Carrier Refrigeration

ContainerLINE November 2017 | XtendFRESH ™ Controlled Atmospheres Enable Fresh Produce to Reach Distant and New Consumers Global demand for fresh fruits and vegetables is expanding as a result of consumer interest in healthy, fresh produce and an increased appetite for crops from distant growing regions – supported in part by rising affluence in emerging economies. How these products get from point of origin to their final destinations varies based on the time sensitivity of each commodity. Because it is fast, air transport has traditionally been employed for the most highly perishable and short-lived produce, such as asparagus, blueberries, raspberries and papayas. But air transport is expensive, and when chilled commodities are air- shipped in non-refrigerated insulated containers, significant breaks in the cold chain can occur. Temperature management can be lost when inspections are conducted under ambient conditions on the tarmac or in other airport areas. This can have a detrimental effect on the quality of the produce. In contrast, ocean transport via refrigerated containers is far less costly than air shipment. And, since the container includes an electric refrigeration system that can be powered on deck, at the port and even when transported via truck or rail car equipped with a generator set, a consistent temperature is maintained to the point of delivery. Marine shipping containers also offer the option of using transit life extension technology. The key to extending the transit life of perishables, beyond what refrigeration alone can do, is to minimize produce respiration. During respiration, fresh produce consumes oxygen (O 2) and emits carbon dioxide (CO2), which causes the produce to ripen too quickly. This can be overcome by using "controlled atmosphere" techniques, which change the composition of air both inside a refrigerated space and around the cargo. With controlled atmosphere systems, sensors measure CO 2 and O2 intermittently and adjust to predetermined levels through fresh air intake and removal of excess CO 2. In cases of highly sensitive and low- respiring produce, sometimes an injection of nitrogen is needed to bring the gas levels into proper balance. Pressing Pause By lowering the O2, increasing CO2 and maintaining them at predetermined levels specific to the produce inside the refrigerated container, controlled atmosphere technology can effectively minimize the respiratory activity of the perishables. Lower respiration helps maintain the freshness and quality of the product and can also delay decay, loss of texture, ripening, aging, dehydration, weight loss and loss of nutrients. Controlled atmospheres can also reduce chilling injury by allowing transport at slightly lower temperatures, which in turn helps maintain quality and condition even longer. As a supplement to good temperature control, controlled atmosphere technology can potentially add days or even weeks to transit shelf life for a large number of fruits and vegetables. This allows produce to travel longer distances, enabling delivery of a greater variety of fruits and vegetables to consumers around the world. By Eduardo Kerbel, Ph.D. Postharvest Technology Business Manager Global Container Refrigeration, Carrier Transicold PART OF A SERIES* Designing the right controlled atmosphere protocol and using the proper controlled atmosphere system will help extend transit life potential of fresh produce. 4

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