Assessment of local fruit paste fortification on nutrient bioavailability and sensory acceptability in real households

Thesis Abstract

The study investigates how fortifying locally sourced fruit pastes affects nutrient bioavailability and sensory acceptability within real household settings, addressing gaps in translating laboratory nutrient enhancements to practical dietary uptake in diverse cultural environments. The aim is to evaluate the impact of fortification on (i) micronutrient bioavailability measured in household-reconstructed meals incorporating fortified paste, and (ii) consumer acceptance and habitual usage in daily routines. Specific objectives include (a) quantifying changes in key micronutrients (vitamin C, iron, and zinc) in fortified paste using validated proxy biomarkers from household samples, (b) assessing in situ bioavailability through simulated in vivo digestion using an in vitro INFOGEST protocol applied to typical meal matrices, (c) evaluating sensory acceptability and usage frequency via a mixed-methods instrument combining hedonic scaling and in-depth household diary interviews, (d) analyzing the influence of socio-economic status, educational level, and cultural preferences on acceptance, and (e) developing a practical model linking fortification level to observed nutrient uptake and consumption patterns. The methodology adopts a mixed-methods, quasi-experimental design conducted over nine months in three peri-urban communities. The population comprises households that regularly use local fruit paste as a staple ingredient. A sample of 180 households will be recruited, with 120 households assigned to a fortified paste condition (with standardized micronutrient premix to achieve target increases in vitamin C, iron, and zinc) and 60 households continuing with conventional paste as controls. Stratified random sampling ensures representation across income strata and ethnic groups. Data collection instruments include (i) laboratory analyses of fruit paste and meal composites for nutrient content using high-performance liquid chromatography (HPLC) for vitamin C and atomic absorption spectroscopy (AAS) for iron and zinc; (ii) in vitro digestion studies on meal composites to estimate bioaccessibility with the INFOGEST protocol, and (iii) a household sensory and usage instrument comprising a nine-point hedonic scale, willingness-to-pay questions, and a six-week food diary augmented by monthly semi-structured interviews. Validity and reliability are established through calibration with certified reference materials, pilot testing, Cronbach’s alpha assessments for instruments, and triangulation of biochemical results with diary data. Data analysis employs multiple techniques descriptive statistics to profile households and consumption patterns, inferential statistics including repeated-measures ANOVA to compare nutrient content and bioaccessibility across time and between groups, and regression analyses to identify predictors of nutrient uptake and acceptability. Thematic analysis of interview data will extract nuanced consumer perceptions, barriers, and enabling factors, guided by the diffusion of innovations theory and the health belief model to interpret motivation and behavior. A conceptual framework integrates nutrient bioavailability, sensory acceptability, and household-level determinants to explain uptake dynamics. Expected findings include (i) modest yet meaningful improvements in predicted nutrient bioavailability from fortified paste within realistic household meal contexts; (ii) higher sensory acceptability and greater usage frequency among households with higher educational levels and positive prior exposure to fortified foods; (iii) identification of cultural or taste-related barriers that limit adoption, and (iv) a robust model predicting fortification level and consumption patterns that optimize nutrient delivery without compromising acceptability. The study contributes to knowledge by translating laboratory fortification gains into real-world dietary outcomes, informing policy on fortification strategies for smallholder ecosystems, and providing a framework for scaling up nutrient-dense fruit pastes with community-based implementation. The main conclusion anticipates that carefully calibrated fortification can enhance nutrient bioavailability in real households without sacrificing sensory appeal for a broad cross-section of consumers, provided cultural preferences and affordability are addressed. Recommendations include tailoring fortification levels to local taste profiles, integrating community education on the nutritional benefits, ensuring supply chain access to premixes, and embedding fortification strategies within existing food-based or school nutrition programs to optimize public health impact.