Enzymatic Synthesis of α-Glucan Microparticles Using Amylosucrases from Bifidobacterium Species and Its Physicochemical Properties

α-Glucan microparticles (GMPs) have significant potential as high-value biomaterials in various industries. This study proposes a bottom-up approach for producing GMPs using four amylosucrases from Bifidobacterium sp. (BASs). The physicochemical characteristics of these GMPs were analyzed, and the results showed that the properties of the GMPs varied depending on the type of enzymes used in their synthesis. As common properties, all GMPs exhibited typical B-type crystal patterns and poor colloidal dispersion stability. Interestingly, differences in the physicochemical properties of GMPs were generated depending on the synthesis rate of linear α-glucan by the enzymes and the degree of polymerization (DP) distribution. Consequently, we found differences in the properties of GMPs depending on the DP distribution of linear glucans prepared with four BASs. Furthermore, we suggest that precise control of the type and characteristics of the enzymes provides the possibility of producing GMPs with tailored physicochemical properties for various industrial applications.

Physicochemical properties of amorphous granular starch (AGS) prepared by non-thermal gelatinization by high hydrostatic pressure (HHP) and spray drying

Corn starch was gelatinized by high hydrostatic pressure (HHP) and spray drying to make amorphous granular starch (AGS), and their physicochemical properties were compared with the conventionally prepared (heat-gelatinized and spray dried) AGS to devise a novel AGS preparation methodology. Pressure-induced (PAGS) and heat-induced AGS (HAGS) maintained their granular shape but lost their birefringence indicating that both methods could prepare AGS. DSC (differential scanning calorimeter) and XRD (X-ray diffraction) analysis confirmed the complete loss of amylopectin double helices and crystallinity of both PAGS and HAGS. However, their swelling power, solubility, RVA pasting properties, acid/shear stability, gel forming ability and textural properties were completely different. PAGS exhibited constrained swelling, suppressed amylose leaching, and reduced viscosity. Notably, HAGS formed a gel without heating, whereas PAGS yielded a viscous paste with water-soluble attributes. Even after reheating, PAGS maintained its granular structure with comparably less swelling and weaker gel strength than HAGS. Consequently, newly developed PAGS exhibited distinctive characteristics compared to the conventional HAGS, such as lower solubility and swelling power, viscosity, textural properties, and high acid and shear stabilities, rendering it a viable option for various applications within the food industry.

Characteristics of physically modified starches

Starch is an abundant natural, non-toxic, biodegradable polymer. Due to its low price, it is used for various purposes in various fields such as the cosmetic, paper, and construction industries as well as the food industry. Due to recent consumer interest in clean label materials, physically modified starch is attracting attention. Manufacturing methods of physically modified starch include pregelatinization, hydrothermal treatment such as heat moisture treatment and annealing, hydrostatic pressure treatment, ultrasonic treatment, milling, and freezing. In this study, toward development of clean label materials, manufacturing methods and characteristics of physically modified starches were discussed.

Effects of Puffing, Acid, and High Hydrostatic Pressure Treatments on Ginsenoside Profile and Antioxidant Capacity of Mountain-Cultivated Panax ginseng

The purpose of this study was to investigate the effects of puffing, acid, and high hydrostatic pressure (HHP) treatments on the ginsenoside profile and antioxidant capacity of mountain-cultivated Panax ginseng (MCPG) before and after treatments. Puffing and HHP treatments decreased extraction yield and increased crude saponin content. The combination of puffing and HHP treatment showed significantly higher crude saponin content than each single treatment. Puffing treatment showed the highest ginsenoside conversion compared with HHP and acid treatments. Significant ginsenoside conversion was not observed in HHP treatment but was in acid treatment. When the puffing and acid treatments were combined, Rg3 and compound K content (1.31 mg and 10.25 mg) was significantly higher than that of the control (0.13 mg and 0.16 mg) and acid treatment (0.27 mg and 0.76 mg). No synergistic effect was observed between acid and HHP treatments. In the case of functional properties, the puffing treatment showed a significant increase in TFC (29.6%), TPC (1072%), and DPPH radical scavenging capacity (2132.9%) compared to the control, while acid and HHP combined treatments did not significantly increase; therefore, the synergistic effects of HHP/puffing and acid/puffing treatments were observed in crude saponin content and ginsenoside conversion, respectively. Consequently, puffing combined with acid or HHP treatments may provide new ways to produce high-value-added MCPG with a higher content of Rg3 and compound K or crude saponin compared to untreated MCPG.

