The physiological processes that take place during ripening of juicy fruits can be divided into two periods. The first period begins at ovule fertili

Ripening of fruits [maturation, growth]

The physiological processes that take place during ripening of juicy fruits can be divided into two periods.

The first period begins at ovule fertilization until seed maturation and termination of the pericarp growth, i.e., the fleshy part of the fruit; second period — from the end of the first period to the full maturity of the pericarp.

During the first period in the seeds and in pericarp occur energetic processes of synthesis. Synthesis processes lead to an increase in the mass of protoplasm, to a thickening of the cell walls and to the accumulation of nutrients (starch, fat, protein).

The second period of fruit ripening is characterized by a collapse of nutrients into simpler substances. Synthetic processes still continue in the seeds. However, the seeds gradually dewater, biochemical processes in them slow down and the seeds go into a dormant state.

In pericarp occurs the transition of starch into sugar, green pigment chlorophyll collapses, and a water-insoluble protopectin, that glues membrane, becomes water-soluble pectin. Due to the dissolution of the pectin pericarp cells lose their interconnection, become rounded, and the pericarp tissue becomes softened.

Nevertheless, it should be noted that in the ripening pericarp also occur synthesis processes, as form pigments, vitamins and essential oils. The waxy substance is deposited on the skin of many fruits. Yet in general at this time in the pericarp decay processes dominate.

Preparation for the separation of the fruit from the mother plant also occurs in the second period of fruit development. In the stalk, forms a layer of loosely interconnected cells (separation layer). At this point takes place separation of the fruit from the mother plant. Thus, the connection between the plant and the fruit during the second period is terminated, and biochemical processes go due to the transformation of substances that were accumulated in the first period.

Parthenocarpic fruits also have two periods in its development, as well as the normal fruit.

In the growth of the fruit play a certain role organic acid auxins affecting plant growth. Produced in the process of metabolism in the living organism, auxins include themselves in the metabolism, and play an important role in the growth process. Auxins are produced in the seeds and hence fall into the pericarp, contributing, as one of the factors, a fruit growth. In the second period of fruit ripening auxin does not allocate, also stops the flow of nutrients from the mother plant, and as a result, stops the growth of the fruit. Taken from http://worldofschool.org

In the fruits that have stopped growth accumulates ethylene gas C2H4, which plays an important role in the maturation of the pericarp. Under the influence of ethylene occurs strengthening of metabolism, respiration rises and it promotes a more rapid maturation of the fruit.

Experiments have shown that it is possible to accelerate the maturation of immature fruits that have completed their growth, if artificially process them with ethylene in special sealed chambers, where injects the necessary for ripening concentration of ethylene. Ripening of green tomatoes under these conditions completes in 5-6 days, but without ethylene — 10-12 days. For the northern regions, where tomatoes ripen on the vines bad, this method of artificial ripening plays a big role.

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