LABORATORY
EXERCISE NO.5
Grading/
Sorting of Fruits and Vegetables
I.INTRODUCTION
Due to variations in growing
conditions and the response of the developing commodity to these, the quality
of any fruit 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. These are
defects of progressive nature and include wilting, yellowing, noted by
excessive softness (overripe condition), pitting and discoloration.
Consumers
buy with their eyes and the visual quality attributes, therefore, have the
greater impact on the consumers decision whether to buy a commodity or not, and
in certain cases, whether to pay a higher price for the commodity. Clearly then,
there is a need for sorting.
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.
II. OBJECTIVES
This exercise will be conducted to:
a.)
Learn
the methods on how grading of commodities is done and
b.)
Demonstrate
the effects of grading/ sorting on the postharvest life of the commodities.
III. MATERIALS AND
METHODS
A.
METHODS
OF SORTING/GRADING
1.
The
students harvested citrus from several trees.
2.
They
divided the different fruits into:
a.
Sound
b.
Damage
c.
Overripe
d.
Blemish
e.
Off
type/off shape
3.
They
classified fruits under each category into different sizes i.e. small, medium
and large. They also weighed the commodities based on sizes.
4.
They
classified 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 is 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.
5.
Then
tabulated all the data.
B.
EFFECTS
OF SORTING
1.
The
students harvested tomato fruits from several plants
2.
They
divided the different vegetables based on:
a.
Soundness
b.
Maturity
3.
They
stored at least (10) vegetables inside the polyethylene bags each bag with
different soundness and maturity. The following treatments shall be used:
T1- sound and mature green
T2- sound with different degrees of
maturity
T3- sound and ripe
T4- no sorting/grading
4.
They
gathered the following data at daily interval
a.
Visual
Quality Rating (VQR)
b.
Change
in color
c.
Number
of days to salability
d.
Presence
of diseases
5.
They
tabulated all the data.
IV. RESULTS/DISCUSSION
B. Effects of Sorting
Table 5
The Daily Visual Quality Rating of
Vegetables as Affected by Sorting
|
Days
|
||||||||
|
Treatment
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
|
Feb. 4
|
Feb. 5
|
Feb. 6
|
Feb. 7
|
Feb. 8
|
Feb. 9
|
Feb. 10
|
Feb. 11
|
|
T1- Sound
and Mature green
|
8
|
8
|
8
|
6
|
6
|
5
|
5
|
5
|
|
T2-Sound
at Different Maturity
|
7
|
7
|
7
|
salable
|
salable
|
salable
|
end
of salability
|
end of salabiliy
|
|
T3-Sound
and Ripe
|
7
|
salable
|
salable
|
salable
|
end
of salability
|
end
of salability
|
end
of salability
|
end of salability
|
|
T4-No
sorting/Grading
|
3
|
salable
|
salable
|
salable
|
end
of salability
|
end
of salability
|
end
of salability
|
end of salability
|
Table 6
The Daily Change in Color of
Vegetables as Affected by Sorting
|
Days
|
||||||||
|
Treatment
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
|
Feb. 4
|
Feb. 5
|
Feb. 6
|
Feb. 7
|
Feb. 8
|
Feb. 9
|
Feb. 10
|
Feb. 11
|
|
T1- Sound
and Mature green
|
Mature
green
|
10-25%
yellow, pink, orange, or red
|
26%-50%
yellow, orange, or red
|
26%-50%
yellow, orange, or red
|
51%-75%
yellow, orange, or red
|
51%-75% yellow, orange, or red
|
51%-75%
yellow, orange, or red
|
Fully colored red
|
|
T2-Sound
at Different Maturity
|
26%-50% yellow, orange, or red
|
51%-75%
yellow, orange, or red
|
Fully
colored red
|
salable
|
salable
|
salable
|
end
of salability
|
end of salability
|
|
T3-Sound
and Ripe
|
Fully
colored red
|
salable
|
salable
|
salable
|
end
of salability
|
end
of salability
|
end
of salability
|
end of salability
|
|
T4-No
sorting/Grading
|
Fully
colored red
|
salable
|
salable
|
salable
|
end
of salability
|
end
of salability
|
end
of salability
|
end of salability
|
Table 7
Days to Salability of Stored
Vegetables with Different Degrees of Maturity and Soundness
|
Treatment
|
Days to
Salability
|
|
T1- Sound and Mature green
|
8 days
|
|
T2-Sound at Different Maturity
|
3 days
|
|
T3-Sound and Ripe
|
1 day
|
|
T4-No sorting/Grading
|
1 day
|
IV. RESULTS AND DISCUSSION
A.
Classification
of Harvested Fruits
Table 1
Classification
of Citrus and the Number of Fruits per Classification
|
Classification
|
Number of Fruits
|
Total
|
|
Sound
|
18
|
|
|
Damage
|
2
|
|
|
Blemish
|
51
|
|
|
Off type
|
27
|
|
|
Overripe
|
14
|
|
|
Total
|
112
|
|
Table 2
Classification
of Fruits According to Size
|
Classification
Fruits
|
Size of Fruits
|
Total
|
||
|
Small
|
Medium
|
Large
|
||
|
Sound
|
4
|
14
|
0
|
|
|
Damage
|
0
|
2
|
0
|
|
|
Blemish
|
21
|
27
|
3
|
|
|
Off type
|
9
|
10
|
8
|
|
|
Overripe
|
7
|
7
|
0
|
|
|
Total
|
41
|
60
|
11
|
|
Table 3
Average
of Fruits with Different Sizes
|
Size
of Fruits
|
Average
Weight (grams)
|
|
Small
|
1700
|
|
Medium
|
3800
|
|
Large
|
470
|
Table 4
Grades
of Fruits and the Numbers per Grade
|
Grade
|
Number/Grade
|
%
Fruits
|
|
Extra
|
|
|
|
Grade I
|
|
|
|
Grade II
|
|
|
|
Culled
|
|
|
|
TOTAL
|
|
|
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