Effects of pectin and heat-moisture treatment on structural characteristics and physicochemical properties of corn starch

Insight into the multi-scale structure and retrogradation of corn starch by partial gelatinization synergizing with epicatechin/epigallocatechin gallate

Starch retrogradation is of great importance to the quality of starch-based food. This study investigated the effect of partial gelatinization (PG) synergizing with polyphenol (epicatechin, EC; epigallocatechin gallate, EGCG) on the multi-scale structure and short/long-term retrogradation of corn starch (CS). The PG synergizing with EC/EGCG substantially suppressed the short/long-term retrogradation properties of CS. These could be confirmed by the decreased storage modulus and viscosity, the relative crystallinity (1.54%, 3.56%), and the retrogradation degree (9.99%, 20.18%) of CS during storage for 1, 14 days after PG synergizing with EGCG and EC, respectively. This is because PG treatment promoted the hydrogen bond interaction between disordered starch molecules and EC/EGCG. These were proven by the larger aggregation, more and brighter fluorescents, and the reduced long/short-range order structures in CS after PG synergizing with EC/EGCG. This study is helpful for the development of foods with enhanced nutrition and low-retrogradation.

Impact of citrus pectin on the foaming behavior, structures, and barrier properties of the starch foam blocks

The starch foam displays weak barrier properties under humid storage, which limits its applications in the food industry. In this study, citrus pectin was loaded to strengthen the starch foam. Results showed that the pectin (4 wt% ∼ 8 wt%) effectively modified the cell structures of the starch foam block. This was attributed to the increased viscosity of the starch melt during foaming and the enhanced cell stability during cooling, which was promoted by the formation of entanglements, hydrogen bonds, and ester bonds between pectin and starch, as confirmed by FTIR and DSC. Moreover, the pectin-starch foam displayed improved mechanical properties under wet storage conditions, mainly due to the limited moisture adsorption and water migration. The foam containing 4 wt% of pectin exhibited the highest compression-recovery ratio (76.7 %) and a reduced adsorbed moisture content (19.22 %) under 95 % RH. Overall, citrus pectin could improve the starch foaming process and the foam blocks barrier properties.

Prolonging heat-moisture treatment time at medium moisture content optimizes the quality attributes of cooked brown rice through starch structural alteration

Brown rice (BR), one of the popular whole grains worldwide, is still limited to consumption due to its rough texture after cooking. Through inspecting structural alteration, this work discloses how heat-moisture treatment (HMT) moisture content (15 %-25 %) and time (1.0 h-3.0 h) modify the starch digestibility and cooked BR texture. The medium moisture content (20 %) allowed the highest pasting viscosity and a uniform network structure of cooked BR. Prolonging the HMT time from 1.0 h to 2.0 h at medium moisture content hindered starch swelling and improved stability. Meanwhile, the relative crystallinity, the surface compactness in nanoscale and R995/1022 decreased, while the gel network structure was improved, contributing to the softened cooked BR texture and the enhanced starch digestibility. Although the resistant starch content raised to 13.55 % after 3.0 h of HMT, the springiness, gumminess and chewiness of cooked BR degraded, and this should be considered in certain conditions.

The effect of heat moisture treatment times on physicochemical and digestibility properties of adzuki bean, pea, and white kidney bean flours and starches

The effects of heat moisture treatment (HMT) times on the physicochemical properties of three bean flours and their starch were analyzed. The colors of L*, b* and ΔE values increased significantly with time. The adzuki bean and pea flours showed better WAI and SP, and better gelation of starch at 2 h. The rheological properties of mixed HMT dough (3:7) exhibited the typical solid-like weak gel behavior. HMT had a significantly decreased on the pasting viscosity of bean flour starch with treated time. HMT caused the starch granules damage, but did not radically change the crystal type. FTIR results showed more proteins attached to the surface of starch granules, and the short-range molecular order decreased the DO at 2 h. In vitro digestibility inferred that RDS converted into SDS and RS. These results indicated that HMT significantly affected the digestibility and physicochemical properties of bean flours.

