Nitro‐blue tetrazolium staining of starch‐synthesizing enzymes in developing rice grains

An in situ nitro‐blue tetrazolium (NBT) staining method was used to locate the activities of enzymes involved in starch synthesis in developing grains of field grown rice (Oryza sativa L.) cultivar Tainung 67 and its early ripening mutant SA 419. The results indicated that all the tested enzymes, including sucrose synthase, invertase, hexokinase, ADP‐glucose pyrophosphorylase, UDP‐glucose pyrophosphorylase and starch synthase, were detectable in developing rice endosperms by using NBT staining. The activity of these enzymes was also measurable by using chemical assays. The expression of enzyme activity, as indicated by the formation of blue formazan precipitate, in growing grain of Tainung 67 were visualized in entire endosperm at 11 days after anthesis (DAA). However, NBT staining shifted from central to peripheral region of endosperm after 18 DAA, and the staining disappeared at 25 DAA. Similar staining patterns were also observed in the growing grains of mutant SA 419, but the shift of staining from central to peripheral endosperm occurred at 11 DAA. Electron microscopy examinations showed that the growing patterns of starch granules, sampled from central and peripheral regions of endosperm, varied between two cultivars, with SA 419 growing faster than Tainung 67. Both cultivars showed that the shifts of NBT staining pattern coincided with the changes in the growing pattern of starch granules located in central and peripheral regions of endosperms. The NBT staining results showed that the activities of sucrose to starch conversion enzymes in mutant SA 419 declined and disappeared earlier than its wild‐type Tainung 67 and therefore it ripened earlier than cultivar Tainung 67. Copyright © 2005 Society of Chemical Industry     

Effects of oligosaccharides on phase transition temperatures and rheological characteristics of waxy rice starch dispersion

BACKGROUND: The creation of starch‐based foods incorporated with functional ingredients such as probiotics is of great current interest in the food industry. This study aimed to investigate the effects of prebiotic oligosaccharides on the phase transition temperatures and rheological characteristics of waxy rice starch dispersions. Four oligosaccharides were applied to the rice starch dispersions: chitooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and xylooligosaccharides. RESULTS: The addition of 125 g kg^?1 oligosaccharides elevated the onset and peak temperatures for gelatinisation of 200–400 g kg^?1 waxy rice starch dispersions. The temperature of the storage modulus (G′) for gelatinisation increased markedly on adding fructooligosaccharides to 200–300 g kg^?1 waxy rice starch. For gelatinisation of 300 g kg^?1 rice starch dispersion the effectiveness of the oligosaccharides in changing the above parameters was as follows: chitooligosaccharides > fructooligosaccharides > isomaltooligosaccharides > xylooligosaccharides. Moreover, their effectiveness was dependent on the amylose content, as illustrated by comparing waxy and non‐waxy rice starches (amylose contents 9–256 g kg^?1). Importantly, the logarithmic G′₉₅ change was linearly and negatively correlated with amylose content. CONCLUSION: The results suggest that oligosaccharide‐containing rice starch dispersions may potentially be used for the formulation of oligosaccharide‐containing starchy functional foods owing to the rheological changes of these starch dispersions. Copyright © 2011 Society of Chemical Industry     

Strikingly high content of grain protein in solution‐cultured rice

A greenhouse experiment was conducted to investigate the nutritional quality of solution‐cultured rice. Five rice cultivars, different in grain amylose content and protein content, were grown under 10, 40 and 80 mg l^?1 nitrogen levels during the period of July 2003 to October 2003. In comparison to their original seeds, the solution‐cultured rice Oryza sativa L grain had strikingly higher protein content across all the cultivars and nitrogen levels, and remarkably lower amylose content in the waxy and low amylose cultivars, which might be due to the sufficiently stable nitrogen supply and well‐controlled temperature and humidity. The highest grain protein content was 163.6 g kg^?1 in this experiment, which is the highest reported rice grain protein content. The residual nitrogen concentration was greater than 12.39 g kg^?1 in the roots, 8.95 g kg^?1 in the stems, and 21.97 g kg^?1 in the flag leaves across all the cultivars and nitrogen treatments at harvesting. The rice grain had a narrow range of grain carbon content and hydrogen content. The average grain carbon and hydrogen contents for all the rice samples were 42.95 ± 0.15 (n = 60) and 6.81 ± 0.04 g kg^?1 (n = 60), respectively. The solution cultured rice grain was characterized with lower carbon–nitrogen mole ratio and lower hydrogen–nitrogen mole ratio, which could be mainly attributed to the increased protein content. The response of plant nitrogen, grain protein and amylose concentration to the supplemental nitrogen level varied with the cultivars. The results in this study suggested that solution culture technology could improve the production potential of rice. Copyright © 2005 Society of Chemical Industry     

