Abstract: Penyllactic acid (PLA) as a natural antifungal agent and sodium alginate (SA) as a carrier were blended to develop a composite preservative for the control of postharvest decay in sweet cherries. The appropriate concentration of sodium alginate was determined by measuring film-forming properties. The efficacy of the preservative coating in maintaining the quality of sweet cherries during cold storage was evaluated by monitoring physiological and quality changes. Addition of 12 g/L sodium alginate to the preservative exhibited good film-forming property in the presence of 6 g/L phenyllactic acid, 5 g/L glycerol and 5 g/L xanthan gum. The preservative significantly inhibited fruit decay, reduced water loss, decreased respiratory intensity, maintained the color and firmness of sweet cherries during storage, and delayed the decrease in soluble solids and titrable acidity content, thereby helping attenuate metabolism intensity, maintain fruit quality and prolong the storage life of sweet cherries.

Key words: penyllactic acid, sodium alginate, coating, sweet cherries, preservation