O. K. Chung

Single-kernel characteristics of hard winter wheats in relation to milling and baking quality

ABSTRACT To investigate relationships of wheat single kernel (SK) characteristics with end-use properties, we used 12 hard winter wheat cultivars harvested at six regions in Kansas in 1993. Significant positive correlations occurred among wheat hardness parameters including near-infrared reflectance hardness score, SK hardness index (SK-HI), and SK peak force (SK-PF) obtained by the Single Kernel Characterization System (SKCS). The SKCS characteristics also were significantly correlated to conventional wheat quality parameters such as test weight, kernel density, and kernel sizing. Flour yields were significantly correlated with SK-PF, SK-HI, and SK weight (SK-WT), suggesting the usefulness of SKCS in evaluating milling quality. The negative correlation of milling score with the standard deviation of SK-HI and SK-PF indicated that uniformity of SK hardness is desirable for good milling performance. However, bread loaf volumes had significant negative correlations with SK diameter and SK-WT, mainly due to ...

Fortifying bread with a mixture of wheat fiber and psyllium husk fiber plus three antioxidants

ABSTRACT A 7:3 (w/w) mixture of wheat fiber (WF) and psyllium husk fiber (PHF) was substituted for 10wt% of flour on a 14% mb, and the protein in the blend was restored to 10.3% by incorporating vital wheat gluten. After adding 0.5% sodium stearoyl 2-lactylate, the blend (100 g) was fortified with a combination of fat-coated ascorbic acid (AsA), proteinencased (PE) β-carotene, and cold-water-dispersible (CWD) all-rac-α-tocopheryl acetate (ToAc) at levels of 72, 5.6, and 115 mg, respectively, of active material. Adding the fiber ingredients to the pup loaf formula increased water absorption 25% and mixing time 50% and imparted stickiness to the dough. The fiber and antioxidant bread showed a 10% reduction in loaf volume and a somewhat inferior crumb grain with an off-color caused by small, black specks on a dark gray background. The crumb of the fiber and antioxidant bread remained much softer than control bread during one to seven days of storage at room temperature. Caramel coloring masked the off-color....

Volatiles in selected commercial breads

ABSTRACT Selected types of commercial breads obtained from local markets, including white sandwich, Irish oatmeal, soft rye, hearty rye, sour dough, home-like white, and onion-basil, were analyzed for volatiles. Using a purge and trap instrument, volatiles were purged directly from fresh crumb and crust samples of each bread type, collected on a trap (Tenax-TA), and transferred to a gas chromatograph. Separated components were detected and identified using mass and infrared spectroscopic detectors. Many components were present in all of the bread samples, with relative amounts varying among bread types and crust and crumb samples of a given bread type. Alcohols were generally the most abundant, followed in approximate order by aldehydes, esters, ketones, acids, various aromatics, terpenes, and hydrocarbons. Flavor additives, such as limonene, carvone, and other related compounds, were found mostly in rye and onion-basil breads. Composition of volatiles from sour dough bread differed greatly from the other...

Gluten, pasting, and mixograph parameters of hard winter wheat flours in relation to breadmaking

ABSTRACT Flour gluten, pasting, and mixogram characteristics of 12 hard winter wheat cultivars grown in six counties in Kansas were analyzed using the Glutomatic System, a Rapid Visco-Analyser, and MIXSMART computer software, respectively, to investigate their relationships with breadmaking. Gluten contents and hydration amounts had significant correlations with water absorption. In addition, gluten parameters were significantly correlated to kernel hardness. One of the most difficult challenges in mixograph usage is to find the optimum water absorption of a given flour. Flour protein contents (FP) and near-infrared hardness scores or FP and gluten parameters could predict mixograph water absorptions, showing R2 values of 0.842 or 0.814, respectively, by multiple regression analysis. For our set of 72 wheat samples, computer-analyzed mixograph parameters were significantly correlated to conventional parameters. Computer-analyzed mixograph midline peak times and bandwidths at 6 min were highly correlated t...

Size distribution and properties of wheat starch granules in relation to crumb grain score of pup-loaf bread

ABSTRACT Twelve hard winter wheat flours with protein contents of 11.8–13.6% (14% mb) were selected to investigate starch properties associated with the crumb grain score of experimentally baked pup-loaf bread. The 12 flours were classified in four groups depending on the crumb grain scores, which ranged from 1 (questionable-unsatisfactory) to 4 (satisfactory). Flours in groups 1, 2, 3, and 4 produced breads with pup-loaf volumes of 910–1,035, 1,000–1,005, 950–1,025, and 955–1,010 cm3, respectively. Starches were isolated by a dough handwashing method and purified by washing to give 75–79% combined yield (dry flour basis) of prime (62–71%) and tailing (7–16%) starches. The prime starch was fractionated further into large A-granules and small B-granules by repeated sedimentation in aqueous slurry. All starches were assayed for weight percentage of B-granules, swelling power (92.5°C), amylose content, and granular size distribution by quantitative digital image analysis. A positive linear correlation was fo...