Rice Starch Molecular Size and its Relationship with Amylose Content

The composition and starch molecular structure of eight rice varieties were studied. Waxy and non‐waxy (long‐, medium‐, and short‐grain) rice varieties from California and Texas were used. The amylose contents were measured using the Concanavalin A method and were found to be related to the type of rice: waxy ≈ 1.0%, short and medium grain 8.7–15.4%, and long grain 17.1–19.9%. The weight‐average molar masses (M_w) of the starches varied from 0.52 to 1.96×10⁸ g/mol. As would be expected, a higher M_w of rice starch correlated to lower amylose content. The range of M_w of amylopectin was 0.82 to 2.50 ×10⁸ g/mol, and there was also a negative correlation of amylopectin M_w with amylose content. Amylose M_w ranged from 2.20 to 8.31×10⁵ g/mol. After debranching the amylopectin with isoamylase, the weight‐average degree of polymerization (DP_w) for the long‐chain fraction correlated positively with a higher amylose content. California and Texas varieties were significantly different in their amylose content, starch M_w (short‐ and medium‐grain only), and amylopectin M_w (p < 0.05).     

The effect of modified starches on the gel properties and protein conformation of Nemipterus virgatus surimi

The study investigated the effect of native cassava starch (NCS), hydroxypropylated starch, acetic acid esterification starch (AAES), acetylated distarch phosphate on gel properties and protein conformation of Nemipterus virgatus surimi. Addition of 10 g kg^?1 NCS or 20 g kg^?1 AAES could significantly promote the gel strength and textural profiles of the surimi gels (p < .05). The water holding ability and whiteness of surimi were remarkably increased when the four types of starch were added at all concentrations (p < .05). In rheological test, the lower G′ was observed in surimi samples added with starch at low temperature, suggesting starch played an inactive filler role in surimi. Along with the increase of starch additive amount, ionic bond and hydrophobic interaction first increased and then decreased, while hydrogen bond first decrease and then increased. According to Raman spectroscopy data, small content of starch promoted the heat‐induced conformational transition of surimi protein from α‐helix to β‐sheet, leading to the change in gel properties of surimi gels. Scanning electron microscopy photographs showed surimi gels added with 20 g kg^?1 starch had the finer and denser network structure. Therefore, 20 g kg^?1 AAES or 10 g kg^?1 NCS or 10 g kg^?1 HS could be proposed to a potential modifier to effectively improve the quality of surimi products.     

Composition of the seeds of some Amaranthus species

The seeds of the five commonly consumed Amaranthus species have been analysed for their chemical composition and starch characteristics. A notably high fat, protein and ash content in the seeds of a sample of A. teunifolious as compared with other species has been demonstrated. All the samples analysed had a high oxalate and phytic acid content. The size of the starch granules from all the samples was in the range 08.2.3μm and the circular shape of granules from all the species was strikingly similar. Amaranthus polygamous and A. gracilis had low amylose starches (111.7 and 97.1 g kg^?1, respectively), and A. spinosus and A. teunifolious had appreciable proportions of amylose (166.7 and 245.0 g kg^?1, respectively).     

Nutritional quality of uncultivated cereal grains utilised as famine foods in western sudan as measured by chemical analysis