Structural properties of the intra- and interhelical cavities of V6-type crystalline starches

V-type crystalline starch is known for its property to enhance aroma retention. Intra- and interhelical cavities are the first-order characteristics of V-type crystalline starch, which can affect its properties from microscopic level. This work aims to provide a detailed analysis of structural attributes of intra- and interhelical cavities and their influence on the properties of V-type crystalline starches. Helix deformation was caused due to the formation of interhelical cavities, which was reflected by the downfield shift of the signals for C1 and C4 as well as the appearance of an independent signal for C3 in 13C CP/MAS NMR spectra. Unit cell and lamellar structure formed by the aggregation of intrahelical cavities exhibited relatively low cell volume and high fractal dimension at crystal cell and lamellar levels. Toward a larger crystal, d-spacing increased with the formation of interhelical cavities, causing low-angle shifts of V-type crystalline starches in X-ray diffraction profiles. Intrahelical cavities enabled V6I-type crystalline starch to show high crystallinity per unit volume and a favorable short-range order, contributing greatly to the stable thermal properties. The flavor quality improvement in starch-based food is attributed to the structural characteristics of helical cavities and their relationship with the properties of V-type crystalline starches.

Effect of Ethanol Extract of Tea on the Microstructural Features and Retrogradation Characteristics of Glutinous Rice Starch

The glutinous rice starch (GRS) regeneration process could lead to decreased product quality and shorter shelf life. The purpose of this study was to analyze the effect of an ethanol extract of tea (EET) on the regeneration properties of GRS. The microstructure of starch was determined via scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy was used to determine the microstructure of starch-polyphenol molecular groups, an X-ray diffraction (XRD) instrument was used to determine the starch crystal structure, a differential scanning calorimeter (DSC) was used to determine the thermodynamic properties of starch, and the inhibitory effect of EET on GRS regeneration was comprehensively evaluated. The effect of EET on the in vitro digestion properties of GRS was also determined. The results showed that the addition of EET in GRS resulted in an increase in solubility and swelling power and a decrease in crystallinity and ΔHr. Compared to the control group, when retrograded for 10 days, the ΔHr of GRS with 1%, 2.5%, 5%, and 10% addition of EET decreased by 34.61%, 44.53%, 52.93%, and 66.79%, respectively. Furthermore, the addition of EET resulted in a decrease in the content of RDS and an increase in the content of SDS and RS in GRS. It was shown that the addition of EET could significantly inhibit the retrogradation of GRS, improve the processability, and prolong the shelf life of GRS products.

The Effects of Naematelia aurantialba on the Pasting and Rheological Properties of Starch and the Research and Development of Soft Candy

To study the effects of Naematelia aurantialba (NA) on the rheological and gelatinization properties of starch, the processing methods of NA were diversified. In this study, the gelatinization and rheological properties of corn starch (CS) and edible cassava starch (ECS) were investigated by adding NA with different mass fractions. Starch soft candy was prepared using NA, CS, and ECS as the main raw materials. Rheological studies showed that both CS-NA and ECS-NA exhibited elastic modulus (G') > viscosity modulus (G″), implying elastic behavior. G' was such that CS+1%NA > CS+5%NA > CS+3%NA > CS > CS+2%NA > CS+4%NA > ECS+4%NA > ECS+3%NA > ECS+5%NA > ECS+2%NA > ECS+1%NA > ECS. The gelatinization implied showed that after adding NA, the pasting temperature of CS-NA and ECS-NA increased by 1.33 °C and decreased by 2.46 °C, while their breakdown values decreased by 442.35 cP and 866.98 cP, respectively. Through a single-factor test and orthogonal test, the best formula of starch soft candy was as follows: 0.4 f of NA, 10 g of white granulated sugar, a mass ratio of ECS to CS of 20:1 (g:g), 0.12 g of citric acid, 1 g of red date power, and 16 mL of water. The soft candy was stable when stored for two days. This study offers a new direction for the research and development of NA starch foods.

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

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

Combined effect of heating temperature and content of pectin on the textural properties, rheology, and 3D printability of potato starch gel

Three-dimensional (3D) printing is one of the emerging techniques which fabricates customized foods with desired sensory characteristics. Rheological properties of 3D printing materials are vitally important in printability which govern the flowability and structural stability. Due to its unique gel-forming characteristics, potato starch has been extensively used in myriad food applications, such as 3D printing. However, little attention has been paid to the combined effect of heating temperature and pectin addition on the properties of potato starch gels. Thus, this study investigated the impact of different pectin contents (1, 1.5, and 2 %) on printability and the rheological and textural properties of potato starch gels heated at different temperatures (70, 80, and 90 °C). The gel heating temperature governs pectin-driven modifications in potato starch gels. Pectin addition increased the 3D printability, viscosity, storage modulus, hardness, gumminess, and springiness of starch gel at higher temperatures (80 °C and 90 °C). In contrast, at lower temperatures (70 °C), pectin addition decreased printability, viscosity, storage modulus, hardness, gumminess, and springiness. Therefore, the gel heating temperature influences the impact of pectin on printability, rheology, and textural properties. Accordingly, the combined effects of pectin and heating temperature should be considered in pectin-based 3D food-printing ink formulations.

