Mild concentration of ethanol in combination with ascorbic acid inhibits browning and maintains quality of fresh-cut lotus root

Abstract

Aqueous solutions of ethanol and ascorbic acid alone and in combination were compared to a commonly used sanitizer, sodium hypochlorite, and a leading commercial antibrowning agent containing calcium ascorbate (CA) for their efficacy to inhibit microbial growth and browning on fresh-cut lotus root. Fresh-cut lotus root slices were immersed in one of 7 treatment solutions including water (control), 30% ethanol (v/v), 30% ethanol (v/v) plus 30gL−1 ascorbic acid (AA), 30% ethanol (v/v) plus 30gL−1 CA, 30gL−1 AA, 30gL−1 CA and 100mgL−1 sodium hypochlorite for 2min, and then packaged in polyethylene bags and stored for 28d at 4°C. Packages were monitored for headspace gas composition, color, texture, aerobic mesophilic bacteria, and yeast and mold populations, electrolyte leakage and sensory attributes. The results indicate that all ethanol treatments, with and without added AA or CA, not only inhibited microbial growth, but also delayed browning more effectively than either AA or CA alone. The combined treatments of Ethanol 30% (v/v) along with 30gL−1 AA or 30gL−1 CA were even more effective than ethanol alone in maintaining quality of fresh-cut lotus slices during cold storage. Increasing ethanol concentration within the range of 5–30% (v/v) when accompanied by 30gL−1 AA, decreased microbial populations and had little effect on quality maintenance of fresh-cut lotus root during cold storage. Ethanol concentrations of 20–30% (v/v) in conjunction with 30gL−1 AA have the potential to inhibit browning and maintain quality of fresh-cut lotus root slices for more than 14d when stored at 4°C. This is the first use of ethanol as a dual control for both browning and microbial growth in fresh-cut lotus root.