The chemical composition of the grain of a number of wild grasses used as food in times of famine in western Sudan are reported and compared with those of the local staple cereals. Species investigated were Cenchrus hiflorus (haskaneet). Dactyloctenium aegyptium (korecb). Echinochloa colona (difra) and Oryza punctata (ruz el wadi). The grain of all species except C biflorus had protein contents in the range 110-140 g kg^?1, broadly similar to those of the local staple cereals. The grain of C biflours possessed a particularly high protein content of 210 g kg^?1. The nutritional quality of the proteins as measured by their chemical scores ranged from 20 for C biflorus to 65 for O punctata compared with scores of 36 and 58 for the local sorghum var Kurgi and millet respectively. Lysine was the limiting amino acid in all cases. Whilst the composition of the protein of sorghum var Kurgi was typical of sorghum generally, that of var Karamaka was unusual in possessing lysine levels of 3.4 g (16 g N)¹, double that normally present in sorghum and raising the chemical score of the protein to 62. The ash content of the famine food cereals was high, attaining 113 g kg¹ in C biflorus. All grains were good sources of zinc and D aegyptium. O punctata and E colonum additionally contained comparatively high levels of iron. Remarkably for a cereal D aegyptium was also very rich in calcium, containing over 10 g kg¹, and possessed high concentrations of manganese. Carbohydrate content of the famine food grains varied from 617 g kg¹ for C biflorus to 748 g kg¹ for O punctata, values comparable to the local staple cereals. The proportion of starch in this fraction ranged from 650 g kg¹ in D aegyptium to 940 g kg¹ in O punctata. Seed oils of all species were predominantly unsaturated containing mainly oleic and linoleic acids.     

Wet‐fractionation of Phaseolus lunatus seeds: partial characterization of starch and protein

The optimum extraction conditions for integral use of Phaseolus lunatus seed, in alkaline medium, are 1:6 (w/v) flour:water ratio, pH 11 and a 1 h extraction time. Three main fractions were produced under these conditions: starch; protein isolate and fibrous residue by‐product. The yield is 288.4 g kg^?1 starch, 188.2 g kg^?1 protein isolate and the remaining quantity, fibrous residue. The starch has 98.4% purity, a 75 °C gelatinization temperature and high syneresis even at high concentrations. It also has high viscosity, good stability and middle retrogradation during the heating–cooling cycle. The protein isolate contains 711.3 g kg^?1 protein as well as 75.5 g lysine kg^?1 protein, 10.1 g methionine kg^?1 protein and 12.2 g tryptophan kg^?1 protein. Its in vitro digestibility is 79% with a 2.5 c‐PER. The fibrous residue contains 63 g kg^?1 of protein, 328.4 g kg^?1 of crude fiber and 567.3 g kg^?1 of NFE. Copyright © 2004 Society of Chemical Industry     

Waxy Gene Factor and Residual Protein of Rice Starch Granules

Residual protein of rice starch granules prepared from milled rice by protein extraction with sodium dodecylbenzene sulfonate or alkaline protease treatment was related to amylose content. SDS-polyacrylamide disc gel electrophoresis confirmed that the major protein in nonwaxy starch granules was the Wx gene product with subunit molecular weight of about 60,000 daltons. The Wx gene product was absent in waxy starch granules.     

Some physicochemical properties of acha (digitaria exilis stapf) and iburu (Digitaria iburua stapf) grains

Some physicochemical properties of two cultivated species of Digitaria (D exilis and D iburua) were studied. Physical properties such as 1000-kernel weight, kernel size and water absorption rate of the grains were determined. Water absorption by both cereals reached a maximum after 24 h steeping. The starch from both cereals exhibited a two-stage pattern of swelling and solubility properties similar to other non-waxy cereal starches. Starch from acha swelled less than iburu, 7·3 compared with 7·8 for iburu. Chemical constituents such as protein, oil, crude fibre, ash, nitrogen-free extract and amylose were also determined. An amylose content of 280 g kg^?1 was obtained for both cereal starches. Brabender amylograms obtained from starch and flour were typical of most normal, non-waxy cereals. Maize starch had relatively higher hot-paste and cold-paste viscosities than starches of the two Digitaria species.     

