Browsing by Author "Kong, Lingyan"
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Item Aligned wet-electrospun starch fiber mats(2019-05) Wang, Hui; Kong, Lingyan; Ziegler, Gregory R.; University of Alabama TuscaloosaElectrospinning is a versatile technique to fabricate non-woven fiber mats with an average fiber diameter ranging from nanometers to micrometers. Fibers produced by electrospinning have potential application in numerous fields owing to their light weight, high surface area, and high porosity. In certain applications, anisotropic properties are desired, which may also improve mechanical strength. This study comprehensively documented the feasibility of directed fiber deposition in wet-electrospinning and offers an inexpensive setup for laboratory investigation. Aligned starch fiber mats were produced and the effects of three operational parameters, i.e., rotational speed, drum location, and coagulation bath composition, were evaluated. The alignment of starch fibers was affected by the ethanol concentration in the coagulation bath and drum rotational speed. Coherent fibers could be obtained in all trials except for the one at the lowest ethanol concentration (60% v/v) and highest rotational speed (500 rpm) when the drum was below the liquid. The tensile strength was influenced by the interaction of location and ethanol concentration, and that of rotational speed and ethanol concentration. This study set a promising example of making aligned biopolymer fiber mats and investigating fiber deposition in wet-electrospinning. Aligned starch fiber mats have potential applications in areas such as tissue engineering and as wound dressings.Item Antioxidant properties and sensory evaluation of microgreens from commercial and local farms(KeAi Publishing, 2020-03) Tan, Libo; Nuffer, Holly; Feng, Jiannan; Kwan, Shu Hang; Chen, Hsiangting; Tong, Xiao; Kong, Lingyan; University of Alabama TuscaloosaMicrogreens are young and tender vegetables or herbs that provide attractive color, flavor, and nutrition. The purpose of this study was to evaluate the nutritional and sensory qualities of broccoli microgreens grown by different methods (hydroponically vs. soil grown) and from different sources (commercial vs. local farm). No significant difference in total phenolic concentration and antioxidant capacity was found in all broccoli microgreens, but a significantly higher chlorophyll concentration was found in farm microgreens than the commercial ones. Moreover, the soil-grown farm microgreens possessed a significantly higher vitamin C concentration than hydroponically-grown farm sample and commercial sample. Participants in the sensory study favored farm samples regardless of growing method, and their overall liking was significantly correlated with taste of the microgreens. In addition, six other microgreens from the local farm were analyzed for their nutritional quality. These conclusions suggested a potential for consumers to still benefit nutritionally by purchasing commercial microgreens at a lower cost; however, it may be worthwhile for consumers to purchase microgreens from local farms for a better sensory experience. (C) 2020 "Society information". Production and hosting by Elsevier B.V.Item Characterization of amylose inclusion complexes using electron paramagnetic resonance spectroscopy(2018-09) Kong, Lingyan; Yucel, Umut; Yoksan, Rangrong; Elias, Ryan J.; Ziegler, Gregory R.; University of Alabama TuscaloosaAmylose is well known to form inclusion complexes with various small molecules including fatty acids. In this study, we prepared amylose inclusion complexes with stearic acid derived spin probes and demonstrated the electron paramagnetic resonance (EPR) spectroscopy as an emerging tool for studying the microstructure and microenvironment of amylose-guest inclusion complex. Two spin probes, namely 5-doxyl-stearic acid (5-DSA) and 16-doxyl-stearic acid (16-DSA), were used as guest molecules in forming amylose-guest inclusion complexes. The molecular dynamics and local polarity of the spin probes and their interaction with amylose in physical mixtures and inclusion complexes were studied using EPR spectroscopy. Complexed guest spin probes could be released when the inclusion complex was dissolved dimethyl sulfoxide (DMSO) and detected by EPR. Since the inclusion complex could not be dissolved in water, the motion of spin probes was restricted in hydrated samples shown by the powder-like slow spectra. Our findings also indicated that the individual association between amylose and the two DSA molecules in forming the inclusion complexes were different. A portion of 16-DSA molecules were not tightly immobilized in the amylose helical channel, but instead were loosely entrapped in the amorphous region of the semicrystalline