Higher Gelatinization Temperature Research Articles

Multi-scale structure of A- and B-type granules of normal and waxy hull-less barley starch

The multi-scale structure of combined (A- and B- type granules), A-type, and B-type granules from normal (NHB) and waxy hull-less barley (WHB) starch was studied, including crystalline structure, molecular branching, nanostructural and fractal characteristics. Particle size distribution was applied to determine the separation purity (>95%), and micrography was used to distinguish between the A-type and B-type granules. Lacking amylose, WHB had higher relative crystallinity, gelatinization temperature, enthalpy, level of scattering intensity and uniformity of orientation of double helices than NHB starch. Generally, B-type granules had higher gelatinization temperature, lower enthalpy, greater relative crystallinity, higher ratio of crystalline to amorphous region, more fa chains in amylopectin, and thicker semi-crystalline lamellae than A-type and combined granules. The results showed that the multi-scale structure of A-type and B-type granules differed greatly, and the characteristics of combined granules were not the same as those of its two constituent granule fractions.

Screening and identification of rice non-floury endosperm mutants with different starch components

Starch components determine rice quality and utilization. Rice floury endosperm grains have poor quality. In this study, we screened 27 non-floury endosperm mutants with different starch components from a mutant population derived from japonica rice variety Nipponbare using urea gelatinizing grain-iodine staining method. Nine mutants of MY03, MY12, MY16, MA06, MA15, MP09, MP20, MP31 and MP40 were chosen for identification of homozygous mutant and analysis of starch components and grain properties. The amylose content in single grain indicated that the screened mutants were homozygous and the stained solution color of gelatinized grain could reflect the starch components of brown rice grain. The MY03, MY12 and MY16 grains had altered amylopectin structures and exhibited high gelatinization temperatures and strong resistances to urea gelatinization. Compared with Nipponbare grains, MA06 and MA15 grains had very high amylose and lipid contents. The MP09, MP20, MP31 and MP40 grains had significantly lower amylose contents than Nipponbare grains. The screened mutants had similar grain transparency to Nipponbare. This study provided a method reference for rapidly screening rice non-floury endosperm mutants from thousands of mutant lines, and the screened mutants were important genetic materials for revealing starch synthesis and regulation and good germplasm resources for rice quality breeding.

The role of different Wx and BEIIb allele combinations on fine structures and functional properties of indica rice starches

This study examined the effects of the combinations of Waxy (Wx) and starch branching enzyme IIb (BEIIb) alleles on starch fine structure and functional properties in indica rice cultivars. The results showed that be2b mutant starches with BEIIb deficiency had higher amylose content, shorter amylose long chains, a higher proportion of amylopectin long chains and molecular order, but a lower proportion of amylopectin short chains and relative crystallinity, resulting in higher gelatinization temperature but lower enthalpy and paste viscosity. Compared with the rice lines carrying Wxb allele, Wxa allele contributed to relatively higher amylose content, longer amylopectin chains, less short-range ordered structure and lower relative crystallinity, leading to a little lower gelatinization enthalpy. This study provides new insight into structure-function relations among rice lines with different allele combinations of starch synthesis related genes, which is a useful strategy for rice quality breeding.

Analysis on the Morphology and Quality Characteristics of Different Varieties of Lotus Root Starch and Whole Powder

The present work reports the differences in the between particle morphology, gelatinization properties, thermal properties and texture propertiesmorphology and quality characteristics of starch particles and whole powders obtained from six different varieties of lotus root. The results showed that the surface of lotus root starch particles was smooth without cracks, but with depressions. Most of the particles were short rod-shaped, but some were elliptical; the whole lotus root powder had rough surface and irregular shape. There was no significant difference between lotus root starch and whole flour in the brightness, but the transparency of starch wassignificantly higher than that of whole flour. The initial gelatinization temperature and enthalpy change value of lotus root starch were higher than that of whole lotus root starch. The gelatinization temperature of starch particlesobtained from 'Hangzhouhuanghetou' was 63.9 ℃, the highest gelatinization temperature among testing samples. The gelatinization temperature of 'Elian No. 6'whole powder was 55.0 ℃, the lowest gelatinization temperature among testing samples.Lotus root starch had better expansion properties and thermal paste stability, and lotus root whole powder hadbetter cold paste stability. The chewiness and ductility of lotus root starch were generally lower than that of whole lotus root powder, butthe elasticity and hardness were similar. Among samples, the chewiness and ductility of starch and whole lotus root starch obtained from 'Elian No. 1' were higher than other varieties.

