Development of pectin-eugenol emulsion coatings for inhibition of Listeria on webbed-rind melons: a comparative study with fig and citrus pectins

The objective of this study was to employ pectin-based antimicrobial coatings for inhibition of Listeria on surfaces of whole webbed-rind melons that cause frequent outbreaks of listeriosis. For this purpose, emulsion-based coatings were developed using citrus pectin (CPEC) or pectin extracted from processing wastes of sun-dried figs (FPEC) and eugenol (EUG). The emulsions of FPEC and CPEC with EUG (droplet size range: 1.99-11.22 mu m) were highly stable for minimum 10 days at 10 degrees C. The FPEC-EUG films showed higher flexibility and degree of wettability than CPEC-EUG films. In contrast, CPEC-EUG films had a higher gas barrier performance against oxygen at 50% relative humidity than FPEC-EUG films. The zone inhibition tests showed that FPEC-EUG films are more effective against Listeria innocua than CPEC-EUG films. However, FPEC and CPEC coatings with 2% EUG caused 2.2 and 2.7 decimal inactivation of Listeria on Galia melons within 1 week, respectively. The pectin coatings with EUG could reduce the risk of listeriosis from webbed-rind melons.