Optimization of pea protein and citrus fiber contents for plant based stirred soymilk yogurt using response surface methodology

This study investigated the optimization of pea protein (PP) and citrus fiber (CF) contents with the goal of producing a clean-label plant-based stirred soymilk yogurt that is free of additives. If CF is absent, a greater PP concentration tends to produce soymilk yogurt with improved physical properties (viscosity, flowability and water holding capacity). A CF concentration of 0.1% helped to improve the physical properties necessary in the production of stirred yogurt; however, an increase in CF concentration to 0.2% or higher would instead cause the physical properties to become unfavorable. The lactic acid bacteria (LAB) count was unaffected by CF content and increased proportionally with PP content. Response surface methodology was employed to investigate how the physical properties were affected by the mixing ratio, and an optimization technique was used to obtain the optimal yogurt mixing ratio. According to the optimization process, the optimal contents of 4% PP and 0.1% CF was obtained with a desirability of 87.1%. This result could provide the basic and fundamental information for developing clean-label plant-based stirred soymilk yogurt as a reference in the future.

Sericulture and the edible-insect industry can help humanity survive: insects are more than just bugs, food, or feed

The most serious threat which humans face is rapid global climate change, as the Earth shifts rapidly into a regime less hospitable to humans. To address the crisis caused by severe global climate change, it will be necessary to modify humankind's way of life. Because livestock production accounts for more than 14.5% of all greenhouse gas (GHG) emissions, it is critical to reduce the dependence of humans on protein nutrients and calories obtained from livestock. One way to do so is to use insects as food. Compared with typical livestock, farming edible insects (or "mini-livestock") produce fewer GHG emissions, require less space and water, involve shorter life cycles, and have higher feed conversion rates. It has been recently reported that consumption of certain insects can prevent or treat human diseases. This review goes beyond entomophagy to entomotherapy and their application to the food industry.

Infusion of fluorescein into corn and waxy rice starches and its controlled release

The effects of concentration, temperature, and time on infusion of fluorescein into corn and waxy rice starches and their controlled release pattern were investigated. At low fluorescein concentration (1 μM), temperature significantly affected infusion efficiency. At high fluorescein concentration (50-150 μM), temperature showed little effect; fluorescein concentration significantly affected infusion efficiency. Corn starch showed relatively higher infusion efficiency than waxy rice starch at high concentration. During controlled release, 50% and 81% of infused fluorescein were released from corn and waxy rice starches, respectively, after bacterial α-amylase treatment. However, 61% and 68% of infused fluorescein were released from corn and waxy rice starches, respectively, after pancreatic α-amylase treatment. The dextrose equivalent (DE) value revealed similar patterns, suggesting that degradation of starch by different α-amylases is a major factor affecting release of fluorescein from starch granules. Moreover, granule size of starch greatly affected enzymatic hydrolysis and controlled release in this system.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01059-2.

Infusion efficiency of fluorescein derivatives of different molecular sizes into various starches under atmospheric and high hydrostatic pressures

Fluorescein isothiocyanate-dextrans (FDs) of different molecular weights were infused into corn, waxy rice, tapioca, and potato starches under atmospheric and high hydrostatic pressures (HHP). FD4, FD10, FD20, and FD40 (Mw 4000, 10,000, 20,000, and 40,000, respectively) were used as infusion materials. Confocal laser scanning microscopy confirmed that all FDs except FD40 infused into corn, waxy rice, and tapioca starches. However, no FDs infused into potato starch. Corn starch had the highest amounts of infused FDs. As molar mass increased, the amount of infused FD decreased in all starches. The infused amounts of FDs in corn starch were similar at 200-300 MPa and atmospheric pressure. Infusion of FDs at 400 MPa was reduced due to partial gelatinization. These results confirm that infusion efficiency is inversely proportional to the molecular weight of the infused material and large materials (Mw > 40,000) cannot be infused into starch granules under atmospheric pressure or HHP.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10068-021-00972-2.