Revealing the mechanism beneath the effects of starch-amino acids interactions on starch physicochemical properties by molecular dynamic simulations

In this study, the effects of different amino acids (AAs) including glycine (Gly), lysine (Lys) and glutamic acid (Glu) on starch physicochemical (gelatinization, swelling capacity, pasting and retrogradation) and morphological characteristics were investigated using differential scanning calorimeter, rapid visco analyser, a novel automatic segmentation methodology, along with both SEM and polarization microscope under normal and polarized light. Results showed that at a concentration of 3% (w/w), the addition of AAs showed no or only limited effects on starch granular morphological properties and crystallinity. Nevertheless, AAs could significantly inhibit starch granular swelling and gelatinization during heating, especially for charged AAs including Glu and Lys, leading to lower swelling capacity but higher gelatinization temperatures (p < 0.05). Moreover, the starch-AAs interactions also significantly decreased the starch viscosities including peak, trough, final and the setback viscosities, through retarding the leaching of starch molecules from inside. The molecular dynamics simulation further reveals that compared with water molecules, in an order of Glu > Lys > Gly, the interactions between AAs and water significantly decreased the number of starch-water hydrogen bonds, maintaining a higher number of starch-starch intra hydrogen bonds. This in turn improved the intra-hydrogen bonds within starch chains, resulting to more stable structures and thus inhibited starch gelatinization as well as its swell capacity. This study provides important information in terms of the application of different of AAs on starch aiming to improve starch physicochemical properties for better food processing and better starch functional properties.

Relative importance of branching enzyme isoforms in determining starch fine structure and physicochemical properties of indica rice.

Down-regulation of starch branching enzymes alters fine structure and starch properties, especially the B-type crystalline pattern and extremely high amylose content identified in the BEIIb-deficiency mutant in the indica rice. The relative importance of the starch branching enzymes in determining the molecular fine structure and starch functional properties were uncovered in this study. An indica rice, Guangluai 4 with high amylose content (AC) and high gelatinization temperature (GT) was used to generate the clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein-9 (Cas9) knockout lines. Five mutant lines were identified including be1-1, be1-2, be2a-1, be2a-2 and be2b-1, and analysis of western blot showed the CRISPR/Cas9 system was successful in inducing mutations in the targeted genes. AC of be2b-1 (34.1%) was greater than that of wild type (WT) (27.4%) and other mutants. Mutations of either BEI or BEIIa did not alter the starch crystallite pattern (A-type). The BEIIb deficiency caused an opaque endosperm phenotype, changed the crystallite pattern from A- to B-type, and dramatically increased the degree of ordered structure, the relative proportion of amylose chains and intermediate to long amylopectin chains, average chain length of amylopectin molecules as well as GT. The BEIIa deficiency had no effect on the proportion of amylose chains, the length of amylopectin intermediate-long chains, conclusion temperature and enthalpy of gelatinization. Down-regulation of BEI increased the proportion of shortest amylopectin chains (fa) but decreased the proportion of long amylopectin chains (fb2 and fb3), leading to a lower GT. It is concluded that the relative importance in determining starch fine structures and functionality was in the order of BEIIb > BEI > BEIIa. Our results provide new information for utilizations of BE-deficient mutants in rice quality breeding.

Starch synthases SSIIa and GBSSI control starch structure but do not determine starch granule morphology in the absence of SSIIIa and SSIVb.

