Determination of acceptable firmness and colour values of tomatoes

Firmness and colour are the most important factors for determination of tomato quality. Two possible minimum firmness limits were suggested for tomato fruits at the point of retail marketing and at home. All 100% marketable fruits should have firmness values above 1.45 N mm−1 but the Instron values of the tomato at the home use stage should have values higher than 1.28 N mm−1. Minolta a∗/b∗ values were less variable for mature green and breaker stages of tomatoes. Separation values between the turning and pink stages were found to be over 0.08 Minolta a∗/b∗ value. For the light red stage that is commonly marketable this was between 0.60 and 0.95. The red stage is a little overripe for normal maturity and its Minolta a∗/b∗ values were found to be from 0.95 to 1.21.