PRESTORAGE HEAT-TREATMENTS INFLUENCE FREE STEROLS AND FLAVOR VOLATILES OF TOMATOES STORED AT CHILLING TEMPERATURE

The objective of this study was to determine the effects of prestorage heat treatments on chilling tolerance of tomatoes, Mature-green 'Agri set' tomato fruit (Lycopersicon esculentum Mill.), either C2H4-treated or not, were immersed in 42C water for 60 min, held in 38C air for 48 hour's, or not treated, and then stored at either 2C (chilled) or 13C (nonchilled) for 14 days before ripening at 20C, Heat-treated fruit s tored at 2C and transferred to 20C ripened normally while nonheated fr uit decayed before reaching red ripe, Color (a/b* ratio), lycopene co ntent, and internal quality characteristics of fruit were similar at t he red-ripe stage irrespective of method of heat treatment, In red-rip e heat-treated fruit, free sterol levels were significantly higher in chilled fruit than in nonchilled fruit, Heating fruit in 38C air resul ted in significantly higher levels of some free sterols compared with heating fruit in 42C water, Of the 15 flavor volatiles analyzed, six s howed significantly decreased concentrations as a result of C2H4-treat ment and seven showed decreased concentrations when stored at 2C befor e ripening, Some volatiles were decreased by the heat treatments, Pres torage short- and long-term heat treatments could allow for storage of mature-green tomatoes at lower temperatures with little loss of their ability to ripen normally.