SENSORY EVALUATION OF HEATED AND CALCIUM-TREATED FRUITS

Postharvest heat treatments have been proposed as non-chemical means for enhancing storage of fruits and vegetables. Various regimes of time and temperature in either hot air or hot water maintain fruit firmness and diminish the incidence and severity of pathological diseases. Treatment with calcium, alone or in combination with heat, has similar beneficial effects. Little attention has been paid to the organoleptic effect of these treatments, upon which consumer acceptability ultimately rests. We heated (38°C, 3 d) mature-green or pink tomatoes (Lycopersicon esculentum, L., cv. 'Daniella') and measured overall consumer preference after the fruit were stored at 12°C for 10 d. Heated and non-heated fruit were rated similarly for acceptability by a taste panel, with no off-flavours being detected. Apples (Malus domestica, Borkh., cv. 'Golden Delicious') were infiltrated with 2% calcium chloride, or heated (38°C, 4 d), or heated and then infiltrated prior to 6 months' storage in air at 0°C. A range of flavour and texture attributes were then rated by tastes panellists. Heated and/or calcium-treated fruit were perceived as crisper, sweeter, and overall more acceptable than untreated fruit. We conclude that, in addition to conferring physiological benefits on stored tomatoes and apples, heat and calcium treatments do not damage and may even improve consumer acceptability.