Fully ripened fruit will not stand handling and hauling and will quickly deteriorate, reaching the consumer in bad condition.
For cannery, full ripening is desired with even coloring. MacGillivray[18] has shown that success in this is largely a matter of care in picking. Cracking and slight softening are not serious defects for this purpose, but molds and bacteria in broken places are serious as they throw the product out of grade or occasion rejection.
Most tomatoes for long distance shipment, are picked before color appears,--at the mature-green stage. One of the great difficulties is to judge this stage correctly; to train ordinary labor to pick by maturity and not by size. Immature-green tomatoes ripen slowly and do not achieve good appearance or table quality.
It is almost impossible to describe the ear marks of a mature-green tomato. Most of those usually cited are of doubtful value--glossy surface, whitish cast of color and the dark ring at the stem scar. The jelly-like or mucilaginous material in the seed cells has sufficiently developed in a mature green tomato so that the fruit may be sliced without cutting seeds. Of course, the tomato is ruined but the method can be used to check one's judgment based on the exterior. Also, one can learn by laying aside tomatoes judged mature-green and immature-green to ripen.
Some efforts have recently been made in Florida to pick tomatoes at the turn, that is, at the first show of color, a practice suggested by Sando[19] some years ago. This should provide fruits of uniform degree of maturity, that would be about ready to sell on arrival and it would eliminate the serious problem of immature-greens. It would require more frequent picking of fields and there could be no delay in packing. There would, doubtless, also be problems of temperature and ventilation in transit. Results of tests thus far have been rather encouraging.
Green wrap tomatoes are received at terminal markets by produce houses that have special ripening rooms where temperature is kept at about 70°, with high humidity to prevent wilting or shriveling. Ethylene gas is used by some to hasten ripening. It does not change the nature of the process, merely speeding it up. Some of these repackers have elaborate equipment for sorting and packing.