Effects of cultivar and growth region on the structural, emulsifying and rheological characteristic of mango peel pectin

Mango peel pectin (MPP) of eight cultivars obtained from different growth regions (China, Thailand, Vietnam, Burma and Australia) exhibit significant different recovery yield and characteristics of structure, emulsifying and rheology. Among the 12 MPP samples, Golek cultivar from Bruma (GoBP) showed the highest galacturonic acid (GalA) content (80.63%), methyl-esterification degree (DM) (71.80%) and average molecular weight (AMW) (1589 kDa). The thermal analysis showed that the endothermic peak of pectin may related to its degree of methoxylation (DM), and highly branched side chains may enhance its thermal stability. The emulsifying properties of MPP were assessed by surface tension, xi-potential, droplet size and microscope observation, showing that GuCP-stabilized emulsion appears to be more stable. As for the rheological behavior, most pectin samples exhibited shear-thinning behaviors and GoBP which had the highest AMW, had the highest viscosity under different shear rate (0.1-100 1/s). GuCP exhibited more elastic-solid characteristics (G' > G ''), which could be used as a functional ingredient in jelly food, while GrCP exhibited higher viscosity (G '' > G') and could be applied as a thickener. In all, the cultivar and growing region have significant effects on the properties of MPP and this study established a foundation for their applications in food industry.