Small Starch Granules Research Articles

Characterization, Functional Properties, and Resistant Starch of Freshwater Macrophytes.

Several aquatic macrophytes such as Colocasia esculenta, Eleocharis dulcis, Nelumbo nucifera, Sagittaria sagittifolia, Trapa bispinosa, and Typha angustifolia possessed carbohydrate mainly in their storage and reproductive parts. Starch morphology, total starch, and amylose content of these six freshwater plant species were determined. Their functional properties, i.e., starch crystallinity, thermal properties, and rheological behaviour were assessed. Large starch granules were in N. nucifera rhizome (>15 μm), medium-sized was N. nucifera seed (8-18 μm), while the rest of the starches were small starch granules (<8 μm). Shapes of the starch granules varied from oval and irregular with centric hilum to elongated granules with the eccentric hilum. Eleocharis dulcis corm starch had significantly higher total starch content (90.87%), followed by corms of C. esculenta (82.35%) and S. sagittifolia (71.71%). Nelumbo nucifera seed starch had significantly higher amylose content (71.45%), followed by T. angustifolia pollen (36.47%). In comparison, the waxy starch was in N. nucifera rhizome (7.63%), T. bispinosa seed (8.83%), C. esculenta corm (10.61%), and T. angustifolia rhizome (13.51%). Higher resistant starch was observed mostly in rhizomes of N. nucifera (39.34%)>T. angustifolia (37.19%) and corm parts of E. dulcis (37.41%)>S. sagittifolia (35.09%) compared to seed and pollen starches. The XRD profiles of macrophytes starches displayed in all the corms and N. nucifera seed had A-type crystallinity. The T. bispinosa seed had CA-type, whereas the rest of the starches exhibited CB-type crystallinity. Waxy starches of C. esculenta corm had higher relative crystallinity (36.91%) and viscosity (46.2 mPa s) than regular starches. Based on thermal properties, high-amylose of N. nucifera seed and T. angustifolia pollen resulted in higher gelatinization enthalpy (19.93 and 18.66 J g−1, respectively). Starch properties showed equally good potential as commercial starches in starch-based food production based on their starch properties and functionality.

Effects of Reduced Nitrogen Fertilization and Irrigation on Structure and Physicochemical Properties of Starch in Two Bread Wheat Cultivars

Nitrogen (N) fertilization and irrigation are significant agronomic factors affecting wheat production, but little information is available on the effects of reduced N fertilization and irrigation on internal starch structure and physicochemical properties associated with the quality of wheat-based foods. In this study, reduced N fertilization and irrigation were separately applied to investigate their effects on composition and morphological changes, crystalline and external region structure features, swelling power, and gelatinization characteristics of starch granules in bread wheat, with a high N-use-efficiency and water-saving wheat cultivar Zhongmai 175 and a widely grown cultivar Jingdong 17. Compared with a non-N control, reduced N fertilization did not change the crystallinity type and short-range ordered degree of starch; however, it significantly increased relative crystallinity, swelling power and gelatinization enthalpy, whereas amylose content and transition temperatures were decreased. Under reduced irrigation, more small starch granules with compact arrangements appeared in comparison with non-water control. Relative crystallinity, swelling power and gelatinization enthalpy of starch were increased, whereas short-range ordered degree and transition temperatures were decreased. Moreover, the starch of the two cultivars appeared to differ in response to both the N and water treatments. The findings indicated that reduced N fertilization or irrigation markedly influenced the structure and physicochemical characteristics of wheat starch, providing important information for developing elite cultivars with high N and water use efficiency and outstanding starch quality.

