Combined Modification of Soluble Dietary Fibers from Apple Pomace by Steam Explosion and Enzymatic Hydrolysis to Improve its Structural, Physicochemical and Functional Properties

Combined modification of steam explosion (SE) and enzymatic hydrolysis (EH) was investigated to enhance the yield and improve the structural, physicochemical and functional properties of soluble dietary fibers (SDFs) from apple pomace. Results indicated that SE-EH combined modification enhanced the SDF content from 17.90 to 25.63%, and SDF/IDF ratio from 30.03 to 56.20%. Compared with the control, monosaccharide composition confirmed the large proportion of Rha, Xyl and Glu and the small proportion of Fuc, Ara, Man and Gal in SDF of apple pomace treated by SE and EH (SDFSE-EH). And the average molecular weight (M-w) of SDFSE-EH was slightly higher than that of SDF of untreated apple pomace (SDFu). In addition, SDFs after modifications showed high water-holding and water-swelling capacity and low oil-holding capacity owing to its fluffy and porous structure. Moreover, SDFs after combined modifications exhibited better abilities of exchanging cations and binding glucose and cholesterols in vitro than SDFs with single or no modification. Therefore, this study provides an effective method for apple pomace modification and adds to its economic value, which can be used as functional additives in food products. [GRAPHICS] .

Automated summary

The combined modification of steam explosion and enzymatic hydrolysis was found to enhance the yield and improve the properties of soluble dietary fibers from apple pomace. The modified fibers had higher SDF content, better monosaccharide composition, and improved water-holding and water-swelling capacity. Additionally, they exhibited enhanced abilities to exchange cations and bind glucose and cholesterols, making them suitable as functional additives in food products.