Effect of Temperature on Firmness of Thermally Processed Fruits and Vegetables

The firmness of many commercially canned fruits and vegetables was measured by puncture, extrusion and Texture Press over the temperature range3–48°C. The firmness almost always decreased with increasing temperature and the firmness-temperature plots were rectilinear. The firmness-temperature coefficient (FT) is defined as the percent change in firmness per degree temperature increase. It ranged from close to zero to about -1.0% for most of the samples tested. The temperature should be kept within narrow limits when making firmness measurements on thermally processed fruits and vegetables, otherwise significant errors can be introduced.