V-type Starch Research Articles

Single-helix inclusion formation of V-type starch-lutein: Investigation of structural, physicochemical, and in vitro release

Lutein is a natural plant pigment with a variety of biological functions. However, its low stability and bioavailability limits its use in the food industry. The ethanol-alkaline (EA) method was utilized to manufacture V-type starch to examine its impact on the stability and release properties of the V-type starch-lutein composite system. The EA treatment increased the amylose content of natural starch and transformed its structure from a typical B-type structure to a more open V-type structure. The results showed that lutein could be efficiently loaded into V-type starch, and fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) revealed that hydrogen bonding interaction, in conjunction with helical cavities rather than surface adsorption, was responsible for the lutein loading by V-type starch. The designed loading system enhanced lutein's photothermal stability, showing a two-fold increase compared to free lutein. V-type starch-lutein systems exhibited protection in gastric fluid and demonstrated sustained release post intestinal digestion. The findings had useful ramifications for the development of efficient delivery strategies for the encapsulation of lipophilic actives.

V-type starches for trimethylamine of sea cucumber intestinal peptides: Adsorption kinetics and mechanism

Trimethylamine (TMA), which is known to severely affect consumer acceptance and application, is the main compound of sea cucumber intestinal peptides. Herein, different V-type crystalline starches (V6a/h, V7a/h, V8a/h) were prepared using high amylose maize starch for the adsorption of TMA. After analyzing the structure of V-type starches, the V8-type starch had a smaller and more evenly dispersed particles with additional surface pores and cracks, and reduced relative crystallinity compared with V6- and V7-type starch. The relative crystallinity of V6a-, V6h-, V7a-, V7h-, V8a-, and V8h-type starches was 59.1%, 51.8%, 42.7%, 41.3%, 40.4%, and 40.1%, respectively. Adsorption models for V-type starches and TMA helped to analyze the adsorption kinetics characteristics and investigate the effect of different V-type starches on adsorption. Moreover, its adsorption kinetics process agreed with pseudo-second-order kinetic model (R2 > 0.96). Note that different V-type starches demonstrate good adsorption effects on TMA, and the removal rate is as follows: V8h > V8a > V7h > V7a > V6h > V6a. Herein, we used environmental protection and food-grade V-type starches to effectively adsorb TMA and ensure a theoretical foundation for enhancing the flavor and quality of functional seafoods.

Mechanism underlying V-type structure formation in maize starch through glycerol–ethanol thermal substitution method

V-type starches have been widely used in food science, agriculture, and biomedical science, but their mechanism of formation in nonaqueous solvents remains unclear. This study performed glycerol–ethanol thermal substitution to prepare V-type starch at atmospheric pressure. Scanning electron microscopy and confocal laser scanning microscopy revealed that breakage of starch particles began in the hilum region and rapidly spread to the periphery with the temperature increased from 100 °C to 130 °C. The Maltese crosses of the starch disappeared and starch particles had the form of doughnut-shaped rings when the glycerol temperature was 140 °C. Glycerol temperature was not found to significantly affect the chain length of amylopectin, meaning that glycerol molecules may stabilize the conformation of amylose through hydrogen bonding, promoting the amylose to form a V-type spiral structure. Additionally, A-type crystallinity and double helix structure proportion of the samples significantly decreased from 30.81 % and 42.21 % to 5.70 % and 16.47 % as the temperature of glycerol was increased to 140 °C, whereas the V-type crystallinity and single helix structure proportion of the samples remarkably increased from 13.26 % and 1.05 % to 37.97 % and 25.09 %, respectively. This study provided a facile and versatile approach to effectively regulate the formation of V-type starch.