Carotenoid and anthocyanin contents of grains of Brazilian maize landraces

BACKGROUND: Carotenoid and anthocyanin contents of 26 maize landraces cultivated in southern Brazil were determined to evaluate their potential as natural colorants or functional food ingredients. RESULTS: The major carotenoids detected in the whole grain flour were zeaxanthin and lutein. Anthocyanins of landraces with purple starchy endosperm (Lingua de Papagaio and Mato Grosso Palha Roxa) were more extractable in methanol–HCl (1%, v/v), exhibiting 2.45 and 0.94 g kg^?1 of whole grains flour, respectively. In contrast, butanol–HCl (30%, v/v) was more effective for the extraction of anthocyanins from the purple‐colored landraces Roxo 29 and Roxo 41; genotypes with pigments localized in the outer parts (pericarp) of grains (2.60 and 2.19 g kg^?1). The Roxo 41 landrace showed the highest concentration of pigments, e.g. 11.72 10^?3 g kg^?1 of total carotenoids and 2.16 g kg^?1 of total anthocyanins. Similarly, the yellow‐colored MPA 1 and the purple‐colored Roxo 29 landraces showed prominent amounts of carotenoids (10.86 10^?3 g kg^?1) and anthocyanins (2.60 g kg^?1), respectively. CONCLUSION: Our findings suggest that the colored grains of maize landraces studied may hold promise for the development of grain‐based functional foods or natural colorants regarding their carotenoid and anthocyanin contents and as genetic resource in breeding programs. Copyright © 2011 Society of Chemical Industry     

Flavonoid content and antioxidant capacity of spinach genotypes determined by high‐performance liquid chromatography/mass spectrometry

BACKGROUND: Flavonoids in different spinach genotypes were separated, identified, and quantified by a high‐performance liquid chromatographic method with photodiode array and mass spectrometric detection. The antioxidant capacities of the genotypes were also measured using two antioxidant assays–oxygen radical absorbance capacity (ORAC_FL) and photochemiluminescence (PCL)–which measure the response to the peroxyl and superoxide anion radicals, respectively. RESULTS: Eighteen flavonoids representing glucuronides and acylated di‐ and triglycosides of methylated and methylene dioxide derivatives of 6‐oxygenated flavonols were identified (patuletin, spinacetin, spinatoside, jaceidin). The total flavonoids ranged from 1805 to 3703 mg kg^?1, indicating 2.0‐fold variation among genotypes. The ORAC_FL and PCL values ranged from 48.7 to 84.4 mmol kg^?1 and from 9.0 to 14.0 mmol kg^?1, respectively, representing as much as 1.7‐fold variation among genotypes. CONCLUSION: The ORAC_FL and PCL values were highly correlated with total flavonoid content (r_xy = 0.96). Copyright © 2008 Society of Chemical Industry     

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α‐glucosidase and α‐amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA‐05 and its wild‐type variety Hwachia against aldose reductase, α‐glucosidase and α‐amylase were examined. The results indicated that the polyphenolics‐rich extracts obtained using 800 g kg^?1 methanol and 500 g kg^?1 ethanol demonstrated inhibitory activities against aldose reductase (IC₅₀ of 0.36–0.46 mg mL^?1) and α‐glucosidase (IC₅₀ of 1.32–1.94 mg mL^?1). The 500 g kg^?1 ethanol extracts also showed α‐amylase inhibitory activities (IC₅₀ of 70.11–80.22 μg mL^?1). Subsequent extracts, prepared further with NaCl and H₂O from precipitates of 800 g kg^?1 methanol or 500 g kg^?1 ethanol extracts, exhibited potent α‐amylase inhibitory activities (IC₅₀ of 17.68–38.68 μg mL^?1). A combination of 500 g kg^?1 ethanol extraction plus a subsequent H₂O extraction produced highest polyphenolics and α‐amylase inhibitors. The SA‐05 α‐amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA‐05 is an advantageous choice for producing anti‐hyperglycaemic compounds.     

Fat reduction in emulsion sausage using an enzyme‐modified potato starch

BACKGROUND: A heat‐stable amylase‐modified potato starch (MPS) was prepared and used as a fat replacer in reduced‐fat emulsion sausages. The effects of fat level (50, 150 and 300 g kg^?1) and MPS addition (20 and 40 g kg^?1) on energy, colour, sensory, and textural properties of emulsion sausages were investigated. RESULTS: The addition of 20 or 40 g kg^?1 of MPS in reduced‐fat sausage (50–150 g kg^?1 fat) reduced total energy (15.1–49.4%), increased lightness, but lowered redness of the products (P < 0.05). The 150 g kg^?1 or 50 g kg^?1 fat sausages containing 20 g kg^?1 MPS had a similar hardness to the 300 g kg^?1 fat control (P > 0.05). Sensory evaluation indicated that the presence of MPS in reduced‐fat sausages increased (P < 0.05) the product's tenderness. CONCLUSION: Overall, the 150 g kg^?1 fat emulsion sausages with 20 g kg^?1 MPS were comparable to the 300 g kg^?1 fat control sausage in colour, texture profile, and sensory properties, but was lower in energy, suggesting that the MPS can be used as a potential fat replacer in sausage products. Copyright © 2008 Society of Chemical Industry     

