Soybean Hulls as an Iron Source for Bread Enrichment

Soybean hulls, a concentrated source of iron, may have potential as a source of iron fortification in baked products. Retention of ⁵⁹Fe in rats from white bread containing intrinsically labeled soybean hulls did not differ significantly (p<0.05) from extrinsically labeled white bread fortified with bakery grade ferrous sulfate (70.4 and 63.1%, respectively). Physical and sensory evaluations of bread containing up to 5% soybean hulls did not differ from white bread in loaf volume, cross-sectional area, tenderness or overall acceptance. These results suggest that soybean hulls are a good source of available iron and may be added to bakery products without deleterious effects in baking performance and sensory acceptability.     

Using the Magma Computer Algebra System in Abstract Algebra Courses

Students meeting their first serious course in abstract algebra commonly experience difficulty understanding many of the basic concepts. This makes it very hard for them to interpret and generate proofs. The first step in reaching an understanding of such concepts is often best achieved by constructing and manipulating instances in particular algebraic structures. Computer algebra systems open up the possibility of students being able to experiment rapidly and conveniently with such concepts in a variety of structures having non-trivial size and complexity. The new Magma computer algebra system has a syntax and semantics based directly on fundamental algebraic notions, and consequently should provide an appropriate learning environment for those branches of mathematics that are heavily algebraic in nature. This paper describes the development of Magma-based exercises and a course methodology that utilizes Magma as a key learning tool in a Pass-level Rings and Fields course given at the University of Sydney.     

Quality and Shelf-life of Fresh Cut Carrot Slices as Affected by Slicing Method

The effects of slicing method on the quality and storage-life of modified atmosphere packaged carrot slices were determined using microscopy, sensory evaluation, microbial counts and a range of physical and chemical tests. Slicing caused physical damage, physiological stress and enhanced microbial growth. The severity of these effects were in the order of blunt machine blade > sharp machine blade > razor blade. These findings provide insights into the magnitude and basis of slicing effects and also confirm the importance of gentle processing and the use of a sharp blade.     

The compositional and functional properties of commercial mozzarella, cheddar and analogue pizza cheeses

The compositional and functional properties of commercial retail and/or wholesale samples (n = 8) of low-moisture mozzarella, cheddar and analogue (pizza) cheeses were compared. Inter-and intravariety differences were evident with intravariety differences in composition being relatively large for the analogue cheese. Cheddar had the lowest mean pH and level of expressible serum and the highest mean levels of proteolysis, expressible fat, and serum calcium and nitrogen (p < 0.05). Compared to mozzarella, the analogue cheeses had significantly lower (p < 0.05) mean levels of total protein and serum calcium, higher levels of total calcium and higher cheese pH. The mean stretchability of the melted mozzarella cheese was significantly higher than that of the melted cheddar or analogue cheeses. The melted cheddar had the highest mean flowability and lowest mean apparent viscosity (p < 0.05). The mean flowability and apparent viscosity of the analogue cheese were numerically lower and higher, respectively, than those of mozzarella.     

Vitamin B6 In Ready-To-Eat Cereals: Analysis By High Performance Liquid Chromatography

Twenty-four ready-to-eat cereals obtained locally were analyzed for their vitamin B₆ content by a recently developed high performance liquid chromatographic (HPLC) procedure. The method uses sulfo-salicylic acid as an extraction agent with subsequent qualitative and quantitative analysis by anion exchange chromatography. All six forms of vitamin B₆ plus their metabolite, pyridoxic acid, can be identified and quantified. Spot checks of the results obtained with this method and with a radiometric-microbiological assay give agreement to within 5%. On the other hand, disagreements of up to 38% are found on comparison with the standard AOAC microbiological procedure used by a commercial laboratory. The results indicate no significant variations between boxes within the same lot, but in one-third of the cereals tested, significant variations were found from lot to lot.     

Transfer of antibiotics between the udder quarters of dairy cows treated for clinical mastitis

Milk samples from all quarters of 13 dairy cows, each treated with an antibiotic preparation for clinical mastitis in one quarter, were collected at each milking during treatment and for at least six milkings thereafter. After storage at —25 °C, these were tested for the presence of antibiotics. Transfer to untreated quarters was found in eight of the 13 cases studied, although in only two cases was the level in untreated quarters greater than 0.01 μ/ml. The main factor affecting transfer was found to be a history of infection in the treated quarter. This was observed in all but one case where transfer had occurred. During the period of study incorporation of milk from untreated quarters would not have raised the antibiotic level in the bulk supply to a level which would have incurred a financial penalty.     

FACILITATED TRANSPORT OF CARBON DIOXIDE: A REVIEW

The effect of reversible chemical reaction upon the diffusion of carbon dioxide in thin liquid film membranes is reviewed. Particular emphasis is placed upon the hydration reaction of CO₂ and catalysis thereof. Theoretical analysis is developed for equilibrium, near-equilibrium and near-diffusion regimes. The important effects of weak acid buffers, proteins and amines upon CO₂ transport are also discussed, as well as the significance of diffusion potentials, particularly in the case of protein systems. Results of experimental investigations of facilitated CO₂ transport are reviewed, as well as general aspects of CO₂ transport in biological systems and absorbers.