Effect of High‐Pressure Processing on the Features of Wheat Milling By‐products

The ability of high hydrostatic pressure processing to promote changes in both the structural properties of fiber and the interaction of fiber with water were addressed. Both coarse and fine bran from milling of common wheat were considered. Treatment‐induced morphological changes were most pronounced in fine bran, whereas treatment of coarse bran resulted in the largest change in water‐holding capacity. The significance of the process‐induced changes is discussed in terms of their practical relevance in the production of fiber‐enriched foods.     

Glyphosate tolerance in maize (Zea mays L.). 2. Selection and characterization of a tolerant somaclone

Summary The progeny of 104 regenerated maize plants were screened for tolerance to the safe broad-spectrum herbicide glyphosate during seed germination and early growth. Seven somaclones showed varying degrees of resistance to the application of the herbicide at 1.2 mM (0.1 kg a.i. in 400 1 ha^-1 of water). Plants capable of a normal growth following treatment with 2.4 mM (0.2 kg ha^-1) glyphosate at the three leaf stage were selfed, and their progeny analyzed. A family able to tolerate the exposure to glyphosate at 2.4 mM was isolated and shown to maintain a photosynthetic rate comparable with control after the application of the herbicide.The selfed progeny of the tolerant somaclone was characterized as to the properties of two targets of glyphosate, the shikimate pathway enzymes 5-enol-pyruvyl-shikimate-3-phosphate (EPSP) synthase and 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) synthase. In vitro tests ruled out the possibility that the tolerance was due to altered forms of these enzymes. Families showed significant variability with regard to EPSP and DAHP synthase levels, measured at different stages during seedling growth; however, not even these traits were correlated with in vivo response to glyphosate. The possible role of other physiological processes in determining the increased tolerance to the herbicide is discussed.Abbreviations DAHP 3-deoxy-D-arabino-heptulosonate-7-phosphate - EPSP 5-enol-pyruvyl-shikimate-3-phosphate - CER carbon-exchange rate - ID₅₀ concentration causing 50% inhibition     

Degradation of Carotenoids in Apricot (Prunus armeniaca L.) During Drying Process

Carotenoids are natural compounds whose nutritional importance comes from the provitamin A activity of some of them and their protection against several serious human disorders. The degradation of carotenoids was investigated during apricot drying by microwave and convective hot-air at 60 and 70 °C. Seven carotenoids were identified: antheraxanthin, lutein, zeaxanthin, β-cryptoxanthin, 13-cis-β-carotene, all-trans-β-carotene and 9-cis-β-carotene; among these, all-trans-β-carotene was found to be about 50 % of total carotenoids. First-order kinetic models were found to better describe all-trans-β-carotene reduction during drying, with a degradation rate constant (k₁) that increased two folds when temperatures increased by 10 °C, in both methods. No differences were found in k₁ between apricots dried by hot air at 70 °C (k₁?=?0.0340 h^?1) and by microwave at 60 °C. The evolution of total carotenoids (117.1 mg/kg on dry basis) during drying highlighted a wider decrease (about 50 %) when microwave heating was employed, for both set temperatures. Antheraxantin was found to be the carotenoid most susceptible to heat, disappearing at 6 h during both trials with microwave as well as during convective hot-air at 70 °C. For this reason, antheraxanthin could be a useful marker for the evaluation of thermal damage due to the drying process. Also the degree of isomerization of all-trans-β-carotene could be a useful marker for the evaluation of the drying process.     

Real-time observation of bimodal proton transfer in acid-base pairs in water

The neutralization reaction between an acid and a base in water, triggered after optical excitation, was studied by femtosecond vibrational spectroscopy. Bimodal dynamics were observed. In hydrogen-bonded acid-base complexes, the proton transfer proceeds extremely fast (within 150 femtoseconds). In encounter pairs formed by diffusion of uncomplexed photoacid and base molecules, the reaction upon contact was an order of magnitude slower, in agreement with earlier reported values. These results call for a refinement of the traditional Eigen-Weller picture of acid-base reactions: A three-stage model is introduced to account for all observed dynamics.     

Detection of Helicobacter and Campylobacter spp. from the aquatic environment of marine mammals

The mechanism by which Helicobacter species are transmitted remains unclear. To examine the possible role of environmental transmission in marine mammals, we sought the presence of Helicobacter spp. and non-Helicobacter bacteria within the order Campylobacterales in water from the aquatic environment of marine mammals, and in fish otoliths regurgitated by dolphins. Water was collected from six pools, two inhabited by dolphins and four inhabited by seals. Regurgitated otoliths were collected from the bottom of dolphins' pools. Samples were evaluated by culture, PCR and DNA sequence analysis. Sequences from dolphins' water and from regurgitated otoliths clustered with 99.8-100% homology with sequences from gastric fluids, dental plaque and saliva from dolphins living in those pools, and with 99.5% homology with H. cetorum. Sequences from seals' water clustered with 99.5% homology with a sequence amplified from a Northern sea lion (AY203900). Control PCR on source water for the pools and from otoliths dissected from feeder fish were negative. The findings of Helicobacter spp. DNA in the aquatic environment suggests that contaminated water from regurgitated fish otoliths and perhaps other tissues may play a role in Helicobacter transmission among marine mammals.