Degree Type

Dissertation

Date of Award

2020

Degree Name

Doctor of Philosophy

Department

Food Science and Human Nutrition

Major

Nutritional Sciences (Human Nutrition)

First Advisor

Manju B Reddy

Abstract

The complementary feeding period typically between 6-24 months of age is where malnutrition begins and perpetuates. This period is characterized by intake of low nutrient dense complementary foods (CFs) which is a major cause of the high prevalence of stunting and anemia in children under 5 years globally. To address this problem, several strategies including the addition of animal-source foods (ASFs), supplementation, and fortification have been used to improve nutrient density of CFs, but these strategies are often expensive, poorly regulated, unsustainable and not readily available in many food insecure settings where nutritious underutilized foods (NUFs) abound. We, therefore hypothesized that improved formulations of CFs with cheap, locally available NUFs such as edible insects could be an eminent strategy to improve infant and young child nutrition particularly during the CFP. Hence, the objectives of the studies in this dissertation were: 1) to determine the factors influencing maternal knowledge, attitudes, and perceptions about use of NUFs among Ghanaian caregivers, 2) to determine the effect of NUFs on improving nutritional status in malnourished rats, 3) to determine the nutritional composition, microbial quality, maternal sensory evaluation and willingness-to-pay for CFs produced from blends of NUFs.

The first study described in this dissertation is a cross-sectional study that assessed the influence of food security status (FSS) and anemia-related knowledge (ARK) on perceptions about two NUFs: an iron-rich plant, Solanum torvum (turkey berry, STO) and Rhynchophorus phoenicis fabricius (palm weevil larvae, RFA) among Ghanaian caregivers. Data was collected on socio-demographic characteristics, FSS, ARK, and perceptions about STO and RFA using a pretested semi-structured questionnaire. High favorable perception was significantly lower for RFA than STO. Caregivers’ ARK was associated with high favorable perception about STO by 3.3–fold (95% CI= 2–5.5, P= 0.001). Compared to food insecure caregivers, food secure caregivers were 2.9 times more likely to have high favorable perceptions about STO and 4.5 times more likely to have low favorable perceptions about RFA (p= 0.001). Focus group discussion (FGD) participants identified STO as “the blood-giving plant” and RFA as “the meat of delight”. Identified barriers to STO use included its “hard to grind numerous seeds”, “bitter taste” and “funny smell”. RFA use barriers included “it’s like a maggot” and “it’s scarce”. FGD participants requested education on nutritional benefits of STO and RFA and processing of these foods into products that can be liked by everyone.

The objective of the second study was to determine the effect of STO and insect powders on improving nutritional status in malnourished rats. Malnutrition was induced in weanling male Sprague Dawley rats by feeding 5% protein, ~2 ppm Fe (LPI) diet for 21-d. During the 14-d repletion, 5 groups of rats (n=8) were fed diets supplemented with Acheta domesticus (cricket, ADO), RFA, STO, ADO + STO (TAD) and casein + ferrous sulfate (PIS, positive control), and non-supplemented group (negative control, LPI). A normal (NOM) group was fed protein-iron sufficient (PIS) diet throughout the study. No differences were found in body weight gain, bone mineral content, lean and fat mass, and organ weights among the edible insects and PIS groups, but these results were significantly higher compared to STO and the LPI groups. An increase in hemoglobin Fe and relative biological value with ADO and RFA was comparable to the PIS group.

In the third study, CFs were developed from flours of orange-fleshed sweet potato (OFSP) and cricket (OFSCri) or palm weevil larvae (OFSPal) or soybean (OFSSoy) in the ratio 70%:30%, respectively. Nutritional and microbial quality of these novel CFs were determined using standard methods and compared with Weanimix (a maize-soybean-peanut blend). Sensory evaluation of porridges was rated on a five-point hedonic scale (1= disliked a lot; to 5= liked a lot) among 170 mothers. All the formulations exceeded the Codex Standard for energy, 400 kcal/100 g except the OFSCri blend (379.15 ± 10.83 kcal/100 g). Both OFSCri (20.33 ± 0.58 g/100g) and Weanimix (16.08 ± 0.13 g/100g) met the protein requirement of 15 g/100 g in the Codex Standard. None of the CFs met iron and zinc densities recommended by the World Health Organization for CFs. The OFSP-based CFs and weanimix were free from Salmonella, Enterobacteria, Bacillus cereus, yeast, or fungus and aerobic plate count was below the Ghana Foods and Drugs Authority standard (1*103 –1*104 cfu/g). All the formulations were ranked above the minimum threshold (Likert scale= 3; neither like nor dislike) of likeness for appearance, aroma, texture/mouthfeel, aftertaste, and overall acceptance.

The aim of the last study was to examine sensory attributes and willingness-to-pay for 2 edible insects and 2 non-insect CFs among 170 Ghanaian mothers under blind, ingredient disclosure, and nutritional and environmental informed conditions. Mothers’ sensory perceptions were positive towards insect CFs. Under blind condition, mothers were able to distinguish between insects and non-insect CFs and showed higher preference for the latter. Under the different conditions, sensory perceptions and overall acceptability of non-insect CFs was significantly higher compared to edible insect CFs. Ingredient disclosure confirmed sensory perceptions under blind condition and influenced the way the sensory attributes were judged under the informed conditions. Besides previous experience with eating insects, nutritional other than environmental benefits may have influenced the high sensory perceptions of the preferred edible insect CF. Almost all the mothers were willing-to-pay for the preferred edible insect CF an amount comparable to existing CFs on the Ghanaian market.

DOI

https://doi.org/10.31274/etd-20200902-1

Copyright Owner

Isaac Agbemafle

Language

en

File Format

application/pdf

File Size

275 pages

Available for download on Sunday, February 28, 2021

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