90 Produce Degradation: Reaction Pathways and their Prevention
nearly as well as Chojuro pears, but they became more susceptible to bruising in
cold storage. Twentieth Century pears were most sensitive to impact and compression
bruising. Increased time in the ripening room produced more softening and increased
the bruise resistance of Chojuro and Twentieth Century pears.^88 Bruising of packaged
tomatoes is affected by the nature and volume of the packaging material used.
Tomatoes on the bottom of boxes exhibit worse bruises. The separated clapboards
and the metal corners of wooden boxes cause the most severe injuries. Tomatoes
packaged in smaller cardboard containers are usually less susceptible to bruising
than those in plastic and wooden boxes.^89 The detrimental effect of Brazilian
“K-wooden boxes” for storage and transportation of tomatoes on shelf-life and
quality (weight, shelf life, color, mechanical damage, firmness, and relative water
content) due to their rough surface was demonstrated by Luengo et al.^90 These boxes
also allow pathogen colonization because of the excessive number of fruit layers and
lateral cut openings. The damage was significantly different and lower using Embrapa
boxes, reducing postharvest losses in tomato fruits. Polypropylene plastic containers,
however, when compared with other plastic and wooden containers, resulted in less
mechanical damage to fruits and did not affect their chemical properties.^91
Tests conducted by Timm et al.^92 using bulk bin designs (two hardwood, one
plywood, and two plastic) and two trailer suspension systems (steel-spring and air-
cushion) indicated that apple fruit positioned in the middle of each bin during
transportation had similar bruise and abrasion damage levels regardless of the bin
design, suspension system, or trip distance. Abrasion damage on the sidewall apples
varied among bin design, suspension system, and trip distance. Damage to sidewall
fruit was significantly less using the air-cushion system. Their results indicate that
higher apple quality can be maintained if bulk apples are transported in plastic bins
of these designs and on semi-trailers having air-cushion suspension.
Mechanical abrasion adversely affects the physiology, green life, and commer-
cial quality of bananas. This includes the physiological development of the fruits
(respiration and ethylene production) and final quality. Air humidity level may be
negatively correlated with the severity of the symptoms.^93 Akkaravessapong et al.,^94
however, found that the relative humidity (RH) at which bananas are stored did not
affect the bruise resistance coefficient, CO 2 or ethylene production, or starch or sugar
content, but low RH significantly increased the rate of water loss by three- to
fourfold. The susceptibility of the fruits to mechanical damage increased rapidly on
the second day after ripening had been initiated. The magnitude of the change was
four- to eightfold. Although RH did not affect susceptibility to mechanical injury,
the tissues damaged at low RH dried to a black color, while those damaged at high
RH remained light brown. Under low RH conditions, desiccation is the dominant
causative factor in postharvest browning of rambutan (Nephelium lappaceum L.).
Landrigan et al.^95 infiltrated mature fruits with known enzyme inhibitors, then either
mechanically damaged them or left them undamaged before storage at 20°C at 95 or
65% RH. All fruits at low RH browned severely. At high RH, infiltration with water,
but not with the enzyme inhibitors salicylhydroxamic acid and catalase, led to a
large increase in browning. It is inferred that enzymes were involved in browning
in damaged tissue under high RH.