Trough Viscosity Research Articles

Morphological, physicochemical, and pasting properties of pre-gelatinized starch prepared by high-pressure homogenizer: A comparative study on starches from different resources

Pre-gelatinized starch, a physically modified starch known for its ability to swell in cold water, has wide applications across various industries. This study assesses the feasibility of high-pressure homogenization (HPH) in producing pre-gelatinized starches and compares their morphological, physicochemical, and pasting properties from different sources. Starches from eleven sources, including mung bean, pea, wheat, sweet potato, cassava, corn, non-waxy rice, waxy rice, chickpea, lentil, and chestnut, were processed using HPH at 150 MPa for three cycles. The resulting pre-gelatinized starch granules exhibited disrupted surface structures, increased water absorption and solubility, decreased crystallinity, and altered gelatinization temperatures. Results showed that waxy rice pre-gelatinized starch had the highest degree of pre-gelatinization (90.27 %) and water absorption index (61.94 %), while chestnut pre-gelatinized starch had the highest water solubility index (21.58 %) and lentil pre-gelatinized starch demonstrated the highest gel strength (2178 g). X-ray diffraction analysis revealed a significant reduction in crystallinity, with values ranging from 13.96 % to 18.29 %. Additionally, the study observed variations in pasting properties, with cassava pre-gelatinized starch exhibiting the highest peak viscosity (5458 cP), trough viscosity (3864 cP), and final viscosity (6536 cP). These findings indicate that HPH is an effective method for producing pre-gelatinized starch with enhanced functional properties, enriching the scientific understanding of pre-gelatinized starches from different sources and promoting their application in the food industry and other sectors.

Characterization of ulvan polysaccharide extracted from Ulva pertusa and its effect on thermal, rheological, and gelling properties of rice flour

Three ulvan fractions (UPs 1–3) were extracted from Ulva pertusa via hot-water extraction. UP1 exhibited a molecular weight of 729,151 Da, while UPs 2 and 3 ranged from 19,952 to 750,384 Da. These fractions differed in monosaccharide, uronic acid, and sulfate levels. Zeta potentials for polysaccharide solutions (0.2–0.6 % w/v) ranged from −34.4 to −25.1, all demonstrating shear-thinning behavior. Incorporating UPs 1–3 solutions (0.2–0.6 % w/v) with rice flour increased gelatinization temperatures and modified pasting properties, increasing peak time, peak viscosity, and trough viscosity while reducing breakdown, final, and setback viscosities. Ulvan polysaccharide improved the viscous behavior of rice flour paste, indicated by increased loss modulus and tan δ (p > 0.05). Furthermore, ulvan polysaccharide improved the microstructure and texture of rice flour gel, with UP1 (0.6 % w/v) forming denser matrices and better texture. Molecular docking analysis suggested that hydrogen bonding is the primary interaction between rice glutelin and ulvan components.

Impact of dehulling, germination and fermentation on the bioactive and functional properties of grey pea flour.

