Active packaging and colour control: the case of fruit and vegetables F. Artes Calero, Technical University of Cartagena, Spain and P.A. Gomez, National Institute for Agricultural Technology, Argentina 20.1 Introduction Consumer satisfaction is related to fresh product quality. This quality is generally associated with visual appearance, colour being one of the most important aspects in the consumers purchase decision. The association of certain colours with the acceptance of fruits and vegetables begins early and is maintained through life. For instance, when the red colour of fruit is enhanced the perceived sweetness level increases. Colour is normally used to determine cceptable limits for a given grade of product and to define colour tolerances for both harvest and trade. Combined with other characteristics it can be used to establish indices of maturity, enabling us to know whether a commodity can be harvested and to predict postharvest life of the product. For this reason colour requirements are more and more prevalent in retailer's specifications A knowledge of fruit and vegetable pigment composition allows us to evaluate the input of postharvest treatments on colour and quality. In fresh as well as in minimally processed products it is crucial to know the factors affecting pigment stability as well as the main changes associated with processing. Analysing pigment composition of fruit and vegetables and their derivatives is important for optimising postharvest treatments during harvest, handling, storage and distribution. In fact, lowering O2 and increasing CO around fruit and vegetables by using controlled atmosphere(CA)or active or passive modified atmosphere packaging(MAP)techniques is commonly a good method for keeping colour stability. On the other hand, one of the main problems that reduces shelf-life of minimal processed fruit and vegetables is the enzymatic browning that occurs on the cut surface area. In this review, an update on the main tools for controlling colour changes is given. To prevent adverse20.1 Introduction Consumer satisfaction is related to fresh product quality. This quality is generally associated with visual appearance, colour being one of the most important aspects in the consumer’s purchase decision. The association of certain colours with the acceptance of fruits and vegetables begins early and is maintained through life. For instance, when the red colour of fruit is enhanced, the perceived sweetness level increases. Colour is normally used to determine acceptable limits for a given grade of product and to define colour tolerances for both harvest and trade. Combined with other characteristics it can be used to establish indices of maturity, enabling us to know whether a commodity can be harvested and to predict postharvest life of the product. For this reason colour requirements are more and more prevalent in retailer’s specifications. A knowledge of fruit and vegetable pigment composition allows us to evaluate the input of postharvest treatments on colour and quality. In fresh as well as in minimally processed products it is crucial to know the main factors affecting pigment stability as well as the main changes associated with processing. Analysing pigment composition of fruit and vegetables and their derivatives is important for optimising postharvest treatments during harvest, handling, storage and distribution. In fact, lowering O2 and increasing CO2 around fruit and vegetables by using controlled atmosphere (CA) or active or passive modified atmosphere packaging (MAP) techniques is commonly a good method for keeping colour stability. On the other hand, one of the main problems that reduces shelf-life of minimal processed fruit and vegetables is the enzymatic browning that occurs on the cut surface area. In this review, an update on the main tools for controlling colour changes is given. To prevent adverse 20 Active packaging and colour control: the case of fruit and vegetables F. Arte´s Calero, Technical University of Cartagena, Spain and P. A. Go´mez, National Institute for Agricultural Technology, Argentina