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Pansteatitis has been identified in wild populations of sharptooth catfish, Clarias gariepinus (Burchell), and Nile crocodiles, Crocodylus niloticus Laurenti, inhabiting the same waters in the Olifants River Gorge in the Kruger National Park, South Africa. Mesenteric and pectoral fat tissue was investigated microscopically and by fatty acid analysis in healthy and pansteatitis-affected catfish from both captive and wild populations. Variation in fatty acid composition between pectoral and mesenteric fat was noted. Composition of mesenteric fat differed between fish from various localities as a result of differences in diet. Pansteatitis in the captive population, resulting from ingestion of high amounts of dietary oxidized fat, reflected higher levels of unsaturated fatty acids within the mesenteric fat. Mesenteric fat of pansteatitisaffected wild catfish was characterized by an increase in moisture content, a decrease in fat content and a decrease in stearic and linoleic acids. The n-3 to n-6 fatty acid ratio of mesenteric fat was higher in pansteatitis-affected wild catfish than in healthy catfish from the same locality, reflecting higher polyunsaturated fat intake by pansteatitisaffected fish. The possible role of alien, invasive, phytoplankton-feeding silver carp, Hypophthalmichthys molitrix (Valenciennes), in the aetiology of pansteatitis in both catfish and crocodiles in the Olifants Gorge is discussed.

This study compares the aetiology of pansteatitis in Lake Loskop, relative to two other impoundments along the Olifants River. Macroscopic and microscopic pathology, age determination and analysis of stomach content, fatty acids and stable isotopes explain the high prevalence of pansteatitis in Oreochromis mossambicus (Peters) and several other species in Lake Loskop. All the dietary indicator comparisons between pansteatitis-affected and healthy fish fail to support a systemic cause. Pansteatitis in Lake Loskop was linked to size and weight of O. mossambicus, but not to ontogenic age. Fish in Lake Loskop showed abnormally high omega-3 to omega-6 fatty acid ratios normally only found in marine fish with no significant difference in degree of assimilation of these fatty acids between pansteatitis-affected and healthy fish. This explains the vulnerability to, but not the occurrence of, pansteatitis. As a cause for the pansteatitis, these results point towards sporadic vitamin E-depleting trigger events, known sporadic fish die-off occurrences that provide surviving fish with a rich source of rancid fats on which to scavenge. The mechanism ties pansteatitis to eutrophication and trophic cascade effects, the intrinsic drivers of the disease and suggests an adaptive management strategy that might be applied by relevant conservation authorities.

The milk composition of free-ranging indigenous African cattle breeds was analysed. These breeds were chosen because they have not been bred specifically for milk production and might be considered the closest to a "natural" or "wild type" of the Bos species. It was found that the nutrient composition of the milk of these cattle, in particular the dry matter, is as low as that of European beef breeds. The content of whey proteins and NPN is also lower than that of dairy breeds. Statistically significant differences in milk fatty acid composition between the Sanga-type cattle and the Afrikaner and its derivatives were observed for the content of lactose, whey protein and non-protein nitrogen, as well as fatty acid composition regarding medium long chain and long chain fatty acids. A genetic relationship is evident and suggests the preference of certain fatty acid synthesis pathways. ________________________________________________________________________________

Physical characterization of a soymilk powder was carried out by electron microscopy. Chemical characterization was analyzed by proximate analysis, mineral composition by atomic absorption spectrometry, fatty acid composition by gas chromatography and protein composition by electrophoresis. The powder consists of large granules of 60-80 μm, which may be hollow, with smaller granules of 10-20 μm attached to them. Powder particles are covered by a layer of fat. During storage at 25 °C fat is spreading over the surface, while at -12 °C the fat is contracting. This change affected chemical stability, resulting in high level of fat oxidation when stored at 4 °C or 25 °C as well as a decrease in unsaturated fatty acids. Storage also affected the chemical properties of the re-constituted soymilk; the pH of a 12% soy powder suspension increased from 6.68 ± 0.05 to 7.06 ±0.08 after 12 months of storage. Storage temperature did not affect the pH of the suspension and this change could also not be ascribed to protein aggregation.

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Canning and evaluation procedures should be standardised to ensure that beans selected, based on canning quality, meet the requirements set by the market and processors. For the purpose of evaluating the canning qualities of small white beans in tomato sauce, three small-scale canning techniques were evaluated, one of which was found to deliver a product with quality parameters similar to those of international standards. Using South African small white bean cultivars and the selected method, Teebus, the cultivar used by industry as the standard to indicate acceptable canning quality, displayed better visual appearance and less split beans than with the other two methods. The percentage washed drained weight and texture values of Teebus were also in agreement with international standards. The evaluation procedure for the small white beans after canning was also optimised, by comparing two procedures, which identified texture, visual appearance (scale 1 to 10), splits (scale 1 to 10), hydration coefficient, clumping, size and colour as the statistically most suitable quality parameters. With the aid of the developed method, it was possible to define standard values for South African 'choice' and 'standard' grade beans, which previously was based only on 'visual inspection' by a trained inspection panel.

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