V6-type amylose. Therefore, EPR spectroscopy provides valuable information on the molecular dynamics and microenvironment of guest molecules and their interaction with amylose in inclusion complex, and can be exploited as a useful tool to study amylose-guest inclusion complex and other host-guest systems.Item Characterization of macromolecular orientation in κ-carrageenan fibers using polarized Fourier-transform infrared spectroscopy(2018-01) Kong, Lingyan; Stapleton, Joshua J.; Ziegler, Gregory R.; University of Alabama TuscaloosaIn the current study, polarized infrared (IR) microspectroscopy was employed to characterize the macromolecular orientation in wet-spun and stretched κ-carrageenan fibers. The fibers were shown to be well oriented by X-ray diffraction, suggesting that the κ-carrageenan molecules were generally aligned along the fiber axis direction. Longitudinal fiber pieces of about 10 μm thick were obtained by focused ion beam (FIB) micromilling. The fiber pieces were examined by polarized IR in transmission mode. Several bands, including those characteristic of κ-carrageenan at 845 and 930 cm⁻¹, were polarization-dependent, demonstrating polarized IR as a useful tool to evaluate macromolecular orientation in carrageenan fibers. Band assignments were discussed by considering the general alignment of molecules and the polarization dependence of vibration modes, and our results agreed well with band assignments from previous reports.Item Characterization of Starch Polymorphic Structures Using Vibrational Sum Frequency Generation Spectroscopy(American Chemical Society, 2014-01-16) Kong, Lingyan; Lee, Christopher; Kim, Seong H.; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaThe polymorphic structures of starch were characterized with vibrational sum frequency generation (SFG) spectroscopy. The noncentrosymmetry requirement of SFG spectroscopy allows for the detection of the ordered domains without spectral interferences from the amorphous phase and also the distinction of the symmetric elements among crystalline polymorphs. The V-type amylose was SFG-inactive due to the antiparallel packing of single helices in crystal unit cells, whereas the A- and B-type starches showed strong SFG peaks at 2904 cm(-1) and 2952-2968 cm(-1), which were assigned to CH stretching of the axial methine group in the ring and CH, stretching of the exocyclic CH2OH side group, respectively. The CH2/CH intensity ratios of the A- and B-type starches are significantly different, indicating that the conformation of hydroxymethyl groups in these two polymorphs may be different. Cyclodextrin inclusion complexes were also analyzed as a comparison to the V-type amylose and showed that the head-to-tail and head-to-head stacking patterns of cyclodextrin molecules govern their SFG signals and peak positions. Although the molecular packing is different between V-type amylose and cyclodextrin inclusion complexes, both crystals show the annihilation of SFG signals when the functional group dipoles are arranged pointing in opposite directions.Item Developing Biopolymer-Based Lutein Emulsion to Improve the in Vitro Bioaccessibility of Lutein and its in Vivo Bioavailability in Neonatal Rats(University of Alabama Libraries, 2023) Zhang, Yanqi; Tan, LiboOxidative stress is a major pathogenic factor in many neonatal diseases. Immature tissues at birth, such as the retina and the brain, are particularly vulnerable to oxidative stress due to their high metabolic rate. Lutein, a dietary antioxidant from leafy vegetables, acts as the macular pigment in the eye and protects the macula from light-initiated oxidative damage. However, the low bioavailability and stability of lutein limit its application as a nutritional intervention. The aim of this research was to develop a novel emulsion system for lutein using food-grade colloids as emulsifiers to improve its storage stability, in vitro bioaccessibility, and bioavailability in neonatal rats.Six types of biopolymers that are safe for infant foods, including three types of octenylsuccinated starches (CTA, HC, and PG) and three types of gum Arabic (TM, TAM, and PHGA), were chosen as emulsifier candidates to prepare biopolymer-based oil-in-water emulsions. The emulsions stabilized by CTA, HC, and TM possessed superior stability by forming gel-like emulsions and were used to prepare lutein emulsions. CTA-, HC-, and TM- stabilized lutein emulsions all exhibited a compact emulsion network and small droplet size. However, the CTA-stabilized lutein emulsion showed the overall best performance in enhancing the storage stability and in vitro bioaccessibility of lutein and was selected for the in vivo studies. In an acute dosing study, neonatal Sprague-Dawley rats received a single oral dose of free lutein or CTA-stabilized