El pardeamiento no enzimático en zumos y purés de fruta

During processing and storage, deleterious changes can occur in fruit juices and purees. One of the major changes that occur result in non-enzymatic development of the brown pigmented materials. The major non-enzymatic reactions involved in fruit juices processing and storage are: Maillard carbohydrate/amino acid reactions, caramelization, which involves the thermal degradation of sugars without amine participation; and ascorbic acid degradation, which can occur by both oxidative and non-oxidative mechanisms. Non enzymatic browning is not always developed in the same way, and it depend on numerous factors; the most important are: temperature, water activity, pH, oxigen and food composition. Temperature has a major effect on non-enzymatic browning. At higher temperature, higher changes in colour are produced.