The ascorbic acid content of strawberries in this study ranged from 32.00 to 37.46 mg/100 g, similar to values reported by Atress and others (2010; Figure 3).
Ascorbic acid of coated and uncoated fruits remained stable during 12 d. However, consistent with previous reports, by day 15 of storage, a reduction of ascorbic acid was observed in chitosan-EAC, pullulan-EAC, and uncoated strawberries (11.12, 12.10, and 12.11 mg/100 g, respectively).
Reduced ascorbic acid content is due to oxidative deterioration, high respiration rate, and accumulation of carbon dioxide in strawberries.
In contrast, by day 15, ascorbic acid content in pectin-EAC coated strawberries was only slightly reduced (27.20 mg/100 g) with no significant differences when compared to previous days (Figure 3).
The delay in ascorbic acid reduction in these samples can be attributed to reduced O2 diffusion, respiration rate, and, consequently, reduced oxidation.
A similar result in fresh-cut papaya, although these studies used a coating based on hydroxypropyl methyl cellulose/chitosan and a coating based on chitosan/pectin, respectively.