Physicochemical Properties Of Starch Research Articles

Molecular structure in relation to swelling, gelatinization, and rheological properties of lotus seed starch

Relationships between molecular structure and physicochemical properties of starch remain to be better defined. This research was a follow-up of previous studies aiming to fill this gap using lotus seed starch (LS) (a novel C-type starch source) as a model system. By means of correlation analysis, the effects of molecular structure on physicochemical properties of LS were revealed. Content and chain length of amylose affected mainly rheological properties of LS. Short and long B-chains differently affected the short-range ordered structure of starch granules, thermal properties, and the transmittance of starch paste. In addition to the influences of amylose and amylopectin internal structure, several “novel” relationships related to the effects of amylopectin external structure were found in the LS-based model system. For instance, the molar amount of clustered A-chains (Aclustered) in lotus seed amylopectin was significantly related to the short-range molecular order in the granules. Moreover, the importance of Aclustered-chains was reflected by their influences on various properties of LS upon gelatinization and retrogradation. Successive influences of the molar amount of Aclustered-chains on starch properties during pasting were revealed. This study highlighted the importance of amylopectin external structure in addition to the under-studied amylopectin internal structure in affecting starch physicochemical properties.

Physicochemical properties of starch in sodium chloride solutions and sucrose solutions: Importance of starch structure.

The influences of sodium chloride (NaCl)/sucrose on starch properties as affected by starch structural characteristics are little understood. In this study, the effects were observed in relation to the chain length distribution (from size exclusion chromatography) and granular packing (inferred through morphological observation and determination of swelling factor and paste transmittance) of starches. Adding NaCl/sucrose dramatically delayed the gelatinization of starch that had a high ratio of short-to-long amylopectin chains and had loose granular packing. The effects of NaCl on the viscoelasticity of gelatinizing starch were related to the flexibility of amylopectin internal structure. Effects of NaCl/sucrose on starch retrogradation varied with starch structure, co-solute concentration, and analytical method. The co-solute-induced changes in retrogradation were highly associated with amylose chain length distribution. Sucrose strengthened the weak network formed by short amylose chains, while the effect was not significant on amylose chains that were capable of forming strong networks.

High and ultra‐high temperature drying of fermented dried noodles: effect on noodle quality and starch properties

SummaryAlthough dried noodles have been industrialised for many years, some technical bottlenecks, such as dense cross‐section structure, poor rehydration ability and the lack of nutritional and flavour substances, still need to be addressed. Fermentation has been used to produce dried noodles to impart a porous structure and microbial metabolites, improving their rehydration properties and the nutritional and flavour quality of dried noodles. However, the current commercially fermented dried noodles exhibit some issues, such as high breakage rate, rough surface and sticky texture that need to be solved. Drying at high (HT) and ultra‐high temperatures (UT) has been shown to improve the quality of dried pasta or noodles. However, HT and UT drying are not currently used to produce fermented dried noodles. This article investigates the changes in the quality and starch physicochemical properties of fermented dried noodles with high (HM), medium (MM) or low moisture (LM) content dried at HT or UT. The results showed that the UT‐LM condition most prominently improved the noodle quality, significantly reduced the cooking loss rate (5.19%) and significantly increased the water absorption rate (191.41%) of the noodles, and improved the rehydration of noodles. In addition, the cross‐linking of the gluten network was analysed using confocal laser scanning microscopy and the AngioTool software. It was found that the UT treatment promoted the cross‐linking of the gluten network, and the highest number of cross‐linking points (976) was achieved under the UT‐LM condition. The tight gluten network reduces the amylose leaching from the noodles, giving the noodles a denser surface structure and lower adhesiveness. In conclusion, UT‐LM drying could be used as an effective drying condition to improve the quality of fermented dried noodles.

