Israel-based StePac has developed polyamide-based packaging technology for blueberries that it says ensures long-lasting freshness in bulk deliveries to distant destinations.

It said this resolves the common challenge faced by growers and exporters from countries such as Chile and Peru which conduct long-haul shipments to faraway markets like China.

StePac said that Chinese importers placed great importance on the appearance of the 'bloom' - the natural powdery white wax on the surface of the fruit which innately protects the fruit and reduces evaporation. Second in importance for them is the taste and third is fruit firmness, it said.

The packaging is designed to not only regulate headspace gas composition but also relative humidity, reducing the risk of condensation build-up.

According to Gary Ward, Ph.D., Technical Development Manager for StePac, blueberries are often packed in polyethylene-based modified atmosphere packaging which minimizes weight loss due to its very low water vapor transmission rate (WVTR).

“This is important, but the advantage of reduced weight loss is outweighed by the disadvantage that condensation will inevitably form and become trapped in the packaging," he said.

"This free moisture is an enemy of the natural bloom and is highly likely to be washed from the surface of the blueberries making it less appealing to the eye and in fact increases the risk of decay.

“The preservation of natural bloom is a far more important parameter than slightly lower weight loss. It is the outward indicator of freshness and translates into higher prices for blueberries in the Chinese market.”