Grading/ Sorting of Fruits and Vegetables

Grading/ Sorting of Fruits and Vegetables

This is from my postharvest handing subject. Due to variations in growing conditions and the response of the developing commodity to these, the quality of any fruits or vegetable at harvest cannot be expected to be in good form. Varying proportions of the crop will depart from “perfect condition” in terms of color, gloss, size, shape and other permanent quality.

Growing conditions and the maturity at harvest determine the potential quality of the commodity at any stage of the postharvest chain. This potential quality cannot be improved after harvest. Thus, ripening of immature mango or banana might result in softening or peel color development but an inferior pulp quality in terms of color, flavor or aroma.

After harvest, quality deteriorates at a rate determined primarily by the response of the commodity to external factors in the environment. Defects arising from improper grading and deterioration are known as condition defects of progressive nature and include wilting, yellowing noted by excessive softness (overripe condition), pitting and discoloration.

Sorting is the process of classifying into groups designated by the person classifying according to whatever criteria he may desire or according to a set criteria. In the absence of the set criteria the classification into which a commodity falls will be subject to variations attributable to individual differences. Thus, grades and standards have to be used to minimize variations in classifications.

Grades and standards provide a common language for classification and therefore help in stabilizing business in the fruit and vegetable industry.

This is how the methods of Sorting/ Grading:

Harvest a commodity fruits from several trees.

Divide the different fruits into:

a.       Sound – showing good appearance, free from damage and injury.

b.      Damage – loss in value and usefulness of commodity due to physical causes.

c.       Overripe.

d.      Blemish – spoil by a flaw, uneven coloration & other characteristics.

e.      Off type/ off shape.

Classify fruits under each category into different sizes example small, medium and large.

Classify the fruits according to grade:

a.       The biggest fruits which are very uniform in every attributes like sizes, shapes, colors, etc. shall be classified as extra. To this, 5% tolerance allowed.

b.      For grade I, the same attributes as in extra are used except that 10% tolerance is allowed.

c.       Fruits which do not fall under extra and grade I but still fit for human consumption shall be classified as grade II.

d.      Heavily damaged fruits not fitted for transport shall be culled.