Effect of a corn starch coating obtained by the combination of extrusion process and casting technique on the postharvest quality of tomato

The aim of this work was to validate the effect of a corn starch coating obtained by the combination of the extrusion process and casting technique on the postharvest quality of tomato fruit (Solanum lycopersicum L.) cv. Imperial. To obtain the study coating, corn starch and plasticizers (sorbitol and glycerol) were processed in a twin screw extruder and subsequently casting technique was used to get the final formulation. Three treatments in freshly harvested tomatoes were applied: Control, Carnauba Wax (CW) and Corn Starch Coating (CSG). Weight Loss (WL), Firmness (F), External Color (∆E), pH, Titratable Acidity (TA), Respiration Rate (RR) and Ethylene Production (EP), were evaluated. The results of this study indicated that CSG was the most effective treatment to maintain physical and chemical quality of tomato cv. Imperial stored at 12 °C. Regarding to WL, CW-covered fruit showed the best results. Likewise, CSG-covered fruit presented the minor RR and EP. Therefore, corn starch coating obtained by a combination of extrusion process and casting technique could be employed to maintain the postharvest quality and extend the shelf life of tomato fruit.

Keywords: starch, coating, extrusion-casting, tomato, postharvest quality.