Phenolic compounds and related enzymes as determinants of quality in fruits and vegetables.
Tomas-Barberan, F. A. and Espin, J. C.
Journal of the Science of Food and Agriculture. Volume 81, Number 9, July 2001. Pages 853-876.
2001
บทคัดย่อ
Phenolic secondary metabolites play an important role in plant-derived food quality, as they affect quality characteristics such as appearance, flavour and health-promoting properties. Their content in foods is affected by many factors that influence phenolic stability, biosynthesis and degradation. In terms of their biosynthesis, the key enzyme phenylalanine ammonia-lyase (PAL) is especially relevant, as it can be induced by different stress (environmental) conditions. In addition, polyphenol oxidases [catechol oxidase] and peroxidases are the main enzymes responsible for quality loss due to phenolic degradation. Different factors affecting phenolic-related food quality are reviewed. These include internal (genetic) and environmental (agronomic) factors, technological treatments applied during postharvest storage of fruits and vegetables, as well as the processing and storage of processed products. Different strategies that are required to either maintain or enhance the phenolic-related quality of foods are critically reviewed. The genetic modification designed to decrease polyphenol oxidases or peroxidases is not always a feasible method, owing to side problems related to the growth and defence of the plant. Agronomic treatments can be used to enhance the phenolic content and pigmentation of fruits and vegetables, although the information available on this topic is very scarce and even contradictory. Some postharvest treatments (cold storage, controlled or modified atmospheres, among others) can also improve the phenolic-related quality, as well as new processing methods such as irradiation (gamma, UV), high-field electric pulses, high hydrostatic pressures and microwaves.