A new method was introduced into the cereals field for the measurement of alpha-amylase. The principle of the method was nephelometry in which the rate of decrease in turbidity of substrate increased linearly with increase in amount of alpha-amylase. The Perkin-Elmer Corp., Oak Brook, Ill. introduced a machine to measure such changes called the Model 191 Grain Amylase Analyzer. One of the advantages of the method, unlike some other methods such as the falling number method, was that it was possible to measure fungal alpha-amylase supplementation in a flour and the natural levels. In spite of the widespread flurry of activity using the Grain Amylase Analyzer, the method has not found widespread acceptance in the flour milling and baking industries. The mechanism of the breakdown of beta-limit dextrin by malted wheat alpha-amylase has been examined bu high-performance gel permeation chromatography. The most important shift in molecular weight from the point of the nephelometric method occurs in the first 33 minutes.

ABSTRACTFresh alkaline noodles prepared from patent flours of the Canadian wheat class Canadian Prairie Spring White (CPSW) AC Karma and AC Vista were characterized by image analysis to numerically evaluate the time‐dependent formation of dark areas (spots) on the noodle surface. The system was able to rapidly detect, measure, and characterize such undesirable discolorations, which commonly form on the surface of raw noodles with time. Variations in minimum spot detection size (0.050–0.250 mm2), in combination with a darkness threshold setting (Δ grey scale units of 2, 5, and 10) were investigated. A linear increase in the number of spots was observed over time for both cultivars with nine combinations of size and darkness. The total number of discolored spots measured was dependent on both detection size and sensitivity (threshold setting). Significant differences (P < 0.05) in the number of darkened spots were detected between the two cultivars only after 24 hr. Similarly, significant differences (P < 0.05) in size of the spots between the two cultivars was observed at 24 hr. Darkening was most rapid within the first hour for both cultivars, followed by a period of stability before a significant (P < 0.05) further increase by 24 hr. Characterization of the darkness distribution indicated significantly different distribution profiles for the two cultivars examined, which was consistent with their noodle brightness (L*) values.

ABSTRACTThe influence of four water absorption levels at 28–34% was examined on the processing and quality attributes of alkaline and white salted noodles prepared from Canadian Western Red Spring (CWRS), Canadian Western Red Winter (CWRW), and Canadian Western Soft White Spring, (CWSWS) flours. A significant decline (>50%) in the work required to produce the noodles was observed over this absorption range for both types of noodles. Significant differences were detected at 2 hr in the alkaline noodle brightness (L*) on the basis of water absorption level between the classes. Within a class, only CWSWS differentiated L* each absorption level, while CWRS differed only at the 28% level. The L* values of the alkaline noodles decreased by 24 hr but maintained their significant differences due to absorption levels. Significant increases in alkaline noodle yellowness (b*) were observed in each class at 2 hr with increasing water absorption. Yellowness values increased over 24 hr with only minor loss in discrimination due to absorption level. Water absorption levels had only a marginal effect on alkaline noodle redness (a*) values at 2 or 24 hr. Although the cooking time within each class was significantly shortened with each increase in water absorption, minimal influence was detected in the textural attributes of cooked alkaline noodles. White salted noodle L* values were significantly higher at 28% absorption for all classes at 2 and 24 hr, but only CWSWS displayed any further influence due to absorption level. Textural characteristics, recovery, resistance to compression, and maximum cutting stress of the white salted noodles significantly declined with increasing absorption levels in all classes.

Salted noodles were prepared using Canadian Western Red Winter (CWRW) or Canadian Western Red Spring (CWRS) patent flours augmented with 15, 30 and 50% rye flour. Addition of incremental amounts of rye flour resulted in significant decreases in both raw and dried noodle brightness, L*, and yellowness, b*. In addition, dry noodle breaking strength, cooked noodle firmness, (MCS), and chewiness (REC) also decreased with increasing rye content. However, an acceptable wheat:rye noodle was still possible with a rye incorporation of 30%. Proportional substitution of high gluten strength flour from the Canadian Western Extra Stron (CWES) class of wheat in exchange for CWRW flour had no significant impact on noodle color but did significantly (p⩽0.05) improve the textural attributes, especially firmness, of the 70:30 wheat:rye blended noodles. The addition of peroxide at a 0.5% concentration was found to significantly improve wheat:rye blended noodle brightness and firmness. The use of peroxidase in the presence or absence of peroxide had no impact on the wheat:rye noodle quality characteristics.