Starch chain-length distributions determine cooked foxtail millet texture and starch physicochemical properties

Starch chain-length distributions play an important role in controlling cereal product texture and starch physicochemical properties. Cooked foxtail millet texture and starch physicochemical properties were investigated and correlated with starch chain-length distributions in eight foxtail millet varieties. The average chain lengths of amylopectin and amylose were in the range of DP 24–25 and DP 878–1128, respectively. The percentage of short amylopectin chains (Ap1) was negatively correlated with hardness but positively correlated with adhesiveness and cohesion. Conversely, the amount of amylose intermediate chains was positively correlated with hardness but negatively correlated with adhesiveness and cohesion. Additionally, the amount of amylose long chains was negatively correlated with adhesiveness and chewiness. The relative crystallinity (RC) of starch decreased with reductions in the length of amylopectin short chains in foxtail millet. Pasting properties were mainly influenced by the relative length of amylopectin side chains and the percentage of long amylopectin branches (Ap2). Longer amylopectin long chains resulted in lower gelatinization temperature and enthalpy (ΔH). The amount of starch branched chains had important effects on the gelatinization temperature range (ΔT). These results can provide guidance for breeders and food scientists in the selection of foxtail millet with improved quality properties.

Exogenous Application of Methyl Jasmonate Promotes Yield and Grain Quality of Rice under Terminal Drought Stress

Exogenous application of methyl jasmonate (MeJA) improves rice drought tolerance, but its effects on rice yield and quality under drought stress during the reproductive phase remain unclear. A pot experiment was conducted to measure rice yield, grain quality, and starch physicochemical properties under three treatments: continuous flooding irrigation throughout the whole growth season (CF), ten days of −40 kPa drought stress at the heading stage (DS), and foliar spraying 100 μmol L−1 MeJA on the first three days of the ten-day −40 kPa heading stage drought stress (DM). An inbred japonica rice variety, Huaidao 5, was the experimental material, and each treatment had 11 replicates for sampling. The results indicated that DS significantly reduced rice yield and quality compared to CF. With increases in superoxide dismutase (+22.2%), peroxidase activities (+10.5%), catalase (+5.0%), and proline content (+5.7%), DM significantly increased 1000-grain weight (+8.6%), filled grain percentage (+3.6%), and yield (+11.1%) compared with DS. Regarding grain quality, DM significantly decreased the chalkiness degree (−12.3%) and protein content (−3.9%) but increased the amylose content (+17.2%) and taste value (+7.3%) relative to DS. In addition, DM improved breakdown viscosity (+17.8%), gelatinization enthalpy (+17.2%), retrogradation enthalpy (+28.0%), 1045/1022 cm−1 ratio (+3.0%), and starch granule morphology compared to DS. In conclusion, exogenous application of 100 μmol L−1 MeJA enhanced the antioxidant capacity of rice leaves, and thus improved starch physicochemical properties to increase grain yield and quality under terminal drought stress.

Ultrasonic modification of lotus starch based on multi-scale structure: Pasting, rheological, and thermal properties

The modulation mechanism of ultrasound on starch physicochemical properties is unclear which limits the application of ultrasound in starch. This study investigated the effect of ultrasound treatment (UT) on pasting, rheological, thermal properties, and multi-scale structure of lotus starch. After 270 W UT, the peak and final viscosity was 2.23 and 2.64 times that of native starch. Whereas, the pasting viscosity decreased under 360 and 450 W UT. UT increased the viscoelasticity of LS, however, the viscoelasticity decreased after 360 and 450 W UT compared with those under a UT power of 270 W. Electrostatic interaction and hydrogen bonding intensified after UT compared with native LS. Some pores appeared on the surface of starch granules and increased with the increase of ultrasound power. Lamellar thickness initially increased from 10.03 nm to 10.26 nm and then decreased to 9.81 nm when the UT power exceeded 270 W. The ordered aggregate structure of starch loosened, while the short-range ordered structure strengthened after UT. The amorphous region expanded, double helices became ordered and compact, and entanglement between starch granules enhanced after UT. This study provided a promising approach to achieve starchy products with suitable quality through understanding multi-scale structure changed via UT.