In vitro fermentation of V-type starch inclusion complexes: The controlled release of ferulic acid and beneficial modulation of the gut microbiota

Consumption of either ferulic acid (FA) or V-type starch (VS) can influence the gut microbiota, but the outcomes of starch complex fermentation and their co-effects on microbial composition are unclear. In this study, a V-type starch–FA inclusion complex (SFC) was constructed, with the digestion resistance being assessed. Furthermore, SFC, its individual components and the corresponding physical mixture (SFM) were fermented in vitro for 24 h using a human fecal inoculum. As reflected by the production of short-chain fatty acids, all starch-containing substrates were fermented to a similar extent at 24 h. Compared with VS and SFM, the starch in SFC showed a faster reduction in molecular size from 9 h onwards, revealing a distinct amylose degradation pattern. Unlike the rapid breakdown of free FA, SFC displayed a progressive release and catabolism of most of the FA by 12 h. While the microbial diversities of SFC, SFM, and VS were generally similar, specific bacteria associated with SFC were identified at each fermentation stage. Overall, SFC displayed high digestion resistance and could facilitate an even degradation of starch and a controlled release of FA, with enrichment of beneficial bacteria specialized for the fermentation.

Tailoring starch-lipid complexes for optimized flaxseed oil emulsion stability, antioxidation, and digestion kinetics

Whereas starch-lipid complex emulsifiers are anticipated to possess both an outstanding amphiphilicity and slowly-digesting characteristics, yet a more sustainable and cost-effective approach remains to be explored. Herein, we systematically prepared starch-lauric acid complexes (SLACs) through a solid encapsulation method under varying reaction temperatures (50–90 °C) and times (0.25–60 h). Complexing index analysis, differential scanning calorimetry, and X-ray diffraction analysis revealed an enhanced degree of complexation in SLACs with prolonged reaction time, evidenced by the inward migration of free lauric acid, as further confirmed by confocal laser scanning microscopy. In vitro digestibility, contact angle, and interfacial tension measurements demonstrated that SLACs exhibited high levels of slowly digestible starch, a low digestion rate, and excellent amphiphilicity, which was particularly notable in SLACs produced at 80 °C for 6 h. Emulsions stabilized by SLACs showed a smaller droplet size, a higher oil loading rate, an increased yield stress, and an improved storage stability compared to V-type starch. Oxidation experiments indicated that SLACs enhanced the oxidative stability of flaxseed oil, with elevated initial oxidation temperatures and reduced levels of oxidative products. In a simulated gastrointestinal digestion model, SLACs-stabilized structured emulsions exhibited sustained release and lower final contents of fatty acids, suggesting superior resistance to bile acids and digestive enzymes compared to PG2000, a chemically modified food starch (i.e. OSA-starch) refined from waxy maize. Our findings provide an effective strategy for enhancing lipid antioxidation and regulating intestinal digestion.

A comparative study on stabilizing and releasing thymol by pre-formed V-type starch and β-cyclodextrin

Cyclodextrins (CD) are well known to form host-guest assemblies with hydrophobic compounds. As a structural homologue, starch-guest inclusion complexes (ICs) have become promising in the food, agriculture, and pharmaceutical industries due to their low cost and versatility. This study compared the stabilizing and releasing abilities for thymol of three kinds of pre-formed V-type starch (Water-V, Salt-V, and Alkali-V) and β-CD. The loading efficiency for thymol decreased in the order of Water-V > Alkali-V > CD > Salt-V when removing the free thymol. Water-V, β-CD, and their ICs had better thermal stability with maximum thermal decomposition temperatures over 320 °C. Under non-cold chain daily storage conditions for 4 d, the percentage of thymol released from starch/CD-thymol ICs was 14% (Water-V), 35% (Salt-V), 34% (Alkali-V), and 43% (CD). The Water-V made ICs had good sustained release properties and long-term antibacterial activity, which kept strawberries fresh for 6 d without decay.

The selective adsorption mechanism of V-type starches for key off-odors of sea cucumber intestinal peptides

The off-odors of sea cucumber intestinal peptide (SCIP) severely limit its application. In this study, the V-type starches were derived from high amylose maize starch to adsorb odors of SCIP and the adsorption mechanism was explored. The inclusion complexes formed by V-type starches and volatile compounds of SCIP were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The electronic nose results revealed a decreasing trend in response values of SCIP, with significant differences before and after deodorization (p < 0.05). Furthermore, 82 volatiles were identified from SCIP, and six were determined as key volatiles using gas chromatography–mass spectrometry. The V6- and V7-type starches with smaller cavity sizes selectively adsorb butyric acid, isobutyric acid and nonaldehyde, and V8-type starches with a larger cavity size selectively adsorb trimethylamine. This study proved that using V-type starches for deodorization could effectively improve SCIP flavor.

