•Kernel morphology and starch properties of cooked high-amylose rice were studied.•Starches with different shapes had different properties during cooking process.•The elongated and interior hollow starches kept their intact status during cooking.•The molecular weight distribution of starch in cooked kernel did not change.•Starch in cooked kernel was not wholly disrupted and highly resistant to digestion.Rice is principally consumed as cooked kernels. A high-amylose rice line, TRS, has a potential to positively impact human health. Though the properties of starch isolated from TRS kernels have been studied, the properties of cooked kernel remain to be resolved. In this study, the changes in kernel morphology and starch properties of brown TRS were investigated during cooking in boiling water. TRS kernel, which had polygonal, aggregate, elongated, and interior hollow starches from the inner to the outer of endosperm, showed different gelatinization properties during cooking. The polygonal starch was gelatinized most completely and fastest, the aggregate starch was partly gelatinized, and the elongated and interior hollow starches kept almost their intact status. The molecular weight distribution of starch in kernel did not show significant change, but starch crystalline structure was not wholly disrupted during the cooking process. The starch in cooked kernel had a very high resistance to digestion.Download high-res image (261KB)Download full-size image

•C-type starch with spherical shape and central hilum was isolated from A. fortunei.•Starch contained two groups of granules with different gelatinization temperatures.•Group 1 and 2 accounted for 45.5% and 54.5% of total granule number, respectively.•The Group 1 and Group 2 granules corresponded to B-type starch and A-type starch.•Group 1 and 2 granules had no difference in morphology, size, and amylose content.Starch was isolated from root tuber of Apios fortunei. Its morphology, thermal properties, and crystalline structure were investigated in this study. The results showed that the starch had spherical, polygonal, and ellipsoidal granule shapes with central hila, showed two separate gelatinization peaks, and exhibited C-type crystallinity. Hot stage microscope observation showed that starch could be divided into two groups of granules with low and high gelatinization temperatures, and the Group 1 and 2 granules accounted for 45.5% and 54.5% of the total granule number, respectively. The gelatinization peak temperatures of Group 1 and 2 starch granules changed from 68.3 to 66.6 °C and from 75.4 to 82.7 °C with the increase of KCl concentration in water from 0 to 2 M. The Group 2 starch granules were further separated from starch through gelatinizing Group 1 granules at 78 °C in 2 M KCl, and displayed intact granular shape, A-type crystallinity, and single gelatinization peak. The Group 1 and 2 starch granules corresponded to B- and A-type starches, respectively, but had no differences in morphology, size, and amylose content. The above results showed that the A- and B-type allomorphs of C-type starch from A. fortunei were distributed in the different starch granules.Download high-res image (224KB)Download full-size image

•C-type starch contains A- and B-type polymorphs and has special properties.•Plant source, morphology, structure, properties of C-type starch are reviewed.•C-type starches with different shapes and hila have specific allomorph distribution.•Environment affects the proportion of A- and B-type polymorphs in C-type starch.•Research on how to better understand and utilize C-type starches is suggested.Amylopectin forms A- and B-type crystallinity in native starch. Starches in higher plants are classified into A-, B-, and C-type starches according to their crystalline types. A- and B-type starches contain only A- and B-type crystallinity, respectively, but C-type starch contains both A- and B-type crystallinity. Therefore, C-type starch is more complex than A- and B-type starch, and has special properties according to the distribution and the proportion of A- and B-type polymorphs. Compared with A- and B-type starches, which have been widely studied and utilized, C-type starch is little reported, especially in allomorph distribution. This review summarizes the progress of C-type starch, including plant source, morphology and size, molecular structure, allomorph distribution, physicochemical property, environment effect, and modification of C-type starch. Some plant seeds, tubers, rhizomes, roots, and fruits contain C-type starches. Their morphology and size, molecular structure, allomorph distribution, and properties are significantly different due to their different plant sources. Environment has obvious effects on the proportion of A- and B-type polymorphs and the physicochemical properties of C-type starch. Some modifications of C-type starch have been summarized. Future research directions on how to better understand and utilize C-type starches are suggested.Download high-res image (96KB)Download full-size image

