Induck Choi

Influence of Bran Particle Size on Bread-Baking Quality of Whole Grain Wheat Flour and Starch Retrogradation

ABSTRACT The influence of bran particle size on bread-baking quality of whole grain wheat flour (WWF) and starch retrogradation was studied. Higher water absorption of dough prepared from WWF with added gluten to attain 18% protein was observed for WWFs of fine bran than those of coarse bran, whereas no significant difference in dough mixing time was detected for WWFs of varying bran particle size. The effects of bran particle size on loaf volume of WWF bread and crumb firmness during storage were more evident in hard white wheat than in hard red wheat. A greater degree of starch retrogradation in bread crumb stored for seven days at 4°C was observed in WWFs of fine bran than those of coarse bran. The gels prepared from starch–fine bran blends were harder than those prepared from starch–unground bran blends when stored for one and seven days at 4°C. Furthermore, a greater degree of starch retrogradation was observed in gelatinized starch containing fine bran than that containing unground bran after storag...

Hydration and Pasting Properties of Oat (Avena sativa) Flour.

Three oat cultivars and one oat breeding line were evaluated for chemical, hydration and pasting properties. Protein, starch and β-glucan levels ranged 11.13∼14.37, 56.37∼64.86 and 3.44∼4.76%, respectively. The oat cultivars Daeyang and Seonyang contained higher β-glucan levels of 4.76 and 4.35%. The Daeyang variety had a higher water absorption index (WAI) of 2.83∼3.35 (g/g), but a lower water solubility index (WSI) of 8.67 ∼11.08%. Daeyang and Seonyang cultivars showed higher peak and trough viscosity, but lower breakdown and setback, indicating that they easily swell, and thus could possibly provide the desirable viscosity of an oat product. The β-glucan levels were correlated positively with WAI, peak and trough viscosity, and negatively to WSI, breakdown and setback viscosity.

Bran Hydration and Physical Treatments Improve the Bread-Baking Quality of Whole Grain Wheat Flour

Fine and coarse bran particles of a hard red and a hard white wheat were used to study the influences of bran hydration and physical treatments such as autoclaving and freezing, as well as their combinations, on the dough properties and bread-baking quality of whole grain wheat flour (WWF). For both hard red and hard white wheat, WWF containing bran prehydrated to 60% moisture content exhibited higher dough water absorption and longer dough mixing time, and it produced bread with a larger loaf volume and lower crumb firmness at zero and seven days of storage than the corresponding WWF containing bran without prior hydration. Hard red and hard white WWF containing bran preautoclaved at 121°C for 2 h and hydrated to various moisture levels (20–60%) produced bread with a loaf volume comparable to that produced by the corresponding WWF containing nonautoclaved bran of 60% moisture content, suggesting that autoclaving bran could substitute for bran hydration to improve the bread-baking quality of WWF. The bran...

Bran Characteristics and Bread-Baking Quality of Whole Grain Wheat Flour

ABSTRACT Variations in physical and compositional bran characteristics among different sources and classes of wheat and their association with bread-baking quality of whole grain wheat flour (WWF) were investigated with bran obtained from Quadrumat milling of 12 U.S. wheat varieties and Buhler milling of six Korean wheat varieties. Bran was characterized for composition including protein, fat, ash, dietary fiber, phenolics, and phytate. U.S. soft and club wheat brans were lower in insoluble dietary fiber (IDF) and phytate content (40.7–44.7% and 10.3–17.1 mg of phytate/g of bran, respectively) compared with U.S. hard wheat bran (46.0–51.3% and 16.5–22.2 mg of phytate/g of bran, respectively). Bran of various wheat varieties was blended with a hard red spring wheat flour at a ratio of 1:4 to prepare WWFs for determination of dough properties and bread-baking quality. WWFs with U.S. hard wheat bran generally exhibited higher dough water absorption and longer dough mixing time, and they produced smaller loaf...