Research progress in extraction, purification, structure of fruit and vegetable polysaccharides and their interaction with anthocyanins/starch

Fruits and vegetables contain polysaccharides, polyphenols, antioxidant enzymes, and various vitamins, etc. Fruits and vegetables polysaccharides (FVPs), as an important functional factor in health food, have various biological activities such as lowering blood sugar, blood lipids, blood pressure, inhibiting tumors, and delaying aging, etc. In addition, FVPs exhibit good physicochemical properties including low toxicity, biodegradability, biocompatibility. Increasing research has confirmed that FVPs could enhance the stability and biological activities of anthocyanins, affecting their bioavailability to improve food quality. Simultaneously, the addition of FVPs in natural starch suspension could improve the physicochemical properties of natural starch such as viscosity, gelling property, water binding capacity, and lotion stability. Hence, FVPs are widely used in the modification of natural anthocyanins/starch. A systematic review of the latest research progress and future development prospects of FVPs is very necessary to better understand them. This paper systematically reviews the latest progress in the extraction, purification, structure, and analysis techniques of FVPs. Moreover, the review also introduces the potential mechanisms, evaluation methods, and applications of the interaction between polysaccharides and anthocyanins/starch. The findings can provide important references for the further in-depth development and utilization of FVPs.

Changes in physiochemical properties and in vitro digestion of corn starch prepared with heat-moisture treatment

To investigate the effect of heat-moisture treatment (HMT) on the physiochemical properties and in vitro digestibility of corn starch, the pasting behavior, viscoelasticity, thermal properties, long/short range structure, morphology and in vitro digestion of corn starch treated with different HMT conditions (HMT-20, 25, 30, 35 and 40 %) were characterized. Results indicated that after HMT, the pasting and disintegration behaviors of corn starch were affected and correlated with the moisture content. The dynamic viscoelasticity of corn starch was changed, and when glassy conditions were reached, the elastic properties decreased with increasing moisture while the viscous properties increased, especially for the HMT-40 %. The thermal stability of starch was improved by HMT, although the enthalpy of pasting (ΔH) was reduced. Additionally, the HMT processing also promoted the conversion of RDS to SDS and/or RS (SDS and RS increased to 39.80 % and 31.68 % for HMT-40 %, respectively), which might attribute to the rearrangement of free starch molecules. The present work provides a potential approach to make functional starches with healthy properties.

Structure, thermal stability, and in vitro digestibility of rice starch-protein hydrolysate complexes prepared using different hydrothermal treatments

In this study, rice starch-protein hydrolysate (WPH-S) complexes with high resistant starch (RS) content were prepared by heat-moisture treatment (HMT) and annealing (ANN). The effects of different hydrothermal treatments on the structure and thermal stability of the WPH-S complexes and their relationship with starch digestibility were further discussed. The results showed that RS contents of ANN-WPH-S complexes (35.09-40.26 g/100 g) were higher than that of HMT-WPH-S complexes (24.15-38.74 g/100 g). Under hydrothermal treatments, WPH decreased the hydrolysis kinetic constant (k) of starch form 4.07 × 10^-2-4.63 × 10^-2 min^-1 to 3.29 × 10^-2-3.67 × 10^-2 min^-1. HMT and ANN promoted hydrogen bonding between WPH and starch molecules, thus increasing the molecular size of starch. In addition, the shear stability of WPH-S mixture was improved with the hysteresis loop area decreased after HMT/ANN treatments, resulting in a more stable structure. Most importantly, the hydrothermal treatment made the scatterers of WPH-S complexes denser and the surface smoother. Especially after ANN treatment, the WPH₆₀-S complex formed a denser aggregate structure, which hindered the in vitro digestion of starch to a certain extent. These results enrich our understanding of the regulation of starch digestion by protein hydrolysates under different hydrothermal treatments and have guiding significance for the development of foods with a low glycemic index.

