Prime and tailings starches of garbanzo beans and peas were separated and the chemical composition, physical properties, thermal behavior, and gel properties were determined. Starch granules <35 μm were 85% in garbanzo beans, 66.8% in a smooth pea cv. Latah, and only 18.4% in a smooth pea cv. SS Alaska. Amylose content of prime starch was 35.9% in garbanzo beans, 44.5–48.8% in smooth peas, and 86.0% in wrinkled pea cv. Scout. Tailings starch amylose content was at least 8% higher than the corresponding prime starch. The endothermic enthalpy value of garbanzo bean and two smooth pea prime starches ranged from 12.1 to 14.2 J/g, while prime starch from wrinkled peas gave a distinctly lower enthalpy value of 1.1 J/g. Differential scanning calorimetry endothermic enthalpy and amylograph pasting properties of prime starch were significantly related to its amylose content (P < 0.05). Prime starches of garbanzo beans and smooth peas produced highly cohesive elastic gels. Wrinkled pea prime starch formed the strongest (though brittle) gel, as indicated by high hardness (21.8 N), low cohesiveness (0.29), and low springiness (0.82). Hardness of gel stored at 22°C and at 4°C was positively correlated with amylose content of starch.

Amylose contents of prime starches from nonwaxy and high‐amylose barley, determined by colorimetric method, were 24.6 and 48.7%, respectively, whereas waxy starch contained only a trace (0.04%) of amylose. There was little difference in isoamylase‐debranched amylopectin between nonwaxy and high‐amylose barley, whereas amylopectin from waxy barley had a significantly higher percentage of fraction with degree of polymerization < 15 (45%). The X‐ray diffraction pattern of waxy starch differed from nonwaxy and high‐amylose starches. Waxy starch had sharper peaks at 0.58, 0.51, 0.49, and 0.38 nm than nonwaxy and high‐amylose starches. The d‐spacing at 0.44 nm, characterizing the amylose‐lipids complex, was most evident for high‐amylose starch and was not observed in waxy starch. Differential scanning calorimetry (DSC) thermograms of prime starch from nonwaxy and high‐amylose barley exhibited two prominent transition peaks: the first was >60°C and corresponded to starch gelatinization; the second was >100°C and corresponded to the amylose‐lipid complex. Starch from waxy barley had only one endothermic gelatinization peak of amylopectin with an enthalpy value of 16.0 J/g. The retrogradation of gelatinized starch of three types of barley stored at 4°C showed that amylopectin recrystallization rates of nonwaxy and high‐amylose barley were comparable when recrystallization enthalpy was calculated based on the percentage of amylopectin. No amylopectin recrystallization peak was observed in waxy barley. Storage time had a strong influence on recrystallization of amylopectin. The enthalpy value for nonwaxy barley increased from 1.93 J/g after 24 hr of storage to 3.74 J/g after 120 hr. When gel was rescanned every 24 hr, a significant decrease in enthalpy was recorded. A highly statistically significant correlation (r = 0.991) between DSC values of retrograded starch of nonwaxy barley and gel hardness was obtained. The correlation between starch enthalpy value and gel hardness of starch concentrate indicates that gel texture is due mainly to its starch structure and functionality. The relationship between the properties of starch and starch concentrate may favor the application of barley starch concentrate without the necessity of using the wet fractionation process.

Cereal Chem. 80(5):627-633Double-null partial waxy wheat (Triticum aestivum L.) flours were used for isolation of starch and preparation of white salted noodles and pan bread. Starch characteristics, textural properties of cooked noodles, and staling properties of bread during storage were determined and compared with those of wheat flours with regular amylose content. Starches isolated from double-null partial waxy wheat flours contained 15.4-18.9% amylose and exhibited higher peak viscosity than starches of single-null partial waxy and regular wheat flours, which contained 22.7-25.8% amylose. Despite higher protein content, double-null partial waxy wheat flours, produced softer, more cohesive and less adhesive noodles than soft white wheat flours. With incorporation of partial waxy prime starches, noodles produced from reconstituted soft white wheat flours became softer, less adhesive, and more cohesive, indicating that partial waxy starches of low amylose content are responsible for the improvement of cooked white salted noodle texture. Partial waxy wheat flours with >15.1% protein produced bread of larger loaf volume and softer bread crumb even after storage than did the hard red spring wheat flour of 15.3% protein. Regardless of whether malt was used, bread baked from double-null partial waxy wheat flours exhibited a slower firming rate during storage than bread baked from HRS wheat flour.

Sedimentation tests have long been used to characterise wheat flours and meals with the aim of predicting processing and end-product qualities. However, the use of the sodium dodecyl sulfate (SDS) sedimentation test for durum wheat (AACC International Approved Method 56-70) has not been characterised for hexaploid wheat varieties with a diverse range of protein quality and quantity. This paper reports the variation associated with important method parameters: sample weight, SDS concentration, technician, grinder and screen aperture (particle size). Sedimentation volumes were recorded every 5 min for 30 min and expressed as specific volume, i.e. sediment volume in mL g −1 meal. Ten diverse hexaploid wheat samples of markedly different protein quality and quantity were examined. The SDS sedimentation assay was shown to be highly robust and reproducible, with ANOVA (analysis of variance) model R 2 values greater than 0.98 (individual time points). The procedure delineated soft and hard hexaploid wheat samples based on a combination of protein quantity and quality. Sample weight (if corrected to unit weight basis), recording time of at least 10 min, SDS stock concentration of at least 10 g L −1 (final), grinder type and screen aperture were minor sources of variation in SDS sedimentation volume relative to the effects due to differences among wheat samples. Interactions among ANOVA model terms were of relatively minor importance.

Protein concentrates before and after defatting from hard and soft wheat flours by water and 1% NaCl solution were characterized by lipid, sodium dodecyl sulphate (SDS) sedimentation, solubility, and breadmaking. Sedimentation values were higher for hard wheat flours than for soft, and in both about three times higher than in separated glutens. Solubility of proteins in SDS was reduced from -23 to 31% in flours to -3 to 19% in gluten concentrates. Defatting did not affect electrophoretic patterns but indicated lowered protein extractability. Gliadins and HMW glutenins were lower in extracts of separated glutens than in the extracts of doughs. Protein concentrates from fractionation with 1% salt solution, differed widely from those separated with water. This especially affected water absorption, dough development, and baking performance. Electrophoresis of gliadinSamples (containing 50 mg protein) of the flour, of lyophilized dough mixed with water and salt, or of gluten fractions from the doughs were extracted with 200 uL 70% ethanol in 1.5-mL microcentrifuge tubes. The mixtures were vortexed every 10 min for 1 hr at 21°C (room tem-Volume 60, No.