•Structures and functional properties of normal rice starches were investigated.•Morphology, size, and crystal type did not significantly varied among rice starches.•Starches had different molecular and crystalline structure and functional property.•Amylose was positively relative to gelatinization and water solubility.•Amylopectin short branch chain was positively relative to hydrolysis and digestion.The structures (morphology, molecule, and crystallinity) and functional properties (gelatinization, hydrolysis, and in vitro digestion) of normal rice starches with different amylose contents were investigated and their relationships were analyzed. The results showed that the morphology, granule size, and crystalline type did not significantly change among rice starches. The molecular structure (amylose content, amylopectin branch-chain content, and amylopectin branching degree) and crystalline structure (relative crystallinity, IR ratio of 1045/1022 cm−1, lamellar peak intensity, and lamellar distance) significantly varied among rice starches, which resulted in different functional properties. The gelatinization temperature and water solubility were significantly positively correlated with amylose content but significantly negatively correlated with amylopectin short branch-chain. The swelling power, hydrolysis and in vitro digestion were significantly positively correlated with amylopectin short branch-chain, relative crystallinity, IR ratio of 1045/1022 cm−1, and lamellar peak intensity but significantly negatively correlated with amylose content and lamellar distance.

•Lotus rhizome C-type starch was separated into five different size fractions.•Different size fractions had different shapes but the same crystallinity.•The granule size was positively correlated with the short-range ordered degree.•Gelatinization Tp, Tc and ΔT were negatively correlated with granule size.•Hydrolysis degree and digestion were negatively correlated with granule size.Lotus rhizome C-type starch was separated into different size fractions. Starch morphologies changed from irregular to elongated, ellipsoid, oval, and spherical with decreasing granule size. The small- and very-small-sized fractions had a centric hilum, and the other size fractions had an eccentric hilum. The different size fractions all showed C-type crystallinity, pseudoplasticity and shear-thinning rheological properties. The range of amylose content was 25.6 to 26.6%, that of relative crystallinity was 23.9 to 25.8%, that of swelling power was 29.0 to 31.4 g/g, and that of gelatinization enthalpy was 12.4 to 14.2 J/g. The very-small-sized fraction had a significantly lower short-range ordered degree and flow behavior index and higher scattering peak intensity, water solubility, gelatinization peak temperature, gelatinization conclusion temperature, consistency coefficient, hydrolysis degrees, and digestion rate than the large-sized fraction. Granule size significantly positively influenced short-range ordered structure and swelling power and negatively influenced scattering peak intensity, water solubility, hydrolysis and digestion of starch (p < 0.01).

•High-amylose maize starch had individual, aggregate and elongated granules.•Aggregate and elongated granules consisted of many subgranules.•Amylose was mainly distributed in the hilum region and circumference of granule.•Aggregate and elongated granules had higher amylose content than individual granule.•Aggregate and elongated granules showed high resistance to gelatinization.High-amylose cereal endosperm is rich in heterogeneous starch granules. In this paper, we investigated the morphology, structure and gelatinization properties of high-amylose maize endosperm starch. Starch had individual, aggregate and elongated heterogeneous granules. Most of individual granules were round with small size and had one central hilum. Aggregate and elongated granules consisted of many subgranules with central hila, and had irregular and rod/filamentous shapes, respectively. Iodine stained starch granules showed five types of polarization colors: blue, purple, fuchsia, dark red, and interior dark blue and exterior brown. Most of individual and aggregate granules had the color of dark red, that of elongated granules the color of interior dark blue and exterior brown. Amylose was mainly distributed in the hilum region and the circumference of starch granules. Aggregate and elongated granules had higher amylose content than individual granules. Elongated and individual granules had the highest and the lowest gelatinization resistance among high-amylose maize heterogeneous starch granules, respectively.

•Starch was isolated from yam rhizome, water chestnut corm, pea and faba bean seed.•Water chestnut and faba bean had CA-type starches, pea and yam had C-type starches.•Starches had different sizes, amylose contents, thermal and pasting properties.•Starches had different hydrolysis degrees of acid, α-amylase and amyloglucosidase.•Water chestnut starch was highly susceptible to heating, acid, enzyme hydrolysis.This study investigated the structural and functional properties of C-type starches from pea seeds, faba bean seeds, yam rhizomes and water chestnut corms. These starches were mostly oval in shape with significantly different sizes and contents of amylose, damaged starch and phosphorus. Pea, faba bean and water chestnut starches had central hila, and yam starch had eccentric hilum. Water chestnut and yam starches had higher amylopectin short and long chain, respectively. Water chestnut and faba bean starches showed CA-type crystallinities, and pea and yam starches had C-type crystallinities. Water chestnut starch had the highest swelling power, granule swelling and pasting viscosity, lowest gelatinization temperatures and enthalpy. Faba bean starch had the lowest pasting viscosity, whereas yam starch had the highest gelatinization temperatures. Water chestnut and yam starches possessed significantly higher and lower susceptibility to acid and enzyme hydrolysis, the highest and lowest RDS contents, and the lowest and highest RS contents, respectively.