ABSTRACTSimple phenolic acid levels were determined on pooled millstreams of five different classes of Canadian wheat milled to ~75, 80, and 85% extraction. Pooled flours and whole grain were analyzed by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) to establish endogenous levels of insoluble bound, soluble esterified, and free phenolic acids. Only ferulic acid was detected in the insoluble bound category, which accounted for >80% of the total phenolic acids present in every flour. The soluble esterified phenolic acids accounted for up to 17% of the overall total phenolic acid content within a flour. The major constituents were sinapic, ferulic, and vanillic acids, with minor amounts of coumaric, caffeic, and syringic acids. Free phenolic acids accounted for a maximum of 6% of the total phenolic content of any prepared flour. Ferulic acid was the major free phenolic acid, while sinapic acid was not detected in any flour. Significant correlations (r = 0.64–0.97, P < 0.05) were observed between insoluble bound ferulic acid, individual soluble esterified acids, and most free acids with polyphenol oxidase activity, as well as color and ash content for each class.

Flours from three Canadian wheat classes were processed into oriental noodles at four water absorptions, without additive or with 1% NaCl, 1% kansui, or 1% NaOH. Noodles were prepared using an Ohtake noodle maker equipped with pressure transducers and a data capture system to measure pressure exerted against the rolls during sheeting. Dynamic rheological properties of the doughs were measured with a Bohlin VOR rheometer 2.5 and 24 hr after processing. Rheological properties were contributed to mainly by the elastic character of the doughs. Water absorption and formulation significantly affected the elastic modulus (G'). These trends were consistent between wheat classes. Dough stiffness showed an inverse relationship to water absorption. When compared to doughs prepared without additive, NaCI had little effect on dough stiffness. NaOH greatly increased dough stiffness ; kansui showed an intermediate effect. Doughs containing NaOH continued to increase in stiffness over 24 hr, indicating that the effect of pH may be time-dependent.

Methodology for the preparation and evaluation of chapattis has been refined and utilized in the evaluation of flours milled to an extraction yield of 85% from Canadian wheat classes. Chapatti doughs were prepared utilizing water absorption and mixing times derived from 500 B.U. farinograph data as guidelines. Raw chapattis of 1 mm thickness, cooked for 40 s at 225 °C on one side and 70 s on the other, followed by puffing in a 275 °C oven yielded optimum performance. Chapatti textural attributes (pliability, tearing force, peak puncturing force and total puncturing force) were evaluated and used to comparatively evaluate the seven major classes of wheat grown in western Canada. HunterLab L∗, a∗ and b∗ values were useful for evaluating the colour of both raw and baked chapattis. Evaluations by a sensory panel indicated that all classes of Canadian wheat except durum wheat produced chapattis that were good to excellent. Chapatti quality of durum wheat was rated as fair which may indicate that the unique character of this class requires a special ranking system. Some correlations were found between sensory and instrumental attributes of chapatti quality but a much larger data set will be required to unequivocally clarify relationships.

The FY sedimentation test is commonly used by manufacturers of steamed and fried noodles as one of their flour quality specifications. The FY sedimentation values of Canadian wheat flours were determined, and some of the factors influencing the test results were examined. FY readings within the first hour for different wheat classes were as predicted on the basis of their relative protein content and strength. In subsequent 2- and 3-hr sedimentation gel volumes, variations in trends existed between the different classes. Canadian Western Red Spring and Red Winter wheat classes increased in sedimentation gel volumes, while the Canadian Prairie Spring and Western Soft White wheat classes decreased. Examination of flours increasing in protein content and dough strength suggested that the latter was associated with the resultant changes in sedimentation volumes with time. Flour extraction rate was also found to have an influence on FY sedimentation values,as the 30% extraction flours' initial readings were all significantly different from those at or above 50 or 60% flour extraction. Effects due to sprout damage were minimal. A minimum two-week aging period after milling was necessary to ensure reproducible discrimination of the sediment interface.

A quantitative assay has been developed for assessing the polyphenol oxidase (PPO) levels in grain without the requirement for seed grinding. Seeds were steeped for 16 hr in water and then catechol substrate was added. The resulting color of the liquid was measured after 30 min using a kinetic microplate reader. The method correlated well (r = 0.85) for both the standard oxygen-electrode method for PPO assay performed on ground grain suspensions and the rate of decrease in brightness (L*) or increase in yellowness (b*) of a raw Cantonese noodle sheet after storage for 4 or 24 hr. A substantial amount of the enzyme is present in steep water and can also be used to assay for the relative PPO activity in the seed. The method should be particularly useful to plant breeders for screening of PPO levels in Canadian Prairie Spring wheats.

