Benefits of a diet rich in fruits and vegetables must be attributed to the synergistic effect of the complex mixture of various phytochemicals present in some kind of foods. Several thousands of these compounds differing in molecular size, polarity, and solubility are here present. Their bioavailability is affected by the distribution in different subcellular organelles, cells, tissues, and organs; there are also significant differences in individual phenolics among fruit species, cultivars of the same fruit, region and orchard productions, and also during storage and food processing. For example, apple polyphenols are concentrated in the pericarp, so that process of peelig wastes the bulk of polyphenols. Moreover, in intact plant tissues, cell walls, polyphenols and enzymes are present in distinct compartments, but when cells are ruptured, these three elements come in contact, and polyphenols can react with polysaccharides and cell wall components. Thus the chemical, qualitative and quantitative information on polyphenols has to be supported by information on the precise localization in the fruit tissues and also in their cellular and extracellular compartments. To reveal the precise localization of polyphenols our cryostabilization method based on ethylene glycol (at -20°C) and glycol methacrylate embedding, at low temperature (6-10°C) has been applied to some fruits (apples, wine grapes, grapefruits, apricots, kiwi, cherries, tomatoes). Here we report the preliminary positive results offered by this inexpensive and easy performing method.
Histochemistry of fleshy fruits polyphenols, cryostabilization and GMA embedding
VALLANIA R;
2005
Abstract
Benefits of a diet rich in fruits and vegetables must be attributed to the synergistic effect of the complex mixture of various phytochemicals present in some kind of foods. Several thousands of these compounds differing in molecular size, polarity, and solubility are here present. Their bioavailability is affected by the distribution in different subcellular organelles, cells, tissues, and organs; there are also significant differences in individual phenolics among fruit species, cultivars of the same fruit, region and orchard productions, and also during storage and food processing. For example, apple polyphenols are concentrated in the pericarp, so that process of peelig wastes the bulk of polyphenols. Moreover, in intact plant tissues, cell walls, polyphenols and enzymes are present in distinct compartments, but when cells are ruptured, these three elements come in contact, and polyphenols can react with polysaccharides and cell wall components. Thus the chemical, qualitative and quantitative information on polyphenols has to be supported by information on the precise localization in the fruit tissues and also in their cellular and extracellular compartments. To reveal the precise localization of polyphenols our cryostabilization method based on ethylene glycol (at -20°C) and glycol methacrylate embedding, at low temperature (6-10°C) has been applied to some fruits (apples, wine grapes, grapefruits, apricots, kiwi, cherries, tomatoes). Here we report the preliminary positive results offered by this inexpensive and easy performing method.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
