Increasing the pressure during high pressure homogenization regulates the starch digestion of the resulting pea starch-gallic acid complexes

Synergistic impact of ultrasound-high pressure homogenization on the formation, structural properties, and slow digestion of the starch-phenolic acid complex

The modification of starch digestibility can be achieved through the formation of complexes with polyphenols. We studied the combined impacts of ultrasound and high-pressure homogenization (UT-HPH) on the structure and in vitro digestibility of rice starch-chlorogenic acid complexes. The development of V-type complexes was supported by our findings, which also showed that synergistic UT-HPH therapy exhibited the highest absorbance value for the complexing index (0.882). Significant alterations in digestibility were also observed in the complexes, with the content of RDS decreasing from 49.27% to 27.06%, the content of slowly SDS increasing from 25.69% to 35.35%, and the percentage of RS increasing from 25.05% to 37.59%. Furthermore, a high positive correlation was found by applying the Pearson correlation coefficient in our research between RS, weight, PSD, and CI. This study presents a sustainable processing approach for utilizing chlorogenic acid in starch-rich food systems.

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 different screw speeds on the structure and properties of starch straws

To illustrate the action mechanism of screw speed on the performance of starch-based straws during the extrusion process, starch-based straws at different screw speeds were prepared using a twin-screw extruder and the structures and characteristics were compared. The results indicated that as screw speeds improved from 3 Hz to 13 Hz, the A chain of amylopectin increased from 25.47 % to 28.87 %, and the B3 chain decreased from 6.34 % to 3.47 %. The absorption peak of hydroxyl group shifted from 3296 cm-1 to 3280 cm-1. The relative crystallinity reduced from 13.49 % to 9.89 % and the gelatinization enthalpy decreased from 3.5 J/g to 0.2 J/g. The performance of starch straws did not increase linearly with increasing screw speeds. The starch straw produced at screw speed of 7 Hz had the largest amylose content, the highest gelatinization temperature, the minimum bending strength, and the lowest water absorption rate in hot water (80 °C). Screw speed had a remarkable impact on the mechanical strength, toughness and hydrophobicity of starch-based straws. This study revealed the mechanism of screw speed on the mechanical strength and water resistance of starch straws in the thermoplastic extrusion process and created the theoretical basis for the industrial production of starch-based straws.

Complexation temperature regulated the structure and digestibility of pea starch-gallic acid complexes during high pressure homogenization

Formation of starch-polyphenol complexes by high pressure homogenization (HPH) is widely used to reduce starch digestibility and delay the postprandial glycemic response, thereby benefiting obesity and associated metabolic diseases. This study investigated the effect of complexation temperature on multi-scale structures, physicochemical and digestive properties of pea starch-gallic acid (PS-GA) complexes during HPH process, while also elucidating the corresponding molecular mechanism regulating in vitro digestibility. The results demonstrated that elevating complexation temperature from 30 °C to 100 °C promoted the interaction between PS and GA and reached a peak complex index of 9.22 % at 90 °C through non-covalent binding. The enhanced interaction led to the formation of ordered multi-scale structures within PS-GA complexes, characterized by larger particles that exhibited greater thermal stability and elastic properties. Consequently, the PS-GA complexes exhibited substantially reduced digestion rates with the content of resistant starch increased from 28.50 % to 38.26 %. The potential molecular mechanism underlying how complexation temperature regulated digestibility of PS-GA complexes might be attributed to the synergistic effect of the physical barriers from newly ordered structure and inhibitory effect of GA against digestive enzymes. Overall, our findings contribute to the advancement of current knowledge regarding starch-polyphenol interactions and promote the development of functional starches with low postprandial glycemic responses.

Development and characterization of an active starch-based film as a chlorogenic acid delivery system

Given its health benefits for the human body, chlorogenic acid (CA) offers promising applications in the food industry. However, the instability and low bioavailability of CA remain to be solved. In this paper, a starch-based film prepared by the homogenization and solution-casting method was used as an effective carrier to alleviate these problems. Homogenization (10-50 MPa) reduced the starch paste viscosity and its particle sizes from 21.64 to 7.68 μm, which promoted the starch recrystallization and induced chemical cross-links between starch-CA, as confirmed by the FTIR result with an appearance of a new CO peak at about 1716 cm-1. Accordingly, the rapidly digestible starch content of the film was reduced to 27.83 % and the CA encapsulation efficiency was increased to 99.08 % (from 65.88 %). As a result, the film system extended CA's release time beyond 4 h and significantly increased the heat-treated CA's antioxidant activity. Besides, the tensile strength and elastic modulus of the film were also improved to 6.29 MPa (from 1.63 MPa) and 160.98 MPa (from 12.02 MPa), respectively, by homogenization. In conclusion, the developed active starch-based film could be used as an edible film for the production of functional food or active food packaging.

Impact of red kidney bean protein on starch digestion and exploring its underlying mechanism

This study aimed to investigate the effect of different proportions of red kidney bean protein (RKP) on the digestibility of co-gelatinized wheat starch (WS) and corn starch (CS), as well as explore the potential underlying mechanisms. The results showed a significant reduction in both the rate and extent of digestion for WS and CS after adding the RKP during co-gelatinization. Furthermore, incorporating RKP at 0 % to 20 % levels increased the content of resistant starch (RS) by 34.89 % and 14.43 % in the digested systems of wheat starch and maize starch, respectively, while decreasing the concentration of rapidly digestible starch (RDS) by 12.24 % and 20.39 %, respectively. Furthermore, RKP was found to inhibit α-amylase in a dose-dependent and non-competitive manner. Its interaction with starch occurred through hydrogen bonds and hydrophobic interactions, resulting in a modification of the short-range ordered structure of starch and ultimately leading to inhibition of starch digestion. The physical barrier effect of RKP on starch digestion also contributed to its inhibitory action. Considering the health-related delay in the rate and extent of postprandial starch digestion, Our findings have important inspirational value for the use of red kidney bean protein in hypoglycemic foods.

