Physicochemical, functional, and microstructural properties of modified insoluble dietary fiber extracted from rose pomace.

Rose pomace, a by-product of the essential oil extraction process, is rich in dietary fiber. Insoluble dietary fiber (IDF) extracted from rose pomace was modified by enzymatic hydrolysis (EH) and ultrasound-assisted enzymatic hydrolysis (UEH) methods, and their physicochemical, functional, and microstructural properties were studied. The results showed that EH treatment performed better in the yield of soluble dietary fiber and the glucose adsorption capacity than UEH which contributed to better oil-holding, swelling, cation-exchange, and cholesterol adsorption capacities. Moreover, cellulose, hemicellulose, and lignin were detected based on Fourier transform infrared spectra and X-ray diffraction patterns. Scanning electron microscopy revealed that IDF had a shaly surface with a loose block structure after modification. In conclusion, different modification degrees have respective advantages, and modified IDF from rose pomace could be utilized in the food industry as a new source of functional ingredients, as well as to increase the economic value of rose products. © Association of Food Scientists & Technologists (India) 2019.