•High-amylose TRS starch had higher resistance to alkali treatment than TQ starch.•Alkali treatment had no significant effect on the crystalline structure of starch.•Alkali treatment increased the hydrolysis of starch by HCl and amylolytic enzymes.•The 0.4% NaOH treatment affected morphology and SAXS peak intensity of starch.•TRS starch treated with 0.4% NaOH had lower AC, and higher To and Tp.Native starches were isolated from mature grains of high-amylose transgenic rice TRS and its wild-type rice TQ and treated with 0.1% and 0.4% NaOH for 7 and 14 days at 35 °C. Alkali-treated starches were characterised for structural and functional properties using various physical methods. The 0.1% NaOH treatment had no significant effect on structural and functional properties of starches except that it markedly increased the hydrolysis of starch by amylolytic enzymes. The 0.4% NaOH treatment resulted in some changes in structural and functional properties of starches. The alkali treatment affected granule morphology and decreased the electron density between crystalline and amorphous lamellae of starch. The effect of alkali on the crystalline structure including long- and short-range ordered structure was not pronounced. Compared with control starch, alkali-treated TRS starches had lower amylose content, higher onset and peak gelatinisation temperatures, and faster hydrolysis of starch by HCl and amylolytic enzymes.

Highlights•The gelatinization began from the end distant from hilum to the center of granule.•The crystallinity changed from C-type to A-type via CA-type during gelatinization.•The crystallinity, amylose and helix content significantly decreased after 70 °C.•The amorphous content and ratio of 1022/995 cm−1 increased after 70 °C.•The peak intensity of crystalline lamellae significantly decreased after 70 °C.The allomorph distribution and granule structure of C-type starch from lotus rhizomes were investigated using a combination of techniques during gelatinization. The disruption of crystallinity during gelatinization began from the end distant from the eccentric hilum and then propagated into the center of granule. The periphery of hilum end was finally gelatinized, accompanied by high swelling. The crystallinity changed from C-type to A-type via CA-type during gelatinization, and finally became amorphous structure. The amylose content, crystal degree, helix content, ratio of 1045/1022 cm−1, and peak intensity of crystalline lamellae of gelatinizing starch significantly decreased after 70 °C. The amorphous content and ratio of 1022/995 cm−1 increased after 70 °C. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs.

Starch granules from high-amylose cereal mutants or transgenic lines usually have different morphologies. It is not clear whether the structure and spatial distribution of starch granules with different morphologies in endosperm is homogeneous or heterogeneous. In the present study, the structure and spatial distribution in endosperm of morphologically different starch granules from high-amylose transgenic rice line (TRS) were investigated. The TRS endosperm had individual, aggregate, elongated, and interior hollow starch granules. The individual and interior hollow granules had the lowest and the highest amylose content and gelatinization resistance, respectively, among the four types of granules. The individual granules were mainly distributed in the middle of the endosperm; the aggregate granules in the starchy endosperm cells between the subaleurone layer and the middle of the endosperm; the elongated granules in the peripheral starchy endosperm cells adjacent to the subaleurone layer; and the interior hollow granules in the subaleurone layer cells.

High-amylose cereal starches usually have heterogeneous starch granules in morphological structure. In the present study, the polygonal, aggregate, elongated, and hollow starch granules were separated from different regions of the kernels of high-amylose rice, and their structures were investigated. The results showed that the polygonal starch granules had low amylose content and high short branch-chain and branching degree of amylopectin, and exhibited A-type crystallinity. The aggregate starch granules had high long branch-chain of amylopectin, relative crystallinity, and double helix content, and exhibited C-type crystallinity. The elongated starch granules had high amylose content and low branching degree of amylopectin and relative crystallinity, and exhibited C-type crystallinity. The hollow starch granules had very high amylose content, proportion of amorphous conformation, and amylose–lipid complex, and very low branch-chain of amylopectin, branching degree of amylopectin, and double helix content, and exhibited no crystallinity. The different structures of heterogeneous starch granules from high-amylose rice resulted in significantly different thermal properties.

