Mechanical and Temperature Effects on Shelf Life Stability of Fruits and Vegetables - Food Shelf Life Stability: Chemical, Biochemical, and Microbiological Changes - page 41

P ACKAGING
The produce is placed in an appropriate packaging material for further processing,
marketing as fresh produce, or storage. Several types of packaging materials are
available varying in cost, rigidity and flexibility, water resistance, and ability to
control atmosphere.
P RODUCE H ANDLING AND T RANSPORT
As the produce moves from one point to another during marketing, packaging plays
an important role in protecting them from damage during handling and transport.
During transport mechanical damage is inflicted on the commodity by the vibrating
vehicle, sudden stops and starts, or rough roads. Furthermore, some vehicles may
not possess refrigeration systems.
POSTHARVEST DISORDERS
Disorders in marketable agricultural produce fall into two groups, namely, disorders
resulting from internal changes such as senescence, and those resulting from external
factors such as unfavorable environments or physical injury. 7 The latter results in
greater losses during marketing of the produce than those originating internally. Care
in handling the produce during and after harvest should be exercised so that quality
is maintained. However, injury may be inflicted on the commodity and this may be
caused by impact, compression, abrasion, puncturing, tearing, or a combination of
any of the above during handling and transport. Mechanical damage due to improper
handling of fruits and vegetables can be grouped into five types: (1) impact, (2)
compression, (3) abrasion, (4) puncture, and (5) tears. 7
I MPACT
This damage occurs when the produce hits a hard surface, with force sufficient to
damage or separate the cells. Externally this is manifested by a bruise or a crack.
Commodities like fruits and vegetables sustain impact damage during harvesting
when the produce is dropped from the harvester to the storage bin, box, or crate. It
can also occur as the commodity moves inside the packinghouse. Danger of impact
can extend to trailers or rail cars while loading or unloading, and during sudden stops.
C OMPRESSION
Placing too much of the produce in a container with limited capacity results in
compression damage. Stacking containers one over the other may damage the pro-
duce at the bottom due to compression, especially if the containers are not rigid
enough. Compression damage is caused by excessive static load on the produce.
A BRASION
This can occur when the produce rubs against each other when packed closely or
conveyed at high speeds, or rubs against surfaces such as unlined containers, con-
veyors, and bins.