Grey pea is a largely overlooked legume in the Nordic countries, and its potential uses in various food products remain unexplored. It is a nutrient-rich crop with low environmental impact, making it an attractive option for sustainable and nutritious plant-based alternatives. To investigate the impact of dehulling, germination, and fermentation on the bioactive (polyphenol content and antioxidant capacity) and functional characteristics (water absorption index, water solubility index, water and oil binding capacity, emulsifying properties and gelation concentration) of grey pea flour. Additionally, protein content and pasting properties (temperature, peak viscosity, trough viscosity, breakdown, final viscosity, and setback) were measured. Dehulling was performed using a runner disk sheller. Germination was carried out for 24 and 48 h at ambient temperature, and fermentation was conducted for 8 h at 43°C using a starter culture. The results indicate that dehulling did not significantly affect functional properties and gelling capacity (p = 0.297 for oil absorption capacity, p = 0.5 for emulsion activity, and p = 0.607 for emulsion stability), but it resulted in a notable decrease in total polyphenol content (TPC) and antioxidant capacity (TAC). Conversely, 48 h of germination increased TAC measured by two methods: FRAP (19%) and DPPH (30%). This process increased through viscosity by 1.2-fold, while it did not significantly affect the water absorption index (WAI), water solubility index (WSI), or the emulsifying properties of grey pea flour. Fermentation significantly improved TPC (p < 0.001 for whole grey peas and p = 0.004 for dehulled grey peas), with a TPC increase of up to 67% in fermented dehulled pea flour. TAC measured by both methods, showed significant increases, ranging from 35 to 104%. However, fermentation reduced emulsifying and pasting properties, as indicated by the peak, through and final viscosity, which may be desirable only for certain food products. Further, germination and fermentation showed significant increases in protein content, by 4 and 8%, respectively. Fermented grey pea flour exhibited enhanced bioactive characteristics, while 48-h germination positively impacted pasting properties. Overall, these processes led to changes in both the bioactive and functional properties of grey pea flour, creating opportunities for the use of these flours in a wide array of food products.

Editing of the soluble starch synthase gene MeSSIII-1 enhanced the amylose and resistant starch contents in cassava

Foods with high amylose and resistant starch (RS) contents have great potential to enhance human health. In this study, cassava soluble starch synthase MeSSIII-1 gene mutants were generated using CRISPR/Cas9 system. The results showed that the storage roots of messiii-1 mutants had higher contents of amylose, RS, and total starch than those in CK. The rates of small and large-sized starch granules were increased. Additionally, amylopectin starch in messiii-1 mutants had a higher proportion of medium- and long- chains, and a lower proportion of short-chains than those in CK. The onset, peak, and conclusion temperatures of starch gelatinization in messiii-1 mutants were significantly lower than those in CK, and the peak viscosity, trough viscosity and final viscosity all increased. MeSSIII-1 mutation could increase the contents of sucrose, glucose, and fructose in cassava storage roots. We hypothesize that these soluble sugars serve a dual role: they provide the necessary carbon source for starch synthesis and act as sugar signals to trigger the transcriptional reprogramming of genes involved in starch biosynthesis. This process results in a collective enhancement of amylose, RS, and total starch contents, accompanied by changes in starch granule morphology, fine structure, and physicochemical properties.

Pasting, structural properties, and in vitro digestibility of water chestnut (Eleocharis dulcis Burm. f., Cyperaceae) starch co-gelatinized with different hydrocolloids

Hydrocolloids have been widely used to modulate the processing properties of native starch, this study aimed to investigate the effects of carrageenan (KC), tamarind seed polysaccharide (TSP), and xanthan gum (XG) on the pasting, rheology, structural properties, and in vitro digestibility of water chestnut starch (WCS). The pasting results showed that XG increased the peak viscosity (PV), trough viscosity (TV), final viscosity (FV) and breakdown viscosity (BD) of WCS gel, but decreased the setback (SB), TSP significantly increased SB. The rheological data found that KC, TSP and XG increased the apparent viscosity and storage modulus (G') and loss modulus (G'') of WCS, which gradually increased by the concentration gradient of hydrocolloids. The hardness of starch with KC increased from 171.52g to 323.36g, and the addition of 0.3% KC and 0.5% KC enhanced the thermal stability. Furthermore, XG significantly increased the resistant starch (RS) content and decreased the hydrolysis rate of starch. These results will provide theoretical references for expanding the application range of WCS.