Granule size distribution and pasting properties of starch in normal, waxy and sweet maize kernels

The granule size and pasting properties of starch and their relationship with quality of maize (Zea mays L.) was investigated. A clear bimodal distribution of granule sizes was found in six cultivars of maize. A number of starch granules were made up of small starch granules in kernels. Normal maize had a smaller proportion of granules &lt;12 μm and a greater proportion of granules &gt;12 μm, whereas sweet maize had a greater proportion of granules &lt;12 μm and a smaller proportion of granules &gt;12 μm. The peak, trough and breakdown viscosities were found higher in waxy maize and lower in sweet maize. The final and setback viscosities were found higher in normal maize and lower in sweet maize. The peak, trough, final and setback viscosities were significantly and negatively correlated to volume percentage of granules &lt;12 μm and significantly positively correlated with the volume percentage of granules &gt;12 μm.

A study on the functional components and health effectiveness of germinated Oryza sativa L. ‘Superhongmi’

This study compares the changes in antioxidant activity, starch molecules, and functional components, including the content of amino acids, minerals, phenolic compounds, phytic acid, and GABA, of pigmented rice cv. ‘Superhongmi’ and brown rice following germination. The results showed that germinated ‘Superhongmi’ had augmented phenol compounds, phytic acid, GABA, and γ-oryzanol, as well as higher antioxidant activity (ABTS, DPPH, and superoxide dismutase like) compared with germinated brown rice. Furthermore, smaller starch granules and less starch crystallization were observed in ‘Superhongmi’ than brown rice after germination. Germination converts the rice grains into an easily digestible nutrient source and germinated ‘Superhongmi’ can be used as a nutritional ingredient for a healthy diet.

Analysis of development, accumulation and structural characteristics of starch granule in wheat grain under nitrogen application

Nitrogen is one of the most important nutrients for wheat growth and has a critical influence on yield and quality. This study aims to examine how medium nitrogen level (240 kg/hm2) affects the starch granule development, starch accumulation, and structural characteristics of wheat starch. The results showed that nitrogen treatment could reduce the biosynthesis of starch and amylose, delay the degradation of starch in pericarp, and promote the proportion of B-type small starch granule in endosperm compared with those in the N0. In addition, the composition and distribution of starch granules were changed, the crystal structure in the inner lamellae and ordered structure in the external region of starch granules were affected, and the swelling power and solubility of starch during wheat development were increased. The effect of nitrogen treatment on the mRNA expression of enzymes related to starch biosynthesis or degradation varied in different developmental stages. During middle and later grain filling stages, AGPase, GBSSI, and GBSSII were lower, and SSS, SBE, and DBE were higher in N240 than in N0. This study indicated that nitrogen application at booting stage significantly affected the structural characteristics of starch, and ultimately determines its quality.

Light-induced ultrastructure changes of amyloplasts and effect of nitrogen fertilization on greening in potato tubers (Solanum tuberosum L.)

Abstract Tuber greening causes potato quality decline and economic loss. We investigated physiological mechanisms of greening by fluorescence and transmission electron microscopy. We then explored the effect of nitrogen level (0, 210, and 315 kg N ha−1) on starch granule size and tuber greening of three commercial cultivars. Results showed that chlorophyll content of tuber skin increased (5–8 times) in a quadratic manner with increasing duration of light exposure (0–7 d) in all cultivars. Light-induced greening occurred in cortical parenchyma 0–1.5 mm below the periderm, where chloroplast auto-fluorescence was evident under ultraviolet light. The greening process involved membrane lose, starch granule dissolution, and grana formation in amyloplasts, along with chloroplast development. Formation of grana lamellae was observed around amyloplasts with a diameter of 9–30 μm. Nitrogen application increased the percentage of small granule starch (

Brassinosteroid receptor mutation influences starch granule size distribution in barley grains