Effects of acetylation, carboxymethylation and crosslinking on some physicochemical properties of starch from tubers of Icacina senegalensis and Cyrtosperma senegalense

Starch extraction from Icacina senegalensis (IS) and Cyrtosperma senegalense (CS) tubers was carried out with water at room temperature. The tubers of Icacina senegalensis and Cyrtosperma senegalense gave a starch yield of 40.9% and 25.5% respectively. The amylose, amylopectin composition of starches from IS and CS tubers were determined to be 10.8%, 89.2% and 24.6%, 75.4 % respectively. The starch extracts were chemically modified to produce cross-linked, carboxymethylated and acetylated starch derivatives. The formation of new chemical bonds in the starch derivatives was confirmed with Fourier Transform Infra-red spectroscopy (FTIR). Both swelling power and gelatinization temperature of IS starch and CS starch increased with acetylation, crosslinking and carboxymethylation while the degrees of substitution for the starch derivatives ranged between 0.33 and 1.45 making the native and modified starches suitable for many industrial applications.

Effects of different food ingredients and additives on the digestibility of extruded and roller-dried maize starch and its application in low glycemic index nutritional formula powder.

Complex interactions among starch, protein, and fat occurred during food processing affects the taste, texture, and digestibility of starch-based food. The physicochemical properties of starch, in particular the slow digestion property, are greatly influenced by the processing techniques such as extrusion and roller-drying treatment. This study argued the effects of various food ingredients and additives on the digestion properties of maize starch treated with extrusion and roller-drying, and designed a nutritional formula for developing low glycemic index products. The extruded group containing raw maize starch, soybean protein isolate, soybean oil, lecithin and microcrystalline cellulose in the ratio of 580:250:58:20:3 had the best slow digestion property. Nutritional formulas were designed at the above ratio, with the supplementary materials including calcium casein peptide, multi-vitamins, sodium ascorbate, fructooligosaccharides, xylitol and peanut meals. The sample containing 10% peanut meal and a 1:3 ratio of fructooligosaccharides and xylitol additions obtained the highest scores in sensory evaluation. A significant slow digestion effect was observed in samples produced from the optimal formula. The results of present study could provide a specific formula and may contribute to the development and production of the low glycemic index nutritional powder. This article is protected by copyright. All rights reserved.

Physicochemical properties of pressure moisture treated (PMT) and heat moisture treated (HMT) starches

Physicochemical properties of pressure moisture treated (PMT, 550 MPa, 10 min) and heat moisture treated (HMT, 100 °C, 10 h) starches were investigated. Effects of PMT and HMT were different depending on starch type. PMT starches showed dramatic changes in moisture sorption isotherm, pasting properties, thermal characteristics, solubility and swelling power (at 90 °C), and in vitro digestibility. The most dramatic difference between PMT and HMT starches was amylopectin melting transition, i.e., broadening in PMT and shift to high temperature in HMT starches. Moreover, B- and C-type starches revealed the more increase in amylopectin melting enthalpy than A-type starch. Both PMT and HMT did not increase the crystallinity but reorganized the amorphous area to compact, resulting in lower rapidly digestible starch and higher slowly digestible starch than those of native starches. Consequently, PMT changed the digestibility and physicochemical properties of starches with different modes of action compared with HMT.

Characterization of Starch Physicochemical Properties and Grain Transcriptome Reveal the Mechanism for Resistant Starch Accumulation

Understanding the physicochemical properties of starch during grain development and the mechanism for resistant starch (RS) accumulation will provide useful information for improving the RS content of wheat. The grains from wheat mutant lines with high RS contents and their corresponding wild-type control were analyzed to characterize the structural and physicochemical properties of wheat starch. A transcriptomic analysis was used to analyze the differentially expressed genes (DEGs) involved in RS accumulation. The results showed that the RS content increased with grain development, along with the total starch content, but a larger increase was observed in the middle and later stages of grain filling. The X-ray diffraction peak intensity and relative crystallinity of starch exhibited the lowest and highest values at 10 days after anthesis, respectively. Regarding the thermal properties of starch, the peak temperature and conclusion temperature generally decreased with grain development; however, the enthalpy values showed no apparent regularity. Compared to control cultivar ZM22, the RS639 and RS683 lines with high RS contents showed high amylose contents and high relative crystallinity and a large proportion of 2.0~9.8 µm starch granules. Furthermore, the transcriptomics analysis revealed that the average relative expression of the glucan-branching enzyme (GBE) α-1,4 glucan phosphorylase (Pho) and starch synthase (SS) in ZM22 was 2.47-, 2.70-, and 2.56-fold higher than that in RS639, respectively; which indicates that the downregulation of the expression of genes encoding GBE, Pho, and SS in wheat grain promotes the accumulation of RS.

