Recent Trends in Controlling the Enzymatic Browning of Fruit and Vegetable Products

Abstract

Enzymatic browning because of polyphenol oxidases (PPOs) contributes to the color quality of fruit and vegetable (FV) products. Physical and chemical methods have been developed to inhibit the activity of PPOs, and several synthetic chemical compounds are commonly being used as PPO inhibitors in FV products. Recently, there has been an emphasis on consumer-oriented innovations in the food industry. Consumers tend to urge the use of natural and environment-friendly PPO inhibitors. The purpose of this review is to summarize the mechanisms underlying the anti-browning action of chemical PPO inhibitors and current trends in the research on these inhibitors. Based on their mechanisms of action, chemical inhibitors can be categorized as antioxidants, reducing agents, chelating agents, acidulants, and/or mixed-type PPO inhibitors. Here, we focused on the food ingredients, dietary components, food by-products, and waste associated with anti-browning activity.

Volatile Composition and Sensory Attributes of Smoothies Based on Pomegranate Juice and Mediterranean Fruit Purées (Fig, Jujube and Quince)

“…The different stages of the smoothie preparation process as well as the ratio of purée:juice were previously described by Cano-Lamadrid et al [ 5 ]. Briefly, the stages of the smoothie preparation process were: Purée preparation: figs (F), jujubes (J), or quinces (Q) were peeled, ground, and heated at 80 °C in a Thermomix device (Vorwerk, Wuppertal, Germany); 10 mL of rhubarb juice per 1 kg of fruit were added to prevent enzymatic browning of the fruit due to the high oxalic acid concentration which chelates copper from the active site of polyphenol oxidase (PPO) [ 11 , 12 ]. After, the particle size of the mixture was reduced in a blender (Symbio, Zelmer, Rzeszów, Poland) until getting a thin purée.…”

Antioxidant Compounds for the Inhibition of Enzymatic Browning by Polyphenol Oxidases in the Fruiting Body Extract of the Edible Mushroom Hericium erinaceus

“…PPOs, including tyrosinase and laccase, are enzymes well-known for their activities related to post-harvest browning pigments in agricultural products [11]. Although these pigment compounds, such as certain secondary metabolites, might be useful for enhancing bioactive compounds in fermentation processes or for helping to preserve protein in forage crops, the browning reactions are generally viewed negatively in food processing or in fresh products [10][11][12]. The dark color reaction occurs via PPOs, which can be induced by wounding or pathogen attacks as part of the defense response in plants and fungi [10,12].…”

Inactivation of Thioglucosidase from Sinapis alba (White Mustard) Seed by Metal Salts

“…Meat-like flavors associated mainly with Maillard reaction can be created by a double enzyme (Flavourzyme) in the two-step hydrolysis of Brassica proteins [ 4 ]. Knowledge of enzymes allows for controlling the enzymatic processes in plant tissue and thus maintain the quality by using a wide range of anti-browning agents against enzymatic browning of fruit and vegetable products [ 5 ].…”