Extraction Process Optimization and Analysis of Functional Characteristics of Soluble Dietary Fibers of Pear Pomace

Abstract:

The soluble dietary fibers (SDF) of pear pomace were prepared by enzymatic hydrolysis using cellulases, and the SDF yield was taken as the evaluation index to optimize the process conditions for the preparation of SDF by enzymatic hydrolysis through single factor experiments and response surface methodology. The physicochemical properties and functional characteristics of the pear pomace SDF were analyzed. The results showed the SDF extraction process to be optimized under the following conditions: an enzyme/substrate mass ratio of 1.1%, reaction time of 5.2 h, material-to-liquid ratio of 1:21, reaction temperature of 37 ℃, and a pH value of 4.5. The resulting experimental SDF yield equaled 6.29%, which was consistent with the theoretical value of 6.23%. The SDF showed improved water holding and swelling capacity compared to the original pear pomace. In addition, SDF could scavenge DPPH (IC50=0.494 mg/mL) and ABTS+ (IC50=0.429 mg/mL) free radicals, demonstrating good antioxidant activity. SDF showed better cholesterol adsorption performance in the intestine (4.81 mg/g), but the adsorption capacity for NO2- in the gastric environment (84.68%) was significantly higher than that in the intestinal environment (16.21%). The SDF of pear pomace seem to have good physical and chemical functional properties, and this study provides a theoretical basis for the high-value utilization of pear pomace.