Stabilization and release of thymol in pre-formed V-type starch: A comparative study with traditional method

Recently, pre-formed V-type starch has become popular as a versatile carrier in encapsulation systems of containing starch-guest inclusion complexes (ICs). However, the differences in stabilizing and dissociating guests between ICs prepared by either the traditional method or the pre-formed “empty” helix method have not yet been elucidated. Here, starch-thymol ICs were prepared using the traditional high temperature-water method and the pre-formed method, covering different complexation temperatures and solvents, to compare the loading capacity, crystalline structure, thermal stability, and release properties. The highest content of thymol in ICs prepared by the pre-formed and the traditional method was 74.2 and 65.3 mg/g, respectively. Different from ICs prepared by the traditional method (V7-type crystal), ICs prepared by the pre-formed method mostly exhibited a V6a structure with larger crystallinities and a better short-range ordered structure. ICs prepared at 90 °C were type II complexes and efficiently protected thymol from rapid heat loss. A slow release was observed in both cases: about 45 % and 75 % of thymol were released from ICs prepared by the pre-formed and traditional methods, respectively, after two weeks of storage at 25 °C.

Complexation of V-type lotus seed starch and butyric acid: Structure and in vitro digestion

Butyric acid (BA), a short-chain fatty acid, significantly impacts gut health but is rarely incorporated as a guest molecule in starch-based products. Owing to their hydrophobic helical cavities, V-type starches can form inclusion complexes (ICs) with BA via hydrophobic interactions. In the current work, V-type lotus seed starches (VLS) were used in complexation with BA, and the structure and in vitro digestion of V-type lotus seed starch-butyric acid complexes (VLS-BAcs) as influenced by preultrasonication were investigated. The results showed that at the suitable ultrasonic power (∼360 W), 28.4% of the additional BA was complexed with preformed VLS. The IC formation significantly increased the crystallinity of starches and retarded amylose retrogradation. Highly crystallized VLS-BAcs exhibited strong thermal stability and hydrophobicity and displayed bound water-dominated structures. Moreover, VLS-BAcs formed at 360 W had a 12.4% higher RS proportion than their untreated counterparts. These obtained findings would provide valuable knowledge on the properties of VLS-BAcs modulated by ultrasound pretreatment and reveal its potential as a novel prebiotic for increasing BA concentration in the gut.

Selective adsorption of volatile compounds of oyster peptides by V-type starch for effective deodorization

Oyster peptides extracted from oysters have strong off-odors, which hinders consumer acceptance. The “empty” V-type starches (V6a, V6h, V7a, V7h, V8a, and V8h) prepared from high amylose maize starch were used as adsorbents to improve the flavor of oyster peptides. The total adsorption rates measured through headspace gas chromatography mass spectrometry (HS-GC-MS) follow the order of V6a > V7a > V6h > V7h > V8a > V8h. Moreover, the V-type starches with different structures exhibit adsorption selectivity. The V6- and V7-type starches with a smaller cavity size show selective adsorption capacity for alcohols, acids, ketones and other similar classes of volatile compounds, while the V8-type starches with a larger cavity selectively adsorb amines. In addition, successful preparation of “empty” V-type starches were confirmed through X-ray diffraction (XRD), and the inclusion complexes (ICs) between V-type starches and volatile compounds of oyster peptides were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and differential scanning calorimetry (DSC). It was found that the O/C ratio of V6a-ICs, V6h-ICs, and V7a-ICs increased, while that of V7h-ICs, V8a-ICs, and V8h-ICs decreased after the deodorization. Pearson's correlations indicated that the adsorption rates of aldehydes, alcohols, ketones, and alkanes have a significant negative correlation with temperature range (ΔT) and enthalpy change (ΔH). While a significant positive correlation was observed between the ratio of peak intensity at 1047/1022 cm−1 and the amine adsorption rate. These results suggested that V-type starch can improve the flavor of aquatic products effectively.