Brassinosteroids (BR) are plant-based steroids which influence several morphogenetic and developmental processes. A barley (Hordeum vulgare L.) genotype Kinai Kyoshinkai-2 (KK-2) carrying the uzu mutation exhibited altered starch granule size distribution. Hybridizing KK-2 with a barley genotype CDC Kendall with bi-modal starch granules produced progeny lines (116, 144 and 168) with almost uni-modal starch granules. Bioassays correlated uzu mutation with defective BR perception. DNA sequence analysis of the BR receptor-1 (BRI-1) gene detected a single-nucleotide A > G substitution at the position 2612 in the kinase domain which resulted in the change of His (CAC) to Arg (CGC) at residue 857 in subdomain IV of the kinase domain of the respective polypeptide. The study focused on the development of barley grain, accumulation of starch and composition influenced by defective BR perception due to the mutation detected in KK-2 and three other barley-breeding lines (116, 144 and 168). Aberrant BRI-1 delayed grain development, amylose synthesis and starch accumulation in the endosperm. The barley breeding lines 116, 144 and 168 carrying the aberrant BRI-1, exhibited altered granule size distribution with significant shift in the diameter maxima, but insignificant differences in amylose concentration. The BRI-1 mutation also altered amylopectin fine structure in both B- and C- type small starch granules, resulting in an increased fraction of short A-type glucan chains (<10 DP) and decreased fraction of B2 chains (25–36 DP) in genotypes carrying the BRI-1 mutation. The results show the influence of BR on barley grain development, starch accumulation, granule size distribution and amylopectin structure.

Pasting, thermal and rheological properties of octenylsuccinylate modified starches from diverse small granule starches differing in amylose content

Waxy maize (a standard starch of normal granule size) and five small granule starches from different botanical sources (rice, wheat B type, oat, quinoa and amaranth) were subjected to 2-octenyl-1-succinic anhydride (OSA) modification. Changes of pasting, gel texture, thermal and rheological properties were investigated. Different small granule starches showed quite different property changes after OSA modification. Pasting viscosity was generally increased in OSA starches, among which OSA oat starch had notably high peak and breakdown viscosity but low setback viscosity. Gel hardness of rice, wheat B type, oat and quinoa starches was reduced by OSA treatment, whereas that of waxy maize and amaranth starches was increased. Amylose content was considered to be the major factor influencing pasting, gel and thermal property of OSA starches. Esterification increased pseudoplastic flow behavior of all starches, while OSA oat starch uniquely had reduced flow consistency coefficient. The dynamic rheological properties were also changed differentially among OSA starches. Viscoelastic properties of rice, wheat B type, oat and quinoa starches were increased after OSA treatment, whereas those of waxy maize and amaranth starches were decreased. This study showed that diverse functionalities from OSA small granule starches may fulfil different demands in product development.

Characteristics of grain quality and starch fine structure of japonica rice kernels following preharvest sprouting

Preharvest sprouting (PHS) is one of the most serious defects that impacts rice production and grain quality. Knowledge about the effects of PHS on the eating and cooking quality (ECQ) of milled rice is limited. Here, we selected four japonica rice varieties to study the influences of PHS on grain quality. The results showed that PHS strongly led to poor grain appearance and the development of small starch granules whose surfaces were eroded. Analysis of starch fine structure revealed that PHS resulted in amylose (AM) degradation; in particular, PHS caused a decrease in the content of long AM chains. Moreover, PHS led to a decrease in the content of short amylopectin (AP) chains in the varieties Yandao 815 (YD815), Wuyugeng 27 (WY27) and Yangeng 13 (YG13), while the variety Sidao 785 (SD785) displayed the opposite trend. We propose that the main reasons for the decrease in starch crystallinity and the pasting profiles of the germinated rice were due to both the tendency of the AM content to decrease and the degree of this decrease in the content of the different AM chains along with changes in AP and other major components. All these changes caused by PHS led to a decrease in both ECQ and palatability of milled rice.

Starch Characteristics, Sugars and Thermal Properties of Processing Potato (Solanum tuberosum L.) Cultivars Developed in Korea