The Effect of Different Induction Methods on the Structure and Physicochemical Properties of Glycosylated Soybean Isolate Gels

Soybean protein isolate (SPI), as a full-valued protein, is rich in nutrients, such as amino acids. However, the isolated structure of soybeans makes it difficult to react and thus prepare good gels. In order to further improve the properties of SPIs and to prepare plant-based gels with good performance, this experiment was conducted to prepare maltodextrin glycosylated soybean isolate (MGSI) by the glycosylation of SPI and maltodextrin (MD), and the gels were prepared by thermal induction, transglutaminase (TGase) induction, and TG-MgCl₂ co-induction of this glycosylated protein to investigate the effects of different induction methods on the structure and properties of the gels produced by MGSIs. Moreover, the effects of different induction methods on the structure and properties of the gels produced by MGSI were investigated. SDS-PAGE protein electrophoresis, FTIR spectroscopy, and endogenous fluorescence spectroscopy revealed that all three inductions result in the covalent bond cross-linking of MGSI during the gel formation process. Compared with thermal induction, the TGase-induced MGSI secondary structure had a higher content of β-folded structures, increased fluorescence intensity of tertiary structures, and produced a red shift. The gel induced by TGase in collaboration with MgCl₂ contains a more β-folded structure and irregular curl and increases the β-turned angle and α-helix content further, the endogenous fluorescence λmax is significantly red-shifted, and the fluorescence intensity increases, demonstrating that the tertiary structure of MGSI unfolds the most, forming multilayered gels with the tightest structures. The three gels were analyzed by rheology and SEM, showing that the TGase-MgCl₂ synergistically induced gel had the highest energy-storage modulus G', viscoelasticity, and water-holding capacity, as well as the densest gel structure. In conclusion, the combined treatment of enzyme and MgCl₂ might be an effective way of improving the structure and gel properties of SPI. This study helps to promote the high-value utilization of SPI and the development of plant protein gels.

Physical modification of maize starch by gelatinizations and cold storage

The effects of gelatinization at three selected temperatures (DSC characteristic peaks temperature: TO, TP, and TC) and subsequent cold storage (CS) treatment on structural characteristics, pasting, and rheological properties of maize starch (MS) were investigated. The pasting, rheological properties of MS was changed with the increase of gelatinization temperature from TO to TC, but were not further significantly changed if the gelatinization temperature was higher than TC. Pasting and thermal properties analysis suggested that gelatinization at TC (TC treatment) significantly increased the gelatinization and pasting temperature of MS. Moreover, TC treatment decreased breakdown viscosity by 8.49 times and setback viscosity by 2.53 times. Dynamic rheological measurements revealed that the TC treatment caused the lower G' and G" of MS, and decreased the thickening coefficient by 55.17 %. These results indicated that TC treatment could enhance the thermal stability properties of MS, inhibiting the shear and short-term retrogradation, the shear-thinning behavior of MS. Interestingly, the CS treatment further inhibited the shear and short-term retrogradation and the shear-thinning behavior of MS. The leaked starch molecules aggregate to form a harder structure after gelatinization and starch molecules were further aggregated after CS treatment, these all were hypothesized to be responsible for these results.

Influence of starch with different degrees and order of gelatinization on the microstructural and mechanical properties of pectin cryogels: A potential pore morphology regulator

The applications of cryogels are defined by their porous morphology as well as mechanical properties. To achieve efficient regulation of porous properties for pectin cryogels, we selected starch as a potential polysaccharide regulator. Pectin/starch composite cryogels with different degrees of gelatinization were formulated, and two ways of starch gelatinization were considered: starch gelatinization occurred before or after pectin crosslinking during forming the hydrogel network. The results showed that high gelatinized starch (73.8 %-100.0 %) rendered pectin cryogels with denser pore morphology and higher mechanical strength. The pore diameter transferred from 160-200 μm to 40-60 μm with the degree of gelatinization, while the total porosity decreased by about 15 % and the specific surface area increased by about 100 m²/g. When starch gelatinization occurred before pectin crosslinking, the hydrogen bond interactions between gelatinized starch and pectin were formed to accelerate the gelation rate of the pectin Ca²⁺-dependent network. When gelatinization occurred after pectin crosslinking, the pre-formed pectin network delayed the breakdown of the starch crystalline structure during gelatinization. The qualitative regulation of the pore morphology in pectin cryogels by incorporating starches with varying degrees of gelatinization was confirmed.

Gallic acid and heat moisture treatment improve pasting, rheological, and microstructure properties of Chinese yam starch-chitosan gels: A comparative study

Nowadays，It is difficult for the polysaccharide-starch system to meet demand of practical production owing to the poor gel properties. Therefore, aiming to further improve the practical application of polysaccharide-starch gel, the effects of gallic acid (GA) and heat moisture treatment (HMT) on the gel properties and microstructure of yam starch/chitosan (YS/CS) composite gels were investigated. Swell power (SP) results showed that GA and HMT treatment respectively reduced the SP of YS gel by 3.24 g/g and 6.03 g/g, given that GA and HMT decrease the rheology of the water phase inhibiting the entry of water into the swollen starch. In the pasting process, HMT reduced pasting viscosity of the HMT/YS system because only little amylose was leached in the medium for elevating its viscosity after HMT. The rheological properties suggested that high temperature treatment of HMT facilitated the disruption and disintegration of starch granules resulting dynamic modulus had a decline trend. The elastic properties of GA/YS gels were enhanced with the addition of GA, which could be supported by the thicken lamellar observed in its microstructure. In general, GA and HMT effectively alter the gel properties of YS/CS gel system, and facilitate its practical application in food industry.

