Maintaining proper transit temperatures

Treated properly, fresh produce maintains its quality and appearance from harvest to consumption. While transportation takes only a few days in produce shelf life that can be as long as a month or more, handling during transit plays a critical role in allowing optimum product life. For instance, allowing some stone fruit to warm up 30% above the recommended transit and storage temperature can cut shelf life by half. Allowing ethylene-sensitive produce to come into contact with fruit or vegetables that produce high volumes of ethylene as they ripen accelerates ripening of the sensitive produce, cutting its potential shelf life.

Plant tissue begins losing moisture immediately after harvest, especially through cut surfaces. Maintaining high humidity levels during transit helps slow this process. Unfortunately, the heating and cooling inherent in the normal refrigeration cycle accelerates this process. Refrigeration unit manufacturers have made great strides in recent years to reduce temperature variation and slow the amount of moisture pulled from produce during transit. Humidity control can be enhanced by topping loads with a shallow layer of ice where appropriate.

ProductTransit Temp
Temp FFreezing
Temp FHumidity
%Ethylene
Production/SensitivityIce
Yes/NoAApples 32-36 30 90-95 Very High/High No Apricots 32 30.1 90-95 Medium/High No Artichokes 33-38 29.9 95-100 Very Low/Low Yes Asparagus, green 32-35 30.9 95-100 Very Low/Medium No Asparagus, white 32-36 — 95-100 — No Avocados 40 31.5 85 High/High No BBananas 56-58 30.6 90-95 Medium/High No Beans, green 40-45 30.7 95 Low/Medium No Beans, haricot 40-45 — 95 — No Beans, lima 37-41 31 95 Low/Medium No Beets 32 30.3 98-100 Very Low/Low Yes Blackberries 32 30.5 90-95 Low/Low No Blueberries 31-32 29.7 90-95 Low/Low No Broccoli 32 30.9 95-100 Very Low/High Yes Brussels sprouts 32 30.5 95-100 Very Low/High Yes CCabbage, green 32 30.4 98-100 Very Low/High Yes Cabbage, Chinese 32 — 95-100 — Yes Cabbage, red 32 30.4 90-95 Very Low/High Yes Carrots, w/greens 32 29.5 98-100 Very Low/High Yes Cauliflower 32 30.6 90-98 Very Low/High No Celery 34-36 31.1 85-90 Very Low/Medium Yes Celery root 33-35 — 95-100 — Yes Cherries 32 28.8 90-95 — No Chicory 33-35 — 95-100 — — Clementines 38-40 — 90-95 — No Coconut, fresh 32-35 30.4 — Low/High No Corn, sweet 34-38 30.9 85-90 — Yes Cranberries 38-40 30.4 90-95 Low/Low No Cucumbers 45-50 31.1 90-95 Low/High No Cucumbers, seedless 50-55 — 85-90 — No EEggplant 46-54 30.6 90-95 Low/Medium No Eggplant, Japanese 46-54 — 90-95 — No Endive, Belgian 36-38 — 95-98 Very Low/Medium No Endive, curly 32 31.9 90-95 Very Low/Medium Yes FFennel 32 — 90-95 — — Figs 34 — 85-90 Medium/Low No GGarlic 32-34 30.5 65-75 Very Low/Low No Grapes 32 29.7 85 Very Low/Low No Grapefruit, AZ, CA 50-55 30 85-90 Very Low/Medium No Grapefruit, FL, TX 50-60 30 85-90 Very Low/Medium No KKale 34-36 — 95-100 Very Low/Medium Yes Kiwifruit 32 29 90-95 Low/High No Kohlrabi 34-36 — 95-100 Very Low/Low Yes Kumquats 40 — 90-95 — No LLeeks 