Differences in physicochemical properties of kernels of two rice cultivars during grain formation

BACKGROUND: Rice varieties with similar apparent amylose content may have different grain qualities. The development of rice quality is a dynamic process that occurs with the formation of rice kernels. In this study, physicochemical properties during the grain formation period were investigated to interpret differences in grain quality between two non‐waxy rice cultivars, Wuyujing3 and 30you917, with similar apparent amylose content. RESULTS: There were significant differences in dynamic changes in 1000‐grain weight, amylose content and pasting and thermal properties during grain formation of the two cultivars. The difference in their apparent amylose contents from 5 days after anthesis (DAA) to 15 DAA was significant, except in the late grain‐filling stage. Wuyujing3 showed a slower increase in 1000‐grain weight than 30you917 from 10 to 25 DAA. The transition temperatures (T_o, T_p and T_c) of developing grain flour of Wuyujing3 were higher than those of 30you917 during the grain formation period. Wuyujing3 showed greater stickiness (higher breakdown and peak viscosity and lower positive setback) than 30you917 according to Rapid Visco Analyser (RVA) profiling. CONCLUSION: The results suggested that the differences in cooking and eating quality parameters of the two mature rices were determined by the differences in grain filling and the dynamic changes in the main rice quality components such as amylose content, grain weight and differential scanning calorimetry and RVA properties, which will help cultivators understand the physical basis of rice quality development. Copyright © 2011 Society of Chemical Industry     

Chemical composition, angiotensin-converting enzyme-inhibitory activity and antioxidant activities of few-flower wild rice (Zizania latifolia Turcz.)

BACKGROUND: The chemical compositions of the stem and leaf sheath of few‐flower wild rice were analysed. In addition, their extracts were evaluated for diphenylpicrylhydrazyl (DPPH) free radical‐scavenging activity, ferric‐reducing antioxidant power and angiotensin‐converting enzyme (ACE)‐inhibitory activity, since these are important properties of sources of nutraceuticals or functional foods. RESULTS: The stems contained more ascorbic acid (0.06 g kg^?1 fresh weight), protein (28.18 g kg^?1 dry weight (DW)), reducing sugars (308.54 g kg^?1 DW), water‐soluble pectin (20.63 g kg^?1 DW), Na₂CO₃‐soluble pectin (44.14 g kg^?1 DW), K (8 g kg^?1 dry matter (DM), S (6 g kg^?1 DM) and P (5 g kg^?1 DM) but less starch, total dietary fibre, Si, Na and Ca than the leaf sheaths. The DPPH free radical‐scavenging IC₅₀ values of the stem and leaf sheath extracts were 19.28 and 21.22 mg mL^?1 respectively. In addition, the ACE‐inhibitory IC₅₀ value of the stem extracts was 38.54 mg mL^?1. CONCLUSION: Both the stem and leaf sheath extracts exhibited good antioxidant properties, while good ACE‐inhibitory activity was detected only in the phosphate buffer solution extracts of the stem. Few‐flower wild rice could be processed into formula feeds for fish, poultry, etc. or functional foods for persons with high blood pressure. Copyright © 2011 Society of Chemical Industry     

Growth, yield and seed composition of native Australian legumes with potential as grain crops

BACKGROUND: Many Australian native legumes grow in arid and nutrient‐poor environments. Yet few Australian herbaceous legumes have been investigated for domestication potential. This study compared growth and reproductive traits, grain yield and seed composition of 17 native Australian legumes with three commercial grain legumes. RESULTS: Seed yields of seven native legumes were > 40% of Cicer arietnum, with highest seed yields and harvest indices in Glycine sp. (14.4 g per plant, 0.54 g g^?1) and Lotus cruentus (10.2 g per plant, 0.65 g g^?1). Five native species flowered earlier than field pea (Pisum sativa) (109 days), though many were slower to flower and set seed. Largest seeds were found in Glycine canescens (17 mg), with seed of other native species 14 times smaller than commercial cultivars. Seed composition of many native legumes was similar to commercial cultivars (200–330 g protein kg^?1 dry weight (DW), 130–430 g dietary fibre kg^?1 DW). Two Cullen species had high fat content (>110 g kg^?1 DW) and Trigonella sauvissima had the highest crude protein content (370 g kg^?1 DW). CONCLUSION: The seed composition and reproductive traits of some wild native Australian legumes suggest they could offer potential as grain crops for soils and environments where the current grain legumes are uneconomic. Further evaluation of genetic diversity, especially for seed size, overall productivity, and reproductive development is needed. Copyright © 2011 Society of Chemical Industry     

