Browsing by Author "Kurwijila, L."

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Integrated food safety and nutrition assessments in the dairy cattle value chain in Tanzania
(ELSEVIER, 2018) Häsler, B.; Msalya, G.; Garza, M.; Fornace, K.; Eltholth, M.; Kurwijila, L.; Rushton, J.; Grace, D.
The consumption of even small amounts of animal-source foods has the potential to improve nutrition, especially in vulnerable households. However, scaling up their production bears food safety risks that are often overlooked due to a disconnect between human nutrition and animal sciences. The aim of this scoping study in Tanzania was to identify opportunities for nutritional and food safety benefits from cow milk. Questionnaires were administered to 156 producers and 157 consumers in 10 villages in Lushoto and Mvomero districts. Farmers reported that veterinary medicines such as oxytetracyclines, penicillin and strep- tomycin were frequently given to cattle, and a majority did not discard milk during or after treatment. Less than half of the producers boiled milk, although sale of fermented milk, made by spontaneous fermentation of raw milk, was common. Cattle management was characterised by low levels of biosecurity, hygienic practices and disease control. A majority of consumers reported not to have enough food to meet their family needs. The Food Consumption Score was acceptable for all households, but significantly higher for households with dairy cattle. When making purchasing decisions, the appearance of milk and trust in the supplier were more important considerations than hygiene practices observed. A total of 26% of consumers reported to consume raw milk “usually” or “sometimes” and 54% of consumers reported to drink fermented milk “usually” or “sometimes”. Consumers had a positive attitude towards milk and concern for quality but most thought there was no risk of illness from milk consumption. The findings promote understanding of the complexity surrounding the local food environment and practices related to the production and consumption of dairy products and allow shaping recommendations for nutrition- sensitive livestock interventions.
Optimisation of activity and storage stability of crude pepsin extracted from adult cattle Abomasa for cheese making
(2001) Ryoba, R.; Kurwijila, L.; Minja, M.; Sorhaug, T.; Stepaniak, L.
The study conducted to investigate the activity and storage stability of crude pepsin extract for use as rennet substitute in cheese processing. The conditions tested were regions of the abomasa, fresh versus dry abomasa drying methods, maceration temperatures (37oC, 24-28oC or 15oC); maceration pH 1-6 for 6 days; activation pH (pH 1-4) and clarification by centrifugation or use of chemicals. The shelf life of the extract was evaluated under storage temperatures ranging from deep freezing at -20oC refrigeration temperatures (<10 oC) and room temperature. Results showed that fundic region of the abomasa had 70.8% pepsin while the pyloric region had only 27% pepsin. Milk clotting activity (MCA) was 1978 and 1800 pepsin units per ml (PU/ml) for sun and shade-dried abomasa respectively. Concentrations of 5, 10, 15, 20, 25% NaCl gave 1845, 2189, 1596, 1021, 462 MCA respectively. Maceration at pH 3 for 3 days at 37 oC gave the highest enzymatic activity (5536 PU/ml). Clearing of the extract by centrifugation at 3000g/15 min gave an extract with 902.3 PU/ml. Clarification by use of di-sodium phosphate (Na2HSO4) gave extract of 1679.1 PU/ml. The enzyme activity of the extract stored under deep freezer temperature was sibnificantly higher (p < 0.05) than ambient and refrigeration temperatures. However, they were significantly lower (p< 0. 001) than the activity of the extract before storage. Therefore, the best pepsin extraction conditions were found to be the use of fundic region of sundried abomasa, macerated at 37oC in an extraction solution containing 5-10% salt at pH 3 for 3 days and clarified after activation at pH2 for 20 min followed by centrifugation of sediment at 3000g/15 min or by use of anhydrous disodium phosphate. The clarified extract could retain its activity for 16 weeks when stored at - 20oC in single use portions