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Lavage or irrigation has been instilled in surgical practice for wound clearance and surgical site infection prevention during and after surgery. Herein, we developed a new irrigation solution using trimethyl chitosan (TMC), a quaternized chitosan derivative. The TMC-saline irrigation solution developed in the study possesses highly effective bactericidal properties with hemostatic and anti-adhesion properties. The anti-adhesion property of TMC was investigated in relation to inflammatory cytokine response and wound healing. TMC-saline irrigation solution showed reduced pro-inflammatory cytokine protein and gene expressions relevant in the cascade of wound healing and cytokine-related orchestration of postoperative adhesion formation. Further development of this multifunctional TMC-saline irrigation solution can be beneficial for surgical applications and postoperative wound management.

Amorphous granular potato starch (AGPS) was prepared through heat treatment of native potato starch (NPS) at 94°C with 53% EtOH, while cross-linked amorphous granular potato starch (CLAGPS) was prepared through cross-linking of NPS with sodium trimetaphosphate/sodium tripolyphosphate (STMP/STPP, 99:1) and heat treatment. Light and polarized microscopy showed that both AGPS and CLAGPS maintained their granule shapes but lost birefringence. DSC and XRD of both AGPS and CLAGPS also revealed complete gelatinization. On the other hand, CLAGPS exhibited no RVA pasting viscosity and AGPS had a higher final viscosity than NPS or CLAGPS. AGPS had a higher RS content than gelatinized potato starch, while that of CLAGPS did not increase, despite the cross-linking modification. Thus, AGPS and CLAGPS had distinct physicochemical properties from each other and from NPS, suggesting their potential applicability to the food, textile, and paper industries.

Here, we present a gold nanoparticle-based colorimetric assay for the determination of molecular weight distribution and branching characteristics of enzymatically hydrolyzed starch. The steric stabilization effect of starch hydrolysate on the colloidal stability of AuNPs was found to be proportional to the ratio of high molecular weight amylopectins, which was clearly reflected by the intensity of the characteristic surface plasmonic resonance (SPR) absorbance peak of the AuNPs. The fractional change of high molecular weight amylopectin over the course of enzymatic hydrolysis reaction could be measured based on the intensity of SPR peak, in which the results correlated well with those obtained by conventional gel permeation chromatography. With the proper calibration of a specific set of enzyme and starch type, this method would provide a fairly simple and fast means of analyzing the molecular weight distribution of starch hydrolysate on site as well as the amylose content in native starch.

The objective of this study was to investigate the impact of removing starch granule-associated proteins (SGAPs), especially starch granule-associated surface and channel proteins, on the overall characteristics of corn and rice starches. Protease treatment predominantly removed SGAPs on surfaces and in channels of the starches without significant damage, as evidenced by confocal laser scanning microscopy coupled with protein-specific and non-reactive fluorescent dye staining. Compared to untreated starches, protease-treated (PT) starches showed higher solubility and lower swelling power. However, there were no changes in their gelatinization and melting temperatures, despite their higher relative crystallinity. The stability of swollen starch granules during shearing was reduced following SGAP removal, reducing their peak, final and setback viscosities of the paste. Taken together these results indicate that SGAP removal predominantly affects the rheological properties of starch. Furthermore, the lower setback in PT-starch pastes suggests short-term retrogradation may be retarded by protease treatment of starch.

The objective of this study was to demonstrate the validity of dynamic semi-dry heat reaction (SDHR) by investigating the effects of static and dynamic SDHR on the characteristics of starch citrates. The starch (normal and waxy corn)-citric acid (CA) mixture was heated in a convection oven (static mode) or a twin-screw extruder without a die (dynamic mode). The ester bonds of starch citrates were confirmed by FT-IR, and their molar degree of substitution did not differ between the reaction modes for the tested starch genotypes. Starch citrates by dynamic SDHR exhibited higher relative crystallinity, resistant starch content, solubility, swelling power, and gelatinization compared to those by static SDHR. Although static SDHR did not show a viscosity development during pasting, dynamic SDHR increased their pasting viscosities. Overall, these results suggest that dynamic SDHR could improve the defects (i.e., lack of solubility, swelling, and pasting attributes) of the traditional starch citrates.

To extract pectin in food industry, HCl is generally used as the major extracting solvent for releasing the pectin from the plant tissues, however it has an environmental issue to use. In this study, food-grade tartaric-, malic, and citric acids were used to produce apple peel pectin as an eco-friendly protocol instead of HCl. Finely-ground lyophilized apple peel was applied as the raw material, and the pectin was extracted by organic acids at 85 °C. The pectin extracted with citric acid displayed greater molecular weight and apparent viscosity compared to other organic acid treatments. Analysis of degree of methyl esterification revealed that the pectins extracted with organic acids were highly methoxylated. From these results, it was suggested that organic acids could be utilized to extract apple peel pectin effectively as a green process. Especially, the extraction process with citric acid as the solvent showed great potential to produce high-viscosity apple peel pectin.

