Morphological and structural characteristics of rice amylose by dynamic high‐pressure microfluidization modification

Effects of dynamic high-pressure microfluidization treatment on the structural, physicochemical, and digestive properties of wheat starch-Lonicera caerulea berry polyphenol complex

Polyphenol complexes can improve the physicochemical and functional properties of starch. In this study, a wheat starch-Lonicera caerulea berry polyphenol complex (WS-LCBP) was prepared using dynamic high-pressure microfluidization (DHPM). The effects of different DHPM pressures (150 and 250 MPa), number of cycles (1 and 3), and LCBP content (0 %, 6 %, 8 %, and 10 %) on the multiscale structure, physicochemical properties, and in vitro digestibility of WS-LCBP were examined. After a single 250 MPa DHPM cycle, Average particle size and water separation rate of WS were reduced by 42.40 % and 16.67 %, the freeze-thaw stability was significantly improved (P < 0.05), and the resistant starch (RS) content 68.67 % was significantly increased (P < 0.05). WS-LCBP has a V-shaped starch structure, which hinders gelatinization and increases enthalpy. The RS content of the WS-LCBP ranged from 72.46 % to 89.09 %, which was significantly higher (P < 0.05) than that of wheat starch subjected to a single 150 MPa DHPM cycle (36.31 %). Three 250 MPa DHPM cycles were beneficial for the formation of WS-LCBP. However, excessive DHPM treatment pressure and frequency reduced the recombination rate of LCBP and wheat starch. This study provides reference data for the industrial production of nutritionally functional wheat-resistant starch using green technologies.

Effect of dynamic high-pressure treatments on the multi-level structure of starch macromolecule and their techno-functional properties: A review

Over the past decades, dynamic high-pressure treatment (DHPT) executed by high-pressure homogenization (HPH) or microfluidization (DHPM) technology has received humongous research attention for starch macromolecule modification. However, the studies on starch multi-level structure alterations by DHPT have received inadequate attention. Furthermore, no review comprehensively covers all aspects of DHPT, explicitly addressing the combined effects of both technologies (HPH or DHPM) on starch's structural and functional characteristics. Hence, this review focused on recent advancements concerning the influences of DHPT on the starch multi-level structure and techno-functional properties. Intense mechanical actions induced by DHPT, such as high shear and impact forces, hydrodynamic cavitation, instantaneous pressure drops, and turbulence, altered the multi-level structure of starch for a short duration. The DHPT reduces the starch molecular weight and degree of branching, destroys short-range ordered and long-range crystalline structure, and degrades lamellar structure, resulting in partial gelatinization of starch granules. These structural changes influenced their techno-functional properties like swelling power and solubility, freeze-thaw stability, emulsifying properties, retrogradation rate, thermal properties, rheological and pasting, and digestibility. Processing conditions such as pressure level, the number of passes, inlet temperature, chamber geometry used, starch types, and their concentration may influence the above changes. Moreover, dynamic high-pressure treatment could form starch-fatty acids/polyphenol complexes. Finally, we discuss the food system applications of DHPT-treated starches and flours, and some limitations.

Effect of Dynamic High-Pressure Microfluidizer on Physicochemical and Microstructural Properties of Whole-Grain Oat Pulp

By avoiding the filtration step and utilizing the whole components of oats, the highest utilization rate of raw materials, improving the nutritional value of products and reducing environmental pollution, can be achieved in the production of whole-grain oat drinks. This study innovatively introduced a dynamic high-pressure microfluidizer (DHPM) into the processing of whole-grain oat pulp, which aimed to achieve the efficient crushing, homogenizing and emulsification of starch, dietary fiber and other substances. Due to DHPM processing, the instability index and slope value were reduced, whereas the β-glucan content, soluble protein content and soluble dietary fiber content were increased. In the samples treated with a pressure of 120 MPa and 150 MPa, 59% and 67% more β-glucan content was released, respectively. The soluble dietary fiber content in the samples treated with a pressure of 120 MPa and 150 MPa was increased by 44.8% and 43.2%, respectively, compared with the sample treated with a pressure of 0 MPa. From the perspective of the relative stability of the sample and nutrient enhancement, the processing pressure of 120 MPa was a good choice. In addition, DHPM processing effectively reduced the average particle size and the relaxation time of the water molecules of whole-grain oat pulp, whereas it increased the apparent viscosity of whole-grain oat pulp; all of the above changes alleviated the gravitational subsidence of particles to a certain extent, and thus the overall stability of the system was improved. Furthermore, CLSM and AFM showed that the samples OM-120 and OM-150 had a more uniform and stable structural system as a whole. This study could provide theoretical guidance for the development of a whole-grain oat drink with improved quality and consistency.