Uncovering the multiscale structure and physicochemical properties of starch extracted from naturally fermented mung bean liquid by wet milling

In this study, mung bean liquid (MBL) was prepared by wet milling and then naturally fermented for 0, 24, 48, 72, and 96 h. Afterward, the starch extracted from MBL was analyzed. The pH of MBL decreases from 6.54 to 4.91 during fermentation. Moreover, the mung bean starch (MBS) granules changed significantly with pitted surfaces, pores and channels. The particle size, molecular weight (Mw) and long chain amylopectin (B2) content of the MBS decreased, whereas the short chain (A) increased from 20.57% to 22.70% with increasing fermentation time. Natural fermentation had no effect on the crystalline type (A) of the MBS but increased the relative crystallinity from 26.53% to 29.23%. However, the intensity ratios of the 995/1022 cm-1 and 1047/1022 cm-1 FTIR spectra increased with fermentation time, reaching maxima of 0.95 and 0.80 after 48 h, respectively. In addition, Fermented MBS increased the trough viscosity (TV), final viscosity (FV), elastic modulus (G') and viscous modulus (G'') but decreased the peak viscosity (PV) and breakdown (BD). Thermal properties revealed that fermentation increased the gelatinisation enthalpy (ΔH) from 9.49 to 10.26 J/g.

Genome-wide association study and KASP marker development for starch quality traits in wheat.

Starch is the main component of wheat (Triticum aestivum L.) flour, and its quality directly affects the processing quality of the final product. To investigate the genetic basis of starch, this study assessed the starch quality traits of 341 winter wheat varieties/lines grown in Emin and Qitai during the years 2019-2020 and 2020-2021. A genome-wide association study was conducted with the genotype data obtained from wheat 40K breeding chips using the mixed linear model. Wheat starch quality traits exhibited coefficients of variation ranging from 1.43% to 23.66% and broad-sense heritabilities between 0.37 and 0.87. All traits followed an approximately normal distribution, except for T. There were highly significant correlations among starch quality traits, with the strongest correlation observed between final viscosity (FV) and trough viscosity (TV) (r=0.748), followed by peak viscosity and breakdown (BD) (r=0.679). Thirty-four single-nucleotide polymorphism markers significantly and stably associated with starch quality traits were identified, clustering in 31 genetic loci. These included one locus for TV, six loci for BD, three loci for FV, two loci for peak time (PT), 12 loci for T, five loci for falling number, and two loci for damaged starch. One PT-related block of 410kb was identified in the region of 596 Mb on chromosome 5A, where significant phenotypic differences were observed between different haplotypes. One Kompetitive allele-specific PCR (KASP) marker for T was developed on chromosome 7B, and two KASP markers for BD were developed on chromosome 7A. Four candidate genes possibly affecting BD during grain development were identified on chromosome 7A, including TraesCS7A02G225100.1, TraesCS7A02G225900.1, TraesCS7A02G226400.1, and TraesCS7A02G257100.1. The results have significant implications for utilizing marker-assisted selection in breeding to improve wheat starch quality.

Effects of synergistic action of courgette polysaccharide and coumalic acid on pasting, rheological, and thermal properties of potato starch

AbstractThe effects of courgette polysaccharides (CP) and coumalic acid (COA) on gelatinization, rheology, thermodynamics, microstructure, freeze–thaw stability, and in vitro digestibility of potato starch (PS) were studied. The synergistic effect of CP and COA on PS was further analyzed. The results showed that peak viscosity (PV) decreased from 6649.00 to 3462.50 mPa s and 3825.00 mPa s, respectively, after CP and COA were added. Under the combined effect of the two, it will be as low as 3225.50 mPa s. Besides, trough viscosity (TV), breakdown viscosity (BV), and final viscosity (FV) had the same trend. The presence of CP and COA can significantly delay the short‐term retrogradation of PS, especially in the case of high dose of CP and low dose of COA. Rheological tests showed that all sample gels belonged to the weak gel system (tan δ &lt; 1) and pseudoplastic fluids. Meanwhile, the results of thermodynamic, Fourier transform infrared, and Raman spectroscopy exhibited that the presence of CP and COA significantly retarded the retrogradation of PS, especially at higher levels. In addition, the presence of CP and COA significantly reduced the formation of PS gel structures, especially when acting together. Furthermore, CP and COA reduced the content of rapidly digestible starch in PS and increased the content of resistant starch. Differently, CP can increase the slowly digestible starch content, whereas COA did the opposite. In the ternary composite system, CP and COA will also interact and restrict each other. Hence, the characteristics of PS can be better improved by adjusting the ratio of CP and COA. Meanwhile, the results of the study can provide potential possibilities for the application of CP and COA in food and improve the quality of PS‐related products.