lutein emulsion. The emulsion group exhibited a significantly higher lutein bioavailability, as evidenced by pharmacokinetic parameters derived from the serum lutein kinetic curve. In two chronic dosing studies, compared to free lutein, daily consumption of lutein emulsion for 14 days in neonatal rats resulted in a significantly higher lutein concentration in the serum and several key organs, including the liver, eye, brain, and spleen.In conclusion, a safe and efficient delivery system for lutein, i.e., the biopolymer-based lutein emulsion, was successfully developed and was shown to improve the bioavailability and tissue status of lutein in neonatal rats. It has great potential to be considered as a carrier for lutein to benefit the health of newborns.Item Effect of guest structure on amylose-guest inclusion complexation(2019-12) Kong, Lingyan; Perez-Santos, Diana M.; Ziegler, Gregory R.; University of Alabama TuscaloosaAmylose-guest inclusion complexes are a type of supramolecular host-guest assembly that can provide protection for and controlled release of guest molecules. The successful and efficient complexation between amylose and guest molecules is governed by factors including: guest structure and chemistry, and process method and parameters. Here we investigated the formation, crystalline structure, and thermal stability of amylose inclusion complexes with a total of ten guest molecules differing in alkyl chain length (C10 and C16), molecular shape (linear vs. branched), and functional groups (alcohol, aldehyde, carboxylic acid, and ester). Their ability to complex with amylose was evaluated using two complexation methods (partitioning from water after heating and partitioning from a DMSO/water solution), and two annealing temperatures (60 and 90 °C). The extent of complexation differed for the two methods, likely due to guest solubility and partitioning behavior in the respective solvent systems. Annealing temperature created inclusion complexes of different structure and dissociation temperature using the water approach. Here we suggest that the so-called “Form I” and “Form II” V-type amylose inclusion complexes differ in their crystal size, crystallinity and arrangement of guest molecules in the helical cavity, rather than being amorphous or crystalline as previously reported. Chain length, molecular shape, and functional groups affected the thermal stability of the inclusion complexes. Shorter chain length, unsaturation, and short branched chains formed inclusion complexes with lower dissociation temperatures. We propose the Form II as a tail-to-tail arrangement of molecules in the helices that leaves the functional groups at the helical openings. Guest compounds that either failed to form complexes from water or formed poor complexes were able to form inclusion complexes with amylose using the DMSO approach, suggesting solubility of the guest, flexibility of the amylose chain, or the partitioning of the guest between the solvent and the helix core affected complexation.Item Electrospinning of Octenylsuccinylated Starch-Pullulan Nanofibers from Aqueous Dispersions(Elsevier, 2020-08-21) Li, Songnan; Kong, Lingyan; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaWe aimed to develop a greener process for dry-electrospinning food-grade modified starch through the elimination of organic solvents. The rheological properties and electrospinnability of aqueous dispersions of commercial octenylsuccinylated (OS) starches with various molecular weight (Mw) were investigated, yet only nanofibers with beads or defects could be obtained from OS starch with the highest Mw, i.e., Purity Gum(@) Ultra (PGU). Further improvement in the fiber morphology was achieved by adding pullulan (PUL) as a minor component in the spinning dope. Smooth, continuous, and bead-free nanofibers (147-250 nm) were obtained from the PGU-PUL dispersions. Shown on an electrospinnability map, the successful electrospinning of 12%, 15%, and 20% (w/v) aqueous PGU dispersions required a minimum addition of 6%, 5%, and 3% (w/v) of PUL, respectively. The addition of PUL contributed to establishing sufficient molecular entanglement for electrospinning. This study provides a promising green process to produce starch-based nanofibers for use in various applications, e.g., drug delivery, wound dressing, and tissue engineering.Item Electrospun Cadmium Selenide Nanoparticles-Loaded Cellulose Acetate Fibers for Solar Thermal Application(MDPI, 2020-07-08) Angel, Nicole; Vijayaraghavan, S. N.; Yan, Feng; Kong, Lingyan; University of Alabama TuscaloosaSolar thermal techniques provide a promising method for the direct conversion of solar energy to thermal energy for applications, such as water desalination. To effectively realize the optimal potential of solar thermal