Large-, medium-, and small-sized granules were separated from normal and high-amylose maize starches using a glycerol centrifugation method. The different-sized fractions of normal maize starch showed similar molecular weight distribution, crystal structure, long- and short-range ordered structure, and lamellar structure of starch, but the different-sized fractions of high-amylose maize starch showed markedly different structural properties. The amylose content, iodine blue value, amylopectin long branch-chain, and IR ratio of 1045/1022 cm–1 significantly increased with decrease of granule size, but the amylopectin short branch-chain and branching degree, relative crystallinity, IR ratio of 1022/995 cm–1, and peak intensity of lamellar structure markedly decreased with decrease of granule size for high-amylose maize starch. The large-sized granules of high-amylose maize starch were A-type crystallinity, native and medium-sized granules of high-amylose maize starch were CA-type crystallinity, and small-sized granules of high-amylose maize starch were C-type crystallinity, indicating that C-type starch might contain A-type starch granules.

Starch gelatinization is important in food processing and industrial use. Granule swelling and gelatinization temperature of 11 starches from different plants were investigated in situ using hot stage microscopy during heating. The amylose content, swelling power, pasting temperature and thermal property of these starches were also measured. The results showed that hot stage microscopy was suitable for measuring granule swelling and the gelatinization temperature of starch during heating. The sectional area swelling percentage of starch granules measured using hot stage microscopy was significantly positively correlated with the swelling power. The gelatinization temperature measured using hot stage microscopy was significantly positively correlated with the pasting temperature and with the thermal property for all 11 starches. For rice starches with the same crystallinity and similar size, the gelatinization temperature was negatively correlated with the amylose content and positively correlated with the swelling power and the sectional area swelling percentage at 95°C.

High-amylose starches are attracting considerable attention because of their potential health benefits and industrial uses. Enzyme hydrolysis of starch is involved in many biological and industrial processes. In this paper, starches were isolated from high-amylose transgenic rice (TRS) and its wild type rice, Te-qing (TQ). The morphological and structural changes of starch residues following Aspergillus niger amyloglucosidase (AAG) hydrolysis were investigated. AAG hydrolysed TQ starch from the granule surface, and TRS starch from the granule interior. During AAG hydrolysis, the content of amorphous structure increased, the contents of ordered structure and single helix decreased, and gelatinisation enthalpy decreased in TQ and TRS starch residues. The A-type polymorph of TRS C-type starch was hydrolysed faster than the B-type polymorph. The short-range ordered structure and B-type polymorph in the peripheral region of the subgranule and the surrounding band of TRS starch increased the resistance of TRS starch to AAG hydrolysis.Highlights► High-amylose rice TRS starch was more resistant to AAG hydrolysis than TQ starch. ► Crystalline structure was hydrolysed faster than the amorphous structure. ► The AAG hydrolysis pattern of TRS starch was different from that of TQ starch. ► A-type polymorph of TRS C-type starch was hydrolysed faster than B-type polymorph. ► The external region with B-type crystal increased resistance of TRS starch to AAG.

Twelve starches were isolated from the tuberous root of sweet potato, the rhizomes of lotus and yam, the tuber of potato, the corm of water chestnut, and the seeds of pea, bean, barley, wheat, lotus, water caltrop, and ginkgo. Their gelatinization processes were in situ viewed using a polarizing microscope in combination with a hot stage. Four patterns of crystallinity disruption during heating were proposed. The crystallinity disruption initially occurred on the proximal surface of the eccentric hilum, on the distal surface of the eccentric hilum, from the central hilum, or on the surface of the central hilum starch granule. The patterns of initial disruption on the distal surface of the eccentric hilum and on the surface of the central hilum starch were reported for the first time. The heterogeneous distribution of amylose in starch granule might partly explain the different patterns of crystallinity disruption and swelling during gelatinization.Highlights► Four patterns of crystallinity disruption during starch heating were proposed. ► The gelatinization began on the proximal or distal surface of the eccentric hilum. ► The gelatinization began from the hilum or surface of the central hilum granule. ► The uneven distribution of amylose in starches resulted in the different patterns.

