Abstract
•Resv and GB decreased decay but, increased weight loss after 2 weeks of SL.•Resv and GB retained higher firmness, acidity, vitamin C and membrane stability than control.•High Resv retained higher phenols than control, in contrast to chitosan but, flavonoids was not affected.•Chitosan, medium and high Resv and medium GB rate retained higher FRSC than control.•α-amylase activity decreased by all treatments while, POD increased compared to control.
Effects of chitosan (1%), trans-resveratrol (resveratrol) (1.6×10−5M, 1.6×10−4M and 1.6×10−3M) and glycine betaine (GB) (10, 15 and 20mM) dipping on quality and biochemical changes of ‘Hindi-Besennara’ mangoes during ripening at shelf life (SL) (18±2°C, 60–70% RH) were studied. Resveratrol, especially at low rate followed by GB, especially at high rate, decreased decay percentage after one and two weeks of SL compared to other treatments. Both compounds at all rates retained higher fruit firmness during SL and higher titratable acidity (TA) (only after one week of SL). Both GB and resveratrol at all rates retained higher vitamin C level than control with no effect on total soluble solids (TSS) after two weeks of SL. These compounds had no effect on weight loss after one week, but increased it after two weeks of SL compared to control. Chitosan showed higher weight loss during SL but, retained higher TA and vitamin C, and lower pH with no significant impact on firmness, TSS and decay compared to control. Chitosan, low and medium resveratrol rates, and low and high GB rates maintained higher membrane stability of peel after two weeks of SL compared to control. All treatments showed lower α-amylase but, higher peroxidase (POD) activities in peel than control after two weeks of SL. High resveratrol rate retained higher total phenols level than control, in contrast to chitosan after two weeks of SL while, total flavonoids was not affected. Compared to initial, peel free radical scavenging capacity (FRSC) decreased after one week followed by a sharp increase after two weeks of SL. Chitosan, medium and high resveratrol rates, and medium GB rate showed higher FRSC than control after one week of SL but, with no differences after two weeks of SL. In conclusion, both trans-resveratrol and GB treatments retained quality of ‘Hindi-Besennara’ mangoes during SL and being suggested as natural alternatives to synthetic chemicals.