The susceptibility to chilling injury (CI) or internal breakdown (IB) was evaluated in the most currently planted yellow- and white-flesh peach [Prunus persica (L.) Batsch] and nectarine [Prunus persica var. nectarine (L.) Batsch] and plum [Prunus salicina Lindel] cultivars from different breeding sources and fruit types. Cultivars were segregated into three categories (Cat. A, B, and C) according to their susceptibility to CI or IB symptoms (mealiness and flesh browning) when exposed to 0 °C or 5 °C storage temperatures. Cultivars in Cat. A did not develop any symptoms of CI after 5 weeks of storage at either temperature. Cultivars in Cat. B developed symptoms only when stored at 5 °C within 5 weeks of storage. Cultivars were classified in Cat. C when fruit developed CI symptoms at both storage temperatures within 5 weeks of storage. Most of the yellow- and white-flesh peach cultivars developed IB symptoms when stored at both storage temperatures (Cat. C). Most of the new nectarine cultivar introductions did not develop CI symptoms when stored at 0 °C or 5 °C after 5 weeks (Cat. A). Three out of six plum cultivars tested had CI symptoms within 5 weeks storage at 0 °C. However, all of the plum cultivars tested developed CI symptoms when stored at 5 °C (Cat. B). The importance of proper temperature management during postharvest handling was demonstrated.

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Causes of postharvest deterioration 3 Effects of temperature on produce 3 Ethylene physiology of fruits and vegetables 4 Wilting and shriveling caused by water loss 4 Relationship of temperature to produce injuries 6 Chilling and freezing of produce 6 Protecting produce temperature during marketing 7 Part II-COOLING METHODS Room cooling 7 Ceiling jets for room cooling 8 Bays for cooling and storage 8 Containers used in room cooling 8 Cooling in railcars or trucks 10 Cooling fruit for controlled-atmosphere storage 10 Cooling with package icing 11 Vacuum cooling of vegetables 11 Hydrocooling of produce 12 Checking hydrocooling operations 13 Forced-air (pressure) cooling 14 Shelf-type forced-air coolers 16 Width of container stack for forced-air cooling 17 Exposure of stacked containers for forcedair coolers 18 Containers for forced-air cooling Conduction cooling of produce Controlling humidity Humidifying with fog spray 20 Packed towers for cooling and humidity control 21 Ice accumulators used with packed towers . 22 Using ice bunkers as a source of coolant . . 22 Liquid nitrogen and liquid and solid carbon dioxide as coolants 23 Choosing the cooling program 23 When to cool 24 Measuring temperatures Part III-DESIGN CALCULATIONS Hydrocooler dimensions and water flow . Air channel dimensions in forced-air coolers Cooling calculations Part IV-COOLING DATA Cooling and storage requirements for California fruits and vegetables Removing heat by respiration Produce cooling times by method of cooling Useful constants COMMERCIAL COOLING OF FRUITS AND VEGETABLES Part I-THE COMMODITY Causes of postharvest deterioration Fruits and vegetables are living organisms which undergo all physiological and pathological processes associated with life. To sustain essential chemical and physiological activities, they draw energy from the food reserves stored within them prior to harvest. They are in a continual state of deterioration from harvest on, and successful marketing depends upon reducing the rate of deterioration by slowing the processes which cause damage.Deterioration of fresh produce (the commodity) results from many things, including physiological breakdown, physical injury to the tissue, moisture loss, or invasion by microorganisms. Decay-producing fungi which attack fresh fruits and vegetables are also living organisms, and may be major contributors to deterioration and loss. Some decay organisms can directly penetrate healthy tissue; others enter only after produce has been weakened or injured. Each fruit and vegetable is, therefore, a complex living system of tissue and microorganisms, and satisfactory produce management requires protection of the produce while discouraging growth and spread of microorganisms.All of the above factors can be interrelated, and all are influenced by temperature. Thus, understanding the relationship of cooling to causes and effects of deterioration is essential if produce is to be properly protected.Like all other living organisms, fresh fruits and vegetables respire through a complex series o...

Storage at 0C of `O'Henry' and `Fairtime' peaches and `Red Jim' and `September Grand' nectarines (Prunus persica L. Batsch) resulted in significantly longer postharvest life than did storage at 5C, due to differences in the development of internal breakdown (IB) symptoms. Conditioning at 20C for 2 days before storage at 0 or 5C generally prolonged the storage life of fruit of these cultivars. The use of elevated CO2 during conditioning helped maintain fruit firmness. Addition of 5% CO2 to air gave the best results in maintaining fruit firmness and freedom from IB symptoms for up to 6 weeks. Reducing the O2 content kept flesh firmness high after storage but did not delay the appearance of IB. Conditioning at 30C using various atmospheres was less effective than conditioning at 20C.

Good quality of fresh `Mission' figs (Ficus carica L.) was maintained for up to 4 weeks when kept at 0, 2.2, or 5C in atmospheres enriched with 15% or 20% CO2. The visible benefits of exposure to high CO2 levels were reduction of decay incidence and maintenance of bright external appearance. Ethylene production was lower, and fruit softening (as measured with a deformation tester) was slower in the high-CO2-stored figs than in those kept in air. Ethanol content of the CO2-treated fruit increased slightly during the first 3 weeks and moderately during the 4th week, while acetaldehyde concentration increased during the first week, then decreased. The results may be applicable to the transport and storage of fresh `Mission' figs, as high CO2 extended their postharvest life, especially near 0C.