High levels of two major starch synthases, SSIIa and GBSSI, in ss3a ss4b double mutant rice alter the starch structure but fail to recover the polygonal starch granule morphology. The endosperm starch granule is polygonal in wild-type rice but spherical in double mutant japonica rice lacking genes encoding two of the five major Starch synthase (SS) isozymesexpressed in endosperm, SSIIIa and SSIVb. Japonica rice naturally has low levels of SSIIa and Granule-bound SSI (GBSSI). Therefore, introduction of active SSIIa allele and/or high-expressing GBSSI allele from indica rice into the japonica rice mutant lacking SS isozymes can help elucidate the compensatory roles of SS isozymes in starch biosynthesis. In this study, we crossed the ss3a ss4a double mutant japonica rice with the indica rice to generate three new rice lines with high and/or low SSIIa and GBSSI levels, and examined their starch structure, physicochemical properties, and levels of other starch biosynthetic enzymes. Lines with high SSIIa levels showed more SSI and SSIIa bound to starch granule, reduced levels of short amylopectin chains (7 ≤ DP ≤ 12), increased levels of amylopectin chains with DP > 13, and consequently higher gelatinization temperature. Lines with high GBSSI levels showed an increase in amylose content. The ADP-glucose content of the crude extract was high in lines with low or high SSIIa and low GBSSI levels, but was low in lines with high GBSSI. Addition of high SSIIa and GBSSI altered the starch structure and physicochemical properties but did not affect the starch granule morphology, confirming that SSIIIa and SSIVb are key enzymes affecting starch granule morphology in rice. The relationship among SS isozymes and its effect on the amount of substrate (ADP-glucose) is discussed.

Study on physicochemical properties of rice landraces for amylose, gel consistency and gelatinization temperature

Rice grain quality depends on physical, biochemical, cooking quality and organoleptic characters. Grain quality analysis in rice involves a physicochemical and sensory tests. In this study, morphologically different 60 rice landraces of Tamil Nadu along with ADT (R) 45 as a check variety were used for physicochemical analysis based on the amylose content (AC), gel consistency (GC) and gelatinization temperature (GT). Highly significant variation (p&lt;0.05) was observed among the 60 landraces for all the characters. Most of the landraces registered low amylose content. Nine landraces exhibited high and 18 landraces exhibited intermediate AC. In the case of a gel consistency, most of the landraces exhibited soft GC, while four landraces viz., Athur kichadi, Kavuni nel, Uppu mulagai and Valan registered medium gel. With respect to GT, all the landraces exhibited high to intermediate GT except Kattu ponni, Kavuni nel and Sugandni samba which were identified with low GT. The check variety exhibited intermediate amylose, soft gel and high gelatinization temperature. The landraces Chennellu, Kattu vanipam, Kichali samba, Kuttala samba, Pome, Revathi, Samba masanam, Saysree, Sembalai, Sivappu Kavuni, Soora kuruvai, Thailand Kavuni, Thanga samba and Thirupathisaram were identified as promising landraces based on intermediate amylose, soft gel consistency and intermediate gelatinization temperature. High genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) coupled with high heritability and high genetic advance as a percentage of mean were recorded in all three characters indicating additive gene action. This indicates that there was a low environmental influence on the expression of these characters and hence one can practice selection. The results of this study provide vital information on amylose content gel consistency and gelatinization temperature of various rice landraces which can be utilized in a breeding programme directed towards improving the cooking and eating quality. Landraces with high amylose content can be further studied for identifying landraces with high resistant starch and low Glycaemic Index. Key words: Amylose content, Gel consistency, Gelatinization temperature, landraces, rice

Rheological behaviors, structural properties and freeze-thaw stability of normal and waxy genotypes of barley starch: a comparative study with mung bean, potato, and corn starches.

The rheological behaviors, structural properties and freeze-thaw stability of starch isolated from Tetonia barley (Normal genotype, Reg. No. CV-334, PI 646199) and Transit barley (Waxy genotype, Reg. No. CV-348, PI 660128) were investigated, along with other common starch sources for comparison. Transit barley starch showed the highest loss tangents (tan δ) during a frequency sweep test, which suggested a predominance of elastic properties over viscous properties. However, the tan δ of Tetonia barley starch was similar to that of potato starch, which indicated more solidity in comparison to Transit barley starch. Transit barley starch had the highest gelatinization temperature and the lowest gelatinization enthalpy (P < 0.05). Moreover, Tetonia and Transit barley starches displayed weak diffraction peak intensities by X-ray diffraction analysis. Additionally, Transit barley starch showed the lowest % syneresis even when freeze-thawed up to five cycles (P < 0.05). However, Tetonia barley starch had the worst freeze-thaw stability (P < 0.05), which was verified via scanning electron microscopy analysis of freeze-thawed starch gels. The results of present study indicate that barley starch can be practically applied as a functional ingredient in some specialty starchy foods.

