Agronomic and physical-chemical evolution of tomatoes during ripening

The decision of the harvesting date, generally based on the percentage of red fruit, has an important impact on the final net yield and quality of the tomatoes for industrial processing. For this reason, the physical-chemical parameters were evaluated in one tomato variety that was harvested at different times with different sowing dates. In order to confirm the best harvesting date, the agronomic aspects considered for this study were: the harvesting dates (i.e., the ideal harvesting date previously calculated by accumulation of heat units, as well as 12 and 4 days before it, and 4 and 11 days after it) and three sowing dates, separated two weeks between them. The total number of fruits collected for each sowing and harvesting dates, were separated in different tomato colour ripening fractions: green, pink, red, sunburned and overmature. The physical-chemical parameters studied in all the above-mentioned tomato fractions were: pH, degreesBrix, consistency, colour and carotenoid content. According to the agronomic information, the best time for harvesting is when 85-90% of the tomato fruit are red and not before. However the quality attributes looked for the tomato fruit, reach their optimum value a week before the agronomic harvesting date and they remain constant for at least a week after, when the% of maturity is still low from the agronomic point of view. For these reason, the selection of the best harvesting date is based on the agronomic aspects more than the physical-chemical parameters, due to the yield expected for harvesting is reached after the analytical quality. This result confirms the harvest practices in tomato crops for tomato Nestle factory in Extremadura, SW Spain.