A research was conducted on the effect of heat treatments on the heating and cooling of the ‘Idared’ apple fruit. The heat treatment was performed as hot water dip (HWD), where fruit were dipped into water at 50 °C, for two, four and six minutes (HWD 500C 2’, HWD 500C 4’ and HWD 500C 6’, respectively). The aim of the study was to determine the effect of heat treatments on the warming and cooling on the fruit which was observed by thermographic images recorded every minute for the duration of 12 minutes in total. The fruit treated with HWD 50°C 6’ achieved the highest temperature (50.6 0C), followed by HWD 500C 4’ (48.2 0C) and HWD 500C 2’ (44.3 0C). The damage to fruit caused by high temperatures (heat damage) was visible only on the fruit treated with HWD 50°C 6’. The differences in maximal temperature of fruit surface were statistically different among all three exposures for the whole duration of recording, meaning that the duration of the hot water dip treatment significantly affects the intensity of fruit cooling after heat treatment.

infrathermal camera, apple, heat treatment, heating, cooling

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia