Mechanical and Temperature Effects on Shelf Life Stability of Fruits and Vegetables - Food Shelf Life Stability: Chemical, Biochemical, and Microbiological Changes - page 71

before being held in the cold store at 10°C. The incidence of hard and lumpy fruit
is minimized. On the other hand, Harvey and co-workers 23 reported that in the
Caribbean, quarantine treatment of papaya using HWT consists of a double dip in
water for 20 min at 46°C followed by 20 min at 42°C. A 15 min, 50°C hot water
immersion treatment was developed by Armstrong 196 to disinfest “Brazilian” bananas
from Mediterranean fruit fly ( Ceratitis capitata Wiedemann), melon fly ( Dacus
cucurbitae Coquillet) and oriental fruit fly ( Dacus dorsalis Hendel). No detrimental
effects on fruit quality and shelf life were detected. In “Arkin” carambola, conditions
for hot water treatment were 43.3 to 43.6°C for 55 or 70 min, or 46.0 to 46.3°C for
35 or 45 min. 198 These conditions did not alter the quality of the fruits, except for
the duller color of heat-treated fruits. Sharp 199 reported that HWT was effective in
controlling Caribbean fruit fly ( Anastripha suspensa Loew) in “Tommy Atkins” and
“Keitt” Florida mangos. The temperature used was 46.1 to 46.7°C for a duration of
45 to 65 min. For Mexican mango cultivars, a temperature of 46.1°C was used for
“Haden”, “Oro”, and “Ataulfo” with exposure times of 90, 75, and 90 min, respec-
tively. 200,201 “Haden” was reported to be acceptable for 12 days without refrigeration
and “Ataulfo” was acceptable for 14 days when stored at 11.1°C.
Mayberry and Hartz 202 carried out studies to extend the storage life of muskmelon
for at least 28 days at 3°C by wrapping individual fruits with polyethylene bags and
dipping the wrapped fruit in hot water at 60°C for 3 min. Hot water treatment
provided adequate control of surface microorganisms and the polyethylene bags
helped to minimize weight loss and the lengthened storage life derived from this
treatment was beneficial to transport of fruits for export.
M OIST A IR H EAT T REATMENT
Anthony and co-workers 203 used moist air heat treatment at a temperature of 52°C,
relative humidity of 90 to 95% on nectarines which were either unwrapped or wrapped
individually in plastic to prevent decay of the fruits. Heat treatments at 52°C for 15,
30, and 45 min slowed softening and ethylene production. Wrapping fruits in plastic
reduced ethylene production by 75% and respiration by 12% but did not influence
softening. The wrap reduced the incidence of skin browning due to heat treatment.
H IGH -T EMPERATURE F ORCED A IR (HFTA) T REATMENT
Armstrong and co-workers 204 developed a high-temperature forced-air (HFTA) dis-
infestation treatment against fruit fly for Hawaiian-grown papayas, using four tem-
perature stages. The four-stage treatment forced hot air over papaya at temperatures
of 43 ± 1, 45 ± 1, 46.5 ± 1, and 49 ± 0.5°C with a relative humidity of 40 to 60%.
Exposure times for the first three stages were 2 h and the last stage was 1 h.
Hydrocooling immediately followed until the fruit center temperature was 30°C or
less. HFTA treatment did not affect fruit quality and was less injurious to papayas
than double-stage hot water treatment or quick run-up vapor heat treatment. 204 Miller
and co-workers 205 tried HFTA on “Tommy Atkins” mangos with some success. The
treatment consisted of exposing mangos to air at a maximum of 51.5 ± 0.2°C for