Physicochemical properties of Neisseria polysaccharea amylosucrase (NpAS)-treated rice and barley starches were investigated at scale-up production. Pre-gelatinized rice and barley starches were treated with significantly lower NpAS dose (0.1 U/mL) but 100 times larger reaction volume (3500 mL), compared to the analytical scale (35 mL) used in the previous study. NpAS-treated starches in this scale-up production were characterized with respect to reaction efficiency (RE), resistant starch (RS) content, amylopectin (AP) branch-chain length distribution, solubility, swelling power, pasting viscosity, and thermal transition properties. The RE enhanced up to 1.8 times by increasing the reaction volume, which improved the RS content and AP branch-chain lengths of NpAS-treated starches. Compared with the native starch, NpAS-treated starches exhibited lower solubility and swelling power, lower pasting viscosity, and a large increase in the melting peak temperature. Consequently, NpAS treatment of pre-gelatinized starches in this study would be a potential way of replacing commercial RS production.

Potato parenchyma cells were characterized to identify the function of intact parenchyma cell walls on their physicochemical properties. Parenchyma cells were separated using pectinase from raw and cooked potatoes (R-Cell and G-Cell, respectively), and investigated with respect to their morphology, chemical composition, starch leaching and swelling power, gelatinization, and pasting property. Potato flour (RPF) and potato granule (PGL) prepared in laboratory were used as controls of R-Cell and G-Cell, respectively. Protein and ash were lost during parenchyma cell isolation. Ungelatinized and gelatinized starches within parenchyma cells were tightly wrapped by intact parenchyma cell walls. Compared to their controls, the parenchyma cell walls prevented starch leaching from R-Cell and G-Cell. R-Cell exhibited the reduced swelling powers and pasting viscosities, while the opposite patterns were observed for G-Cell. R-Cell revealed the increased gelatinization temperatures than native potato starch. Overall, potato parenchyma cells may expand the industrial availability of dehydrated potato products.

Granular and non-granular cationic starches were prepared through the reaction of tapioca and corn starches with 2,3-epoxypropyl trimethyl ammonium chloride (ETMAC) using conventional and ultra high pressure (UHP)-assisted reactions. The cationic starches were characterized with respect to morphology, degree of substitution (DS), FT-IR, 13C NMR, X-ray diffraction pattern, solubility and swelling power, pasting viscosity, and flocculating activity. Non-granular (relative to granular) cationic starches possessed higher DS values. While DS values of non-granular cationic starches were lower for UHP-assisted (relative to conventional) reaction, granular cationic starches did not differ for both reactions. For flocculation activity, granular cationic starches with lower solubility and higher swelling power were higher than non-granular counterparts with reversed patterns in solubility and swelling power, regardless of conventional and UHP-assisted reactions. Overall results suggested that flocculation activity of cationic starches may be directly associated with their swelling powers (relative to DS values).

Combinations of 4 rice starches with amylose (AM) contents of 0%, 15%, 22%, and 28% and 8 hydrocolloids (xanthan, guar gum, CMC, sodium alginate, HPMC, κ-, ι-, λ-carrageenan) were used (4.75% starch and 0.25% hydrocolloid). With a few exceptions, addition of a hydrocolloid increased peak and final η, breakdown, setback, G″, and η*, K, and ηa,100 values. It is concluded that the AM content of the starch was a greater determinant of pasting, paste, and gel properties than was the added hydrocolloid at the 19:1 (w/w) starch–hydrocolloid ratio used. Reinforced is the previous conclusion that the properties of a starch–hydrocolloid combination are determined by the specific combination.

Cationic dextrins were prepared through substitution reaction of dextrin with low and high addition levels of 2,3-epoxypropyltrimethylammonium chloride (ETMAC), respectively. Conventional cationization reactions were carried out for 5 h under continued stirring. UHP-assisted cationization reactions were conducted at three pressurization levels of 100, 300 and 500 MPa for a pressure holding time of 30 min. Degree of substitution (DS) of UHP-assisted cationic dextrins ranged from 0.58 to 1.51, and in general, their DS values were enhanced with increasing pressure levels. FT-IR and 13 C NMR spectra indicated the presence of C N bond, which provided clear evidence about incorporation of cationic moieties onto dextrin molecules. In flocculation test, UHP-assisted cationic dextrin revealed higher flocculating activity. Overall results suggested that UHP-assisted cationization reaction could modulate reactivity and flocculating activity of dextrin by controlling pressure levels and reaction mixture compositions, and cationic dextrins likely possessed a higher potential to replace synthetic polymer-based flocculants.