Changes in structures and digestibility of amylose-oleic acid complexes following microwave heat-moisture treatment

Amylose-oleic acid complexes (AOA) were exposed to microwave heat-moisture treatment (M-HMT) with different moisture content (MC), and the variations in structures and digestibility were investigated. M-HMT caused the dissociation of helical structures and destruction of short-range molecular order of AOA. Meanwhile, the molecules of amylose and oleic acid rearranged and more amylose-oleic acid complexes were formed during M-HMT, the complexing index of AOA was increased from 25.41 % to 41.20 % when treating at 35 % MC. Moreover, the relative content of single helix increased with increasing MC, resulting in higher V-type relative crystallinity. With ≥30 % MC, the treated complexes showed greater thermostability than that of original AOA. The treatment increased the enzymatic digestibility of AOA, and sample treated with 35 % MC had the highest resistant starch content of 82.33 %, which was 17.96 % higher than that of native AOA. The improved enzyme resistance should be correlated to increased molecular interplay and formation of amylose-oleic acid complexes.

Characterization of a novel starch-based foam with a tunable release of oxygen

Here, we used techniques of extrusion and coating to produce starch-based foams with a combined function of buffering and controlled release of oxygen. The foams presented open-cell structures and showed a compression recovery ratio of 94%. After coating with poly(vinyl alcohol) solution, in which calcium peroxides were loaded, the developed functional foams showed a behavior of controllable oxygen release under a wet condition, as well as a high compression strength (≥2.2 MPa). Also, these foams showed an improved moisture resistance with a reduction in maximum moisture absorption from 25 to 14%. Under a vibrated storage condition to simulate food transportation, guavas packaged with functional foams showed a reduced physical damage, and browning index from 5.00 to 2.97, owing to the foams' superior buffering ability and self-regulation of storage atmosphere. The functional packaging system of the starch-based foams developed in our work is promising for fruit and vegetable preservations.

Rheological Properties of Wheat Flour Modified by Plasma-Activated Water and Heat Moisture Treatment and in vitro Digestibility of Steamed Bread

The study investigated the effects of plasma-activated water (PAW) and heat moisture treatment (HMT) on the rheological properties of wheat flour and the in vitro digestibility of steamed bread partially replaced by the modified wheat flour. After HMT, the gelatinization temperature of wheat flour increased and the gelatinization enthalpy reduced. The solubility and swelling power of wheat flour increased after the heat-moisture treatment. The solubility of modified flour after PAW-HMT treatment was lower than that of distilled water (DW)-HMT at the same temperature. The wheat flour with HMT had higher storage modulus (G') and loss modulus (G"), and had better ductility and deformability. Common wheat flour was partially replaced by modified flour to make steamed bread. The results indicated that the volume, height, diameter and specific volume of steamed bread were significantly decreased with the addition of HMT flour. However, the hardness, viscosity and chewiness increased significantly. The resistant starch content of steamed bread with the modified wheat flour increased. The results provide new insights for the development of new functional steamed bread.

Effects of Inca peanut seed albumin fraction on rheological, thermal and microstructural properties of native corn starch

In this work, the effect of Inca peanut seed albumin fraction (IPA) on the rheological, thermal and microstructural properties of native corn starch (NCS) was firstly studied. Compared to the NCS, IPA addition could obviously decrease the transparency of NCS, and the transparency of NCS and NCS-IPA suspensions decreased during the storage time. The textural paraments of NCS pastes with or without IPA reached to the maximum at a concentration of 5%. Steady shear rheological tests showed that all systems were non-Newtonian fluid, and the consistency coefficient (K) values reached to the maximum at 5% IPA concentration. The storage and loss modulus values of NCS-IPA pastes were higher than those of NCS pastes, and curves of loss angle (tan δ) indicated that all pastes were typical weak gel. With the increasing addition of IPA, DSC analysis showed that the thermal properties (To, Tp and Tc) of NCS were significantly changed, whereas, there was no distinct difference in the enthalpy. Microscopy illustrated that there were some wrinkle shrinkage and severe folds on the NCS-IPA granules. Fourier-transform infrared (FT-IR) spectroscopy showed that the hydrogen bonding was primarily interaction forces between IPA and NCS molecules.