Influence of collapsed structure on stability of β-carotene in freeze-dried mangoes

This study aimed to investigate the effect of structural collapse of freeze-dried mangoes on stability of β-carotene. Three different freeze-drying protocols were performed to produce collapse and non-collapse structures of freeze-dried mangoes. Thermal transitions of samples were determined using a differential scanning calorimeter. β-carotene content was monitored during storage using high-performance liquid chromatography. The β-carotene degradation followed first-order kinetics. Mangoes freeze-dried at above ice melting temperature revealed structural collapse which decreased β-carotene degradation rate. These dense and collapsed structures formed prevented oxygen penetration through the solids. Liquid nitrogen freezing also gave structural collapse coincided with surface cracking on freeze-dried mangoes. Such structure showed no protective effect on β-carotene as similar degradation rate to non-collapsed systems was observed. The cracking on mango surface potentially allows high oxygen penetration through the solids thus promoting β-carotene loss. These findings give benefit to the production of freeze-dried fruits to increase storage stability of β-carotene.

► The results showed that structural collapse decreased β-carotene degradation rate.
► The dense structures formed prevented oxygen penetration through the solids.
► The finding gives benefit to the production of freeze-dried fruits to increase stability of β-carotene.