Characterisation of grain quality in diverse sorghum germplasm using a Rapid Visco-Analyzer and near infrared reflectance spectroscopy

BACKGROUND: Twenty‐two diverse sorghum landraces, classified as normal and opaque types obtained from Ethiopia, were characterised for grain quality parameters using near infra‐red spectroscopy (NIRS), chemical and Rapid Visco‐Analyzer (RVA) characteristics. RESULTS: Protein content ranged from 77 to 182 g kg^?1, and starch content from 514 to 745 g kg^?1. The NIRS analysis indicated the pig faecal digestible energy range from 14.6 to 15.7 MJ kg^?1 as fed, and the ileal digestible energy range from 11.3 to 13.9 MJ kg^?1 as fed. The normal sorghums had higher digestible energy than the opaque sorghums, which exhibited lower RVA viscosities, and higher pasting temperatures and setback ratios. The RVA parameters were positively correlated with the starch content and negatively correlated with the protein content. The normal and opaque types formed two distinct groups based on principal component and cluster analyses. CONCLUSION: The landraces were different for the various grain quality parameters with some landraces displaying unique RVA and NIRS profiles. This study will guide utilisation of the sorghum landraces in plant improvement programs, and provides a basis for further studies into how starch and other constituents behave in and affect the properties of these landraces. Copyright © 2011 Society of Chemical Industry     

Improving the application of gibberellic acid to prolong dormancy of yam tubers (Dioscorea spp)

With the aim of reducing the cost and time needed to treat yam tubers with gibberellic acid (GA₃), this study compared several new methods of application with the established dipping procedure (150 mg kg^?1 for 1 h). Both GA₃‐containing soil paste (25 mg kg^?1) and gelatinized starch (860 mg kg^?1) were applied to tuber heads of Dioscorea alata and D cayenensis‐rotundata in the Ivory Coast. Soil paste, gelatinized starch and dipping consistently prolonged dormancy and reduced fresh matter losses by 23–39% in D cayenensis‐rotundata 3‐year means. Although dipping reduced the storage losses most efficiently, soil paste and gelatinized starch used considerably less GA₃. Both new treatments were easily prepared and quickly applied. Soil paste was most effective when the treatment was repeated before the end of dormancy. The third new method, spraying the tubers with a GA₃ solution (150 mg kg^?1), was not effective. In general, the optimal time of application was immediately post‐harvest. For D alata, treatment only 1 month after harvest was particularly ineffective, whereas D cayenensis‐rotundata tubers could be treated with some effect up to the end of dormancy. To achieve extended storage periods of healthy tubers of D cayenensis‐rotundata, GA₃ application may be recommended as post‐harvest practice. Copyright © 2003 Society of Chemical Industry     

Effects of rice properties and emulsifiers on the quality of rice pasta

Two commercial rice flours (GTIndica and GTJaponica, with amylose contents of 306.8 and 185.2 g kg^?1 respectively) and their blended flours were used to make rice pasta. The effects of two emulsifiers (distilled glyceryl monostearate (GMS) and a commercial emulsifier (KM3000)) on the pasting and thermal properties of dried rice pasta were investigated using a Rapid Visco Analyser (RVA) and a differential scanning calorimeter (DSC). The rice pasta made from high‐amylose rice flour had better extrusion properties, better texture, whiter colour, less cooking loss and better eating quality than that made from low‐amylose rice flour. The maximum amount of low‐amylose rice flour that could be blended in for making an acceptable quality of rice pasta was 500 g kg^?1. A soft texture, low adhesiveness and low gumminess of cooked rice pasta were obtained by adding 10 g kg^?1 GMS. SEM investigations showed that use of an emulsifier restricted the swelling of starch granules, especially for the pasta made from high‐amylose rice flour. © 2001 Society of Chemical Industry