatic activity that affects the polyphenols present in the pod. Some studies carried out on cocoa beans show that temperatures of 96 °C for 6.4 min can greatly decrease the enzymatic activity and obtain the highest content of polyphenols [ 60 ].…”

Exploring the chemical composition and coloring qualities of cacao fruit epicarp extracts

“…45 Diverse strategies exist for polyphenol oxidase inactivation, such as reducing agents or enzymes, changing pH, and increasing temperature. 46 The most straightforward enzyme inactivation strategy is temperature. However, increasing the temperature affects the avonoid's thermolabile structure.…”

Preparative Separation of Procyanidins from Cocoa Polyphenolic Extract: Comparative Study of Different Fractionation Techniques

“…Cocoa polyphenolic extract was produced on a lab scale from unfermented cocoa beans (Trinitary variety ICS-39 were clone in Colombia) using the procedure described by Toro-Uribe et al [49,55]. Briefly, the unfermented cocoa beans (pulp free) with low polyphenol oxidase enzyme activity was obtained by placing the beans in a solution of 70 mM ascorbic acid/L-cysteine (1:1 v/v) at 96 • C for 6.4 min followed by immediately cooling in ice water for 30 min according to Toro-Uribe et al [65]. Then, the beans were oven dried at 70 • C for 3 h (Binder model FD 23, Tuttlingen, Germany) and ground using a cryogenic ball mill (Cryomill MM 400, Retsch GmbH, Haan, Germany).…”