Relationships of Free Lipids with Quality Factors in Hard Winter Wheat Flours

ABSTRACT Hard winter wheat (Triticum aestivum L.) flours (n = 72) were analyzed for free lipids (FL) and their relationships with quality parameters. The two main glycolipid (GL) classes showed contrary simple linear correlations (r) with quality parameters. Specifically, kernel hardness parameters, flour yields, and water absorptions had significant negative correlations with monogalactosyldiglycerides (MGDG) but positive correlations with digalactosyldiglycerides (DGDG). MGDG showed negative correlations with gluten content but positive correlations with gluten index. The percentages of DGDG in FL had significant positive correlations among cultivars (n = 12) with mixograph and bake mix times (r = 0.71, P < 0.01 and r = 0.67, P < 0.05, respectively), mixing tolerance (r = 0.67, P < 0.05), and bread crumb grain score (r = 0.71, P < 0.01). These results suggest that increasing DGDG in FL could contribute to enhancing wheat quality attributes including milling, dough mixing, and breadmaking quality charact...

Prediction of Baking Characteristics of Hard Winter Wheat Flours Using Computer-Analyzed Mixograph Parameters

ABSTRACT The objective of this research was to determine whether computer-analyzed (objective) mixograph parameters could replace conventional mixograph parameters in the evaluation of flour quality. The 642 hard winter wheat flours, collected from federal regional performance nurseries in 1995 and 1996, were analyzed by a conventional and computerized mixograph. Mixograph bandwidths at 6 min (BW6) showed the most significant linear correlation with subjective mixing tolerance scores (r = 0.81, P < 0.1%, n = 642). Prediction models of conventional and experimental baking parameters were developed by continuum regression using computer-analyzed mixograph parameters of a calibration set (n = 282). The developed models could estimate conventional mixograph mixing time and tolerance scores, baking water absorption and mixing time, and bread loaf volume, showing R2 values of 0.86, 0.74, 0.68, 0.80, and 0.51, respectively, for a validation set (n = 380). These results indicated that computer-analyzed mixograph ...

Estimation of Free Glycolipids in Wheat Flour by HPLC

ABSTRACT The chloroform-acetone mixture (4:1, v/v) was an effective solvent for eluting the nonpolar lipid fraction, including free fatty acids, from the polar lipid (glycolipid and phospholipid) fractions from free lipids of 21 hard winter wheat flours using a solid-phase extraction system. Amounts of monogalactosyldiglycerides (MGDG) and digalactosyldiglycerides (DGDG) in the glycolipid fraction were determined by normal-phase HPLC with a gradient system using an evaporative light-scattering detector (ELSD) and a diode array detectors (DAD). Unsaturated fatty acids showed higher UV absorbances from 200 to 213 nm when compared with saturated palmitic acid. However, significant linear correlation coefficients were obtained between the peak areas measured by a DAD and GL contents determined by an ELSD, suggesting that fatty acid composition of flour GL could be fairly constant. Using an ELSD as a reference, equations for determination of MGDG or DGDG quantities were derived from the peak areas of a DAD by ...

Volatile Compounds in Five Starches

ABSTRACT Volatile compounds in commercial wheat, corn, potato, waxy corn, and tapioca starches and in laboratory-prepared wheat, corn, and potato starches were collected, separated, and identified by a purge and trap concentrator (P&T) interfaced to a gas chromatograph (GC) equipped with a Fourier transform infrared detector (FTIRD) and a mass selective detector (MSD). Hexanal was the most abundant compound in the corn and potato starches and in the laboratory-prepared wheat starch as determined by total ion chromatogram (TIC) peak areas. Hexanal was the third most abundant compound in commercial wheat starch after 2-ethyl-1-hexanol and benzaldehyde. Among the volatile organics, the level of aldehydes was the highest, followed by alcohols, ketones, benzenes, esters, and terpenes. Specific compounds identified, the majority of which appear to be degradation products of lipid peroxidation, include hexanal, heptanal, octanal, nonanal, decanal, benzaldehyde, 2-propanone, 2-propanol, 1-butanol, 2-ethyl-1-hexan...

Characteristics of noodle flours from Japan

ABSTRACT The compositions and physical properties of Japanese salt and alkaline noodle flours were contrasted and compared to those of flours from U.S. hard white and soft white wheats (HWW and SWW) and from Australian SWW wheats often segregated for salt noodles. The alkaline noodle flours averaged 11.5% protein, which was 3% higher than the salt noodle flours, and they had lower ash content (0.35 vs. 0.41%). Granulation of the salt noodle flours showed the same proportion of small particles (<38 μm) as in soft wheat flours but different levels of intermediate and large particles. The level of small particles was ≈10% greater in salt noodle flours than in the alkaline noodle flours. The alkaline noodle flours had ≈8% more fine particles and 2.5% more damaged starch than the HWW flours, which is consistent with fine grinding of hard wheat flour in the noodle flour. Starch damage also was higher in the salt noodle flours (5.3%) than in the SWW flours. The salt noodle flours had a higher sodium dodecyl sulf...