Seven processing potato (Solanum tuberosum L.) cultivars were evaluated for biochemical properties, starch morphology, crystallinity and thermal properties. One-way ANOVA results indicated a significant difference in those quality properties of individual potato cultivar. Dry-matter, total starch, and reducing sugar contents were ranged in 21.34 ~ 24.88%, 15.6 ~ 18.3%, and 0.24 ~ 1.09%, respectively. Glucose and fructose contents were ranged in 1.03 ~ 5.28% and 0.59 ~ 3.69 mg/g DW, respectively. Saebong, a round-oval shape with white-fleshed potato cultivar, was higher in dry-matter and total starch contents. The cultivars of Atlantic, Jinseon, and Saebong showed lower reducing sugar contents ranged in 0.24 ~ 0.27 mg/g DW. The extracted potato starches showed a similar morphology, which was round, oval or elliptical shape with mixed sizes of large, medium and small starch granules and glossy surface with regular pattern. The X-ray diffraction patterns were a typical B-type, which was generally observed in root plants. The major crystallinity peaks were at 5.5°, 14°, 17°, 19°, and 22° in 2Ɵ. There was a positive correlation between the onset temperature (To) with dry-matter and total contents, but a negative correlation with reducing sugar, glucose and fructose contents. The variations in physicochemical and starch properties of different potato cultivars could be directly related to the use of potato, which make them useful for industrial application.

Variation in amylose concentration to enhance wheat flour extrudability

Composition and functionality of five waxy wheat (Triticum aestivum L.) genotypes were elaborately investigated and related to end-product attributes of extrudates. As such, the interaction between starch biopolymers and protein in extrusion processing could be studied. Furthermore, the effect of an increasing amylose-concentration was studied by the use of blends. Waxy genotypes absorbed more water, gave rise to stiffer doughs and had higher onset and peak gelatinization temperature. In contrast, a lower pasting temperature and final viscosity and higher peak viscosity and breakdown could be observed. The volume percentage of small starch granules showed to be negatively correlated with peak temperature and positively with final viscosity and holding strength as well as with extrudate hardness. This was also positively correlated with amylose concentration. Expansion index was highest at a slightly decreased amylose concentration of 16.6%. Markedly higher moisture content for all amylose-free extrudates was attributed to a combination of increased solubility of amylopectin and reduced water evaporation at die emergence. It was hypothesized that an interplay with protein content and composition was laying at the basis of the observed differences. Moreover, the altered pasting behavior of waxy wheat may enhance the extrudability of gluten containing wheat flour.Starch granule size distribution is related to extrudate texture. Amylose content affects expansion index, water absorption and texture of extrudates. Interaction between starch content and protein composition and quality was observed. Waxy genotypes are strongly varying in their protein composition and functionality. Maximum expansion was obtained for blends containing 25% waxy flour.

Comparison of physicochemical properties of very small granule starches from endosperms of dicotyledon plants

In this study, 6 very small granule starches (VSGSs) were isolated from endosperms of dicotyledon Amaranthus cruentus, Agriophyllum squarrosum, Chenopodium quinoa, Euryale ferox, Mirabilis jalapa, and Vaccaria hispanica. Their morphologies and physicochemical properties were investigated. Most VSGSs with granule size <3 μm were spherical or polygonal, and their apparent amylose contents ranged from 19.4 to 33.1% with A. cruentus starch the lowest and E. ferox starch the highest. All VSGSs had the same A-type crystalline structure with relative crystallinities from 23.3 to 29.6%. Though 6 VSGSs had slight differences in short-range ordered structure and lamellar repeat distance, their lamellar peak intensities exhibited significant differences. The gelatinization temperatures showed significant differences among 6 VSGSs with C. quinoa starch the lowest and M. jalapa starch the highest. The 6 VSGSs had significantly different pasting viscosities with peak viscosities from 1887 to 4579 mPa s, hot viscosities from 1704 to 3479 mPa s, breakdown viscosities from 56 to 1170 mPa s, final viscosities from 2419 to 4811 mPa s, and setback viscosities from 715 to 1821 mPa s. The digestion properties of starches were significantly different among 6 VSGSs. The above results could provide some references for applications of these VSGSs.