Odor-scavenging capabilities of pre-formed “empty” V-type starches for beany off-flavor compounds

Off-flavors have garnered significant attention in research due to their impact on overall flavor, which leads consumers to avoid purchasing or consuming food products with off-flavors, even if they offer health benefits. However, there has been limited research on encapsulating off-flavor compounds as a means to mask them and to improve the flavor profiles of food products. Starch, particularly its amylose component, is well-known for its ability to form inclusion complexes (ICs) with various small molecules, providing protection and controlled release of these encapsulated guest molecules. The complexation interaction between starch and guest compounds is influenced by factors such as the structure and chemistry of the guest, as well as the process method and parameters. In the present study, nine different beany off-flavor compounds, including hexanal (HAL), 3-hexanol (HOL), benzaldehyde (BAL), 1-octen-3-ol (OOL), 1-octen-3-one (ONE), 2-pentylfuran (PTF), trans-2-nonenal (NAL), trans, trans-2,4-nonadienal (NAD), and trans, trans-2,4-decadienal (DEC) were used as model off-flavors to examine their complexation ability with three types of preformed “empty” V-type high amylose maize starches (HAMS), namely V6h, V7, and V8. The successful formation of inclusion complexes was characterized using complementary techniques, including X-ray diffraction (XRD), differential scanning calorimetry (DSC), and gas chromatography-mass spectrometry (GC-MS). The results revealed that the complexation of off-flavor compounds with the starches did not significantly alter the original structures of the starches. Additionally, the IC samples prepared using the gas phase (GP) approach exhibited significantly higher encapsulation efficiency compared to the direct contact (DC) approach, as indicated by GC-MS analysis. Among the V-type starches, V6h HAMS demonstrated the highest complexation efficiency for all selected beany off-flavor compounds when the ICs were prepared using the GP approach. This study suggests that both V6h and V8 starches exhibit effective scavenging abilities for beany off-flavor compounds. Further, complexation properties depend on the properties of the off-flavor compounds, the type of V starch used, and the IC preparation approach.

Adsorption characteristics of V-type starch for off-odors of sea cucumber intestinal peptides in solid-phase environment

With the concern of the strong fishy odor of sea cucumber intestinal peptides, the deodorization potential of V-type starch with a flexible cavity was investigated. By gas chromatography-mass spectrometry and electronic nose, it was confirmed that V-type starch effectively deodorized key off-odor compounds (isobutyric acid, butanoic acid, 1-octen-3-ol, nonanal, and trimethylamine), and the optimum deodorization performance (adsorption ratio of 92.45%) was achieved after 8 h adsorption at the sea cucumber intestinal peptide to starch ratio of 1:15 (w/w). In the Fourier transform infrared spectrum of the V-type starch inclusion complexes, a new characteristic peak was observed at 1563 cm−1 when the sea cucumber intestinal peptide to starch ratio was 1:1 (w/w). The presence of this peak was attributed to the complexation between V-type starch and trimethylamine. For the first time, we demonstrated that the V-type starch could deodorize aquatic products, and this study contributes to the application of starch materials.

Evaluation of physicochemical properties and in vitro starch digestion of noodles enriched with thermally assisted potassium carbonate treated sweet potato residue

In this study, we investigated the effect of thermally assisted potassium carbonate treatment sweet potato residue (TAPC-SPR) and its addition (0%, 5%, 10% and 15%) on the texture, multi-scale structure (microstructure, crystalline structure, short-range ordered structure) and in vitro starch digestibility of the noodles. The results demonstrated that the ratio of total dietary fiber (TDF) (75.62%–87.25%) and pectin (19.36%–23.36%) were increased, and the particle size distribution (175.67 μm–47.42 μm) was decreased in TAPC-SPR than sweet potato residues (SPR). This study suggested that suitable TAPC-SPR (5% and 10%) contributed to improving the texture properties of noodles, containing hardness, springiness, chewiness and adhesiveness. Sensory evaluation showed that noodles with suitable TAPC-SPR (5% and 10%) had an overall sensory acceptability relative to control. In addition, the intermolecular hydrogen bond interaction, the structure order, V-type starch complex and dense structure were observed. These structural changes limit the interaction of amylase with starch, elevate the resistant starch (RS) content, and lower the predicted glycemic index (pGI).

