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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Microbial and Chemical Food Safety » Research » Publications at this Location » Publication #330112
Research Project: Integration of Multiple Interventions to Enhance Microbial Safety, Quality, and Shelf-life of Foods

Location: Microbial and Chemical Food Safety

Title: Effects of pulsed electrical field processing on microbial survival, quality change and nutritional characteristics of blueberries

Author
item Jin, Zhonglin
item YU, YUANSHAN - Guangdong Academy Of Agricultural Sciences
item Gurtler, Joshua

Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2016
Publication Date: 12/8/2016
Citation: Jin, Z.T., Yu, Y., Gurtler, J. 2016. Effects of pulsed electrical field processing on microbial survival, quality change and nutritional characteristics of blueberries. LWT - Food Science and Technology. 77:517-524. doi: 10.1016/j.lwt.2016.12.009.

Interpretive Summary: Blueberry fruits could be contaminated with pathogenic or spoilage microorganisms. In this study, the combination of pulsed electric fields (PEF) and a sanitizer solution was able to achieve up to 99.9% reduction of E. coli and Listeria as well as 99% reduction of natural background bacteria without causing any changes in color and appearance of the blueberries. Anthocyanins and phenolic compounds in blueberries increased by 10 and 25%, respectively, after PEF treatments. These results demonstrate the possibility of PEF to be used to enhance the safety and improve the quality and nutritional value of fruits and their derived products.

Technical Abstract: Whole fresh blueberries were treated using a parallel pulsed electric field (PEF) treatment chamber and a sanitizer solution (60 ppm peracetic acid [PAA]) as PEF treatment medium with square wave bipolar pulses at 2 kV/cm electric field strength, 1us pulse width, and 100 pulses per second for 2, 4, and 6 min. The effects of PEF on native microbiota and artificially-inoculated Escherichia coli K12 and Listeria innocua populations on blueberries were determined. Color, texture, anthocyanins and total phenolic compound concentrations were also evaluated. The combination of PEF and PAA was able to achieve up to 3 log reduction of E. coli and Listeria as well as 2 log/g reduction of native microbiota. PEF treatments did not cause any changes in color and appearance of the blueberries. The treatments did, however, cause the blueberries to soften in texture. Anthocyanins and phenolic compounds in blueberries increased by 10 and 25%, respectively, after PEF treatments. The results demonstrate the potential of PEF applications to enhance the safety and improve the quality and nutritional value of fruits and their derived products.