Energy-size relationship and starch modification in planetary ball milling of quinoa

The effects of speed (250–450 rpm) and time (10–50 min) on milling energy (E), particle size distribution (PSD), crystallinity degree (CD), damaged starch (DS), microstructure, hydration and pasting properties of flours obtained in a planetary ball mill (PBM) were investigated. As increasing milling severity quinoa flours showed polydispersed PSD (peaks at 417, 40 and 2 μm) with a shift towards smaller size and greater dispersion (Span: 3.0–5.2) as well as particles with rounded edges and polished surfaces (SEM images). The relationship E − D50 were satisfactorily predicted by the Walker's equation. The hydration tests as function of temperature and milling conditions revealed a complex flour behavior due to differences in PSD, composition, and DS content. The increasing milling energy caused a decrease in peak viscosity (PV), trough viscosity (TV) and final viscosity (FV) of up to 36%, 29%, and 25%, respectively. Significant correlations between flour attributes were found (DS-CD, r = −0.83, p < 0.01; PV-D50, r = 0.92, p < 0.01; TV-D50, r = 0.94, p < 0.01; FV-D50, r = 0.90, p < 0.01) denoted the increase of starch degradation as milling severity rises. These results can be used to improve the manufacture and the selection criteria of quinoa flour with specific functional attributes.

Pasting, rheology, structural properties and in vitro digestibility of potato starch complexes co-gelatinized with squash polysaccharides

The effects of extraction of squash polysaccharide from water (WESP) and subcritical water (SWESP) on gelatinization, rheology, thermodynamic, micro-structure, freeze-thaw stability and digestibility of potato starch (PS) were studied. The WESP and SWESP decreased peak viscosity, trough viscosity, breakdown viscosity, final viscosity, storage modulus and loss modulus of PS. Conversely, the setback viscosity, pasting temperature and peak time increased. All gel samples belonged to the weak gel system. The thermodynamic and fourier spectroscopic results demonstrated a significant retardation of PS retrogradation in the presence of WESP and SWESP. It was consistent with the microstructure characterization detected by scanning electron microscopy that both WESP and SWESP had a significant inhibitory effect on the formation of the PS gel structure. Moreover, the existence of WESP and SWESP compromised the freeze-thaw stability of PS gel. Meanwhile, WESP and SWESP also affected the digestibility of PS and reduced the eGI value of PS, which was conducive to stabilizing blood sugar fluctuations. This study helped to better understand the interaction of PS with WESP/SWESP in the gel system, and supplied a way to improve the quality of PS-related products. In addition, it also contributed to the industrial production and application of WESP and SWESP.

Physicochemical, Phytochemical and Antioxidant Properties of Organic Sweet Potato Flour and Its Application in Breadstick

