In Vitro Bio-Accessibility and Consumer Acceptability of Zinc Bio-Fortified Mushroom-Heat and Moisture Treated Millet Complementary Porridge in Vihiga County, Kenya
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Date
2023-10
Authors
Karenya, Susan
Journal Title
Journal ISSN
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Publisher
Kenyatta University
Abstract
Zinc is a crucial micronutrient for human physiological processes like infant growth, reproductive health, immune system function, and vision. Zinc deficiency can lead to poor growth, intellectual impairment, prenatal complications, and increased morbidity and mortality. Zinc supplementation or food fortification is recommended to decrease the severity and incidence of severe childhood infectious diseases in populations at risk for zinc deficiency. Given their nutrient density, vital mineral content, and human-promoting compounds, edible mushrooms in this case have great potential for improving the nutritional value of usually carbohydrate-rich diets. There is limited information on the bio-accessibility of zinc from bio-fortified mushrooms when added to heat and moisture treated finger millet porridge. This study was conducted to determine whether heat- and moisture-treated finger millet combined with biofortified mushroom powder effectively increased zinc bio-accessibility and its acceptability. This study adopted a completely randomized experimental design. The study evaluated the effect of zinc supplementation on the zinc content of oyster mushroom fruit-bodies grown on straws with varying concentrations of zinc sulfate. The mushrooms were harvested, dried, and milled into fine powder and those with the highest zinc were mixed with HMT finger millet in different ratios of 100:0 (control), 95:5, 90:10, 85:15, and 80:20. The total zinc content of biofortified mushroom and zinc bio-accessibility in millet-mushroom flour blends were determined using atomic absorption spectrometry and a simulation method of gastro intestinal digestion, respectively. In addition, 25 semi-trained panelists, including mothers and caregivers aged 18-45, evaluated porridges made from HMT finger millet-mushroom composite flours at a postnatal clinic. Adding zinc to growth substrates had a significant (p˂0.05) effect on zinc content in mushroom. Zinc levels. Substrates without ZnSO4 produced mushrooms containing 8.9 mg Zinc, which increased by 30.9% when 600 mg ZnSO4 was added. Furthermore, HMT finger millet porridge without mushrooms had a Phytic acid: zinc molar ratio of 60.3, which decreased to 34 when 20% (w/w) mushroom powder proportions were added. Despite having the highest bio-accessible zinc with the least effect on texture and appearance, a 20% mushroom proportion in HMT finger millet porridge considerably compromised the taste, aroma and general consumer acceptability. Bio-accessibility of zinc was increased from 16.57% to 21.653% when blended with 20% mushroom powder. Blending HMT finger millet flour with mushroom powder improved zinc bio-accessibility of the porridge. However, when added beyond a certain limit, mushroom reduced organoleptic qualities of the porridge, which affected overall consumer acceptance. The study recommends, therefore, that mushroom powder be added to finger millet flour in the appropriate proportions to enhance nutritional and health benefits of porridge while minimizing possible negative impacts on sensory properties.
Description
A Research Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science (Food Nutrition And Dietetics) School of Health Sciences of Kenyatta University, October 2023.
Keywords
In Vitro Bio-Accessibility, Consumer Acceptability, Zinc Bio-Fortified Mushroom-Heat, Moisture Treated Millet, Complementary Porridge, Vihiga County, Kenya