A technique was developed for investigating granular reaction patterns of anionic starch derivatives, utilizing the optical sectioning capability of reflectance confocal laser scanning microscopy in combination with 3D anaglyphic imaging (3D glasses required for visualization). The method facilitated improved visualization of internal granular reaction patterns by discarding optical sections comprising the highly-reacted external granule surface (generating 3D image constructs from sections constituting exclusively internal regions of granules) and minimizing confounding background signal associated with non-starch constituents (e.g., proteins). For wheat starch A-type granules substituted with a propylene oxide analog (POA), granular reaction patterns revealed that reagent reached the hilum region of granules through channels, and primarily entered the granule matrix via lateral diffusion from channel surfaces, producing relatively homogeneous reaction patterns. The homogeneous nature of POA granular reaction patterns was attributed to the relatively low reactivity of the reagent (rate of diffusion > rate of reaction).

Twenty-one members of five families of hydrocolloids were used. Xanthan alone increased the temperature at which the rapid increase in viscosity was observed; all other hydrocolloids lowered the temperature of initiation of the rapid viscosity increase. Addition of all hydrocolloids (guar gum, methylcellulose (MC), sodium alginate, carboxymethylcellulose (CMC), xanthan) other than hydroxypropylmethylcellulose (HPMC) increased peak viscosities. Increases in final viscosities were generally more modest. Final viscosities increased with increasing MW for CMC and MC products. HPMC appeared to have an optimum size for increasing final viscosity. Both starch-alone and starch–hydrocolloid composite pastes exhibited gel-like characteristics. Addition of any of the hydrocolloids made the pastes/gels less solid-like. G′ increased upon addition of increasing MW preparations of guar gum and HPMC. Both G′ and G′′ increased as the MW of CMC increased. Addition of the carrageenans increased peak and final viscosities, G′, G′′, tan δ, and η* in the order λ > ι > κ.

Reactivity and property of corn starches hydroxypropylated under ultra high pressure were investigated as a function of either pressure levels or pressure holding times. Corn starch was derivatized with propylene oxide (PO) either at 0.1–400 MPa for 15 min or at 400 MPa for 5–25 min, and assessed with respect to molar substitution (MS), X-ray diffraction pattern, solubility, swelling power, gelatinization, and pasting behavior. While an increase in pressure level enhanced MS values of UHP-assisted PO starch derivatives, starch reactivity was less influenced by pressure holding time. UHP-assisted PO reaction reduced reaction time to the greatest extents compared to long reaction time in conventional PO reaction. UHP-assisted PO starch derivatives revealed similar solubilities/swelling powers, and gelatinization properties, regardless of pressure levels. Higher gelatinization temperature was observed for UHP-assisted PO starch derivatives and their respective controls relative to native starch, implying that UHP-assisted reaction might involve starch annealing.

The impact of granule type (A/B-type granule ratio) on the reactivity and physical properties of chemically-modified wheat starch was investigated. Waxy and normal wheat starches were fractionated into highly-purified A- and B-type granule fractions, and reconstituted into fractions possessing pre-defined A/B-type granule ratios (weight basis). Starch granule fractions were derivatized with either propylene oxide (PO) or PO analog (POA), and assessed with respect to molar substitution (MS), swelling, gelatinization, and pasting properties. For POA (MS < 0.025) and PO (MS ≈ 0.1) starch derivatives, no differences in the relative reactivities of A-type and B-type granules or among the reconstituted wheat starches of varied A/B-type granule contents were observed within a genotype. Despite the similar reactivities of reconstituted wheat starch fractions possessing varied A/B-type granule contents, variations in swelling, gelatinization, and pasting properties were observed across the modified reconstituted starch granule fractions. Thus, substitution did not completely eradicate inherent property differences observed between unmodified reconstituted wheat starch granule fractions (based on differing A/B-type granule contents).

Potential roles of ultra high pressure (UHP) in starch granule reactivity and properties of acetylated starch were investigated. Corn starch was substituted with acetic anhydride at pressure range of 0.1–400 MPa for 15 min; also, conventional reaction (30 °C, 60 min) was conducted as reaction control. Native and acetylated corn starches were assessed with respect to degree of substitution (DS), X-ray diffraction pattern/relative crystallinity, starch solubility/swelling power, gelatinization, and pasting behavior. For the UHP-assisted acetylated starches, DS values increased along with increasing pressure levels from 200 to 400 MPa, and reaction at 400 MPa exhibited maximum reactivity (though lower than the DS value of the reaction control). Both UHP-assisted and conventional acetylation of starch likely occurred predominantly at amorphous regions within granules. Gelatinization and pasting properties of the UHP-assisted acetylated starches may be less influenced by UHP treatment in acetylation reaction, though restricted starch solubility/swelling were observed.