Applicable Plant Proteins and Dietary Fibers for Simulate Plant-Based Yogurts

Effects of plant proteins and dietary fibers on the physical properties of stirred soy yogurt were investigated. Buffering capacity against lactic acid was not affected by the protein concentration for any of the four proteins that were examined: isolate soy protein (ISP), pea protein (PP), rice protein (RP), and almond protein (AP). Three proteins other than AP exhibited an increase in buffering capacity (dB/dPH) following a physical treatment, whereas AP saw a decrease in buffering capacity. Furthermore, physically treated PP revealed a significant increase in viscosity, reaching up to 497 cp in the pH 6.0~6.2 range during the titration process. Following fermentation, PP produced the highest viscosity and coagulum strength with no syneresis. In the case of dietary fiber, Acacia Fiber (AF) was completely dissolved in the solvent and did not affect the physical properties of the fermented coagulum. Soy fiber (SF) was also not suitable for fermented milk processes because precipitation occurred after the physical treatment. In the case of citrus fiber (CF), however, syneresis did not occur during storage after the physical treatment, and the viscosity also increased up to 2873 cP. Consequently, PP and CF were deemed to be a suitable plant protein and dietary fiber for stirred soy yogurt, respectively.

Impact of starch granule-associated channel protein on characteristic of and λ-carrageenan entrapment within wheat starch granules

This study investigated the physicochemical characteristics of protease-treated wheat starch (PT-WST) to understand the role of starch granule-associated proteins (SGAPs) and the potential capability of PT-WST to provide a nutrient delivery system (NDS). Protease treatment was conducted at 4 °C and 37 °C (PT04 and PT37), respectively. A model delivery system was assessed with PT37 granules infiltrated by λ-carrageenan (λC) under variations of molecular size (λC hydrolysates produced from 0, 2.5, 100, and 500 mM HCl solution), agitation time, and temperature. Protein-specific (3-(4-carboxybenzyl)quioline-2-carboxaldehyde) or non-reactive (methanolic merbromin) fluorescent dye staining revealed that removal of SGAPs on surfaces and channels were more effective for PT37 than for PT04. Consistent amylose content, swelling, and gelatinization temperature before and after protease treatment suggested minimal impact on the starch structure. PT37 presented higher solubility and pasting viscosity than PT04. This resulted from excessive SGAP removal, which enhanced entrapment capacity. λC molecular size and agitation temperature showed a negative correlation with the content of λC entrapped within PT37, and this content depended on the interplay between the agitation time and λC molecular size. As λC molecular size decreased, the λC distribution became uniform throughout the granules, which confirmed the potential of PT-WST as a carrier for NDS.

A brief history and spectroscopic analysis of soy isoflavones

The production of soybean continues to increase worldwide. People are showing more interest in the beneficial health effects of soybeans than before. However, the origin and history of soybeans are still being discussed among many researchers. Chromatographic methods enable the desirable separation of a variety of isoflavones from soybeans. The structures of isolated soy isoflavones have been successfully identified in tandem with spectroscopic analytical instruments and technologies such as liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopy. The theoretical background behind spectroscopy may help improve the understanding for the analysis of isoflavones in soybeans and soy-derived foods. This review covers the origin of the English name of soybean and its scientific name, Glycine max (L.) Merrill, based on the evidence reported to date. Moreover, the reports of soy isoflavones discovered over a period of about 100 years have been briefly reviewed.

Effect of hydrothermal treatment on physicochemical properties of amorphous granular potato starch (AGPS)

Using restructuring technology, A- or B-type crystalline granular potato starch was produced from amorphous granular potato starch (AGPS). AGPS was prepared using ethanol-heat processing, and hydrothermal treatments were performed with different moisture contents (18, 29, 200% d.b.) and temperatures (4, 25, 40, 60, 80 °C) for 3 weeks. AGPS showed no endothermic peak in a DSC thermogram, while hydrothermally treated AGPS (HAGPS) revealed endothermic peaks. In X-ray diffraction, AGPS displayed an amorphous pattern, and HAGPS displayed A- or B-type crystalline patterns depending on treatment temperature and moisture content. Neither AGPS nor HAGPS had typical RVA pasting curves, and their viscosities gradually increased. Raman spectroscopy and FT-IR confirmed that ordered structure and crystalline regions increased in HAGPS. Resistant starch (RS) and slowly digestible starch (SDS) contents of HAGPS increased but rapidly digestible starch (RDS) content decreased compared to AGPS. These results elucidated that hydrothermal treatment could change the physicochemical properties of AGPS and produce an identical material, such as granular potato starch with A-type and B-type crystalline granular potato starch.