Physicochemical properties and molecular structure of starches from different wheat varieties and their influence on Chinese steamed bread.

Starch is one of the key factors for the texture of Chinese steamed bread (CSB). In this study, the molecular structures and physicochemical properties of starches from 11 wheat varieties with amylose content (AC) of 1.75%-28.79% were investigated. Northern style CSB was made using these wheat varieties to explore the structure-property-quality relationship of starches. AC was negatively correlated with the pasting and gelatinization properties. The relative crystallinity (RC) had a negative correlation with AC but a positive correlation with gelatinization. The molecular structure results from the fluorophore-assisted capillary electrophoresis spectrophotometer indicated that the length of short amylopectin chains (βAp,i ) was positively correlated with hot paste and cool paste viscosities. The amount of medium amylopectin chains (hAp,iii ) was positively correlated with peak and breakdown viscosities but negatively correlated with setback viscosity. The hAp,iii had positive correlations with gelatinization temperatures and RC. The amount of long amylopectin chains (hAp,v ) had a positive correlation with peak temperature. For the CSB texture, βAp,i had negative correlations with hardness and chewiness, whereas had a positive correlation with resilience. The hAp,iii was negatively correlated with springiness and resilience. The hAp,v was negatively associated with resilience. PRACTICAL APPLICATION: Starch has a vital role in wheat flour products. Clarifying the structure-property-quality relationship of starches will help illuminate the role of starch molecular structure in CSB production and provide valuable information for the control of CSB quality. It also provides a significant reference for wheat breeding.

Cultivation pattern affects starch structure and physicochemical properties of yam (Dioscorea persimilis)

Yam (Dioscorea spp.) is a major food source in many countries due to its tuber rich in starch (60 %–89 % of the dry weight) and various important micronutrients. Orientation Supergene Cultivation (OSC) pattern is a simple and efficient cultivation mode developed in China in recent years. However, little is known about its effect on yam tuber starch. In this study, the starchy tuber yield, starch structure and physicochemical properties were compared and analyzed in detail between OSC and Traditional Vertical Cultivation (TVC) with Dioscorea persimilis “zhugaoshu”, a widely cultivated variety. The results proved that OSC significantly increased tuber yield (23.76 %–31.86 %) and commodity quality (more smooth skin) compared with TVC in three consecutive years of field experiments. Moreover, OSC increased amylopectin content, resistant starch content, granule average diameter and average degree of crystallinity by 2.7 %, 5.8 %, 14.7 % and 9.5 %, respectively, while OSC decreased starch molecular weight (Mw). These traits resulted in starch with lower thermal properties (To, Tp, Tc, ΔHgel), but higher pasting properties (PV, TV). Our results indicated that cultivation pattern affected the yam production and starch physicochemical properties. It would not only provide a practical basis for OSC promotion, but also provide valuable information on how to guide the yam starch end use in food and non-food industries.

Accumulation characteristics and structural properties of starch in different spatial positions of wheat endosperm under nitrogen application

Starch accumulation in wheat endosperm has spatial differences. In this study, the accumulation, granule size distribution, physicochemical properties of starch in different spatial positions in wheat endosperm and response to nitrogen treatment were analysed. Results indicated that the starch content in the inner endosperm was higher than that in the outer endosperm. The total starch and amylose contents in the inner and outer endosperms decreased and increased after nitrogen treatment, respectively. The starch granules that accumulated in the inner endosperm were larger than those in the outer endosperm 10 days after anthesis. The amount of C-type starch granules in the inner endosperm was less than that in the outer endosperm, and nitrogen treatment increased the C-type starch granules in the inner endosperm. After nitrogen treatment, the short chains decreased, whereas the middle and long chains increased in the inner and outer endosperms. Nitrogen treatment also increased the crystal area in the inner and outer endosperms, especially the single helix in the inner endosperm. These conclusions provide new insights into the mechanism of starch accumulation in wheat endosperm and its response to the external environment.

