Dietary fiber extraction from citrus peel pomace: Yield optimization and evaluation of its functionality, rheological behavior, and microstructure properties

• Published in: Journal of food science Vol. 88; no. 8; pp. 3507 - 3523
• Main Authors: Chen, Lily, Wu, Yincai, Jiang, Xinjia, Gan, Diansong, Fan, Jingxin, Sun, Yanmei, Liu, Wenliang, Li, Xianggang
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.08.2023
• Subjects: Agricultural wastes; Cellulase; Chemical properties; Citrus fruits; citrus peel pomace; Design of experiments; Dietary fiber; Economic impact; Environmental risk; Enzymes; Experimental design; Food packaging; Fruits; Liquor; Optimization; Packaging materials; Physicochemical properties; physiochemical properties; Pseudoplasticity; Raw materials; Recycling; Rheological properties; Rheology; structural characteristics; Ultrasonic imaging; Ultrasonic testing; Ultrasound; Variance analysis; dietary fiber; citrus peel pomace; rheological properties; structural characteristics; physiochemical properties
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/1750-3841.16702

Citrus fruits were widely used in processing and production, generating a large amount of peel pomace and a low utilization rate, resulting in substantial economic losses and environmental risks. It was important to extract compounds from citrus peel pomaces and find suitable preparation methods to improve their yield and physicochemical properties. Grapefruit peel pomace (GP) and navel orange peel pomace (OP) were used as raw materials in this study to prepare green and edible soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). Analysis was done on the effects of solid–liquid ratio, cellulase hydrolysis time, cellulase dosage, and ultrasonic time on dietary fiber (DF) yield. To obtain the best DF preparation conditions, we used range analysis, variance analysis, and orthogonal experimental design. We also analyzed the structural, physicochemical, and rheological characteristics of SDF and IDF. According to the study's findings, SDF and IDF showed a loose and expansive structure with reduced particle size, higher specific surface area, and noticeably better physical and chemical properties after treating GP and OP with ultrasound‐assisted composite enzyme method. Both SDF solution and IDF suspension were discovered through rheological analysis to be non‐Newtonian pseudoplastic fluids, which was advantageous for expanding their applications in the field of food packaging. In conclusion, DF prepared using the ultrasound‐assisted composite enzyme method was an excellent source of edible packaging materials, offering a benchmark for the recycling of other citrus peel wastes and ultimately paving the way for new methods of recycling citrus waste.