conversion, it is desirable to construct an assembly with localized heating. Specifically, photoactive semiconducting nanoparticles, when utilized as independent light absorbers, have successfully demonstrated the ability to increase solar vapor efficiency. Additionally, bio-based fibers have shown low thermal conductive photocorrosion. In this work, cellulose acetate (CA) fibers were loaded with cadmium selenide (CdSe) nanoparticles to be employed for solar thermal conversion and then subsequently evaluated for both their resulting morphology and conversion potential and efficiency. Electrospinning was employed to fabricate the CdSe-loaded CA fibers by adjusting the CA/CdSe ratio for increased solar conversion efficiency. The microstructural and chemical composition of the CdSe-loaded CA fibers were characterized. Additionally, the optical sunlight absorption performance was evaluated, and it was demonstrated that the CdSe nanoparticles-loaded CA fibers have the potential to significantly improve solar energy absorption. The photothermal conversion under 1 sun (100 mW/cm(2)) demonstrated that the CdSe nanoparticles could increase the temperature up to 43 degrees C. The CdSe-loaded CA fibers were shown as a feasible and promising hybrid material for achieving efficient solar thermal conversion.Item Electrospun single-phase spinel magnetic high entropy oxide nanoparticles via low-temperature ambient annealing(Royal Society of Chemistry, 2023) Han, Xiao; Li, Dian; Zhou, Jingyi; Zheng, Yufeng; Kong, Lingyan; Li, Lin; Yan, Feng; University of Alabama Tuscaloosa; University of Nevada Reno; Arizona State University; Arizona State University-TempeHigh entropy oxide nanoparticles (HEO NPs) with multiple component elements possess improved stability and multiple uses for functional applications, including catalysis, data memory, and energy storage. However, the synthesis of homogenous HEO NPs containing five or more immiscible elements with a single-phase structure is still a great challenge due to the strict synthetic conditions. In particular, several synthesis methods of HEO NPs require extremely high temperatures. In this study, we demonstrate a low cost, facile, and effective method to synthesize three- to eight-element HEO nanoparticles by a combination of electrospinning and low-temperature ambient annealing. HEO NPs were generated by annealing nanofibers at 330 degrees C for 30 minutes under air conditions. The average size of the HEO nanoparticles was similar to 30 nm and homogenous element distribution was obtained from post-electrospinning thermal decomposition. The synthesized HEO NPs exhibited magnetic properties with the highest saturation magnetization at 9.588 emu g(-1) and the highest coercivity at 147.175 Oe for HEO NPs with four magnetic elements while integrating more nonmagnetic elements will suppress the magnetic response. This electrospun and low-temperature annealing method provides an easy and flexible design for nanoparticle composition and economic processing pathway, which offers a cost- and energy-effective, and high throughput entropy nanoparticle synthesis on a large scale.Item Encapsulation and stabilization of β-carotene by amylose inclusion complexes(2018-03) Kong, Lingyan; Bhosale, Rajesh; Ziegler, Gregory R.; University of Alabama TuscaloosaIn the present study, we report a novel composition based on amylose (or starch) inclusion complex with an amphiphilic material as an effective encapsulation platform technology to incorporate guests of interest. Specifically, the encapsulation of β-carotene in amylose-surfactant and amylose/starch-ascorbyl palmitate (AscP) inclusion complexes was investigated. Surfactants of different hydrophilicity/lipophilicity were selected to cover a broad range of HLB values. The formation of the inclusion complexes was characterized by X-ray diffraction and differential scanning calorimetry. The ability of amylose-surfactant system to encapsulate β-carotene was dependent on the HLB value of the surfactants, instead of their ability to induce inclusion complexation. The incorporation of β-carotene hindered amylose-surfactant inclusion complex formation, whereas no significant effect was observed on structural and thermal properties of starch-AscP inclusion complex in the presence of β-carotene. The X-ray diffraction pattern of amylose-AscP-β-carotene showed that β-carotene molecules did not crystallize into a separated phase and thus were suggested to be homogeneously immobilized within the polycrystalline amylose-AscP inclusion complexes. During a storage period of six weeks at 20 and 30 °C, the stability of β-carotene was improved by encapsulation in starch-AscP inclusion complexes compared with that in physical mixtures of the three components.Item Encapsulation in Amylose