Mutating or inhibiting genes encoding starch branching enzymes (SBEs) can increase the amylose content (AC) of cereals. We analyzed endosperm starches from three rice cultivars with different ACs and from transgenic lines derived from them. The transgenic lines had simultaneously inhibited SBE I and IIb genes. Compared with the starch from their wild-type parents, the starch from transgenic lines showed significantly increased apparent ACs and lamella size and decreased relative crystallinity, double helix content, and lamellar peak scattering intensity, and altered short-range ordered structure in the external region. These changes were more prominent in the line derived from the high-AC cultivar than in those derived from waxy and low-AC cultivars. Inhibiting both SBE I and IIb changed the crystalline structure of starch from A-type to CA-type in lines derived from waxy and low-AC cultivars, and from A-type to C-type in that derived from the high-AC cultivar.

This study investigated the physicochemical properties of rhizome starch of A. altaica for the first time. The results were compared to those obtained from two common starches (potato and rice). The rhizome had a starch content of 49.8%. Isolated starch granules were mostly oval in shape with a central Maltese cross and an average long axis of 6.25 μm. The starch contained 35.5% amylose and had lower gelatinization and pasting temperatures than rice and potato starches and a swelling power comparable to potato. Altaica starch had high breakdown and setback viscosities. X-ray diffraction revealed B-type starch with relative degree of crystallinity of 17.5%. Starch possessed a high susceptibility to hydrolysis by acid, porcine pancreatic α-amylase and Aspergillus niger amyloglucosidase when compared with potato and rice starches.Highlights► The rhizome of Anemone altaica is widely used in traditional Chinese medicine. ► The rhizome had starch content of 49.8%, and starch contained 35.5% amylose. ► Starch grain was oval with central Maltese cross and average long axis of 6.25 μm. ► Starch had high swelling power and low gelatinization and pasting temperatures. ► B-type starch possessed high hydrolysis degrees of acid, PPA and AAG.

Lotus seed and rhizome starches have been used as functional foods in east Asia for thousands of years. In this paper, starches were isolated from lotus seed and rhizome, and their physicochemical properties were compared. Seed starches were small oval granules, rhizome starches had small oval granules and large elongated granules. Seed starches showed significantly higher amylose content and gelatinization temperature and lower swelling power than rhizome starches. Seed starches exhibited an A-type X-ray diffraction pattern with higher crystalline degree, while rhizome starches showed a C-type pattern which changed from C- to A-type with gradually increasing crystalline degree during acid hydrolysis. The degree of order in starch external region was higher in rhizome than in seed. The external region structure of rhizome starches became more ordered during acid hydrolysis. Rhizome starches had higher rate of acid hydrolysis and lower rate of porcine pancreatic α-amylase hydrolysis than seed starches.Highlights► Seed starch grain was oval, rhizome starch grain was oval or elongated in shape. ► Seed starch had higher amylose and gelatinization temperature than rhizome starch. ► A-type seed starch had higher crystalline degree than C-type rhizome starch. ► Rhizome starch crystalline changed from C- to A-type during acid hydrolysis. ► Seed starch had lower acid hydrolysis, higher PPA hydrolysis than rhizome starch.

In this paper, endosperm starches were isolated from a high-amylose transgenic rice line (TRS) and its wild type rice Teqing (TQ) kernels at different developmental stages. TQ and TRS starches showed similar amylose contents and shapes at early developmental stage, then the amylose content increased with kernel development. The rate of increase in amylose content was much faster in TRS starches than that in TQ starches. TRS starches showed heterogenous granules at the middle and late developmental stages. TQ starch crystallinity remained A-type, but TRS starch crystallinity changed from A- to C- via CA-type. TRS starches showed higher gelatinization temperatures, lower gelatinization enthalpies, lower swelling powers, and lower hydrolysis rates at middle and late developmental stages compared with TQ starches. The amylose content had a significantly negative correlation with crystallinity, gelatinization enthalpy, swelling power, enzyme digestibility, and acid hydrolysis.Highlights► TQ and TRS starches showed similar amylose contents and shapes at early developmental stage. ► Heterogeneous TRS starches had higher amylose content than homogeneous TQ starches did at middle and late developmental stage. ► TRS starch crystallinity changed from A- to C- via CA-type with kernel development. ► TRS starches showed different crystal, thermal and hydrolytic properties from TQ with amylose content increase. ► The amylose content had negative correlations with crystallinity, gelatinization enthalpy, swelling power, enzyme digestibility, and acid hydrolysis.

