Produce Degradation Pathways and Prevention

Water and Its Relation to Fresh Produce 275

which involves intercellular and intracellular ice formation. Wills et al. (1998)
described the physiological effects of freezing on fresh produce and how it initiates
desiccation and osmotic stress of cellular structures. Expansion of water during thawing
results in physical damage to the cell structure, and the affected cells rarely resume
normal metabolism or regain normal texture, appearing flaccid and water-soaked. Fresh
produce may also suffer chilling injury, which occurs at temperatures above the freezing
point of the produce. This injury is attributed to the imbalance of metabolism and loss
of cellular compartmentalization at suboptimal temperatures. Chilling injury is a func-
tion of time and temperature. Short exposure to temperatures that result in chill injury
may have minimal effect, but extended periods result in irreversible damage.

TABLE 9.2

Recommended Storage Conditions for Temperature and Relative

Humidity, Approximate Shelf Life Under Optimum Conditions, and

Highest Freezing Points for Some Selected Fruits and Vegetables

Product

Temperature

(°C)

Relative

Humidity (%)

Approximate

Storage Life

Freezing

Point (°C)

Fruit

Apple –14 90–95 1–12 months –1.5

Apricot 0–0.6 90–95 1–3 weeks –1.1

Blackberry 0 90–95 2–3 days –0.8

Raspberry 0 90–95 2–3 days –1

Strawberry 0 90–95 3–7 days –0.8

Cherry 0 90–95 2–7 weeks –1.8 to –1.7

Nectarine 0 90–95 2–4 weeks –0.9

Peach 0 90–95 2–4 weeks –0.9

Pear –1.7 to –0.6 90–95 2–7 months –1.6

Watermelon 10–15.6 90 2–3 weeks –0.4

Vegetable

Broccoli 0 95–100 10–14 days –0.6

Cabbage 0 98–100 5–6 months –0.9

Cantaloupe 0–2.2 95 5–14 days –1.2

Carrot 0 98–100 7–9 months –1.4

Sweet corn 0 95–98 5–8 days –0.6

Cucumber 10–12.8 95 10–14 days –0.5

Garlic 0 65–70 6–7 months –0.8

Honeydew 7.2 90–95 3 weeks –0.9

Lettuce 0 98–100 2–3 weeks –0.2

Mushroom 0 95 3–4 days –0.2

Onion 0 65–70 6–8 months –0.9

Pea 0 95–98 1–2 weeks –0.8

Potato 3.3–4.4 90–95 5–10 months –0.6

Spinach 0 95–100 10–14 days –0.3

Tomato 12.8–21.1 90–95 1–3 weeks –0.6

Source:From Gast, K.L, Bulletin 4135, 1991. The University of Maine Cooperative Exten-

sion. With permission.