Generation of a Mixolab Profile After the Evaluation of the Functionality of Different Commercial Wheat Flours for Hot‐Press Tortilla Production

Refined wheat flours commercially produced by five different U.S. and Mexican wheat blends intended for tortilla production were tested for quality and then processed into tortillas through the hot‐press forming procedure. Tortilla‐making qualities of the flour samples were evaluated during dough handling, hot pressing, baking, and the first five days on the shelf at room temperature. The predominant variables that affected the flour tortilla performance were wet gluten content, alveograph W (220–303) and P/L (0.70–0.94) parameters, farinograph water absorption (57%) and stability (10.8–18.7 min), starch damage (5.43–6.71%), and size distribution curves (uniform particle distribution). Flours produced from a blend of Dark Northern Spring (80%) and Mexican Rayon (20%) wheat had the highest water absorption, and tortillas obtained from this blend showed the highest diameter and lowest thickness. The whitest and best textured tortillas were obtained from the flour milled from three hard types of Mexican wheat blend. A Mixolab profile was generated from the best tortilla flours, those produced by mills 3 and 4. The Mixolab profile showed that a good flour for hot‐press tortillas had a relatively lower absorption and short dough mix time compared with a bread flour and should have a significantly higher gluten compared with an all‐purpose flour. Compared with bread flour, the tortilla flour had higher retrogradation and viscosity values. The Mixolab profile proved to be a good preliminary test to evaluate flours for hot‐press tortillas.     

Modeling First Break Milling of Debranned Wheat Using the Double Normalized Kumaraswamy Breakage Function

Debranning of wheat affects flour quality, initially by altering the breakage of wheat kernels during first break. The double normalized Kumaraswamy breakage function was applied to model the effect of debranning on wheat breakage during first break milling, in which type 1 breakage describes a relatively narrow distribution of midsized particles, whereas type 2 breakage describes a wide size range of predominantly small particles extending to very large particles. Mallacca (hard) and Consort (soft) wheats were debranned and milled at three roll gaps under sharp‐to‐sharp and dull‐to‐dull dispositions. Type 1 breakage increased at longer debranning times, whereas type 2 breakage decreased, for both wheat varieties under both dispositions. Sharp‐to‐sharp milling tended to produce more type 1 breakage than dull‐to‐dull. A mechanism of wheat breakage is proposed to explain the coproduction of very large and small particles via type 2 breakage and, hence, the effect of debranning. The proposed mechanism is that small particles of endosperm arise from scraping of large flat particles of wheat bran under the differential action of the rolls, such that removal of the bran reduces the production of the large bran particles and thus reduces the opportunity for the scraping mechanism that produces the very small particles.     

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

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 Bühler 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 volume of bread than WWFs of U.S. soft and club wheat bran. WWFs of two U.S. hard wheat varieties (ID3735 and Scarlet) produced much smaller loaves of bread (<573 mL) than those of other U.S. hard wheat varieties (>625 mL). IDF content, phytate content, and water retention capacity of bran exhibited significant relationships with loaf volume of WWF bread, whereas no relationship was observed between protein content of bran and loaf volume of bread. It appears that U.S. soft and club wheat bran, probably owing to relatively low IDF and phytate contents, has smaller negative effects on mixing properties of WWF dough and loaf volume of bread than U.S. hard wheat bran.     