Inclusion Complex Enhances the Stability and Release of Vitamin D(MDPI, 2023) Liu, Simiao; Kong, Lingyan; Huang, Tianzhuo; Wei, Xiaohui; Tan, Libo; Luo, Hailing; Zhang, Hao; China Agricultural University; University of Alabama TuscaloosaVitamin D plays a significant role in the physiological functions of the human body. However, the application of vitamin D in functional foods is limited due to its sensitivity to light and oxygen. Therefore, in this study, we developed an effective method to protect vitamin D by encapsulating it in amylose. In detail, vitamin D was encapsulated by amylose inclusion complex, followed by structural characterization and evaluation of its stability and release properties. The results of X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy showed that vitamin D was successfully encapsulated in the amylose inclusion complex, and the loading capacity was 1.96% +/- 0.02%. The photostability and thermal stability of vitamin D after encapsulation was increased by 59% and 28%, respectively. In addition, in vitro simulated digestion showed that vitamin D was protected through the simulated gastric environment and can be released gradually in the simulated intestinal fluid, implying its improved bioaccessibility. Our findings provide a practical strategy for the development of functional foods based on vitamin D.Item Encapsulation of Aroma and Off-Flavor Compounds into Preformed "Empty" V-Type Starch(University of Alabama Libraries, 2022) Zhou, Jingyi; Kong, Lingyan; University of Alabama TuscaloosaStarch consists of two homopolymers of glucose, including amylose and amylopectin. The amylose component has been found to be able to form inclusion complexes with a wide variety of small molecules that could control the release and retention profiles of guest compounds. Inclusion complex between starch and aroma/flavor has attracted more attention in recent years due to its ability to reduce evaporation, to prevent volatile loss, and to enhance stability during storage and application. The main objective of this research was to determine the potential of preformed "empty" V-type starch to encapsulate aroma and off-flavor compounds and structure-complexation ability relationship in starch inclusion complexes prepared with aroma and/or off-flavor compounds. In addition, this study also aimed to investigate consumers' purchase intention of food products deodorized by "empty" V-type starch. First, novel "empty" V-type method was employed to prepare the inclusion complex between three types of "empty" V-type starches and six aroma compounds. All three types of starches presented ability to form inclusion complex with selected aroma compounds. Both starch type and aroma compounds' chemical structures were shown to significantly affect the complexation process and physicochemical properties of the formed inclusion complexes, including crystalline characteristics and thermal properties. In addition, the same approach was utilized to prepare inclusion complex between three types of "empty" V-type starches and a cyclic aroma compound, thymol, at two different concentrations. Besides starch type, aroma's concentration was also found to significantly influence inclusion complexes' properties. Among all, V6h inclusion complex prepared at a starch/thymol ratio of 5:1 and 2:1 showed the highest encapsulation efficiency and loading efficiency, respectively. All inclusion complexes displayed potent aroma retention ability, which preserved more than 70% of thymol after 8-hour of heat treatment. In addition, the "empty" V-type starch had also been examined for its ability to mask the off-flavors found in soy milk. Among all, gas phase approach was more effective approach to scavenge beany off-flavors compared to direct contact approach, and V6h-type starch was the most effective type of starch to mask all the tested beany off-flavor compounds. Lastly, consumers' willingness-to-purchase of "empty" V-type starch deodorized soy milk was further examined to determine the factors that could affect consumers' food choice. The survey results showed that sensory quality, environmental concern, and gender were significantly associated with consumers' purchase intention of "empty" V-type starch processed soy milk. Moreover, more than 80% of the participants' attitudes toward "empty" V-type starch was positive and they thought it is an interesting approach and looking forward to the launching of the real products. In combination of the potent encapsulation efficiency, aroma preservation capability, and moderate consumers' purchase intention, the V6h-type starch could be a potential aroma delivery and/or off-flavor masking material, that could be further applied into food formulations. Future research is warranted to explore the inclusion