Evaluation of Physicochemical Properties of Starch from Brazilian Carioca Beans (Phaseolus vulgaris)

AbstractThe objective of this study is to characterize Carioca bean starch extract from selected cultivars and harvests in different crop years. The starch is analyzed for amylose content, granule morphology, thermal transition (gelatinization and dissociation of retrograded starch), pasting properties, and in vitro digestibility. Carioca bean starch presents high levels of amylose, ranging from 40.06% to 42.60%. The thermal transition study demonstrates high gelatinization temperatures, from 70.8 to 76.6 °C and intense retrogradation. In vitro digestibility of the granular starch evidenced a high content of resistant starch. It is demonstrated for the first time that different cultivars from Brazilian Carioca beans as well as cultivation in distinct crop years are associated with slight differences in the physicochemical characteristics of their starches.

Effects of heat moisture treatment on the structural, physicochemical and digestibility properties of potato starch–soybean peptide complexes

SummaryIn this study, potato starch (PS) was complexed with soybean peptides (SPTs) with different molecular weights under heat moisture treatment (HMT) at different moisture contents. The results showed that PSSPT complexes formed under HMT were characterised by weaker and fuzzier polarised cross patterns, and more agglomerates. After HMT, higher gelatinisation temperatures and lower enthalpies were observed for PSSPT complexes. In particular, higher gelatinisation temperatures were observed when moisture levels were higher during HMT. Compared with physically mixed counterparts, the PSSPT complexes under HMT displayed higher pasting temperatures and lower swelling power, and peak viscosity. Higher moisture content during HMT led to a less thermodynamically stable B‐polymorphic structure converting to a more stable A‐type polymorph. Higher SDS content was found in the PSSPT complexes subjected to HMT with lower moisture content, while relatively higher RS content was associated with higher moisture content of HMT. These results could be attributed to restructuring of the amylose/amylopectin chains, the physical barrier of SPT and interactions between the negatively charged groups in PS and the side chains in SPT. This study will advance our understanding of food multicomponent interactions, as well as guidance for the application development of low‐glycaemic index foods containing SDS and RS in the field of fine food processing.

Molecular characteristics and physicochemical properties of very small granule starch isolated from Agriophyllum squarrosum seeds

Novel starch resources isolated from accessible botanical origins are of special interest to food scientists in the context of food security. In this study, Agriophyllum squarrosum starches (AS-1, AS-2, and AS-3) were isolated from three ecotypes of A. squarrosum seeds and compared with quinoa starch (QS). The mean particle diameter of AS granules ranged from 1.12 to 1.15 μm, and AS amylopectin had a significantly higher Mw than QS (p < 0.05). Compared with QS, AS samples had more branching and substitution of amylopectin structures. The peak viscosity, breakdown viscosity, and swelling degree of the AS samples were significantly lower than those of QS (p < 0.05). AS showed a lower crystalline degree and higher gelatinization temperatures, and the freshly cooked AS showed a slower digestibility rate than QS. The physicochemical properties and chain profiles of AS facilitate the application of AS and the domestication of A. squarrosum crops.

Green banana starch enhances physicochemical and sensory quality of baru almond‐based fermented product with probiotic bacteria

SummaryThis study aimed to isolate and characterise green banana starch (GBS) and to investigate the effect of adding 0%, 1.5%, 3.0%, 4.5% and 6.0% GBS on physicochemical and sensory properties of a fermented product based on baru almond (Dipteryx alata Vogel) water extract with probiotic bacteria. GBS showed high gelatinisation temperature (73.37 °C), enthalpy (16.61 J g−1) and final viscosity (239.6 RVU). On the contrary, it showed a low tendency to retrograde (67.53 RVU), water solubility (0.02%), water absorption (1.85 g g−1) and gel hardness (6.7 N). Higher addition levels of GBS increased firmness, reduced syneresis and positively affected pH, titratable acid, soluble solids and colour of baru almond‐based fermented products. The incorporation of 4.5% GBS was well accepted and preferred over the control sample (no GBS addition). GBS can be used as a natural thickener. The baru almond‐based fermented product with 4.5% GBS stands out for having potential probiotic properties and for being a promising dairy alternative.

