Masters Degrees (Food Science)

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Browsing Masters Degrees (Food Science) by browse.metadata.advisor "Dalton, A."

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    Development of three microbiologically safe, sensory acceptable food products as possible supplements to the diet of undernourished children (5 – 6 years)
    (Stellenbosch : Stellenbosch University, 2008-12) Lombard, Matthys du Toit; Witthuhn, R. C.; Dalton, A.; Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science.
    The physical and mental development of underprivileged children, living in developing countries, is detrimentally affected by the exposure to poverty, malnutrition and poor health. The aim of the present study was to determine the possible risk of nutritional deficiencies of children (aged 5 – 6 years) in a low socio-economic community in the Grabouw area of the Western Cape, South Africa. The nutritional status of the children was evaluated by using anthropometric measurements (weight and height). Furthermore, the dietary intake provided by the meals offered at the schools they attended (Agapé 1 and Agapé 2), was assessed using the school menus. The latter were analysed using the FoodFinder3® computer programme (Medical Research Council of SA, Tygerberg, South Africa). Three supplementary food products (biscuit, health bar and soy milk-based drink) were subsequently developed to address possible nutritional deficiencies. The microbial stability of the products was determined, after which sensory acceptability of all three products was determined using a consumer panel consisting of children (n = 51; M:F = 27:24; 5 – 6 years) from the mentioned schools within the low socio-economic community. Anthropometric results were in agreement with those found by the National Food Consumption Survey (NFCS) (1999) and the South African Vitamin A Consultative Group (SAVACG) (1995), with stunting found to be most prevalent (16%). Only 5% of the children were found to be underweight and none were found to be wasted. The developed biscuit and health bar was found to be microbiologically safe when stored for at least 30 d at 25° and 35°C respectively, and the soy milk-based drink for 7 d if stored at refrigeration temperatures (5°C). Concerning the sensory preference, no significant difference was found between the preference for any of the developed products by the males and the females. For the specific products the preference for the biscuit did not differ significantly from the health bar, nor did the health bar differ significantly from the soy milk-based drink, but the biscuit did differ significantly (p = 0.006) from the soy milk-based drink for preference. The biscuit was found to be the most preferred of the three products and the soy milk-based drink the least. The majority of the juvenile consumer panel (95%) found all three developed food products acceptable and could, therefore, be considered possible supplementary foods in a school nutrition programme. The aim of nutritional supplementation is to supplement the existing diet and in doing so ensuring a more ideal nutrient intake closer to what is recommended by the recommended dietary allowance (RDA). It is proposed that nutritional deficiencies should, however, not only be addressed by means of nutritional supplementation, but should also be assisted by the nutrition education of the parent/guardian so as help them to make informed nutritional choices and in doing so providing their children with the nutrients necessary for optimal mental and physical development.
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    Development of value-added products using the neck flesh of Cape Hake (Merluccius Capensis)
    (Stellenbosch : Stellenbosch University, 2002-12) Van der Merwe, Marla; Hoffman, Louwrens C.; Dalton, A.; Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science.
    ENGLISH ABSTRACT: The focus of this study was the development of food products produced from the neck flesh of Cape hake (Merluccius capensis) as a means of adding value to hake heads. The product prototypes that have been developed include curried fish chowder (packaged in stand-up pouches), fish spread (packaged in plastic casings) and Chakalaka hake (packaged in both cans and retortabie pouches). A formula for fish stock, which was used as a base ingredient in the three product prototypes, has also been standardised. Shelf life testing was regarded an essential part of the development processes for the refrigerated product prototypes i.e. the curried fish chowder and the fish spread. Shelf life determinations involved microbiological testing based on set microbiological standards as well as sensory monitoring and pH testing. Proximate chemical- and mineral analyses were performed on freeze-dried samples of the developed product prototypes. The efficiency of the antimicrobial peptides enterocin 1071 A and 1071 B, as biological preservatives, versus that of conventional artificial preservatives was evaluated in the fish spread prototype. Three batches of fish spread were prepared: one containing the enterocin crude extract; the second a combination of sodium benzoate and potassium sorbate, while the third batch containing no preservatives served as the control. Microbiological- and histamine tests coupled with organoleptic monitoring and pH testing were carried out over a 21-day period. It was concluded that although enterocins 1071A and 1071B had some preserving effect in the fish spread, the artificial preservative combination was the superior preserving agent. However, neither the biological preservatives nor the artificial preservative combination succeeded in providing a satisfactory shelf life. The preserving agents used in this study were however not necessarily included at optimum levels and higher levels could possibly lead to an improved shelf life. The influence of two processing temperatures [121°C (249.8°F) and 116°C (240.8°F)] and two food container types (retortable pouch and can) on the sensory quality characteristics of the Chakalaka hake-prototype was investigated. The results indicated that the shorter processing time obtained with a higher processing temperature resulted in a product of better sensory quality. The sensory quality characteristics of Chakalaka hake processed in cans at 121°C were closest to that considered desirable for the product.