complexes' release behavior under various parameters, such as different temperature, storage, and pH conditions, that could encounter during food processing. In addition, factors that could further improve the encapsulation efficiency of inclusion complexes should be examined, and sensory profiles of the "empty" V-type starch processed food products could also be evaluated.Item Fabrication of kappa-carrageenan fibers by wet spinning: Addition of iota-carrageenan(Elsevier, 2013-01) Kong, Lingyan; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaTaking advantage of the gelation process of kappa-carrageenan, we have developed a wet-spinning process to fabricate micro-scale fibers from kappa-carrageenan. Effects of three important spinning parameters, i.e. coagulation bath composition, spinning rate and post-spinning mechanical drawing, on fiber morphological and tensile properties have been discussed. In the present report, we studied the addition of iota-carrageenan on thermal and rheological properties of the bicomponent gels and the fibers spun from them. It was found that kappa- and iota-carrageenan underwent phase separation in the bicomponent gel. Upon addition of i-carrageenan, the diameter and compliance of the blend fiber was increased. (C) 2012 Elsevier Ltd. All rights reserved.Item Fabrication of kappa-Carrageenan Fibers by Wet Spinning: Spinning Parameters(MDPI, 2011-10-11) Kong, Lingyan; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaThis study demonstrates the fabrication of kappa-carrageenan fibers by a wet-spinning method and discusses three important spinning parameters: coagulation bath composition, spinning rate and post-spinning mechanical drawing. The as-spun fiber diameter decreased with KCl and ethanol concentration in the coagulation bath. In general, the ultimate tensile stress and elongation at break both increased for KCl concentration from 0.1 to 0.5 M with and without ethanol, with no significant change above 0.5 M. Spinning rate affected the dope flow and thus the polymer orientation (apparent viscosity) and fiber morphology. At spinning rates between 0.25 mL/min and 0.33 mL/min, the fiber diameter reached a minimum and the fiber surface was smooth. Both an increase and decrease from this spinning rate range increased the fiber diameter and roughness of the fiber surface. Post-spinning drawing of the fiber resulted in even smaller fiber diameter.Item Fabrication of pure starch fibers by electrospinning(Elsevier, 2014-05) Kong, Lingyan; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaMany efforts to spin starch fibers are reported in the patent and research literature. All reported spinning methods are dependent upon addition of non-starch components, e. g. other polymers, plasticizers or cross-linkers. In the present study, we demonstrate a method of producing pure starch fibers by an electrospinning technique. This method involves choosing an appropriate solvent for native high amylose starch and spinning on a modified electrospinning setup. Resulting starch fibers have diameters in the order of microns. Coagulation solvent composition can affect the crystallinity of the starch fibers. Post-spinning treatments were employed to increase the crystallinity and cross-link the starch fibers. The novel starch fibers have potential in various applications, e. g. in the food, textile, and biomedical industries. (c) 2013 Elsevier Ltd. All rights reserved.Item Formation of starch-guest inclusion complexes in electrospun starch fibers(Elsevier, 2014-07) Kong, Lingyan; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaWe have demonstrated a method of fabricating starch fibers with an average diameter in the order of micrometers. In the present study, the formation of starch-guest inclusion complexes in the electrospun starch fibers was evaluated. Two methods were used to electrospin starch fibers with starch-guest inclusion complexes: a dope mixing method, where guest material was mixed into the starch dispersion prior to electrospinning, and a bath mixing method, where guest material was mixed into the coagulation bath into which starch dispersions were electrospun. Three selected guest compounds, palmitic acid, ascorbyl palmitate, and cetyl-trimethylammonium bromide, formed inclusion complexes with starch in the electrospun starch fibers. The presence of native lipids was not necessary to induce the inclusion complex formation. Encapsulation of these molecules in electrospun starch fibers may increase their stability during processing and storage, while providing controlled release properties. (C) 2013 Elsevier Ltd. All rights reserved.Item Inclusion complex formation between high amylose corn starch and alkylresorcinols from rye bran(Elsevier, 2018-09-01) Gunenc, Aynur; Kong, Lingyan; Elias, Ryan