Dipping fresh‐cut apples in citric acid before plasma‐integrated low‐pressure cooling improves Salmonella and polyphenol oxidase inactivation

Abstract

BACKGROUND Ready‐to‐eat fruit and vegetable products have gained tremendous popularity in recent years. The main challenges associated with these minimally processed products are their short shelf life and high food safety concerns. In this study, our goal was to develop an integrated process to both reduce the Salmonella population by >5 log CFU g−1) and to reduce polyphenol oxidase activity, followed by quickly cooling the product. We compared the effect of a sequential treatment of dipping in citric acid (CA) followed by cold plasma (CP) treatment on the inactivation of Salmonella Typhimurium, polyphenol oxidase (PPO) activity, browning, total phenolic content and the moisture loss of cut apples during the plasma‐integrated low‐pressure cooling (PiLPC) process. RESULTS The greatest inactivation of Salmonella (5.68 log CFU g−1) and the highest PPO inactivation (78%) were observed after dipping cut apples in 5% CA, followed by 3 min of CP treatment. The color of cut apples remained relatively unchanged, with a fresh‐like appearance during 7 days of storage at 4 °C after this combined treatment. Although the low‐pressure cooling time was increased when samples were pre‐dipped in CA, related to those undipped, the moisture loss was reduced by more than 50% during the PiLPC process. No significant reduction in phenolic content was observed during the PiLPC when the samples were pre‐dipped in 5% CA. CONCLUSION These results indicate the potential of this integrated process for the inactivation of endogenous food enzymes and bacterial pathogens in fresh‐cut apples. © 2021 Society of Chemical Industry.

Inhibitory effects of peppermint extracts on the browning of cold-stored fresh-cut taro and the phenolic compounds in extracts

“…The addition of p-Coumaric acid, a cinnamic acid, significantly inhibited the browning of potato juice (Zolghadri et al, 2019). Dipping fresh-cut apples into citric acid, a arboxylic acid, improved the color appearance during 7 days of storage at 4°C (Adam et al, 2022). In this study, ferulic acid, 2-Hydroxycinnamic acid and p-Coumaric acid, and other cinnamic acids and derivatives were all abundant in peppermint extracts (Supplementary Data 1).…”

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“…Consumer demand for fresh-cut fruits and vegetables has continuously increased due to their convenience, safety, and nutritional quality ( Adam et al, 2021 ). Fresh-cut fruits and vegetables have been observed to deteriorate more rapidly than intact ones leading to increased surface browning, textural breakdown, development of off-flavor, and microbial proliferation ( Glicerina et al, 2022 ).…”

Recent advances in processing and preservation of minimally processed fruits and vegetables: A review – Part 1: Fundamentals and chemical methods

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