Starch structure-property relations in Australian wild rices compared to domesticated rices

There are many genetic differences between Australian wild rices (AWRs) and domesticated rices (DRs), causing differences in starch molecular structure and starch-related functional properties; these are examined here for polished AWRs and polished DRs. Starch structural parameters for amylopectin and amylose were obtained using size-exclusion chromatography, with and without enzymatic debranching. Thermal properties of starch, in-vitro digestibility and texture of three AWRs were measured and compared to those of typical DRs. The results showed that AWR starches had (a) higher amylose content than most DRs, resulting in a higher gelatinization temperature, (b) fewer amylopectin short chains, causing a higher gelatinization enthalpy, and (c) more amylose shorter chains and more amylopectin longer chains, both causing a slower in-vitro digestion rate. The textural characteristics of AWRs are not significantly different from those of DRs. These findings suggest that AWRs are a potential source of nutritionally-desirable but palatable slowly-digestible starch.

Traditional sour cassava starch obtained with alterations in the solar drying stage

After natural fermentation and solar drying, sour cassava starch acquires expansion property. Traditionally, solar drying occurs without protection, and consequently physical contamination can arise. Thus, the aim of this study was to produce sour cassava starch using a low-cost solar dryer to prevent contamination, whilst retaining the expansion property. The samples were characterized in relation to chemical composition, microscopy and physical contaminants, as well as expansion, thermal, pasting, structural and technological properties. In addition, biscuits were prepared and compared with commercial samples. The solar dryer provided faster drying and lower moisture levels than the control. The specific volumes of the sun-dried products were similar to the control, with minimized contamination. The granules of the starches showed slight erosion on their surface, which was probably due to amylolytic enzymes. X-ray diffraction showed a typical A-type pattern. DSC analysis resulted in higher gelatinization temperatures and enthalpy changes for the sour cassava starch. The pasting properties showed a reduction in the viscosity peak at neutral pH. Although the cassava starch biscuits made with sour cassava starch dried in the solar dryer presented lower expansion levels in relation to the other biscuits produced with commercial sour cassava starch, they had desirable sensory characteristics.

Effects of alternate wetting and drying irrigation management and air temperature during grainfill on rice grain physicochemical and functionality traits of US inbred varieties

AbstractBackground and objectivesDeclining irrigation resources and warming cropping seasons present challenges to rice production. The alternate wetting and drying (AWD) management system conserve water, but its impact on rice grain quality is not well understood. To determine the effects of AWD irrigation management and varying seasonal temperatures on rice grain quality, a field experiment with two AWD irrigation methods and continuous flood (CF), as a control, was conducted in one year. Two environmental temperatures were observed as a result of two plating dates, one month apart.FindingsResults revealed that AWD relative to CF, at either planting date, had minimum effect on grain quality traits of seven US varieties having diverse physicochemical and functional properties. On the other hand, mild warmer air temperatures that occurred during the grainfill period of the first planting were associated with lower head rice yield and higher chalkiness in brown and milled rice of some US varieties. The functional traits of apparent amylose content of low amylose varieties, Tp of a high gelatinization temperature variety, and total carbon were sensitive to air temperature changes during grain development.ConclusionsAWD had no significant impact on rice grain quality, while some US varieties were more resilient to warmer temperature during grainfill on milling yield, chalk, and functional traits.Significance and noveltyThis study demonstrated that rice varieties can withstand moderate soil moisture stress from AWD management with minimum negative effects on grain appearance traits and functional properties.