Sweet potato flour (SPF) is used to produce food products worldwide due to good biological activity in the human diet and low cost. In this experiment, sweet potato tubers were processed into flour including purple-SPF, yellow-SPF and orange-SPF and applied in breadsticks. The proximate, physical, phytochemical and antioxidant properties of flour and breadsticks were investigated. The carbohydrate, moisture, ash, fat, protein and fiber contents of SPF ranged from 82.19 - 85.21, 4.12 - 5.78, 1.30 - 2.46, 0.32 - 0.86, 4.07 - 4.74 and 3.58 - 5.65 %, respectively. The water activity (aw) of SPF ranged from 0.2277 - 0.2695. The phytochemical analysis showed that purple-SPF and purple-SPF based breadstick products exhibited the highest total phenolic contents (TPC), total flavonoid contents (TFC) and total anthocyanin contents (TAC), while total carotenoid contents (TCC) was observed in both orange-SPF and breadstick made from orange-SPF. In addition, purple-SPF and breadstick produced from purple-SPF had the highest antioxidant activity against ABTS, FRAP, DPPH and metal chelating activity. The X-ray diffraction patterns of SPF samples showed a C-type crystal structure, with a crystallinity ranging from 19.43 - 31.05 %. The scanning electron micrographs of SPF granules revealed that they were mostly round and spherical, with a size range between 5 - 28 µm. The viscosity characteristics of yellow-SPF had the highest peak viscosity (307.97 ± 9.87 RVU), trough viscosity (200.81 ± 10.07 RVU), breakdown (108.42 ± 3.13 RVU), final viscosity (277.75 ± 8.60 RVU) and setback (76.95 ± 4.03 RVU). The physical quality showed breadstick from yellow-SPF had the highest hardness and fracturability with values of 11,537.67 ± 190.58 g and 11,143.33 ± 161.97 g, respectively. These results indicate that sweet potato flour composite breadstick has high phytochemical and antioxidant potential and may be applied in the food industry.

Genome-wide association study identifies loci and candidate genes for RVA parameters in wheat (Triticum aestivum L.).

The gelatinization and retrogradation characteristics of wheat starch affect the eating quality of Chinese-style food. Rapid Visco Analyzer (RVA) parameters have been widely used as important indicators to evaluate and improve the quality of wheat starch. However, the genetic basis of RVA parameters remains to be further explored. In the present study, a natural population was genotyped using 90K single nucleotide polymorphism (SNP) arrays, and the RVA parameters of this population grown in five environments were evaluated. The results showed that 22,068 high-quality SNP markers were identified and distributed unequally on the chromosomes. According to the genetic distance, 214 wheat materials were divided into four groups. Except for the pasting temperature (PTT), six parameters followed a normal distribution. Based on the general linear model, 969 significant association SNPs were detected by genome-wide association studies (GWAS), and chromosomes 7A and 2B had the most associated SNPs. Breakdown viscosity (BV) was associated with the most SNPs (n = 238), followed by PTT (n = 186), peak viscosity (PV; n = 156), trough viscosity (TV; n = 127), and final viscosity (FV; n = 126). According to the average linkage disequilibrium (LD), 33 stable quantitative trait loci (QTLs) were identified for single parameters in multiple environments, of which 12 were associated with BV, followed by peak time (PT; n = 8) and PTT (n = 7). On the other hand, 67 pleiotropic QTLs were identified for multiple parameters. Three candidate genes-TasbeIIa, TasbeI, and TassIIa-were screened for phenotyping analysis. The grain width and the weight of the TasbeIIa and TaSSIIa knockout (KO) lines were significantly lower than those of the TasbeI KO lines and the control (CK). The KO lines had smaller endosperm cells, smaller A-type starch granules, and higher amylose content. The TasbeI KO lines showed normal RVA curves, while the TasbeIIa KO lines showed flat curves. However, the TaSSIIa lines failed to paste under the RVA temperatures. Conclusively, the SNPs/QTLs significantly associated with the RVA parameters and genetic resources with novel haplotypes could be used to improve the quality of wheat starch.

Effects of deamidated gluten protein on wheat starch properties and rheological properties of starch-gluten dough

To further investigate the interaction between starch and gluten protein, deamidated gluten protein with varying degrees of organic acid (citric acid) was mixed with wheat starch in various proportions, and the solubility, pasting, and rheological properties of the blend flour were investigated. The solubility of the sample powder increased significantly as the deamidated protein content increased. The gelatinization results also demonstrated that the deamidated protein content increased the peak viscosity, trough viscosity gradually decreased, and peak viscosity time shortened. The results of the rheological measurement revealed that the elastic modulus (G′), viscous modulus (G″), and creep recovery of the mixed flour showed regular changes with the continuous change of the mixed powder proportion. Furthermore, consistent alterations were observed in the effects of proteins with varying degrees of deamidation in the same proportion on farinaceous characteristics. FTIR analysis of the gluten protein revealed that the primary secondary structures were the β-sheet and β-turn; different levels of damage were observed.

