Universidade de Lisboa, Portugal
Fresh figs are very appreciated and have been associated with health benefits. However, these fruits are highly perishable. In this study, edible coatings were studied envisaging their positive effect in enhancing figs shelf-life.
?Fig fruits were harvest at ‘green ripe’ stage and coated with emulsion based edible coatings produced with 2% w/v chitosan and 1% w/v sodium alginate and olive oil (25% w/w and 100% w/w, respectively). After coatings application by immersion and drying, the coated fruits were sprayed with crosslinking solutions (tripolyphosphate and calcium chloride, respectively). The coated fruits as well the control, were maintained at 4 ºC and analyzed after 1, 7, 14 and 19 days of storage. After each time interval, fruits were maintained at 25 °C for 2 days in order to simulate consumer handling conditions. The physiology (CO2 production) and quality attributes (fungal decay, color, weight loss, firmness, total soluble solids (TSS) and titratable acidity (TA)), were evaluated.
The main results have shown that coatings were effective on delaying postharvest ripening indicators, such as softening, mass loss by evaporation and respiration rate. In addition, the edible coatings delayed TSS production and TSS/TA ratios (fruit maturity index), which increased significantly in control fruits associated with the over-ripening and senescence processes. Results from physiology and quality parameters suggested that the maximum shelf life period for control fruits was 7 days, while coated figs could be stored with optimal quality up to 19 days, at 4 °C plus 2 days at 25 °C.