Insights into the aggregation structure and physicochemical properties of heat-moisture treated wheat starch and its associated effects on noodle quality

In this work, impacts of heat moisture treatment (HMT) on the aggregation structure and physicochemical properties of wheat starch were investigated, and relationship between starch physicochemical properties and quality performance of noodles fortified with HMT-treated starches was revealed. Results show that HMT reduced the ordered degree of starch aggregation structures (e.g., crystalline and short-range ordered molecular structures) but increased their rigidity and thermostability, and in turn, retarded starch enzyme hydrolysis, swelling, breakdown, and reassociation during digestion, heating and cooling. Then, the limited swelling and reassociation ability of starch molecules after HMT may contribute to a weaker gel strength and herein a lower absorption, hardness, springiness, and chewiness of noodles. Notably, HMT-30 fortified noodles presented more obvious changes. Hence, it can be concluded that quality attributes of noodles could be tailored by modulating starch gel structure through HMT.

Genetic Diversification of Starch Branching Enzymes during Maize Domestication and Improvement.

Elucidating the genetic basis of starch pasting and gelatinization properties is crucial for enhancing the quality of maize and its utility as feed and industrial raw material. In maize, ZmSBE genes encode important starch branching enzymes in the starch biosynthesis pathway. In this study, we re-sequenced the genomic sequences of ZmSBEI, ZmSBEIIa, ZmSBEIIb, and ZmSBEIII in three lines called 335 inbred lines, 68 landrace lines, and 32 teosinte lines. Analyses of nucleotide polymorphisms and haplotype diversity revealed differences in the selection patterns of ZmSBEI, ZmSBEIIa, ZmSBEIIb, and ZmSBEIII during maize domestication and improvement. A marker-trait association analysis of inbred lines detected 22 significant loci, including 18 SNPs and 4 indels significantly associated with three maize starch physicochemical properties. The allele frequencies of two variants (SNP17249C and SNP5055G) were examined in three lines. The frequency of SNP17249C in ZmSBEIIb was highest in teosinte lines, followed by landrace lines, and inbred lines, whereas there were no significant differences in the frequency of SNP5055G in ZmSBEIII among the three lines. These results suggest that ZmSBE genes play an important role in the phenotypic variations in the starch physicochemical properties in maize. The genetic variants detected in this study may be used to develop functional markers for improving maize starch quality.

Physicochemical properties of starch in rice flour with different hardening rates of glutinous rice cake (mochi)

The hardening rate of glutinous rice cake (mochi) made by Kagura-mochi (Kag) was two times higher than that of Hakusanmochi (Hak). Protein in the waxy rice indicated a similar distribution and content; therefore, the textural properties of the rice product were dependent on the physicochemical properties of starch in the rice flour. Urea-induced gelatinization, differential scanning calorimetry, and rapid visco analysis revealed that starch in Kag was less easily gelatinized than that in Hak. The solubility and swelling power at 70 °C of starch in Kag rice flour were slightly lower than that in Hak. Relative crystallinities of starch in Kag and Hak rice flour were 55.1% and 49.3%, respectively. The chain length distribution of the short chain of amylopectin in Kag rice flour was lower than that in Hak. The low short-chain content in Kag may be related to the increase in the hardening rate of the mochi made by Kag.

Creating high-resistant starch rice by simultaneous editing of SS3a and SS3b.

Creating high-resistant starch rice by simultaneous editing of SS3a and SS3b.

Effects of Source Strength and Sink Size on Starch Metabolism, Starch Properties and Grain Quality of Rice (Oryza sativa L.)

