Location: 　　　　　　Dalian area, Liaoning Province, China
Time Frame: 　　　　 July 2006
Product: : 　　　　　　Fresh blueberries
Packaging: 　　　　　Clamshell plastic tills, vented on two top edges
Cooling Method: 　　　Forced-air cooling, reefer van refrigeration source

Result: 　　　　 　　　Dramatic Shelf-life Improvement, Big Increase In Profit

PARAMETER 　　　　　　　BEFORE　　　　　　　　 AFTER
Shelf Life, days 　　　　　　3 to 4 　　　　　　　　　10 to 12
Product Losses 　　　　　　60% 　　　　　　　　　　< 5%

THE STORY

In April we were approached by a farm manager from Liaoning Province, near Dalian. His crop was blueberries. He had come to Shanghai to explore ways to improve his quality by cooling the berries. We were the last company he came to. That day he had seen two other companies in Shanghai. Each wanted to sell him a vacuum cooling chamber.

Vacuum cooling is not a good method for blueberries - either hydrocooling or forced air are preferred for this product. Further discussion with the farmer revealed that the berries were already packaged into plastic consumer tills with ventilation holes at two sides on the top edges. This precluded the use of hydrocooling systems

We recommended forced air cooling to him and explained how it would work. We discussed the containers he was packing in and developed an understanding of it. Subsequently he mailed us a plastic till sample, and it was as we expected

His production was modest, about 500 Kg a day. In asking about his cold storage situation, he responded that he was using a refrigerated shipping container (reefer) as a cold storage unit. Since his daily production volume was small, this opened up some new and very economical options for him, as explained below.

FA cooling systems usually include auxiliary refrigeration because typical cold storage rooms do not have sufficient cooling power to handle cooling several tons of produce in a few hours. Also, if already cooled produce is in storage, the use of the same room for cooling hot product can cause the hot air generated in the cooling heat-exchange process to warm the stored product

However, the Dalian farmer only needed to cool a small amount. Further, he shipped 100% of what he processed each day. We ran the numbers and they showed that the refrigeration of the shipping container would have sufficient power to cool his product. there was no problem expected in heating stored product.

We proposed to him a force-air system without included or additional refrigeration. We recommended humidity control to minimize weight loss, and the farmer agreed that this would be desirable.

The results were spectacular. After a successful, although difficult, installation in a rural area, our sales staff followed up with the customer one month later. He reported that before using our cooling system he had experienced 60% loss of his packaged product with an average shelf-life of 3 to 4 days. After incorporating forced air cooling into his process, shelf-life increased to 10-12 days and losses were less than 5%.

With blueberries selling at high market prices, the profit gain was substantial. He plans to expand in the near future and requested that we work with his company in developing their post-harvest handling systems.