Surface sterilisation using chemical or physical methods influence microbial growth and quality of green asparagus

초록

In the present study, the different effects of surface disinfectants and sterilisation methods on the antimicrobial efficacy and preserving quality of green asparagus (Asparagus officinahs L.) during cold storage were evaluated, both initially after sterilisation pre-treatment and after 21 days of storage. Hot water (H2O), sodium hypochlorite (NaClO) solution, hot NaClO solution, chlorine dioxide (ClO2), ozone (O-3) and UV-C exposure were used for surface sterilisation with no pre-treatment as a control group. The visual quality, physiological and biochemical characteristics, and the correlation between sterilisation pre-treatments and green asparagus quality were analysed. In this research, all tested disinfectants and sterilisation pre-treatments were more effective in reducing the microbial load than the control group. The O-3, ClO2 and NaClO pre-treatments showed remarkable effectiveness in inhibiting the growth of bacteria (especially Escherichia coli), yeast and mould with a lower number of microorganisms after 21 days of cold storage. Meantime, hot water washing was better to preserve the nutritional and visual quality and led to minimal damage to green asparagus with higher soluble solids content (SSC) and hue angle values and lower electrolyte leakage (EL). No significant influence was observed on firmness and gas conditions in any of the packages. Significant correlation was present between sterilisation pre-treatments and SSC and colour. Although all pre-treatments effectively inhibited the development of microorganisms and significantly extended the shelf life of green asparagus, the O-3, ClO2 and NaClO pre-treatments are more worth consideration.

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