Zinc Blotting Assay for Detection of Zinc‐Binding Prolamin in Barley (Hordeum vulgare) Grain

In plants, zinc is commonly found bound to proteins. In barley (Hordeum vulgare), major storage proteins are alcohol‐soluble prolamins known as hordeins, and some of them have the potential to bind or store zinc. ⁶⁵Zn overlay and blotting techniques have been widely used for detecting zinc‐binding protein. However, to our knowledge so far this zinc blotting assay has never been applied to detect a prolamin fraction in barley grains. A radioactive zinc (⁶⁵ZnCl₂) blotting technique was optimized to detect zinc‐binding prolamins, followed by development of an easy‐to‐follow nonradioactive colorimetric zinc blotting method with a zinc‐sensing dye, dithizone. Hordeins were extracted from mature barley grain, separated by SDS‐PAGE, blotted on a membrane, renatured, overlaid, and probed with zinc; subsequently, zinc‐binding specificity of certain proteins was detected either by autoradiography or color formation. The dithizone staining method gave similar reproducibility to the radioactive blotting. The detected zinc‐binding protein was identified as B‐hordein by Western blotting.     

Impacts of SSIIa‐A Null Allele on Durum Wheat Noodle Quality

A small increase in amylose content may impact end‐product quality of wheat. The effect of elevated amylose content in durum wheat is not known. We surveyed 255 durum wheat accessions and found two genotypes that lacked the SGP‐A1 protein. These genotypes were crossed to Mountrail, an adapted durum genotype, to create populations segregating for the SSIIa‐Ab null allele. Our goal was to determine the influence of allelic variation at the SSIIa‐A locus on semolina properties and end‐product quality with noodles as a test product. Amylose content increased 3% and cooked noodle firmness increased 2.8 g·cm for the SSIIa‐Ab class compared with the SSIIa‐Aa class for the PI 330546 source, but no change in either trait was detected between classes for the IG 86304 source. The SSIIa‐Ab class had a 10% reduction in flour swelling compared with the SSIIa‐Aa class for both crosses. Grain protein and semolina yield did not differ between SSIIa‐A classes. The relationship between flour swelling power and noodle firmness did not differ between SSIIa‐A allelic classes within a cross. The different results for amylose content and noodle firmness between these sources may be because the two sources of the SSIIa‐Ab null mutation contributed different linkages to the segregating populations. Results show that the SSIIa‐Ab allele could be used to produce durum‐based products that are slightly more firm in texture. However, the effect of the SSIIa‐Ab allele may depend on the source.     

Expression,Purification, and Functional Analysis of Three Low‐Molecular‐Weight Glutenin Subunits from Wheat Cultivar Cheyenne

Glutenins, which form the network of gluten protein, are of great importance for the quality of flour products. Glutenins can be divided into HMW and LMW subunits according to molecular weight. Three genes for LMW glutenin subunits (LMW‐GS), named lmw‐cnd1, lmw‐cnd2, and lmw‐cnd3 with open reading frames of 1,053, 903, and 969 bp, respectively, were cloned from wheat cultivar Cheyenne. Heterologous expression vectors of the three LMW‐GS were constructed, and the recombinant proteins LMW‐CND1, LMW‐CND2, and LMW‐CND3 were overexpressed in Escherichia coli. After cell disruption with ultrasound, target proteins of high purity were obtained by using Ni²⁺ affinity chromatography. Farinograph and TAPlus measurements were used to investigate the effects of the three LMW‐GS on the characteristics of flour and dough. The results showed that the addition of each LMW‐GS can lead to an increase in the elasticity of the dough. Moreover, LMW‐CND2 and LMW‐CND3 promoted the strength of the dough. All three LMW‐GS caused a decrease of hardness and increase of springiness and cohesiveness of dough according to texture profiling results. Consequently, all three LMW‐GS have positive effects on the processing characteristics of dough and can improve bread quality to different extents.     

VERTEBRAL OSTEOSCLEROSIS IN A CAT SECONDARY TO RHABDOMYOSARCOMA

A 5–year–old cat was presented for pelvic limb weakness. Sclerosis of the vertebral body of T–10 was visible on thoracic radiographs. A compressive lesion at this area was noted on myelography. A tumor was partially removed at surgery, but the cat was killed because of poor postoperative response. Rhabdomyosarcoma was diagnosed at necropsy, with bone marrow necrosis and myelofibrosis, and new bone proliferation of the body of T–10. Causes of bone necrosis are discussed.     

