Effect of steam explosion treatment on physicochemical, functional and structural properties of pomelo fruitlets

This study was aimed to investgate the effects of steam explosion (SE) with different temperatures at 120–220 °C on the physicochemical, functional and structural properties of pomelo fruitlets. SE treatment changed monosaccharide composition, increased total dietary fiber (TDF) and soluble dietary fiber (SDF) contents of pomelo fruitlets. Especially at 160 °C SE treatment, TDF and SDF content was 13.57% and 25.94% higher than that of the control one ( p  < 0.05). Moreover, water- and oil-holding capacity, swelling capacity, and in vitro hypolipidemic activity (based on bile acid salt binding capacities increased by 7.95%–17.13% and pancreatic lipase inhibition capacities increased by 2.46%–6.75%) of pomelo fruitlets were significantly increased by appropriate SE conditions at 140–160 °C. This might be related to the fragmentation and porous surface structure of SE treated sample. In addition, SE treated pomelo fruitlets had higher crystallinity and thermal stability due to the rearrangement of cellulose molecular chains. It was revealed that SE treatment can effectively improve the physicochemical properties and hypolipidemic activity of pomelo fruitlets through structural changes. Our findings can provide the theoretical basis for the high value application of pomelo fruitlets as functional products through SE modification.