Effect of particle size and microstructure on the physical properties of soybean insoluble dietary fiber in aqueous solution

Technological Advancements of Insoluble Dietary Fiber from Food By-Product Processing: A Review

Insoluble dietary fibers (IDFs) represent one of the most promising candidates for novel food formulations, since they can be produced from a wide range of food by-products and wastes, have health benefits, and often enhance the rheology and stability of foods. Recently, the most innovative engineering and processing aspects of these attractive ingredients have received considerable attention. The present work is aimed at enlightening the technological state of the art regarding IDFs (much less investigated than soluble fibers, as discussed in this review). The review begins with a brief but crucial discussion on the definition of this type of dietary fiber by highlighting the raw materials, functional properties, physiological activity, and stabilization capacity in food products. The analysis of the rheological methods dedicated to the technical investigations of these ingredients and recent advancements are discussed. Finally, food processing technologies used in the formulation of foods containing insoluble IDFs, such as homogenization techniques, are discussed.

Blending pectin and κ-carrageenan converted the liquid yogurt induced by pectin into the solid yogurt

Effects of 0.11 %-0.17 % pectin and the mixture of 0.03 % κ-carrageenan and 0.11 %-0.17 % pectin on texture and microstructure of yogurt were investigated in this work. Rheology analysis demonstrated that adding 0.11 %-0.17 % pectin before fermentation inhibited gelation of yogurt and liquid yogurt was formed. However, when the above κ-carrageenan/pectin mixture was added, yogurt was gelled and solid-like. It was demonstrated by CLSM that milk protein aggregated into separated particles in the liquid yogurt induced by pectin, while milk protein aggregated into a continuous network in the solid yogurt induced by the mixture. Adding 0.11 %-0.17 % pectin into the casein micelle suspension induced aggregation of casein micelles into separated particles, which was the same in the corresponding liquid yogurt samples. Moreover, casein micelles precipitated in the pectin/casein micelle mixtures after storage for 3 h. However, when the above mixture was added into the casein micelle suspension, tightly-connected casein micelle aggregates appeared and the resultant κ-carrageenan/pectin/casein micelle mixtures were stable after storage for 3 h. These results indicated that the pectin-casein micelle interaction played an essential role in formation of the liquid yogurt and κ-carrageenan altered this interaction. Thus, blending κ-carrageenan and pectin converted the liquid yogurt induced by pectin into the solid yogurt.

Effect of structural characteristics on the physicochemical properties and functional activities of dietary fiber: A review of structure-activity relationship

Dietary fibers come from a wide range of sources and have a variety of preparation methods (including extraction and modification). The different structural characteristics of dietary fibers caused by source, extraction and modification methods directly affect their physicochemical properties and functional activities. The relationship between structure and physicochemical properties and functional activities is an indispensable basic theory for realizing the directional transformation of dietary fibers' structure and accurately regulating their specific properties and activities. In this paper, since a brief overview about the structural characteristics of dietary fiber, the effect of structural characteristics on a variety of physicochemical properties (hydration, electrical, thermal, rheological, emulsifying property, and oil holding capacity, cation exchange capacity) and functional activities (hypoglycemic, hypolipidemic, antioxidant, prebiotic and harmful substances-adsorption activity) of dietary fiber explored by researchers in last five years are emphatically reviewed. Moreover, the future perspectives of structure-activity relationship are discussed. This review aims to provide theoretical foundation for the targeted regulation of properties and activities of dietary fiber, so as to improve the quality of their applied products and physiological efficiency, and then to realize high value utilization of dietary fiber resources.

Stabilization of emulsions prepared by ball milling and cellulase treated pomelo peel insoluble dietary fiber: Integrity of porous fiber structure dominates the stability

Emulsion gels from the pomelo peel insoluble dietary fiber (PIDF) were developed. The emulsification potentials of PIDFs subjected to various degrees of ball milling (M-PIDFs), cellulase hydrolysis (C-PIDF), and cellulase hydrolysis followed by ball milling (CM-PIDFs) were evaluated. Emulsions prepared by M-PIDFs for different lengths of ball milling time exhibited similar stability characteristics, confirming that M-PIDF emulsion stability might be determined by the three-dimensional structure formed by M-PIDF stacking and oil droplet capture. C-PIDF had characteristics resembling those of Pickering particles. CM-PIDF emulsions got destabilized with ball milling time prolongation. Interface tension and particle size of C/CM-PIDF decreased gradually during ball milling. Rheological and fluorescence microscopy results revealed that the intact internal crosslinking structure frameworks were disrupted in CM-PIDF emulsions. Therefore, intact fiber-based networks, rather than small particle size or low interfacial tension, determine the stability of PIDF emulsions. This study deepens the understanding of PIDF as a clean emulsifier.

Characterization of selected dietary fibers microparticles and application of the optimized formulation as a fat replacer in hazelnut spreads

The present work demonstrates the application of the spray drying technique to produce microparticulates of different dietary fibers with particle sizes<10 µm. It examines their role as potential fat replacers for hazelnut spread creams. Optimization of a dietary fiber formulation containing inulin, glucomannan, psyllium husk, and chia mucilage to obtain high viscosity, water holding capacity, and oil holding capacity was conducted. Microparticles containing 46.1, 46.2, and 7.6 weight percentages of chia seed mucilage, konjac glucomannan, and psyllium husk showed a spraying yield of 83.45 %, a solubility of 84.63 %, and viscosity of 40.49 Pas. When applied to hazelnut spread creams, microparticles substituted palm oil by 100 %; they produced a product with a total unsaturated and saturated fat reduction of 41 and 77 %, respectively. An increase in dietary fibers of 4 % and a decrease in total calories of 80 % were also induced when compared with the original formulation. Hazelnut spread with dietary fiber microparticles were preferred by 73.13 % of the panelist in the sensory study due to an enhancement in brightness. The demonstrated technique could be used to increase the fiber content while decreasing the fat content in some commercial products, such as peanut butter or chocolate cream.

Preparation of soybean dreg fiber solid emulsifier and its effect on the stability of Pickering emulsion

High purity insoluble dietary fiber (HPIDF) was extracted from Okara by compound enzyme method, and solid emulsifiers with different particle sizes were prepared by wet grinding. Its composition, structure and physicochemical properties were studied, and the influence mechanism of solid emulsifiers with different particle sizes on emulsifying properties and interface stability of Pickering emulsion was systematically studied. The results showed that the particle size of HPIDF decreased significantly, the ζ-potential, contact Angle and swelling capacity of HPIDF ncrease significantly (p < 0.05). HPIDF forms an adsorption layer at the oil-water interface, and some of them are connected to form a bridge network structure, which plays a role of steric hindrance. And the emulsion has excellent stability under different environmental factors. HPIDF are suitable raw materials as natural food-grade solid emulsifiers. It is cost-effective and eco-friendly to realize the high-value utilization of Okara resources, reduce resource waste, and extend the industrial chain.