Mineral Compositions of Korean Wheat Cultivars

Twenty-nine Korean wheat cultivars were analyzed for 8 important minerals (Cu, Fe, Mn, Zn, Ca, K, Mg and P) using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). A hierarchical cluster analysis (HCA) was applied to classify wheat cultivars, which has a similarity in mineral compositions. The concentration ranges of the micro-minerals Cu, Fe, Mn, and Zn: 0.12~0.71 mg/100 g, 2.89~5.89 mg/100 g, 1.65~4.48 mg/100 g, and 2.58~6.68 mg/100 g, respectively. The content ranges of the macro-minerals Ca, K, Mg and P: 31.3~46.3 mg/100 g, 288.2~383.3 mg/100 g, 113.6~168.6 mg/100 g, and 286.2~416.5 mg/100 g, respectively. The HCA grouped 6 clusters from all wheat samples and a significant variance was observed in the mineral composition of each group. Among the 6 clusters, the second group was high in Fe and Ca, whereas the fourth group had high Cu, Mn and K concentrations; the fifth cluster was high in Zn, Mg and P. The variation in mineral compositions in Korean wheat cultivars can be used in the wheat breeding program to develop a new wheat cultivar with high mineral content, thus to improve the nutritional profile of wheat grains.

Substituting Normal and Waxy-Type Whole Wheat Flour on Dough and Baking Properties

Normal (cv. Keumkang, KK) and waxy-type (cv. Shinmichal, SMC) whole wheat flour was substituted at 20 and 40% for white wheat flour (WF) during bread dough formulation. The flour blends were subjected to dough and baking property measurement in terms of particle size distribution, dough mixing, bread loaf volume and crumb firmness. The particle size of white wheat flour was the finest, with increasing coarseness as the level of whole wheat flour increased. Substitution of whole wheat flour decreased pasting viscosity, showing all RVA parameters were the lowest in SMC40 composite flour. Water absorption was slightly higher with 40% whole wheat flour regardless of whether the wheat was normal or waxy. An increased mixing time was observed when higher levels of KK flour were substituted, but the opposite reaction occurred when SMC flour was substituted at the same levels. Bread loaf volume was lower in breads containing a whole wheat flour substitution compared to bread containing only white wheat flour. No significant difference in bread loaf volume was observed between normal and waxy whole flour, but the bread crumb firmness was significantly lower in breads containing waxy flour. The results of these studies indicate that up to 40% whole wheat flour substitution could be considered a practical option with respect to functional qualities. Also, replacing waxy whole flour has a positive effect on bread formulation over normal whole wheat flour in terms of improving softness and glutinous texture.

Variations in vitamin E, phenolic content, and antioxidant properties of different wheat cultivars of South Korea

ABSTRACT The vitamin E, total phenolic content (TPC), and antioxidant activity (AA) profiles of 32 whole wheat cultivars were investigated. Samples were classified based on its hardness (HW: hard wheat, MW: medium wheat, and SW: soft wheat) for easy identification. Total vitamin E content ranged from 64.38SW2 to 111.83MW9 mg/kg; α-tocopherol (6.03MW13 to 21.98MW2 mg/kg), β-T (2.14MW8 to 21.01MW9 mg/kg), α-tocotrienol (4.28MW12 to 9.34MW9 mg/kg), and β-T3 (38.71MW16 to 61.07MW9 mg/kg) were the predominant homologs, with β-T3 as the highest. AA ranged from 334.40MW4 to 584.80HW4 μmol gallic acid equivalent/kg while TPC varied from 1139.70SW6 to 2772.60MW1 μmol GAE/kg. Significant differences in the vitamin E content, TPC, and AA were found among the cultivars regardless of its hardness index. A very weak correlation was found between TPC and AA while a moderate negative correlation was observed between vitamin E content and AA. Results from this study can serve as basis of further studies on the bioactive profiles of Korean wheat cultivars.

Classification of 31 Korean Wheat (Triticum aestivum L.) Cultivars Based on the Chemical Compositions

Whole grain wheat flour (WGWF) is the entire grain (bran, endosperm, and germ) milled to make flour. The WGWF of 31 Korean wheat (Triticum aestivum L.) cultivars were analyzed for the chemical compositions, and classified into groups by hierarchical cluster analysis (HCL). The average composition values showed a substantial variation among wheat varieties due to different wheat varieties. Wheat cv. Shinmichal1 (waxy wheat) had the highest ash, lipid, and total dietary fiber contents of 1.76, 3.14, and 15.49 g/100 g, respectively. Using HCL efficiently classified wheat cultivars into 7 clusters. Namhae, Sukang, Gobun, and Joeun contained higher protein values (12.88%) and dietary fiber (13.74 %). Regarding multi-trait crop breeding, the variation in chemical compositions found between the clusters might be attributed to wheat genotypes, which was an important factor in accumulating those chemicals in wheat grains. Thus, once wheat cultivars with agronomic characteristics were identified, those properties might be included in the breeding process to develop a new variety of wheat with the trait.