The source strength and sink demand as well as their interaction have been demonstrated to co-regulate the synthesis of starch and determine the grain quality, but the knowledge of the underlying physiological mechanisms is limiting. An indica variety, Yangdao 6, and a japonica variety, Jinxiangyu 1, were planted with three treatments, including normal growth plant (CK), leaf-cutting (LC) and spikelet-thinning (ST). The transcript levels of starch metabolic genes, physicochemical characteristics of starch and appearance, milling, cooking and tasting qualities of rice under different treatments were determined. The ST treatment increased the relative expression of genes related to the synthesis of short branch-chains of amylopectin (SSI, BEI, BEIIb) and amylose (GBSSI) and reduced the relative expression of medium-long to long branch-chains of amylopectin synthesis genes (SSIIa, SSIIIa, SSIIIb, ISA1). When comparing ST with the CK treatment, starch granules became smoother with higher contents of short branch-chains and lower ratios of medium-long and long branch-chains of amylopectin; the crystallinity and the value of 1045/1022 cm−1 was decreased; for pasting properties, the setback and pasting temperature were decreased; the peak viscosity, hot viscosity, breakdown and final viscosity were significantly increased. Meanwhile, the ST treatment improved the appearance, milling and cooking and tasting qualities. The opposite results were observed under the LC treatment. These results indicated that source strength and sink size would regulate expression levels of starch metabolic genes, which is pivotal for the contents of amylose and short/long branch chains ratio of amylopectin, thus changing the structure and physicochemical properties of starch and grain quality. Here, we speculated that the improved source strength in terms of higher leaf/canopy photosynthesis and small sink size, such as small panicle size, would be preferred traits in high grain quality rice breeding.

Comparisons of rice taste and starch physicochemical properties in superior and inferior grains of rice with different taste value

The difference in grain yield between superior grains (SG) on the upper part and inferior grains (IG) on the lower part of the same panicle was widely reported. To date, variations in rice taste quality between SG and IG and the related starch physicochemical properties remained poorly understood. Here, rice cultivars with different taste quality (NT, normal taste; GT, good taste) were grown to investigate the mechanism underlying taste difference between SG and IG and the correlation between cooked rice taste and starch properties. In this study, the taste value of GT rice was 32.2% higher than that of NT rice across the cultivars. The GT rice comprised a series of typical taste qualities of larger stickiness, smaller hardness, lower apparent amylose content (AAC), and lower protein content (PC). The taste quality differed among rice grains on the same panicle; SG achieved 21.9% and 17.0% higher taste value than IG in GT rice and NT rice, respectively. The higher taste value in SG was owing to the larger stickiness and lower PC. Meanwhile, SG of GT rice achieved the lowest PC (8.2%) and gluten content (5.6%), which might indicate a better health value. Additionally, larger and smoother granules, more fa (DP < 12), lower crystallinity, and larger 1045/1022 cm−1 ratios were found in SG starch compared to IG starch. These led to a weaker swelling power and lower gelatinization enthalpy in SG starch, while gelatinization temperature and retrogression enthalpy were the opposite. Moreover, SG starch exhibited higher storage modulus, loss modulus, slowly digestible starch contents, and resistant starch contents than IG. Our results revealed a great difference in taste quality between SG and IG in rice. The larger and smoother starch granules and shorter chain length could increase the ordered structure of starch, thus improving swelling power, gelatinization properties, and rheological characteristics and facilitating better taste quality of SG over IG. Besides, the lower PC (especially gluten content), higher slowly digestible starch, and higher resistant starch content indicated a more promising health value of SG in the food industry.

Effects of different altitudes on the structure and properties of potato starch.

The main element influencing the quality of potato starch is the environment. To investigate the effects of different altitude cultivation locations on the molecular structure and physicochemical properties of starch, two potato varieties, Jiusen No.1 B1 and Qingshu No.9 B2, were planted in three different altitude zones: A1 at low altitude (Chongzhou 450m), A2 at middle altitude (Xichang 2800m), and A3 at high altitude (Litang 3650m). The results showed that the average volume, number, surface area diameter, average branched polymerization degree, crystallinity, and gelatinization temperature of two potato granules in high altitude areas were significantly lower than those in middle and low altitude areas were, and the gelatinization performance of potato starch was affected according to the correlation of starch structure characteristics. Potato starch with more short-branched chains and less long branched chains resulted in a lower gelatinization temperature in high altitude areas. The results showed that Jiusen No. 1 and Qingshu No. 9 were mainly affected by accumulated radiation and accumulated rainfall in Litang, a high altitude area, and by effective accumulated temperature in Xichang, a middle altitude area. This study quantified the influence of meteorological factors on the main starch quality of potato tubers. The results can be used as a theoretical basis for the scientific planting of high-quality potatoes.