Postharvest decay caused primarily by fungal pathogens results in significant losses of fresh fruits during storage and transit and in the market. Controlling postharvest decay and maintaining fruit quality is important to consumers’ acceptance and the profitability of the fresh fruit industry. In this presentation, the use of antimicrobial packaging with or without modified atmosphere (MA) to control postharvest fruit decay and maintain fruit quality of fresh fruits is presented. In our research on blueberries, sulfur dioxide-emitting packaging pads, liners, sheets, or bags with MA capability were evaluated for the effectiveness in controlling decay, reducing water loss, and maintaining fruit quality. In one study, Dual SO₂-emitting pad (SO₂ was initially released up to 10 ppm and then declined and stabilized at a low concentration), Slow SO₂-emitting pad (SO₂ was released at a low and constant concentration), or MA bag alone significantly reduced fruit rots during cold storage compared to nontreated control. Dual SO₂ pad in combination with MA bag or Slow SO₂ pad in combination with MA bag provided even better control, but Dual SO₂pad can cause bleaching on blueberry fruit due to SO₂ injuries. In another study, SO₂-emitting liners with modified atmosphere capability was effective in reducing fruit rots, reducing water loss and maintaining fruit quality. Our results showed that the combination of Slow SO₂-emitting pad and MAP bag is a promising method for control of postharvest fruit rots while maintaining blueberry fruit quality and that SO₂-emitting liners are also an effective means of preserving blueberry quality during extended storage, particularly when combined with MA. The simplicity of assembling a package with a single liner versus using a conventional liner followed by a SO₂-emitting sheet or pad could be of benefit to blueberry packers. Challenges and prospects of antimicrobial packaging for fresh fruits will also be discussed.

Dr. Chang-Lin Xiao

Research Leader/Supervisory Research Plant Pathologist, USDA ARS San Joaquin Valley Agricultural Sciences Center

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