Development and effect of an N-3 fatty acid-rich spread on the nutritional and cognitive status of school children

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dc.contributor.advisor Smuts, C. M.
dc.contributor.advisor Witthuhn, R. C.
dc.contributor.advisor Wolmarans, P. Dalton, Annalien en_ZA
dc.contributor.other University of Stellenbosch. Faculty of Agrisciences. Dept. of Food Science. 2006-10-09T08:28:27Z en_ZA 2010-06-01T08:12:55Z 2006-10-09T08:28:27Z en_ZA 2010-06-01T08:12:55Z 2006-03
dc.description Thesis (PhD (Food Science))--University of Stellenbosch, 2006.
dc.description.abstract Long-chain polyunsaturated fatty acids (LCPUFA), especially the n-3 LCPUFA metabolic products eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play an important role as regulators in many biological processes. To date hake (Merluccius capensis) heads, a rich source of EPA and DHA, have been discarded at sea. The South African Fisheries Policy Development Committee concerned with the environmental impact of this practice has rendered it undesirable. The high prevalence of under-nutrition amongst children in South Africa can be addressed by the supplementation of their diet with this unexploited fish source. The aim of the current study was to develop a microbiologically safe and sensory acceptable sandwich spread using fish flour prepared from fish heads, as a prime ingredient. The intervention trial aimed to compare the effects of an increased dietary intake of n-3 LCPUFA, specifically DHA, on the blood fatty acid levels and absenteeism (as indicator of immune function), as well as the cognitive status, of the subjects. The microbiological content of the sandwich spread was determined after storage for 20 d at 5°C and 15 d at 25°C. Sensory evaluation was performed by consumers (n = 95; M:F = 44:51; 6 – 9 yr) to determine acceptance of the five different flavours individually incorporated into the sandwich spread to mask the fishy note and to provide different flavour options. For the intervention trial subjects (n = 351) were stratified within class group (A - E) and gender and randomly assigned to two treatment categories, an experimental group (EG; n = 174) receiving 25 g sandwich spread.d-1 (191.66 mg DHA. d-1) and a control group (CG; n = 177) receiving an analogous placebo. On school days (104 d), each subject received two sandwiches consisting of two slices of bread (ca. 60 g), spread with 25 g of either the placebo or the experimental spread. Blood samples were drawn at baseline and post intervention. Plasma fatty acid and red blood cell (RBC) membrane status, C-reactive protein levels, as well as vitamin and micronutrient status, were determined. Trained test administrators conducted a battery of cognitive tests. According to South African Government health standards, the sandwich spread remained microbiologically safe after storage. Male and female consumer respondents revealed a significant difference between gender preferences of the five different spread flavours (p <0.05). Significant treatment effects (p <0.05) were observed in n-3 LCPUFA status of the EG, as well as for their absenteeism from school. The two subtests of the Hopkins Verbal Learning test, Recognition and Discrimination Index, showed significant differences between the EG and CG (p <0.05) post intervention in the Grade 2 subjects. The Spelling tests also showed a significant difference between the two groups (p <0.05). In the current study a microbiologically safe and sensory acceptable sandwich spread was developed and tested during an intervention trial, and could possibly in future, provide a healthier option in the School Nutritional Programme. This study proved that supplementation of children (6 - 9 yr) with n-3 LCPUFA, with specific reference to EPA and DHA from a marine source, could have a beneficial effect on their fatty acid status and absenteeism from school. Based on the outcomes of the Hopkins Verbal Learning test and Spelling test, the current study proved that an n-3 fatty acid-rich spread improved the learning ability and memory of children. en_ZA
dc.format.extent 1134862 bytes en_ZA
dc.format.mimetype application/pdf en_ZA
dc.publisher Stellenbosch: University of Stellenbosch
dc.subject Theses -- Food science en_ZA
dc.subject Dissertations -- Food science en-ZA
dc.subject.lcsh Fishery products -- Analysis en_ZA
dc.subject.lcsh Eicosapentaenoic acid en_ZA
dc.subject.lcsh Docosahexaenoic acid en_ZA
dc.subject.lcsh Omega-3 fatty acids en_ZA
dc.subject.lcsh Unsaturated fatty acids in human nutrition en_ZA
dc.subject.lcsh Children -- Nutrition -- South Africa en_ZA
dc.subject.other Food Science en_ZA
dc.title Development and effect of an N-3 fatty acid-rich spread on the nutritional and cognitive status of school children en_ZA
dc.type Thesis en_ZA
dc.rights.holder University of Stellenbosch
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