COATING GUAVAS WITH CELLULOSE-BASED OR CARNAUBA-BASED EMULSIONS INTERFERES WITH POSTHARVEST RIPENING

Harvested, mature-green guava (Psidium guajava L.) fruit were coated w ith cellulose- or carnauba-based emulsions to compare the effect on fr uit ripening and quality of ripened fruit. Coatings containing 2% or 4 % hydroxypropylcellulose significantly slowed softening an average of 35% or 45%, respectively, compared to uncoated fruit (a delay of 1 to 2 days in September and 4 to 5 days by January). A 5% carnauba formula tion slowed softening by 10% to 30% and was most effective at reducing weight loss. Neither of the cellulose- nor the carnauba-based coating s affected the decay susceptibility of softened fruit, but coated frui t did not develop as much color, had a lower soluble solids concentrat ion, and were more prone to surface blackening in storage than uncoate d fruit.