J.; Ziegler, Gregory R.; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Alabama TuscaloosaThe formation of high amylose corn starch (HACS)-alkylresorcinol (AR) inclusion complexes was demonstrated using HACS and a crude AR extract from rye bran, and was confirmed by complementary characterization techniques. Inclusion complex was extracted using hot 2-propanol/water (3:1), and thirteen different AR homologs were identified in the 2-propanol/water extract. However, this extraction regime was insufficient to remove all guests from the inclusion complexes, but did result in annealing of the V-type crystallinity, yielding an endotherm with higher onset and peak temperatures and dissociation enthalpy. The remaining guest compounds were recovered by disruption of the inclusion complexes with DMSO followed by liquid-liquid extraction. A total of nine AR homologs were recovered and two saturated long alkyl chain AR homologs (C21:0 and C19:0) were obviously enriched in the complexes compared to the crude AR extract. The formation of HACS-AR inclusion complexes may have the potential to inhibit staling in baked goods.Item Inhibition of starch digestion by gallic acid and alkyl gallates(Elsevier, 2020-05) Gutierrez, Alyssa San Andres; Guo, Jiayue; Feng, Jiannan; Tan, Libo; Kong, Lingyan; University of Alabama TuscaloosaAs phenolic compounds, alkyl gallates may inhibit the activity of digestive enzymes for starch. Furthermore, their alkyl chains may facilitate starch inclusion complexation and results in an increased resistant starch (RS) content or slowly digestible starch (SDS) content, which may further retard starch digestion. The significance of such inhibition is that the rate of starch hydrolysis into glucose is reduced, thereby preventing hyperglycemia and related metabolic diseases. This study examined the inhibitory effects on in vitro enzymatic digestion of starch by gallic acid and five alkyl gallates of varying alkyl chain lengths, i.e., butyl gallate, octyl gallate, dodecyl gallate, hexadecyl gallate, and octadecyl gallate. Raw and cooked potato starch (PS) and high-amylose maize starch (HAMS) were tested. For both types of raw starch, gallic acid and all the alkyl gallates significantly (p < 0.05) increased RS content except for octadecyl gallate. In the case of cooked starch, the RS contents were markedly decreased (p < 0.05) as compared to those in raw starch, because gelatinization caused an overall greater susceptibility to enzymatic digestion. The reduction in RS content was less in cooked HAMS than that in cooked PS, due to a higher gelatinization temperature range of HAMS. The aforementioned effect of gallates on RS content was also found for cooked PS, while cooked HAMS experienced increased RS only with gallic acid and butyl gallate. Overall, for the digestion of both starches, regardless of raw or cooked, gallic acid and alkyl gallates with shorter chains demonstrated the strongest inhibitory effects. Our findings indicate that shorter alkyl gallates are effective in inhibiting enzymatic digestion of starch and therefore may have potential in modulating glycemic response.Item Inhibitory Effect of Ascorbic Acid on in vitro Enzymatic Digestion of Raw and Cooked Starches(Frontiers, 2021) Guo, Jiayue; Gutierrez, Alyssa; Tan, Libo; Kong, Lingyan; University of Alabama TuscaloosaAscorbic acid, also known as vitamin C, was previously reported to inhibit the activity of pancreatic alpha-amylase, the primary digestive enzyme for starch. A major implication of such inhibition is a slowed rate of starch digestion into glucose, which thereby reduces postprandial hyperglycemia. The aim of this study was to explore the inhibitory effects of ascorbic acid at various concentrations on the in vitro digestion of high amylose maize starch (HAMS) and potato starch (PS) in both raw and cooked conditions. Resistant starch (RS) content, defined as the starch that remained after 4 h of simulated in vitro enzymatic digestion, was measured for the starch samples. Upon the addition of ascorbic acid, the RS contents increased in both raw and cooked starches. Cooking significantly reduced the RS contents as compared to raw starches, and less increase in RS was observed with the addition of ascorbic acid. The inhibitory effect of ascorbic acid on the digestion of raw starches showed a dose-dependent trend until it reached the maximum extent of inhibition. At the concentrations of 12.5 and 18.75 mg/mL, ascorbic acid exhibited the most potent inhibitory effect on the in vitro starch digestion in raw and cooked conditions, respectively. Overall, our results strongly indicate that ascorbic acid may function as a glycemic modulatory agent beyond other important functions, and its effects persist upon cooking with certain concentrations applied.