High-amylose cereal starch has a great benefit on human health through its resistant starch content. In this paper, starches were isolated from mature grains of high-amylose transgenic rice line (TRS) and its wild-type rice cultivar Te-qing (TQ) and digested in vitro and in vivo. The structural changes of digestive starch residues were characterized using DSC, XRD, 13C CP/MAS NMR, and ATR-FTIR. TQ starch was very susceptible to digestion; its residues following in vitro and in vivo digestion showed similar structural characteristics with TQ control starch, which suggested that both amorphous and crystalline structures were simultaneously digested. Both amorphous and the long-range order structures were also simultaneously hydrolyzed in TRS starch, but the short-range order (double helix) structure in the external region of TRS starch granule increased with increasing digestion time. The A-type polymorph of TRS C-type starch was hydrolyzed more rapidly than the B-type polymorph. These results suggested that B-type crystallinity and short-range order structure in the external region of starch granule made TRS starch resistant to digestion.

High-amylose cereal starch has a great benefit on human health through its resistant starch (RS) content. Enzyme hydrolysis of native starch is very helpful in understanding the structure of starch granules and utilizing them. In this paper, native starch granules were isolated from a transgenic rice line (TRS) enriched with amylose and RS and hydrolyzed by α-amylase. Structural properties of hydrolyzed TRS starches were studied by X-ray powder diffraction, Fourier transform infrared, and differential scanning calorimetry. The A-type polymorph of TRS C-type starch was hydrolyzed faster than the B-type polymorph, but the crystallinity did not significantly change during enzyme hydrolysis. The degree of order in the external region of starch granule increased with increasing enzyme hydrolysis time. The amylose content decreased at first and then went back up during enzyme hydrolysis. The hydrolyzed starches exhibited increased onset and peak gelatinization temperatures and decreased gelatinization enthalpy on hydrolysis. These results suggested that the B-type polymorph and high amylose that formed the double helices and amylose–lipid complex increased the resistance to BAA hydrolysis. Furthermore, the spectrum results of RS from TRS native starch digested by pancreatic α-amylase and amyloglucosidase also supported the above conclusion.

Wheat mature seeds have large, lenticular A-type starch granules, and small, spherical B-type and irregular C-type starch granules. During endosperm development, large amyloplasts came from proplastid, divided and increased in number through binary fission from 4 to 12 days after flowering (DAF). Large starch granules formed and developed in the large amyloplast. One large amyloplast had only one large starch granule. Small amyloplasts came from the protrusion of large amyloplast envelope, divided and increased in number through envelope protrusion after 12 DAF. B-type starch granules formed and developed in small amyloplast from 12 to 18 DAF, C-type starch granules formed and developed in small amyloplast after 18 DAF. Many B- and C-type starch granules might form and develop in one small amyloplast. The amyloplast envelopes were asynchronously degraded and starch granules released into cell matrix when amyloplasts were full of starch granules. Apparent amylose contents of large starch granules were higher than that of small starch granules, and increased with endosperm development. The swelling powers and crystallinity of large starch granule were lower than that of small starch granules, and decreased with endosperm development. Small starch granules displayed broader gelatinization temperature ranges than did large starch granules.

•The whole section method of mature cereal seed was established in the study.•The method was suitable for developing, germinated, and gelatinized cereal seed.•The rice, maize and wheat seeds were longitudinally and transversely sectioned.•The endosperm cell had different shape and size in different regions of endosperm.•Starch and storage protein had heterogeneous distribution in endosperm.The morphology of endosperm cell and starch and the distribution of storage protein affect the kernel weight and endosperm quality of cereal crops, and are of interest for crop breeders. They are significantly different in different regions of endosperm. Therefore, it is very important for in situ investigation of the morphology of endosperm cell and starch and the distribution of storage protein in mature cereal seed. In the present study, we reported a method for preparing the whole section of mature rice, maize, and wheat seeds. The section could be easily stained with fluorescent brightener 28, iodine solution, and coomassie brilliant blue R250 to exhibit the cell wall, starch, and storage protein. The observation of whole section of seed showed that the morphology of endosperm cell and starch and the distribution of storage protein were significantly different in different regions of endosperm of rice, maize, and wheat seed. The method could in situ investigate the morphology of endosperm cell and starch and the distribution of storage protein in not only mature cereal seed but also developing, germinated, and gelatinized cereal seed. This study was very useful for investigation of cereal seed development and utilization.