Real World Evaluation of Packaging Strategies and SO2 Fumigation for Shipment of Blueberry Fruit from Chile to North America

Blueberry (Vaccinium corymbossum L. cv. Brigitta) fruit were harvested at commercial maturity (> 80% blue) from two different farms in the Maule region of Chile on January 9 and 10, 2013, and packaged the over the next two days using several different packaging strategies that included perforated and non-perforated films and fumigation with SO₂. Fruit from farm 1 were placed into: 125 g polystyrene clamshells sealed in low density polyethylene (LDPE) packages (VF101) containing a total of 1.6 kg fruit; 340 g clamshells (one dry pint) in LDPE packages (VF202) containing 4.1 kg fruit; loose fruit in LDPE packages (VF101) containing 1.6 kg fruit; and 125 and 340 g clamshells without packages.  Fruit from farm 2 were placed into 125 g clamshells in LDPE packages (VF101) containing a total of 1.6 kg fruit; 340 g clamshells in LDPE packages (VF102) containing 4.1 kg fruit; 340 g clamshells in LDPE packages (VF103) containing 6.1 kg fruit; and 125 and 340 g clamshells without packages. Packages had 0 or 2 perforations for fruit from both farms and a portion of the fruit from farm 1 were fumigated with SO₂ for about 10 min prior to packaging.  Fruit entered the refrigerated distribution chain for shipment to the United States upon packaging, were shipped by sea container from Chile about 11 days after packing, and arrived in the United States 28 days later.  Transport through the U.S. distribution chain required an additional 8 days. Thus, fruit arrived in Michigan 40 days after harvest and were evaluated after an additional 2 days at 2 °C to simulate regional distribution.  Fruit were evaluated at that time and after an additional 3 days at 12 °C to simulate retail holding.  Assessments included fruit firmness, degree of internal discoloration, decay, and shrivel, and visual sensory analysis. Perforated packages had higher O₂ (14.6 vs, 8.9%, respectively) and lower CO₂ (4.8 vs, 6.6%, respectively) than non-perforated packages. The greatest effect on storability was the source of the fruit; fruit from farm 2 were in much poorer condition than those from farm 1.  The retail holding period significantly reduced the quality of the fruit, especially for farm 2.  Packaging tended to improve quality over non-packaged berries. Perforated LDPE packages performed similarly to non-perforated packages. Smaller clamshell containers yielded the highest quality fruit. Fumigation with SO₂ suppressed decay and improved visual appearance.