Effect of Different Fertilizer Types on Quality of Foxtail Millet under Low Nitrogen Conditions.

In order to clarify the effect of different fertilizers on foxtail millet quality under low nitrogen conditions, we used JGNo.21 and LZGNo.2 as experimental materials and set up five treatments, including non-fertilization, nitrogen, phosphorus, compound, and organic fertilizers, to study the regulation of different fertilizer types on agronomic traits, nutrient fractions, and pasting characteristics of foxtail millet under low nitrogen conditions. Compared with the control, all of the fertilizers improved the agronomic traits of JGNo.21 to a certain extent. Nitrogen and compound fertilizer treatments reduced the starch content of JGNo.21; the starch content was reduced by 0.55% and 0.07% under nitrogen and compound fertilizers treatments. Phosphorus and organic fertilizers increased starch content, and starch content increased by 0.50% and 0.56% under phosphorus and organic fertilizer treatments. The effect of each fertilizer treatment on protein content was completely opposite to that of starch; different fertilizer treatments reduced the fat content of JGNo.21 and increased the fiber content. Among them, nitrogen and phosphorus fertilizers increased the yellow pigment content; the yellow pigment content increased by 1.21% and 2.64% under nitrogen and phosphorus fertilizer treatments. Organic and compound fertilizers reduced the content of yellow pigment; the yellow pigment content was reduced by 3.36% and 2.79% under organic and compound fertilizer treatments. Nitrogen and organic fertilizers increased the fat content of LZGNo.2; the fat content increased by 2.62% and 1.98% under nitrogen, organic fertilizer treatment. Compound and phosphorus fertilizer decreased the fat content; the fat content decreased by 2.16% and 2.90% under compound and phosphorus fertilizer treatment. Different fertilizer treatments reduced the cellulose and yellow pigment content of LZGNo.2. The content of essential, non-essential, and total amino acids of JGNo.21 was increased under compound and nitrogen fertilizer treatments and decreased under organic and phosphorus fertilizer treatments. The content of essential, non-essential, and total amino acids of LZGNo.2 was significantly higher under compound, nitrogen, and organic fertilizer treatments compared with control and significantly decreased under phosphorus fertilizer treatments. Nitrogen and compound fertilizer treatments significantly reduced the values of peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, and pasting time of each index of JGNo.21; phosphorus and organic fertilizer treatments improved the values of each index. In contrast, the pasting viscosity of LZGNo.2 increased under phosphorus fertilizer treatment and decreased under nitrogen fertilizer treatment. Reasonable fertilization can improve the quality of foxtail millet, which provides a scientific theoretical basis for improving the quality of foxtail millet.

Effects of Eucommia ulmoides leaf powder on the gelatinization, rheology, and gel properties of sweet potato starch

This study aimed to explore the feasibility of employing Eucommia ulmoides leaf powder (ELP), which is a novel medicinal and food homologous material, to improve the physicochemical properties of sweet potato starch (SPS) gel. The effects of ELP on the gelatinization, rheology, and gel properties of SPS were investigated. The Brabander viscosity test results showed that ELP could reduce the peak viscosity, trough viscosity, final viscosity, and setback value of SPS. The rheological tests showed that the SPS-ELP gels had shear-thinning behavior, and that the ELP could decrease the apparent viscosity, shear stress, G′, G″ of SPS-ELP gels and make the gels exhibit stronger liquid-like behavior. The X-ray diffraction pattern indicated that the ELP could decrease the relative crystallinity and retard retrogradation of SPS-ELP gels, which was cofirmed by microscopic structure analysis. The ELP had a significant effect on the color difference of the gels, resulting in a yellow-green color. The addition of ELP also reduced the hardness of SPS-ELP gels, and increased the median particle size D50, volume mean diameter D [4,3], and area mean diameter D [3,2] of gel particle size distribution. These findings suggest that ELP has a good potential in improving starch gel properties.