Foetal Protection against Bovine Virus Diarrhoea Virus after Two‐step Vaccination

In order to assess the efficacy of a two‐step vaccination protocol with respect to foetal protection against transplacental infections with bovine virus diarrhoea virus (BVDV) with special attention to BVDV‐2 seronegative heifers were vaccinated with an inactivated BVDV‐1 vaccine and boostered with a modified live BVDV‐1 vaccine after 4 weeks. A second group was left unvaccinated as control. Between days 30 and 120 of pregnancy the heifers of both groups were intranasally challenged with a mixture of BVDV‐1 and ‐2. All heifers of the vaccinated group gave birth to nine clinically healthy, seronegative (precolostral) and BVDV‐free calves. In contrast in the control group four BVDV viraemic underdeveloped calves were born. Additionally, one calf was stillborn and another viraemic calf was not viable and died 2 days after birth. All six calves of the control group were viraemic with BVDV‐2. This study demonstrated for the first time that two‐step vaccination of breeding cattle with a modified live BVDV vaccine 4 weeks after application of an inactivated BVDV vaccine was capable of providing a foetal protection against transplacental infection with BVDV‐2.     

Ultrasound Enhanced Immersion Protocols for Masculinization of Nile Tilapia, Oreochromis niloticus

Androgen immersion protocols have been unsuccessful in consistently producing all-male tilapia at a high enough ratio for them to be commercially viable. This study explored the use of ultrasound to improve on the results of previous immersion studies. Variables tested include two hormones (trenbolone acetate-TBA and 17α-methyldihydrotestoterone-MDHT) at two concentrations (100 and 250 μg/L) and with or without ultrasound (cavitation level). All hormone treatments with ultrasound and non-ultrasound resulted in significantly higher masculinization than the appropriate controls ( P < 0.05). Among pairs of treatments of the same hormone at the same dose, all ultrasound treatments resulted in significantly higher number of males compared with non-ultrasound treatments with the exception of MDHT 250 μg/L ( P 0.05). Comparing across all ultrasound treatments, TBA 250 μg/L with ultrasound had higher masculinization than all the other ultrasound treatments ( P 0.05). Comparing across all non-ultrasound treatments, TBA 250 μg/L had higher ( P 0.05) masculinization than MDHT 100 μg/L and TBA 100 μg/L with non-ultrasound. Two of the three replicates of TBA 250 μg/L ultrasound treatment resulted in 100% males and the highest mean percentage (98%) of males. This study thus demonstrated the potential of a short-term immersion protocol using ultrasound to more predictably produce all-male, commercially viable tilapia seed.     

Nuclear transfer using a bovine mammary epithelial cell line (BMEC)

The developmental potential of nuclei from a bovine mammary epithelial cell line (BMEC) in nuclear transfer was investigated. For nuclear transfer donors, BMEC cells (passage 15) were cultured for 4–5 days after seeding at cell densities of 1.0 × 10⁵ cells/cm² (high‐density group) or 0.8 × 10⁴ cells/cm² (low‐density group). First, the effective electric stimulation for fusion of enucleated oocytes with BMEC cells was examined. Fusion rates reached maximum with two DC pulses of 30 V/150 µm for 20 µs in the high‐density group and with two DC pulses of 25 V/150 µm for 10 µs in the low‐density group. The fusion rate (37.5%) in the high‐density group was significantly (P < 0.005) lower than in the low‐density group (71.4%). Second, the in vitro developmental potential of nuclear transfer embryos derived from BMEC cells was examined. In the high‐density and low‐density groups, 18.8% and 24.1% of fused oocytes, respectively, developed to blastocyst stage. The results of this study indicate that nuclei from BMEC cells support the development of nuclear transfer embryos to the blastocyst stage and that the efficiency of oocyte–cell fusion is affected by the culture conditions of the donor BEMC cells before nuclear transfer.