Effect of improved extrusion cooking technology (IECT) on structure, physical properties and in vitro digestibility of starch

Extrusion can modify the structure and physical properties of starch, while the extent of improved extrusion cooking technology (IECT) affects the starch with high moisture content and different crystal types remaining unclear. Therefore, the influence of IECT at different screw speeds on the structure, physical properties and in vitro digestibility of corn (A-type), potato (B-type) and pea (C-type) starches with high moisture content (42 %) was explored. Results indicated that IECT treatment caused similar variations on structure, physical properties, and in vitro digestibility of the 3 types of starches. The contents of slowly digestible starch (SDS) and resistant starch (RS) decreased by IECT treatment, accompanied by a reduction of crystallinity, enthalpy of gelatinization, gelatinization temperature and viscosity, while the content of rapidly digestible starch (RDS) and the ratio of bound water increased. And the changes in in vitro digestibility of starch were closely related to the damage to starch structure caused by IECT. Furthermore, most of starch granules were in the agglomeration stage by appropriate IECT treatment, which induced the exposure of a great quantity of enzyme binding sites to enhance the in vitro digestibility.

Probing gallic acid-starch interactions through Rapid ViscoAnalyzer in vitro digestion

Phenolic compounds are known inhibitors of starch digestion through binding with α-amylase. However, a growing body of research shows that phenolic-starch interactions at the molecular level may interfere with this inhibition potential. In this study, we evaluated the effect of Gallic Acid (GA) as a model phenolic compound on starch digestion kinetics carried out in vitro in a Rapid ViscoAnalyzer (RVA). The results showed that when GA was added before cooking of starch in order to promote starch-GA complexation, the rate of digestion of starch was similar to that of starch alone, and faster than when GA was added after cooking of starch. The results demonstrated that when GA was introduced after cooking of starch, GA inhibited α-amylase strongly and that inhibition increased with starch paste viscosity only for potato and wheat starches. No correlation was found between starch molecular characteristics and the inhibiting capacity of GA at different starch concentrations. However, the apparent influence of starch chain length distribution suggested that physical effects (such as the absorption of GA at the surface of the starch paste) may play a role in the capacity of GA to inhibit α-amylase.

Effects of ultrasound-induced V-type rice starch-tannic acid interactions on starch in vitro digestion and multiscale structural properties

V-type starch-polyphenol complexes, known for their improved physicochemical properties compared to native starch, are challenging to form efficiently. In this study, the effects of tannic acid (TA) interaction with native rice starch (NS) on digestion and physicochemical properties were investigated using non-thermal ultrasound treatment (UT). Results showed the highest complexing index for NSTA-UT3 (∼ 0.882) compared to NSTA-PM (∼0.618). NSTA-UT complexes reflected the V6I-type complex having six anhydrous glucose per unit per turn with peaks at 2θ = 7°, 13°, and 20°. The maxima of the absorption for iodine binding were suppressed by the formation of V-type complexes depending on the concentration of TA in the complex. Furthermore, rheology and particle size distributions were also affected by TA introduction under ultrasound, as revealed by SEM. XRD, FT-IR, and TGA analyses confirmed V-type complex formation for NSTA-UT samples, with improved thermal stability and increased short-range ordered structure. Ultrasound-induced addition of TA also decreased the hydrolysis rate and increased resistant starch (RS) concentration. Overall, ultrasound processing promoted the formation of V-type NSTA complexes, suggesting that tannic acid could be utilized for the production of anti-digestion starchy foods in the future.

Synergistic impact of heat-ultrasound treatment on the properties and digestibility of Sagittaria sagittifolia L. starch-phenolic acid complexes

The current research investigated the multi-scale structural interactions between arrowhead starch (AS) and phenolic acids, such as ferulic acid (FA) and gallic acid (GA) to identify the mechanism of anti-digestion effects of starch. AS suspensions containing 10 % (w/w) GA or FA were subjected to physical mixing (PM) followed by heat treatment at 70 °C for 20 min (HT) and a synergistic heat-ultrasound treatment (HUT) for 20 min using a dual-frequency 20/40 KHz system. The synergistic HUT significantly (p < 0.05) increased the dispersion of phenolic acids in the amylose cavity, with GA showing a higher complexation index than FA. XRD analysis showed a typical V-type pattern for GA, indicating the formation of an inclusion complex, while peak intensities decreased for FA following HT and HUT. FTIR revealed sharper peaks possibly of amide bands in the ASGA-HUT sample compared to that of ASFA-HUT. Additionally, the emergence of cracks, fissures, and ruptures was more pronounced in the HUT-treated GA and FA complexes. Raman spectroscopy provided further insight into the structural attributes and compositional changes within the sample matrix. The synergistic application of HUT led to increased particle size in the form of complex aggregates, ultimately improving the digestion resistance of the starch-phenolic acid complexes.