Mild alkali treatment alters structure and properties of maize starch: The potential role of alkali in starch chemical modification

Normal and waxy maize starches were treated with mild alkali treatment (pH 8.5, 9.9, 11.3) in two temperature-time combinations (25 °C for 1 h and 50 °C for 18 h) to investigate the effect on starch structure and properties. Mild alkali treatment partly removed the starch granule-associated proteins and lipids of normal (from 0.31 % to 0.24 % and from 0.77 % to 0.55 %, respectively) and waxy maize starches (from 0.22 % to 0.18 % and from 0.24 % to 0.15 %, respectively). Gelatinization enthalpy of waxy maize starch increased with alkali treatment from 16.20 J·g−1 to 21.95 J·g−1, indicating that amylopectin (AP) rearrangement and AP-AP double helices formation might occur. But amylose could inhibit these effects by restricting mobility of amylopectin, and no such changes occurred for normal maize starch. Alkali treatment decreased gelatinization temperature and increased peak and final viscosity. Alkali treatment decreased trough viscosity and increased setback of normal maize starch. The hydrothermal treatment promoted the effect of alkali, attributed to the more rapid molecular motion at higher temperature. Normal and waxy starches showed different changes after alkali treatment, indicating that amylose played an important role in controlling the effect of alkali and hydrothermal treatment, primarily as an obstructer of amylopectin rearrangement in mild alkali treatment.

Interaction of anthocyanins, soluble dietary fiber and waxy rice starch: Their effect on freeze-thaw stability, water migration, and pasting, rheological and microstructural properties of starch gels

This study aimed to investigate the effect of the interaction of black rice anthocyanins (BRA), soluble dietary fiber from extruded rice bran (ES) and waxy rice starch (WRS) on the physicochemical properties of starch gels, including gelatinization properties, rheological properties, freeze-thaw stability, water migration, molecular structure and gel microstructure. The results showed that the pasting temperature (PT) of the mixtures was increased, and the peak viscosity (PV), trough viscosity (TV), final viscosity (FV) and setback viscosity (SV) were significantly reduced when ES and BRA were added to WRS in different proportions (ES:BRA, 4:0, 4:0.4, 4:1, 4:2, 8:0, 8:0.8, 8:2, 8:4). Both ES and BRA could enhance the viscosity of WRS gels, and ES exhibited strong ability on improving the strength of gels. The presence of ES and BRA improved the water retaining capacity of WRS gels, but weakened the freeze-thaw stability. ES, BRA and WRS formed non-covalent bonds (hydrogen bonds) through hydrophilic groups during gelatinization, which improved the gel properties. In addition, the steric hindrance formed by ES and BRA inhibited starch retrogradation. These results might contribute to the development of starch-based food formulations with good quality.

Rod-Shaped Starch from Galanga: Physicochemical Properties, Fine Structure and In Vitro Digestibility.

This work investigated the physicochemical properties, structural characteristics, and digestive properties of two non-conventional starches extracted from Galanga: Alpinia officinarum Hance starch (AOS) and Alpinia galanga Willd starch (AGS). The extraction rates of the two starches were 22.10 wt% and 15.73 wt%, which is lower than widely studied ginger (Zingiber officinale, ZOS). But they contained similar amounts of basic constituents. AOS and AGS showed a smooth, elongated shape, while ZOS was an oval sheet shape. AOS and ZOS were C-type starches, and AGS was an A-type starch. AOS showed the highest crystallinity (35.26 ± 1.02%) among the three starches, possessed a higher content of amylose (24.14 ± 0.73%) and a longer amylose average chain length (1419.38 ± 31.28) than AGS. AGS starch exhibits the highest viscosity at all stages, while AOS starch shows the lowest pasting temperature, and ZOS starch, due to its high amylose content, displays lower peak and trough viscosities. Significant differences were also found in the physicochemical properties of the three starches, including the swelling power, solubility, thermal properties, and rheological properties of the three starches. The total content of resistant starch (RS) and slowly digestible starch (SDS) in AOS (81.05%), AGS (81.46%), and ZOS (82.58%) are considered desirable. These findings proved to be valuable references for further research and utilization of ginger family starch.