Recent advances in essential oil complex coacervation by efficient physical field technology: A review of enhancing efficient and quality attributes

Although complex coacervation could improve the water solubility, thermal stability, bioavailability, antioxidant activity and antibacterial activity of essential oils (EOs). However, some wall materials (such as proteins and polysaccharides) with water solubility and hydrophobic nature limited their application in complex coacervation. In order to improve the properties of EO complex coacervates, some efficient physical field technology was proposed. This paper summarizes the application and functional properties of EOs in complex coacervates, formation and controlled-release mechanism, as well as functions of EO complex coacervates. In particular, efficient physical field technology as innovative technology, such as high pressure, ultrasound, cold plasma, pulsed electric fields, electrohydrodynamic atomization and microwave technology improved efficient and quality attributes of EO complex coacervates are reviewed. The physical fields could modify the gelling, structural, textural, emulsifying, rheological properties, solubility of wall material (proteins and polysaccharides), which improve the properties of EO complex coacervates. Overall, EOs complex coacervates possess great potential to be used in the food industry, including high bioavailability, excellent antioxidant capacity and gut microbiota in vivo, masking the sensation of off-taste or flavor, favorable antimicrobial capacity.

Nonthermal physical modification of starch: An overview of recent research into structure and property alterations

To tailor the properties and enhance the applicability of starch, various ways of starch modification have been practiced. Among them, physical modification methods (micronization, nonthermal plasma, high-pressure, ultrasonication, pulsed electric field, and γ-irradiation) are highly potential for starch modification considering its safety, environmentally friendliness, and cost-effectiveness, without generating chemical wastes. Thus, this article provides an overview of the recent advances in nonthermal physical modification of starch and summarizes the resulting changes in the multi-level structures and physicochemical properties. While the effect of these techniques highly depends on starch type and treatment condition, they generally lead to the destruction of starch granules, the degradation of molecules, decreases in crystallinity, gelatinization temperatures, and viscosity, increases in solubility and swelling power, and an increase or decrease in digestibility, to different extents. The advantages and shortcomings of these techniques in starch processing are compared, and the knowledge gap in this area is commented on.

Latest developments in the applications of microfluidization to modify the structure of macromolecules leading to improved physicochemical and functional properties

Microfluidization is a unique high-pressure homogenization technique combining various forces such as high-velocity impact, high-frequency vibration, instantaneous pressure drop, intense shear rate, and hydrodynamic cavitation. Even though it is mainly used on emulsion-based systems and known for its effects on particle size and surface area, it also significantly alters physicochemical and functional properties of macromolecules including hydration properties, solubility, viscosity, cation-exchange capacity, rheological properties, and bioavailability. Besides, the transformation of structure and conformation due to the combined effects of microfluidization modifies the material characteristics that can be a base for new innovative food formulations. Therefore, microfluidization is being commonly used in the food industry for various purposes including the formation of micro- and nano-sized emulsions, encapsulation of easily degradable bioactive compounds, and improvement in functional properties of proteins, polysaccharides, and dietary fibers. Although the extent of modification through microfluidization depends on processing conditions (e.g., pressure, number of passes, solvent), the nature of the material to be processed also changes the outcomes significantly. Therefore, it is important to understand the effects of microfluidization on each food component. Overall, this review paper provides an overview of microfluidization treatment, summarizes the applications on macromolecules with specific examples, and presents the existing problems.