IRON CONTENT, SENSORY EVALUATION, AND CONSUMER ACCEPTANCE OF FOOD COOKED IN IRON UTENSILS

The purpose of this study was to determine the effect of cooking food in iron utensils on the iron content, sensory quality, and consumer acceptance/ preference of the food. Hamburger patties and applesauce were cooked in iron and in glass utensils and were analyzed for iron content by atomic absorption spectrophotometry and evaluated by a trained sensory panel, by consumers, and for chroma, pH, and refractometer changes. Cooking hamburger patties and applesauce in iron utensils increased iron in the food, did not affect sensory quality or consumer acceptance/preference of hamburger patties, but affected the color and flavor and decreased consumer acceptance/preference for applesauce.     

Shortening as a factor in meat ageing

Summary. Shortening during the slow and rapid phases of rigor mortis onset determines largely the extent to which beef ages. For meat stored at 15°C for 3 days, shear-force values are uniformly low at shortenings of 0% to 20% of the freshly excised muscle length. However, there is a four- to five-fold increase in toughness as shortenings proceed from 20% to 40%. This is followed by a decline in toughness as shortenings increase further from 40% to 55%. With increasing shortenings beyond 20%, progressive decreases occur in the extent to which meat ages until at 40% shortening, ageing has declined to zero.     

INHIBITION OF STAPHYLOCOCCUS AUREUS AND BACILLUS CEREUS ON A VEGETARIAN FOOD TREATED WITH NISIN COMBINED WITH EITHER POTASSIUM SORBATE OR SODIUM BENZOATE

Various amounts of nisin (0, 10³ and 5 × 10³ IU/g) in combination with either potassium sorbate (0, 2, and 3%) or sodium benzoate (0, 0.06 and 0.12%) were tested for effectiveness in inhibiting growth of Staphylococcus aureus C10 and Bacillus cereus B7 inoculated on a vegetarian food. The strains used were isolated from vegetarian foods obtained commercially in Taiwan, and the test food, spice and dried bean curd, was selected for the study based on ability to support the growth of these organisms. After treatment with a preservative combination, the surfaces of sterilized food samples were inoculated, samples were stored in vacuum or nonvacuum packages at either 4C or 30C, and at appropriate times, tested for microbial growth. Growth of both isolates was unaffected by vacuum-packaging treatment; however, a bacteriostatic effect was found at 4C. Data indicated that during the 14-day storage at 4C, vacuum-packaged samples treated with 5 × 10³ IU/g nisin and 0.12% sodium benzoate significantly (p < 0.05) decreased the counts of S. aureus C10 and B. cereus B7 by 2.61 and 3.02 log₁₀ CFU/g, respectively. In the vacuum-packaged samples treated with 5 × 10³ IU/g nisin and 3% potassium sorbate, counts for C10 and B7 were decreased by 2.35 and 2.64 log₁₀ CFU/g, respectively. Thus, the combined treatment extended the shelf-life of the vegetarian food .     

Scanning Electron Microscopy and Transmission Electron Microscopy Study of Ferroelectric Domains in Doped BaTiO3

This paper describes the results of detailed studies carried out on Ca-doped and Nb-doped BaTiO₃ using scanning electron microscopy and transmission electron microscopy. The techniques used were topographical contrast, selected-area diffraction, and microdiffraction Kikuchi pattern analysis. By these methods it was possible to unambiguously identify the different types of domain boundaries. Also, evidence was obtained for the existence of an unconventional 90% domain boundary which has not previously been reported.     

Undulating Structure in Complex Silicate Glasses

Complex silicate glasses (e.g. commercial plate, sheet, and ophthalmic compositions), mica, and fused SiO₂ were carefully examined in the electron microscope using Pt-C replicating techniques. The complex glasses show an undulating structure at 300 to 500 Å, whereas the mica and fused SiO₂ do not. The low contrast observed between peak and valley is consistent with a small difference in chemical composition. The observed structure is explained in terms of an extension of the anionic model for molten silicates whereby the peaks and valleys result from clustering of silicate anions accompanied by partial expulsion of cations to the periphery.