Composition of hairless canary seed oil and starch-associated lipids and the relationship between starch pasting and thermal properties and its lipids

Hairless canary seed was recently approved as a novel food. It has great potential as a source of small starch granules but none is reported about its starch lipids. This study investigated composition of lipids from wholegrain flour and starch granules of two hairless canary seed varieties. This is the first study to determine starch lipids in canary seed and their relationships to starch properties. Canary seed had oil yields of 73 and 49 g/kg subject to the extraction method and solvent type. The major fatty acids in oil were linoleic, oleic and palmitic. Canary seed starch surface lipids were higher than that of wheat starch and comprised of free fatty acids, triacylglycerols and fatty acid alkyl esters with palmitic, linoleic, oleic and stearic being the main fatty acids. The internal starch lipids were also higher than that of wheat starch consisting of monoacyl lipids and free fatty acids with palmitic, linoleic and oleic present as the dominant fatty acids. Starch surface and internal starch lipids and their fatty acids significantly correlated with most of starch pasting and gelatinization properties. The results suggest a role for starch lipids in determining functionality of starch, and eventually its utilization in food applications.

Effect of small granules in potato starch and wheat starch on quality changes of direct heated surimi gels after freezing

The effects of small granule starches on the changes in quality of direct heated surimi gels after freezing and thawing were evaluated by comparing four varieties of starch: native potato starch (PN), native wheat starch (WN), potato and wheat starches with small granules separated from native starches (PS and WS). PS and WS absorbed less water and had a lower water-absorbing ability during the thermal processing, which caused the formation of smaller ice crystals, less structural damage, lower drip loss and less textural changes after freezing and thawing. In addition, due to the large granule size of two potato starches, large ice crystals and voids, more drip loss and structure changes were observed in surimi gels containing two potato starches than that containing two wheat starches. Results indicated that addition of small granule starch could reduce the quality changes of direct heated surimi gels after freezing and thawing.

Effects of high temperature during two growth stages on caryopsis development and physicochemical properties of starch in rice

Global warming may affect the development of rice at different growth stages, thereby decreasing rice yield and deteriorating grain quality. The difference in rice responses to high temperature during primordial differentiation (PD) and pollen filling (PF) stages has been rarely studied. In this paper, two temperature treatments (40 °C and 30 °C) at the two stages (PD and PF) were imposed to four rice groups under the controlled temperature chambers. Compared with rice under normal temperature, high temperature-stressed rice showed accelerated growth rate, smaller caryopsis and decreased yield. Moreover, high temperature affected the starch physicochemical properties, resulting in lower apparent amylose content and higher order degree, gelatinization temperatures, and thereby increased peak, trough and final viscosities in starch. High temperature during PD stage inhibited cell development and starch deposition, thus leading to small starch granule and low retrogradation. However, temperature-stressed rice during PF stage showed increased starch accumulation and larger granule size. Therefore, effects of high temperature during the two stages on caryopsis development and starch properties were partly similar but also notably different. These results enriched and deepened the study of high temperature-stressed rice and served as an important reference for the processing and utilization of rice starch in food industry.

Octenylsuccinylation differentially modifies the physicochemical properties and digestibility of small granule starches

The impact of starch granule size on 2-octenyl-1-succinic anhydride (OSA) modification remains unclear. To investigate changes of structural, physicochemical, digestibility and emulsifying properties due to OSA modification, five small granule starches (from wheat, rice, oat, quinoa and amaranth) were selected and compared with a standard large granule starch (waxy maize). OSA starches were prepared in 3% (volume by weight) OSA reagent with continuous stirring for 6 h under constant pH of 8.5. The hypothesis was that property changes induced by OSA treatment can be more efficiently achieved in small granule starches (< 10 μm diameter). Small granule OSA starches generally had greater emulsion stability, swelling power and digestibility after gelatinization than waxy maize OSA starch, likely due to the unique physical properties and specific molecular structures of small granule starches, i.e. low sedimentation coefficient, low DP of amylopectin and highly branched amylopectin with short chain length. Granule sizes of OSA starches significantly impact on swelling power, amylose leaching, digestibility and emulsifying capacity, but to different extents depending on botanical origin.