Profil Gelatinisasi dan Sifat Fisik Tepung Campolay Masak Penuh dan Lewat Matang (Pouteria campechina) Gelatinization Profiles and Physical Propertis of Ripe and Over Ripe Canistal Flour (Pouteria campechiana)

This research aims to study gelatinization profile and physical properties of ripe and overripe canistel flour. Data statistically analyzed using the independent sample T-tes. Analyzed of the chemical properties of canistel fruits include water content, starch content, and sugar content, while analyzed canistel flour includes gelatinization profile, shape and size of starch granules with color test. The results of the analyzed showed that the water content and sugar content of ripe canistel fruit is higher than those of overripe canistel fruit, while the lower starch content. The total starch and amylose content of ripe canistel flour is higher than that of overripe flour. Analyzed the results of gelatinization profile ripe canistel flour has a peak viscosity, final viscosity, and higher gelatinization temperature than the finished canistel flour and the gelatinization faster time. Analysis of the physical properties of the color parameters of canistel flour produces the reddish yellow color, while of the shape and size of the canistel flour starch granule shape that are round with size ranges between 2-7 µm.Keywords: Canistel fruit, canistel flour, gelatization profile.

Annealing process improves the physical, functional, thermal, and rheological properties of Andean oca (Oxalis tuberosa) starch

AbstractThe characteristics of a native starch limit its application in the food industry; for this reason, it is important to investigate alternatives for obtaining modified starches with better characteristics and more possibilities of application. Oca (Oxalis tuberosa) starch was subjected to annealing process with a temperature of 42 and 50°C and starch:water ratios of 1:6 and 1:2 during 24 hr. The effects of the annealing process on thermal, structural, and rheological properties were investigated. The annealing at 50°C and 1:6 (starch:water) ratio yielded a starch with high peak viscosity, stability ratio, gelatinization temperature, and gel firmness, but low solubility and low swelling power. All annealed starch gels had a more elastic behavior (G′ &gt; G″), lower viscosity and greater stability to retrogradation compared to native starch. The annealing process caused the rearrangement of amylopectin and amylose in the starch granule, obtaining a more orderly structure, which increased the thermal stability and functional properties of oca starch.Practical applicationsFew studies have been reported on chemical, physical, or enzymatic modification of native starches using the annealing process, none on oca starch. The annealing process improves the thermal stability and functional properties of oca starch, which can expand its application in the food industry. The starch produced in this work can be used as raw material for noodles, gluten‐free bakery products, and as a thickening agent.

Study on enhanced mechanical, barrier and optical properties of chemically modified mango kernel starch films

The main aim of this study was to chemically modify mango kernel starch (MKS) and assess its impact on packaging film properties. MKS exhibited limited application due to low solubility, retrogradation, higher gelatinization temperature and hydrophilicity. These limitations could be effectually overcome by integrating modifications to native starch. Chemical modifications of MKS were performed by oxidation and benzylation with a low degree of substitution. X‐ray diffractogram presented A‐type pattern of crystal structure which was in accordance to endosperm starch. Fourier‐transform infrared (FTIR) spectra of the native and modified starch samples exhibited strong bands in the regions corresponding to OH and CH stretching. Additionally, absorption bands were found in the regions for carbonyl and aromatic phenyl vibrations signifying the substitution of functional groups within native starch. Modified starch films presented increased lightness L* representing that the films were lighter in colour than native film. Tensile strength (TS) of modified films was found to increase more than twice that of native starch film. Starch recrystallization was interrupted by oxidation thereby preventing retrogradation. Benzylation lowered the water vapour permeability by 58% and improved UV absorption by 80% when compared with native film.

Physicochemical, crystalline characterization and digestibility of wheat starch under superheated steam treatment

This paper explored the impact of superheated steam (SS) treatment on the physicochemical, crystalline characteristics and in vitro digestibility of wheat starch. Upon SS treatment, treated samples showed lower swelling power, solubility, and viscosities, but had higher gelatinization temperature, which might be due to the partial gelatinization of starch granules. This agreed with micromorphology characterization, indicating the degradation of Maltese cross. In addition, SS treatment decreased the long-range crystalline and short-range order of starch, compared to native starch sample. This change of physicochemical and structural properties was responsible for the decrease of starch hydrolysis rate. Meanwhile, SS treatment obviously increased the slowly digestible starch (SDS) and resistant starch (RS) content from 10.6% to 7.9% (native starch) to 17.2% and 13.6% (150 °C, 1 min), respectively. This knowledge indicates that superheat steam technology possibly is a promising strategy in starch modification.