Enhanced Antioxidant Capacity of Puffed Turmeric (Curcuma longa L.) by High Hydrostatic Pressure Extraction (HHPE) of Bioactive Compounds

Turmeric (Curcuma longa L.) is known for its health benefits. Several previous studies revealed that curcumin, the main active compound in turmeric, has antioxidant capacity. It has been previously demonstrated that puffing, the physical processing using high heat and pressure, of turmeric increases the antioxidant and anti-inflammatory activities by increasing phenolic compounds in the extract. The current study sought to determine if high hydrostatic pressure extraction (HHPE), a non-thermal extraction at over 100 MPa, aids in the chemical changes and antioxidant functioning of turmeric. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) analyses were conducted and assessed the content of total phenol compounds in the extract. The chemical changes of curcuminoids were also determined by high performance liquid chromatography (HPLC). Among the three variables of ethanol concentration, pressure level, and treatment time, ethanol concentration was the most influential factor for the HHPE of turmeric. HHPE at 400 MPa for 20 min with 70% EtOH was the optimal extraction condition for the highest antioxidant activity. Compositional analysis revealed that 2-methoxy-4-vinylphenol was produced by puffing. Vanillic acid and ferulic acid content increased with increasing HHPE time. Synergistic effect was not observed on antioxidant activity when the turmeric was sequentially processed using puffing and HHPE.

Starch nanoparticles prepared by enzymatic hydrolysis and self-assembly of short-chain glucans

Enzymatic hydrolysis and self-assembly are considered promising methods for preparation of starch nanoparticles (SNPs) because they are environmentally friendly, and time- and cost-effective. These methods are based on the self-assembly of short-chain glucans released from the α-1,6 bonds in amylopectin. Since their discovery, many studies have described the structural and physicochemical properties of self-assembled SNPs. Self-assembled SNPs can be prepared by two methods: using only the soluble portion containing the short-chain glucans, or using the whole hydrolyzate including both insoluble and soluble fractions. Although the structural and physical properties of self-assembled SNPs can be attributed to the composition of the hydrolyzates that participate in self-assembly, this aspect has not yet been discussed. This review focuses on SNPs self-assembled with only soluble short-chain glucans and addresses their characteristics, including formation mechanisms as well as structural and physicochemical properties, compared with SNPs prepared with total hydrolyzates.

Enzymatically elongated rice starches by amylosucrase from Deinococcus geothermalis lead to slow down the glucose generation rate at the mammalian α-glucosidase level

Amylosucrase (AS) catalyzes the transfer of a glucosyl unit from sucrose onto α-1,4-linked glucan polymers in starch. In this study, AS from Deinococcus geothermalis (DgAS) was applied to produce modified rice starches with slowly digestible properties. DgAS-treated waxy and normal rice starches showed significantly (p < 0.05) elevated degrees of polymerization, suggesting that the external chains were elongated. Additionally, the crystalline structures of starches changed from A- to B-type, and the temperature transition properties of enzymatically modified rice starches increased. The amounts of slowly digestible starch (SDS) increased remarkably (20.1% and 18.8%; waxy and normal rice starches, respectively), and the DgAS-treated rice starches were slowly hydrolyzed to glucose at the mammalian mucosal α-glucosidase level. Thus, DgAS-treated rice starches can be used to produce SDS-based ingredients that attenuate the glucose spike after glycemic food ingestion.

Enhancement of Minor Ginsenosides Contents and Antioxidant Capacity of American and Canadian Ginsengs (Panax quinquefolius) by Puffing

The effects of puffing on ginsenosides content and antioxidant activities of American and Canadian ginsengs, Panax quinquefolius, were investigated. American and Canadian ginsengs puffed at different pressures were extracted using 70% ethanol. Puffing formed a porous structure, inducing the efficient elution of internal compounds that resulted in significant increases in extraction yields and crude saponin content. The content of minor ginsenosides (Rg2, Rg3, compound K) increased with increasing puffing pressure, whereas that of major ginsenosides (Rg1, Re, Rf, Rb1, Rc, Rd) decreased, possibly due to their deglycosylation and pyrolysis. Furthermore, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, total phenolic content, total flavonoid content, amount of Maillard reaction products, and acidic polysaccharides content increased with increasing puffing pressure, but 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity did not. There was no substantial difference in the results between puffed American and Canadian ginsengs. Consequently, these results suggest that puffing can be a promising novel technology for processing P. quinquefolius to achieve higher levels of minor ginsenosides and obtain value-added products.