Observation of the Optical &amp; Chemical Properties of Starch Granules

Starch granules in fresh and processed foods are routinely identified by a variety of chemical and microscopic methods. In the teaching laboratory, the use of cross-polarized light in a microscope (monocular or binocular) quickly demonstrates the presence of starch granules by their characteristic birefringence, often called a Maltese cross. In the present study, we first identified raw potato starch granules by their birefringence, followed by three overlapping chemical methods to confirm the presence (or absence) of starch. First, Lugol's iodine solution, a starch indicator, immediately stained the granules black. Second, amylase digested the small starch granules within 30–60 minutes. Third, glucose test strips demonstrated the presence of glucose that resulted from the enzymatic breakdown of starch granules by amylase. Fourth, we also confirmed that the starch granules were broken down by the enzyme amylase by observing the “digested” product under crossed polarization and noting the disappearance of the birefringent effect. Although the demonstration of starch has long been a staple in teaching laboratories, we have combined the optical and chemical demonstrations of starch for the same lab, with each serving as a confirmation for the other.

Accurate quantification of small and large starch granules in barley and malt

The proportion of small and large starch granules in barley and malt is often neglected, leading to underestimation of their importance in processes in which they are used. This study aimed to accurately determine the volume and number based percentages of small and large starch granules for three barley varieties, their micro-malted malts and three commercial malts. Quantitative starch isolation was performed and starch granule proportions were estimated using microscopic and image analysis, taking the non-sphericity of the large starch granules into account. Results show that barley starch consists of 32–39 volume% of small starch granules. Upon malting, this percentage is reduced to 17–27 volume%, showing that small granules are hydrolyzed faster than large granules during this process. The analyzed commercial malt samples have a small starch granule content of 22–25 volume%. Malt hence still contains a substantial amount of small starch granules, which can be expected to impact processing.

Cooking, morphological, mechanical and digestion properties of cooked rice with suppression of starch branching enzymes

Kernel components and some physicochemical properties of cooked rice were investigated and compared between a popular japonica rice Wu-xiang 9915 (WX) and its transgenic line (WX-SBEI/IIb−) with suppression of starch branching enzyme I/IIb. The starch content, especially amylopectin content, was significantly lower in WX-SBEI/IIb− than in WX. Brown rice flour had markedly higher gelatinization temperature in WX-SBEI/IIb− than in WX. The cooked kernels of WX-SBEI/IIb− had significantly lower volume swelling, leached material amount and wet weight than those of WX during cooking. Starch granules in WX kernel could be gelatinized completely and gradually from the exterior to the interior of endosperm, leading to breakage of cooked kernels. However, aggregate, elongated and small starch granules in the exterior of WX-SBEI/IIb− endosperm could not be gelatinized completely and remained their morphologies during cooking, leading to a high resistance of kernels to cooking. Brown rice flour of WX-SBEI/IIb− had significantly lower pasting viscosities, storage modulus and loss modulus but higher loss angle tangent than that of WX. The cooked kernels of WX-SBEI/IIb− had considerably higher hardness, springiness and cohesiveness but lower adhesiveness than those of WX. The starch in cooked kernels was more resistant to digestion in WX-SBEI/IIb− than in WX.

Different gelatinization characteristics of small and large barley starch granules impact their enzymatic hydrolysis and sugar production during mashing

This study investigates the impact of different gelatinization characteristics of small and large barley starch granules on their enzymatic hydrolysis and sugar production during mashing. Therefore, a barley malt suspension was consecutively incubated at 45, 62, 72 and 78 °C to monitor starch behavior and enzymatic starch hydrolysis and sugar production. The combination of microscopic and rapid visco analyses showed that small starch granules persisted longer in the system and were present non-gelatinized at temperatures higher than 62 °C. HPAEC-PAD analysis showed that 8% of the total amount of starch, predominantly small granules, gelatinized at temperatures between 62 °C and 78 °C. Due to their delayed gelatinization in this system, their enzymatic hydrolysis yielded relatively more dextrins compared to what was observed for large granules. It was concluded that small granules should be taken into account when optimizing enzymatic hydrolysis of barley starch, like in brewing, distilling or bio-ethanol production.