Are
the Fruits and vegetables we eat are alive?
Me, I do believe that the fruits and
vegetables we eat are alive. Why? Because they respire. And they also die.
Fruits and vegetables are living tissues derived from diverse plant parts, and
a consequence of this diversity is the remarkable variation in postharvest
behavior. An appreciation of this feature is indispensable in formulating
recommendations for handling and sorting commodities.
The response of commodity to its
surroundings and to the method of handling depends on their morphological and
anatomical features. Examples of these are the plant organ utilized, nature of
fruit wall, surface area to volume ratio, number and the amount of stomates,
lenticels or cuticles, and the amount of hairs and/or spines.
Table 1
Surface to Weight and Surface to Volume Ratio of Commodities with
Various Shapes and Sizes
Commodity
|
Fruit Weight (grams)
|
Fruit Volume (mL)
|
Surface Area (cm3)
|
SW
|
SV
|
a.
carrot
|
103.5
|
104.5
|
105
|
1.014
|
1.00
|
b.
cucumber
|
183.3
|
210.5
|
180.5
|
0.98
|
0.86
|
c.
potato
|
94.8
|
95.5
|
90
|
0.95
|
0.94
|
d.
calamansi
|
14.1
|
11.5
|
25
|
1.77
|
2.17
|
e.
pechay
|
67.6
|
66.5
|
710.5
|
10.51
|
10.68
|
Table 2
Moisture Loss in Commodities with Various Shapes and Sizes
Days
|
Weight in Grams
|
||||
Commodity
|
|||||
1
|
2
|
3
|
4
|
5
|
|
1
|
78.9
|
176.8
|
74.9
|
12
|
84.8
|
2
|
76.4
|
175.7
|
74.2
|
11.4
|
79.9
|
3
|
74.8
|
174.5
|
73.6
|
11.0
|
74.6
|
4
|
73.9
|
173.6
|
72.4
|
10.6
|
70.2
|
5
|
73.1
|
172.7
|
71.9
|
10.1
|
68.6
|
6
|
72.6
|
171.9
|
71.1
|
9.7
|
63.4
|
7
|
71.7
|
171.1
|
70.4
|
9.3
|
60.7
|
8
|
70.5
|
170.2
|
69.6
|
8.9
|
58.5
|
9
|
69.3
|
169.6
|
69.0
|
8.4
|
54.4
|
10
|
68.5
|
169.0
|
68.3
|
8.1
|
52.3
|
From the table shown above it shows
that:
-
Within the commodities of comparable size, the
more nearly the commodity approaches a sphere, the less its surface to volume
ratio.
-
Within the commodity or commodities with
similar shape, the smaller the size, the larger the surface to volume ratio.
-
The greater the surface to volume ratio or
surface to weight ratio, the greater the evaporative surface of the commodity.
-
All other factors being equal smaller
commodities should have a greater tendency to lose moisture.
-
Gas exchange is also facilitated in a commodity with a high surface to volume
ratio. The effect of this ratio on some physiological processes constitutes a
subtle implication of shape and size.
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