Polyphenols in dessert apples and their stability during cold storage

摘要

Polyphenols contribute significantly to the organoleptic criteria of apples and their processed products such as juices and ciders (Lea, 1990). In addition, their consumption as constituents of fruits and vegetables in the diet might be related to a health protecting action against cardiovascular disease and some cancers (Hertog et al., 1993). Polyphenols are with concentrations up to 7 grams per kilograms of fresh matter in some cider apple varieties (Sanoner et al., 1999) and in the range 0.5-2 g/kg FW in common dessert varieties (Nicolas et al, 1994). Six polyphenol categories can be listed (figure 1): hydroxycinnamic acids, catechins, procyanidins and dihydrochalcones are present in the whole fruit. Flavonols and anthocyanins are essentially found in the skin. Much data can be found about polyphenol concentrations in apples (Nicolas et al., 1994) and more precisely about their stability during cold storage in regular or controlled atmospheres (Burda et al, 1990; Piretti et al, 1994; Reay, 1998; Awad and Jager, 2000; Van der Sluis et al, 2001). However, great discrepancies exist in the published data and most studies do not present data concerning the procyanidins which were shown to be the most abundant polyphenols in dessert apple varieties (Guyot et al, 2002).