ARS | Publication request: A novel treatment combination for the dual control of enzymatic browning and pathogen growth on apple slices

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 12, 2013
Publication Date: N/A

Technical Abstract: Commercially-produced apple wedges have recently been associated with several recalls due to foodborne pathogen contamination. The fresh-cut industry faces a major technical challenge due to the antagonistic relationship between chemicals used to control spoilage and pathogenic microorganisms (usually oxidizers) and those used to control browning reaction (usually reducing agents). New technologies to control cut-surface browning and pathogen growth are critically needed. This study evaluated the effect of low concentrations of ethanol in combination with ascorbic acid for the inhibition of browning and inactivation of E.coli on apple slices. Apples (c.v. Golden Delicious, Red Delicious, Granny Smith, and Fuji) were cut into wedges, dipped in treatment combinations containing 1% ascorbic acid and 30%-50% ethanol, followed by dewatering, packaging (gas permeable film bags), and storage (1.5 ºC). Product quality was evaluated on days 0, 1, 3, 5, 7 and 14. In contiguous experiments, Golden Delicious apple wedges were dip inoculated with Escherichia coli O157:H12 and followed the same treatment and storage conditions as above. The surviving E.coli populations on apple wedges were enumerated via selective media on days 0 and 14. Results indicate that the combination containing 30% ethanol significantly reduced E.coli populations immediately after treatment and further during cold storage (undetectable at day 14). These treatment combinations also inhibited the growth of aerobic bacteria, and yeast and mold during storage. Treatment combinations with 1% ascorbic acid and 30% ethanol also effectively inhibited browning reaction on the cut surfaces, and maintained the quality of apple wedges throughout cold-chain storage. However, treatments containing more than 40% ethanol caused unacceptable softening of the apple tissue softening. The dual control of browning and pathogen inactivation effect of the ascorbic acid and ethanol combination on apple slices can be an effective tool for the enhancement of both produce quality and safety of fresh-cut apples.