Anti-Browning Agents

The browning process is a natural phenomenon that occurs in fruits, vegetables and beverages, which has become a major problem and challenge in the food industry. Browning has a significant impact on the appearance, nutritional and organoleptic properties of food, resulting in a shorter shelf life and a decrease in market value as well as safety. Enzymatic browning occurs mainly through the action of enzymes, such as polyphenol oxidase (PPO)and peroxidase (POX). These enzymes can be found in microorganisms and higher plants (potatoes, apples, pears, bananas, mushrooms, and avocados). In the presence of oxygen, enzymatic browning takes place when these enzymes catalyze the oxidation of phenols to quinones. Subsequently, these quinones undergo spontaneous polymerization or the reaction of quinones with amino acids or proteins to form brown pigments^[1]. Since browning is an oxidative reaction, it can be alleviated by the removal of oxygen from the cut surface of fruits or vegetables. However, this is not always feasible. Thus, a more feasible and practical approach to prevent browning is to use anti-browning agents. In the food industry, sulfite compounds are the most commonly used anti-browning agents. Nevertheless, sulfite compounds are prone to various adverse health effects, such as allergies. Recently, a group of natural products called metabolites have attracted much attention for their anti-browning ability.

Applications

The application of plant or microbial metabolites as anti-browning agents has attracted the attention of many food researchers. Several examples of metabolites used as anti-browning agents are listed below.

• Polyphenols used as anti-browning agents

Polyphenols are considered the largest group of metabolites in fruits, vegetables, and herbs. They present in various form such as phenolic acids, flavonoids, and other phenolics. Many studies have reported a strong positive correlation between total polyphenol content and the ability of anti-browning. The anti-browning property of polyphenols could be due to their redox property, which allows the polyphenols to act as reducing agents, singlet oxygen quenchers, and hydrogen donators^[2].

• Carotenoids used as anti-browning agents

Carotenoids are plant metabolites naturally present in many fruits and vegetables. Depending on the presence of oxygen in the carotenoid structure, they can be classified into two main carotenoid groups, namely oxygenated xanthophylls and unoxygenated carotenes. The application of carotenoids as anti-browning agents in fresh-cut products is promising because of their ability to scavenge the free radicals associated with the development of browning.

• Organic acids used as anti-browning agents

Organic acids are a type of primary metabolites that can be found naturally in plants or microorganisms. They are great enzyme inhibitors that can inactivate PPO by lowering the pH in the medium. Based on the mechanism of food browning, organic acids exhibit excellent anti-browning property. In addition, organic acids are safe and have no intake restrictions for humans. Therefore, it is possible to replace the chemical anti-browning agents by natural organic acids^[3].

What Can We Do?

Alfa Chemistry has a profound research foundation in the field of anti-browning agents. In our company you can find the appropriate metabolites for the research of anti-browning agents. Alfa Chemistry will serve you with the most abundant experience and affordable price. Please feel free to contact us if you have a need.

References

1. Dias, C.; et al. Natural-based antioxidant extracts as potential mitigators of fruit browning. Antioxidant, 2020, 9(8): 715.
2. Kasote, D.M.; et al. Significance of antioxidant potential of plants and its relevance to therapeutic applications. International Journal of Biological Sciences. 2015, 11: 982-991.
3. Hamdan, N.; et al. Prevention of enzymatic browning by natural extracts and genome-editing: a review on recent progress. Molecules. 2022, 27: 1101.

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