32 30.7 95-100 Very Low/Medium Yes Lemons 45-48 29.2 85-90 — No Lettuce, Boston 32 — 90-95 Low/Medium Yes Lettuce, iceberg 34-36 31.7 98-100 Very Low/High Yes Lettuce, romaine 32 31.7 95 — Yes Limes 55 29.1 85-90 — No MMangoes 55 30.3 85-90 Medium/Medium No Melons, bitter 53-55 — 85-90 Low/Medium No Melons, cantaloupe 35-40 29.9 90 High/Medium No Melons, honeydew 45-50 30.5 90-95 — No Melons, mixed 50 30.5 90-95 — No Melons, pepino 40-42 — 85-90 Low/Medium No Melons, water 50-60 31.3 90 Very Low/High No Mushrooms 34-38 30.4 85-90 — No NNectarines 31-32 30.4 90-95 Medium/High No OOkra 43-45 28.7 85-95 Low/Medium No Onions, dry 32 30.6 65-70 Very Low/Low No Onions, green 32 30.4 95-100 Low/High Yes Oranges, AZ 32-48 30.6 85-90 Very Low/Medium No Oranges, CA 45-48 30.6 85-90 Very Low/Medium No Oranges, FL 32-34 30.6 85-90 Very Low/Medium No Oranges, TX 32-48 30.6 85-90 Very Low/Medium No Oranges, blood 40-44 — 90-95 — No PPapayas 50-55 — 85-90 — No Parsley 32 — 95-100 — Yes Parsnips 33-35 — 95-100 — Yes Passion fruit 45-54 — 85-95 Very Low/High No Peaches 32 30.4 90-95 High/High No Pears 32 29.2 90-95 High/High No Peas, green 32-35 30.9 85-95 Very Low/Medium Yes Peppers, bell 45-50 30.7 85-90 Low/Low No Peppers, chili 38-44 30.7 60-70 Low/Medium No Persimmons 40-45 — 90-95 Low/High — Pineapple, green 50-55 30 85-90 — No Pineapple, ripe 45 30 85-90 Low/Low No Plantains 54-58 — 85-90 Low/High No Plums 32 30.5 90-95 Medium/High No Pomegranates 41 — 90-95 — No Potatoes 45-50 30.9 90 Very Low/Medium No Potatoes, new 45-50 30.9 90 Very Low/Medium No Pummelos 45-48 — 85-90 — No Pumpkins 50-60 30.5 50-75 Low/Medium No QQuince 31-32 — 90 — No RRadicchio 32-34 — 95-100 — No Radishes 32 30.7 95-100 Very Low/Low Yes Raspberries, black 32 30 90-95 Low/Low No Raspberries, red 32 30.9 90-95 Low/Low No Rhubarb 33-35 — 95-100 Very Low/Low No Rutaba gas 32 — 98-100 — No SSatsumas 37-39 — 85-90 High/High No Shallots 32 — 95-100 Low/Low Yes Spinach 32 31.5 95-100 Very Low/High Yes Squash, hard 50-55 30.5 70-75 Low/Medium No Squash, soft 41-50 31.1 95 Low/Medium No Squash, zucchini 45-50 — 90-95 Very Low/Low No Strawberries 32 30.6 90.95 Low/Low No Sweet potatoes 55-60 — 85-90 Low/Low No TTangerines 40 30.1 90-95 Very Low/Medium No Tomatoes, green 62-68 — 85-88 Very Low/High No Tomatoes, pink 62-68 — 85-88 High/Low No Tomatillos 55-60 — 85-90 Very Low/Medium No Turnips 32 — 85-90 Very Low/Low No WWatercress 33-35 — 95-100 Very Low/High Yes Source: US Department of Agriculture

In general, shippers and receivers know their products well and take appropriate measures to maintain the best possible transportation environment. Drivers with long experience with produce usually are expert as well. However, truckload fleets have a constant need for new drivers, some of whom may be unfamiliar with proper handling of fresh produce. The following table provides a quick guide to proper temperature requirements, icing options, and sensitivity to ripening gases. Copy it, and make it available to drivers as part of their standard paperwork.