Wheats representing the five major common wheat classes grown in western Canada were milled on an Allis-Chalmers laboratory mill, and individual streams were composited on the basis of ascending ash content to represent extraction rates of approximately 30, 50, 60, 70, and 75%. Raw Cantonese noodles prepared from these flours were: 1) assessed for raw noodle color with a HunterLab reflectance spectrocolorimeter, and 2) assessed for cooked noodle texture with an Instron Universal Testing Machine. Raw noodle brightness (L*) decreased, and yellowness (b*) increased with time and decresed with flour refinement for all wheat classes. Red-green chromaticity (+/-a*), on the other hand, was class dependent; the color in raw noodles either increased (became redder) or decreased (became greener) at 4 hr after preparation. All the raw noodles became redder after 24 hr. In general, raw noodles prepared from different wheat flours were comparably ranked in terms of brightness and yellowness for each level of flour refinement. Interaction effects between wheat class and flour refinement were minimal. Instron Universal Testing Machine textural measurements included maximum cutting stress, resistance to compression, and surface firmness. Increases in flour protein levels and strengths from the different classes were accompanied by increases in the values of textural properties of the cooked noodles. Within classes, the effects on textural properties caused by differences in flour refinement were not pronounced, with the exception of the Canada Western Red Spring class. Thus, the overall rankings of noodle quality according to color and texture are largely independent of flour refinement. A straight-grade flour can be satisfactorily used, therefore, for the comparative evaluation of the noodle-making quality of different flours.

A laboratory procedure for preparing and evaluating end-product characteristics of Chinese steamed buns from Canadian wheat flours is described. A blend of 60% Canada Western Red Winter (80% patent) and 40% Canada Western Soft White Spring (straight grade) wheat flours was evaluated and subsequently used as the control flour. Buns were prepared by a straight dough procedure using only flour, yeast and water. Evaluation of bun quality included measurement of volume with a loaf volumeter, symmetry by the width-to-height ratio, physical measurements of hardness, cohesiveness and gumminess with the Instron Universal Testing Machine, and color (L*, a*, b*) of crust and crumb using the HunterLab Labscan II Colorimeter. Buns prepared from different classes of Canadian wheats were evaluated. Both Canada Western Red Winter and Canada Western Red Spring wheat flours produced steamed buns which were similar to the control, whereas those made from a non-blended Canada Western Soft White wheat flour produced a less appealing product.Key words: Wheat, steamed buns, test-baking, flour, quality evaluation

Gradient SDS-PAGE analysis of some Canadian wheat cultivars and breeders' lines revealed that there was variation in the mobility of the high molecular weight (HMW) glutenin subunit 7. One group of cultivars/lines had a subunit 7 band that was comparable to that found in the cultivar Chinese Spring, whereas another group had a slightly more mobile band comparable with the subunit 7 band in Bezostaya. This latter band was designated as HMW glutenin subunit 7* in order to differentiate it from the subunit 7 component present in cultivars such as Chinese Spring. Reversed-phase high-performance liquid chromatographic (RP-HPLC) analysis showed that subunits 7 and 7* had comparable elution times. Quantitatively, the proportion of subunit 7 relative to the total amount of HMW glutenin subunits was significantly higher (41·2± 1·5 %) than subunit 7* (27·1 ±0·9 %). The relative proportions were consistent within each group of cultivars as indicated by low coefficients of variation, 3·6 and 3·4 %, respectively. Similarly, the absolute peak area, on a per cent protein basis, was significantly higher for subunit 7 than for subunit 7*. Subunit 7* was found in combination with subunit 9 or subunit 8 or a variant of subunit 8 (as determined by RP-HPLC) designated subunit 8*. This indicated that there are at least three alleles controlling this subunit. Subunit 7 was present in combination with subunits 8 or 8*, and thus there are at least two alleles controlling this subunit. Subunit 7 may be associated with greater dough strength and decreased extractability of gluten proteins. The identification, therefore, of these subunits could be useful for selection purposes in a wheat breeding program.

A new class of sterically protected monofunctional-silane bonded phase columns (C8 and CN) was evaluated to determine resolution capabilities and long-term stability in the reversed-phase high-performance liquid chromatography (RP-HPLC) separation of wheat storage proteins. Up to 450 separations were performed using the high temperature (50-degrees-C) and low pH (< 3) conditions required to resolve gliadins and glutenins. Superior resolution of these proteins was achieved with the new wide-pore, sterically protected columns as compared to that from conventional silica-based RP-HPLC columns. Statistical analysis of retention times and quantified peak areas also indicated improved stability and reproducibility as compared to that from conventional RP-HPLC columns. Column-to-column variability also appeared minimal. Analysis of storage proteins (gliadins or gliadins and glutenins) of different wheat varieties and high molecular weight glutenin subunits exemplified the suitability of these columns for varietal identification and the study of quality-related wheat storage proteins.