Abstract
The applicability of commonly used postharvest treatments to control produce decay is often limited by toxicity regulations and residual by-product accumulation. Chlorine is the most widely used sanitizer in the produce industry for improving microbial quality and extending shelf-life of most minimally processed fruits and vegetables. Although effective, recent environmental and public health concerns associated with the use of chlorine have stimulated the produce industry to identify alternative treatments equivalent to chlorine in antimicrobial effectiveness. This study compared the effectiveness of alternative post-harvest treatments, hydrogen peroxide and citric acid, to the current industry standard, chlorine, in improving the microbiological quality of lowbush blueberries. Significant differences (p < 0.05) in antimicrobial effectiveness existed among treatments allowed the same contact time. Samples treated with 100 ppm chlorine resulted in the greatest microbial reduction in total aerobes, yeast, and mold counts compared to samples treated with 0.5% hydrogen peroxide, 0.5% citric acid, or distilled water; however, chlorine was second in antimicrobial effectiveness when a 1% hydrogen peroxide treatment was administered. Overall, samples treated with 1% hydrogen peroxide for 120 seconds resulted in population reductions two times greater than reductions observed on samples treated with 100 ppm chlorine. Results indicate postharvest treatments of 1% hydrogen peroxide are an effective alternative to chlorine for improving the microbiological quality and safety of lowbush blueberries during processing without compromising blueberry color.