Controlled ethylene-releasing from V-type starch coated with sodium alginate for banana ripening via changing the humidity of environment

A carrier of storing and releasing ethylene was prepared using V-type starch (VS) or cross-linked VS as core and sodium alginate (SA) as shell. Fourier Transform InfraRed spectra revealed that the VS was successfully cross-linked and its stability in water was enhanced. Scanning electron microscopy (SEM) images confirmed that ethylene was encapsulated into VS or cross-linked VS and then coated with SA-Ca2+ matrix to form close-knit beads. The SA beads contained 0.48–0.67 mol ethylene per Kg starch and maintained a very slow ethylene-releasing rate at 4 °C for 7 d in a dry storage condition. SA shell absorbed the water from the air and swelled after being exposed to an environment with certain humidity, triggering a stable release of ethylene within 7 h. In the ripening process, banana treated with 30 mg ethylene carriers in a 2.5 L container had a delayed maturation compared to the pure ethylene treatment along, and finally, ripening effect of carriers was equal to 10 nmol L−1 ethylene gas. This carrier can accomplish stability gas storage in dry condition, precisely controlled and targeted applications of ethylene under humidity ambience for agricultural applications.

Ultrasonication-mediated formation of V-type lotus seed starch for subsequent complexation with butyric acid

V-type starches comprise single helical structures that can be complexed with other small hydrophobic molecules. The development of the subtypes of these assembled V-conformations is dependent on the helical state of the amylose chains during complexation, which is influenced by the pretreatment employed. In this work, the effect of preultrasonication on the structure and in vitro digestibility of preformed V-type lotus seed starch (VLS) and its potential for complexing with butyric acid (BA), was investigated. The results showed that ultrasound pretreatment did not affect the crystallographic pattern of the V6-type VLS. The optimal ultrasonic intensities increased the crystallinity and molecular ordering of the VLSs. With an increase in the preultrasonication power, the pores on the VLS gel surface decreased in size and were more densely distributed. The VLSs formed at 360 W were less vulnerable to digestive enzymes than their untreated counterparts. Additionally, their highly porous structures could accommodate numerous BA molecules, and thus generated inclusion complexes via hydrophobic interactions. These findings would provide valuable insights into the ultrasonication-mediated formation of VLSs and suggest their potential application as carriers for the delivery of BA molecules to the gut.

High hydrostatic pressure (HHP) reinforces solid encapsulation of d-limonene into V-type starch and its application in strawberry storage

The formation of inclusion complexes (ICs) between V-type starch and flavors is traditionally conducted in an aqueous system. In this study, limonene was solid encapsulated into V6-starch under ambient pressure (AP) and high hydrostatic pressure (HHP). The maximum loading capacity reached 639.0 mg/g after HHP treatment, and the highest encapsulation efficiency was 79.9 %. X-ray Diffraction (XRD) results showed that the ordered structure of V6-starch was ameliorated with limonene, which avoided the reduction of the space between adjacent helices within V6-starch generated by HHP treatment. Notably, HHP treatment may force molecular permeation of limonene from amorphous regions into inter-crystalline amorphous regions and crystalline regions as the Small-angle X-ray scattering (SAXS) patterns indicated, leading to better controlled-release behavior. Thermogravimetry analysis (TGA) revealed that the solid encapsulation of V-type starch improved the thermal stability of limonene. Further, the release kinetics study showed that a complex prepared with a mass ratio of 2:1 under HHP treatment sustainably released limonene over 96 h and exhibited a preferable antimicrobial effect, which could extend the shelf life of strawberries.

