Byung-Kee Baik

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...

Identifying Rare FHB-Resistant Segregants in Intransigent Backcross and F2 Winter Wheat Populations

Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.). Infected grain is usually contaminated with deoxynivalenol (DON), a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red winter wheat breeding lines with little or no scab resistance were each crossed to a donor parent (VA01W-476) with resistance alleles at two QTL: Fhb1 (chromosome 3BS) and QFhs.nau-2DL (chromosome 2DL) to generate backcross and F2 progeny. F2 individuals were genotyped and assigned to 4 groups according to presence/ absence of resistance alleles at one or both QTL. The effectiveness of these QTL in reducing FHB rating, incidence, index, severity, Fusarium-damaged kernels (FDK) and DON, in F2-derived lines was assessed over 2 years. Fhb1 showed an average reduction in DON of 17.5%, and conferred significant resistance in 3 of 4 populations. QFhs.nau-2DL reduced DON 6.7% on average and conferred significant resistance in 2 of 4 populations. The combination of Fhb1 and QFhs.nau-2DL resistance reduced DON 25.5% across all populations. Double resistant lines had significantly reduced DON compared to double susceptible lines in 3 populations. Backcross derived progeny were planted in replicated yield trials (2011 and 2012) and in a scab nursery in 2012. Several top yielding lines performed well in the scab nursery, with acceptable DON concentrations, even though the average effect of either QTL in this population was not significant. Population selection is often viewed as an “all or nothing” process: if the average resistance level is insufficient, the population is discarded. These results indicate that it may be possible to find rare segregants which combine scab resistance, superior agronomic performance and acceptable quality even in populations in which the average effect of the QTL is muted or negligible.

Functional and Nutritional Characteristics of Wheat Grown in Organic and Conventional Cropping Systems

The effects of organic versus conventional farming practices on wheat functional and nutritional characteristics were compared. Soft white winter wheat and hard red spring wheat were obtained from multiyear replicated field plots near Pullman, Washington, and Bozeman, Montana. Test weight, kernel weight, and kernel diameter tended to be greater in both soft and hard organic wheat than in conventional wheat in the Pullman studies. Phenolic content and total antioxidant capacity tended to be lower in organic than in conventional wheat. Flour ash, P, and Mg contents in whole wheat flour varied in parallel among cropping systems, but levels were not consistently associated with either organic or conventional cropping systems. Protein contents of whole wheat and refined flours were similar in organic and conventional wheat from Pullman when fertility levels were similar. Higher fertility was associated with higher protein content in both organic and conventional cropping systems. Soft wheat flour from a low-fe...

Volatile Organic Compounds of Whole-Grain Soft Winter Wheat

The aroma from volatile organic compounds (VOC) is an indicator of grain soundness and also an important quality attribute of grain foods. To identify the inherent VOC of wheat grain unaffected by fungal infestation and other extrinsic factors, grains of nine soft wheat varieties were collected at various days postanthesis (DPA) and analyzed for VOC. Ten VOC were detected in all nine varieties at all DPA. 3-Methyl-1-butanol, 2-methyl-1-butanol, 1-pentanol, hexanal, and 1-hexanol were the predominant VOC in concentration. The VOC concentration generally decreased as grain matured from 25 to 40 DPA. Hexanal and 1-hexanol were the most abundant VOC in five and four varieties at 1.30–2.99 and 1.21–5.46 μg/kg of wheat grain, respectively, at 40 DPA. The VOC profiles of wheat grains infected with fungal diseases and stored for several months were uniquely different from that of sound grain.

Functional and Nutritional Characteristics of Soft Wheat Grown in No-Till and Conventional Cropping Systems

The effects of no-till versus conventional farming practices were evaluated on soft wheat functional and nutritional characteristics, including kernel physical properties, whole wheat composition, antioxidant activity, and end-product quality. Soft white winter wheat cultivar ORCF 102 was evaluated over a two-year period from three long-term replicated no-till versus conventional tillage studies in Oregon. Wheat from the no-till cropping systems generally had greater test weight, kernel diameter, and kernel weight and had softer kernels compared with wheat from the conventional tillage systems. Compared with the conventional systems, no-till whole wheat flour had lower protein and SDS sedimentation volume. Ash content as well as most minerals measured (calcium, copper, iron, magnesium, and zinc), except for manganese and phosphorus, were generally slightly lower in no-till than in conventional wheat. Whole wheat flour from the no-till cropping systems generally had slightly lower total phenolic content an...

Effects of Bran Prehydration on Functional Characteristics and Bread-Baking Quality of Bran and Flour Blends

The effect of bran prehydration on the composition and bread-baking quality was determined using bran and flour of two wheat varieties. Bran was hydrated in sodium acetate buffer (50mM, pH 5.3) to 50% moisture at 25 or 55°C for 1.5 or 12 h. The soluble sugar content in bran increased with prehydration. Decreases in phytate and soluble fiber were observed in prehydrated bran, but insoluble fiber was not affected by prehydration. Likewise, free phenolic content decreased, and there was little change in the content of bound phenolics in prehydrated bran. The compositional changes were greater in the bran prehydrated at 55 than at 25°C, and for 12 than for 1.5 h. Addition of prehydrated bran delayed dough development of bran and flour blends and slightly increased water absorption of dough. A higher loaf volume of fresh bread and lower crumb firmness of bread stored for 10 days were observed in bread containing bran prehydrated at 25°C than in bread containing nonhydrated bran or bran prehydrated at 55°C. The...