Phytochemical Changes during Minimal Processing of Fresh Fruits and Vegetables

Abstract

Minimally processed fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber. Moreover, they are rich in biologically active compounds, called phytochemicals, which impart health benefits beyond basic nutrition. The most thoroughly investigated dietary components in fruit and vegetables acting as antioxidants are phenolic acids, flavonoids, anthocyanins,lycopene, vitamins A, B, and C, tocopherols, and sulfides (Robles-Sanchez et al., 2007). It is important to consider that the antioxidant content of fresh fruit and vegetable tissues can be affected by maturity, agricultural practices,postharvest handling, minimal processing, and storage conditions (Sacchetti et al., 2008). The consumption of fresh-cut fruits and vegetables has increased worldwide in the last decade owing to their convenience, freshness, and improved quality. Fresh-cut fruits and vegetables are products that are partially prepared so that no additional preparation is necessary for their use. A major challenge facing the industry, however, is the rapid quality deterioration and reduced shelf life of fresh-cut products compared with whole fruits and vegetables due to physiological disorders and decays (Siddiqui et al., 2011). The preparation procedure generally includes processes such as washing, peeling, cutting, trimming, slicing, shredding, dicing, and coring. The processes used for preparing fresh-cut fruits and vegetables induce mechanical injury in the tissue, causing destruction of surface cells and removing natural barrierssuch as cuticles and skins, which makes tissues more susceptible to water loss and decay (Siddiqui et al., 2011). In addition, membrane lipid degradation may cause loss of lipid components and of cell compartmentalization. The mixing of substrates and enzymes that are normally separated can initiate reactions that normally do not occur, which could affect the phytochemical content and antioxidant capacity of the produce (González-Aguilar et al., 2005). In addition, as a consequence of damage caused by processing, there is an increase in respiration rate which may accelerate deterioration products, and therefore shorten their shelf life (Siddiqui et al., 2011). In conclusion, process wounding induces a number of physiological disorders which may accelerate product decay and degradation and loss of nutrients, such as vitamins and phytochemicals. Much research has still to be done in order to develop safe fresh-cut fruit and vegetables products with high sensory quality and nutritional value. However, the presence of high amounts of bioactive compounds in fresh tissue does not always ensure a complete incorporation of these compounds into the organism. Of all the nutrients and bioactive compoundsincorporated with food, only a fraction can be effectively utilized by the body ? and that fraction depends on the bioavailability of the specific compound (Bouayed et al., 2012; Parada and Aguilera, 2007). The purpose of this chapter is to collect and explain updated information regarding changes in bioactive phytochemical compounds, including their bioactive content and the antioxidant capacity of fresh fruits and vegetables during minimal processing, and how this process affects the bioaccessibility and bioavailability of bioactive compounds.