Enhancing Wet Starch Noodle Properties: Investigating the Impact of Acetylated and Ozonized Sago (Metroxylon sago Rottb.) Starch

This study explores the impact of ozonation and acetylation on sago starch, targeting improvements in noodle production. Functional properties were examined, including water content, water absorption index (WAI), water solubility index (WSI), and amylose content. Ozonation generally decreased water absorption (from 18.32% in native sago (NS) to 18.29% in ozonated sago (OS)) and solubility (from 12.39% in NS to 15.2% in OS). Conversely, acetylation increased solubility (from 19.04% in acetylated sago (AS) to 17.55% in ozonated-acetylated sago (OAS)). Modifications reduced amylose content (from 31.67% in NS to 23.13% in AS), impacting noodle texture and physiochemical properties. Modified sago starch noodles cooked faster but absorbed less water, resulting in higher cooking loss. For instance, cooking time decreased from 5 minutes (NS) to 6 minutes (AS), while water absorption decreased from 90.22% (NS) to 75.42% (AS). Additionally, cooking loss increased from 19.39% (NS) to 12.04% (AS). Pasting properties were affected, with increases observed in trough viscosity (TV), breakdown (BV), and final viscosity (FV). For instance, TV increased to 2758.5 RVU in OAS compared to 1903 RVU in AS. Modified sago starch noodles showed faster cooking times, lower water absorption, and higher cooking loss. Texture profile analysis (TPA) indicated softer textures for modified noodles, possibly due to enhanced expansion after modification.

Effects of synergistic action on rheological and thermal properties of potato starch complexes co-gelatinized with caffeic acid and squash polysaccharides extracted with water and subcritical water

In order to broaden the application range of squash polysaccharide (WESP/SWESP) and caffeic acid (CAA) and improve the quality of potato starch (PS) products, the effects of WESP/SWESP and CAA on the gelatinization, rheology, thermodynamics, microstructure and in vitro digestion of PS were investigated. Meanwhile, the synergistic effect of WESP/SWESP and CAA on PS was further analyzed. Differently, due to WESP and SWESP had different monosaccharide composition and structure, they had different effects on the system. Pasting properties results showed that the presence of WESP/SWESP and CAA significantly reduced the peak viscosity, trough viscosity, breakdown viscosity and final viscosity of PS, especially under the combined action. In rheological tests, all sample gels belonged to the pseudoplastic fluids and weak gel system (tan δ < 1). Besides, thermodynamic properties revealed that WESP/SWESP and CAA synergistic effect had better retrogradation delay effect. In the ternary system, WESP/SWESP, CAA and PS can form a new network structure and improve the stability of the gel system. In addition, the results of infrared spectroscopy, Raman spectroscopy, x-ray diffraction and scanning electron microscopy exhibited that the ternary system can promote the accumulation and winding of the spiral structure of PS chain, and make the structure of PS gel network more orderly and stable. Furthermore, compared with PS gel, the ternary system had lower RDS and higher SDS and RS content, suggesting that the addition of WESP/SWESP and CAA at the same time was more conducive to reducing the hydrolysis rate of PS. This work revealed the interaction between WESP/SWESP, CAA and PS, which improved the physicochemical and digestive properties of PS. It will provide a theoretical basis for improving the quality of potato starch-related products and developing functional foods.