Physicochemical and retrogradation properties of modified chestnut starches

Physicochemical properties of acetylated (AC), cross-linked (CL), and hydroxypropylated (HP) chestnut starches were investigated. Modified chestnut starch showed low RS and amylose contents. AC revealed the highest solubility and HP showed the highest swelling power at 60 °C. CL showed the lowest solubility and swelling power at both 60 and 90 °C. AC and HP showed a lower pasting temperature and higher peak viscosity than native chestnut starch (NC). Modified chestnut starch formed gels at higher solid content than NC. CL had the lowest freeze-thaw stability, and AC and HP showed the strongest tolerance to freeze-thaw cycles. Amylopectin melting enthalpy of NC dramatically increased over the first 2 days and continued increasing gradually until day 24. On the other hand, all the modified chestnut starches showed a slight increase in amylopectin melting enthalpy, indicating retarded retrogradation. CL showed the lowest degree of retrogradation, followed by HP, AC, and NC.

Change of Ginsenoside Profiles in Processed Ginseng by Drying, Steaming, and Puffing

Korean ginseng (Panax ginseng Meyer) was processed by drying, steaming, or puffing, and the effects of these processes on the ginsenoside profile were investigated. The main root of 4-year-old raw Korean ginseng was dried to produce white ginseng. Steaming, followed by drying, was employed to produce red or black ginseng. In addition, these three varieties of processed ginseng were puffed using a rotational puffing gun. Puffed ginseng showed significantly higher extraction yields of ginsenosides (49.87-58.60 g solid extract/100 g of sample) and crude saponin content (59.40-63.87 mg saponin/g of dried ginseng) than nonpuffed ginseng, respectively. Moreover, puffing effectively transformed the major ginsenosides (Rb1, Rb2, Rc, Rd, Re, and Rg1) of ginseng into minor ones (F2, Rg3, Rk1, and Rg5), comparable to the steaming process effect on the levels of the transformed ginsenosides. However, steaming takes much longer (4 to 36 days) than puffing (less than 30 min) for ginsenoside transformation. Consequently, puffing may be an effective and economical technique for enhancing the extraction yield and levels of minor ginsenosides responsible for the major biological activities of ginseng.

Characteristics of granular cold-water-soluble potato starch treated with alcohol and alkali

The characteristics of cold-water-soluble potato starch (CWSS) produced using alcoholic-alkaline treatment were determined using scanning electron microscopy, rapid visco analysis (RVA), X-ray diffraction, differential scanning calorimetry, storage modulus (G'), loss modulus (G″), and gel images. Scanning electron microscopy revealed a damaged crystalline structure when CWSS was suspended in ethanol. The RVA analysis of native starch showed a peak value of viscosity at high temperatures, whereas the viscosity of CWSS did not show such a peak. The DSC diagram of native starch showed a gelatinization peak temperature; however, no such peak was observed for CWSS. Cold-water solubility tremendously increased in CWSS owing to the loss of crystallinity. The values of G' and G″ in CWSS decreased with increasing temperature; the opposite was observed for normal potato starch. These results indicate that alcoholic-alkaline treatment affects the starch structure and produces totally different physicochemical properties from native starch; this makes CWSS feasible for use in a variety of food materials.

Puffing, a novel coffee bean processing technique for the enhancement of extract yield and antioxidant capacity

Puffing of coffee beans, which induces heat- and pressure-derived physicochemical changes, was applied as an alternative to roasting. Roasted or puffed coffee beans with equivalent lightness values were compared. The moisture content was higher while the crude fat and protein compositions were lower in puffed beans than in roasted beans. The pH was lower and the acid content was higher in puffed beans than in roasted beans. The roasted beans exhibited greater specific volumes, while the puffed beans displayed greater extraction yields. The trigonelline and total phenolic contents were greater in puffed beans than in roasted beans resulting in an enhanced antioxidant capacity. Sensory evaluation of roasted and puffed coffee bean brews revealed that puffing did not affect the flavor or overall acceptance. The current study provides evidence that puffing is an alternative to roasting coffee beans with various benefits.

