TEXTURAL PROPERTIES OF FRUITS AND VEGETABLES AND THEIR CHANGES DURING FREEZING AND STORAGE AT LOW TEMPERATURES

Abstract

Five sour cherry varieties (Pándy, Érd, Meteor, M63 and M136), four apple varieties (Starkrimson, Idared, Goldenspur, Jonathan), two peach varieties (Elberta and Champion) and two pear varieties (Hardy and Alexander) grown in Hungary were investigated. Changes of commercial carrots during pretreatment and freezing were also studied. Textural properties were studied during ripening, freezing and thawing using the texture profile method of SZCZESNIAK et al. (1963), penetrometric measurement (LÁSZTITY et al., 1973) and organoleptic control. Both the penetrometric and organoleptic methods were found to be satisfactory for classifying the fruits of different degree of maturity. Textural changes occurring during freezing were strongly affected by the variety and also by maturity degree. Frozen and thawed products were always softer than fresh products and this was valid also for the texture after cooking. A chilling of sour cherries before freezing and immersion of some vegetables into a solution of lower pH decreased textural changes during freezing.