Ripening
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This lemon will turn yellow as it ripens. |
Ripening is a process in
fruit that causes them to become more
edible. In general, fruits become
sweeter, less
acidic, less
green, and softer as they ripen.
Stages of a plant's life are influenced by
hormones. An important
plant hormone involved with ripening is the
chemical ethylene, a
gas created by plants from the
amino acid methionine. Ethylene increases the intracellular levels of certain
enzymes in fruit and
fresh-cut products, which include:
*
Amylase, which hydrolyzes
starch to produce simple
sugars, and
*
Pectinase, which hydrolyzes down
pectin, a substance that keeps fruit hard.
Other enzymes break down the
lime pigment chlorophyll, which is replaced by
blue,
yellow, or
red pigments.
Hormone levels in fruit are often connected to
pollination. If too few
seeds in a multiseeded fruit are formed (by
fertilization of the
ovules), the flesh of the fruit may not develop in some areas, and ripening will be retarded or prevented. Fruit growers increasingly monitor seed ratios in developing and/or mature fruit and adjust pollination management accordingly.
Many fruits are picked prior to full ripening because ripened fruits do not ship well. For example,
bananas are picked when green and artificially ripened after shipment by gassing them with ethylene.
SmartFresh, is a technology to maintain fresh-picked quality of whole fruits and vegetables. 1-Methylcyclopropene (1-MCP 0.14%) works with the ripening process to dramatically slow down ethylene production and prevent over-ripening and problems associated with aging.