Characterization of amorphous granular starches prepared by high hydrostatic pressure (HHP)

Amorphous granular starches (AGS) and non-granular amorphous starches (non-AGS) of corn, tapioca and rice were prepared using high hydrostatic pressure (HHP) treatment with ethanol and water washing, respectively and their physicochemical properties were investigated. Water holding capacity and apparent viscosity of AGS and non-AGS were higher than those of native one in all starches. In RVA pasting properties, AGS and non-AGS showed higher pasting temperature and lower peak viscosity than those of native one. Furthermore, non-AGS showed distinctively lower peak viscosity compared to that of AGS possibly due to its non-granular structure. Apparent viscosity of non-AGS revealed relatively lower than commercial pre-gelatinized starch because of heat and pressure-induced gelatinization. Maintaining granular structure in HHP treated pre-gelatinized starch provide a distinctive physicochemical characteristics compared to native starch and preparation of gelatinized starch with different gelatinization and washing methods could cause big differences in their physicochemical properties.

Retrogradation kinetics of chestnut starches cultivated in three regions of Korea

Retrogradation kinetics of chestnut starches from three different regions of Korea were investigated during storage at 4 °C. The retrogradation properties were determined using four DSC characteristics: glass transition temperature ( T g ' ), ice melting enthalpy (ΔH_i), amylopectin melting enthalpy (∆H_r) and degree of retrogradation (DR). The Gongju (GJ) starch showed the highest gelatinization enthalpy (∆H_g) value, followed by Gwangyang (GY) and Hadong (HD). T g ' of all samples gradually increased with increasing storage time, while ∆H_i decreased as the storage time increased. ∆H_r of all samples significantly increased after 2 days of storage. DR, calculated based on ∆H_g and ∆H_r, showed a similar tendency with ∆H_r. The retrogradation rates of three chestnut starches were analyzed using the Avrami equation, and the time constants (1/k) were obtained. GY, GJ and HD showed the fastest retrogradation rate in T g ' , ∆H_i, and ∆H_r, respectively suggesting that each sample experienced different retrogradation kinetics in different region.

Broad substrate specificity of a hyperthermophilic α-glucosidase from Pyrobaculum arsenaticum

Pyrobaculum arsenaticum is a hyperthermophilic archaeon that thrives at 95°C. This strain encodes a putative GH31 intracellular α-glucosidase (Pars_2044, PyAG) in its genome. The recombinant PyAG (rPyAG) was optimally expressed in Escherichia coli at 37°C for 4 h after IPTG induction. The purified rPyAG is a homotetrameric α-glucosidase that exhibited highly thermostable properties. Maximum p-nitrophenyl-α-D-glucopyranoside (pNPG) hydrolysis activity was observed at 90°C and pH 5.0. The enzyme mainly recognized the non-reducing end of the substrate, releasing the glucose unit. rPyAG also had broad substrate specificity, cleaving maltose (α-1,4-linkage), kojibiose (α-1,2-linkage), and nigerose (α-1,3-linkage) with similar efficiency. Based on these results, rPyAG can be used to modify health-relevant sugar conjugates linked by α-1,2- or α-1,3-bonds.

Characterization of acetylated corn starch prepared under ultrahigh pressure (UHP)

To investigate the impact of ultrahigh pressure (UHP) on the physicochemical properties of the UHP-assisted starch acetate, common corn starch was subjected to either conventional (0.1 MPa, 30 degrees C, 60 min) or UHP-assisted (400 MPa, 25 degrees C, 15 min) acetylation reactions at three levels (4, 8, or 12%) of acetic anhydride. Without significant changes in starch granule crystal structure, UHP-assisted reaction exhibited lower degree of substitution values than conventional reaction across reagent addition levels. An increase in reagent addition levels exhibited common trends in starch solubility/swelling power, gelatinization, and pasting properties for the conventional and UHP-assisted starch acetates relative to native starch. Within an equivalent derivatization level, however, the UHP-assisted (relative to conventional) starch acetates revealed restricted starch solubility/swelling power, reduced gelatinization temperatures, and lower pasting viscosities. Overall, this result suggested that UHP treatment in acetylation reaction might influence the physicochemical properties of starch acetate by facilitating the formation of lipid-complexed amylose or altering granular reaction patterns to acetic anhydride.