Preparation and characterization of V-type starch nanoparticles by an oil-water interface method

This study aimed to prepare V-type starch nanoparticles composed of debranched starch and fatty acid using a novel, simple, and fast oil-water interface method. The average size of the starch nanoparticles was 144–377 nm and included two different sizes of particles: large particles of approximately 110–1000 nm and small particles of approximately 30–105 nm. The average size was smaller for starch nanoparticles prepared at 25 °C was smaller than at 60 °C. The XRD pattern indicated that the starch nanoparticles were V-type structures, including VⅠ-type and VⅡ-type. The long-range and short-range order of starch nanoparticles were affected by the preparation conditions. Stirring treatment disrupts the orderly arrangement of the helical structures, resulting in a low relative crystallinity of the starch nanoparticles.

Molecular encapsulation of cinnamaldehyde in V-type starch: The role of solvent and temperature

In this study, starch-cinnamaldehyde complexes were prepared by wet method (aqueous ethanol solvent) and dry method (solvent-free) under different temperatures to regulate the formation ability, release behavior, and antibacterial activities of starch-cinnamaldehyde complexes. Successful inclusion complexes (ICs) between V-type starch and cinnamaldehyde were detected only at the wet method preparation over 65 °C. Increasing the complexing temperature facilitated the formation and ordered structures of wet method-prepared starch-cinnamaldehyde ICs, but not for those prepared by dry method. The encapsulation efficiency of cinnamaldehyde in wet method ranged from 15.25 to 62.38 mg/g, significantly higher than that in dry method (12.39–17.20 mg/g). In wet method, ethanol concentration at 50% (w/w) could elevate the complexation efficiency compared with ethanol concentration at 40 and 60% (w/w). Notably, IC prepared using 50% (w/w) aqueous ethanol at 75 °C (75 °C 50% IC) contained the highest cinnamaldehyde content (62.38 mg/g) and largest degree of long- and short-range molecular order. Despite the high volatility of cinnamaldehyde, the 75 °C 50% IC sustainably released the cinnamaldehyde for over two weeks at 50 °C and 57% relative humidity, and it also exhibited significant inhibition against Staphylococcus aureus and Escherichia coli.

Complexation temperature regulation of the ordered structure of “empty” V-type starch

“Empty” V-type starch is a potential carrier for versatile applications in novel ways. This study provided a facile and efficient preparation method of excellent “empty” V-type starch, in which the ordered structure of the carrier was regulated by the complexation temperature without additional annealing treatment. Thymol was used as a model guest material to examine the relationship between the crystalline structure and loading capacity of V-type starch. Increasing the complexation temperature from 30 to 90 °C led to more perfect crystallites in the V-type starch, a significant increase in crystallinity from 25.2 % to 40.2 %, and an increase in enthalpy changes from 6.11 to 14.57 J/g. As the ordered structure contributed to improving the loading capacity of V-type starch, the V-type starch prepared at 90 °C (90-V) showed the highest encapsulation capacity (33.97 mg/g) for thymol. Our findings provide a new paradigm for preparing V-type starch facilely and efficiently.

Complexation with pre-formed “empty” V-type starch for encapsulation of aroma compounds

Aroma compounds are low-molecular-weight organic volatile molecules and are broadly utilized in the food industry. However, due to their high volatility and evaporative losses during processing and storage, the stabilization of these volatile ingredients using encapsulation is a commonly investigated practice. Complexation of aroma compounds using starch inclusion complex could be a potential approach due to the hydrophobicity of the left-handed single helical structure. In the present study, we used starch of three different V-type structures, namely V6h, V7, and V8, to encapsulate six different aroma compounds, including 1-decanol (DN), cis-3-hexen-1-ol (HN), 4-allylanisole (AN), γ-decalactone (DA), trans-cinnamaldehyde (CA), and citral (CT). The formed inclusion complexes samples were characterized using complementary techniques, including X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results showed that upon complexation with aroma compounds, all V-subtypes retained their original crystalline structures. However, different trends of crystallinity were observed for each type of the prepared inclusion complexes. Additionally, among three V-type starches, V6h-type starch formed inclusion complexes with aroma compounds most efficiently and promoted the formation of Form II complex. This study suggested that the structure of aroma compounds and the type of V starch could both affect the complexation properties.