Tropentag, September 17 - 19, 2018 in Ghent "Global food security and food safety: The role of universities"

Edible Mushrooms: Novel Food Fortification Approach Towards Food Security

¹Université Evangélique en Afrique (UEA), Food Science and Technology, DR Congo
²Jomo Kenyatta Univ. of Agriculture and Technology, Food Sci. & Techn., Kenya

Abstract

Physicochemical attributes of mushrooms (Agaricus bisporus & Pleurotus ostreatus) and their blends with maize flour, as well as the colour and sensory acceptability of the fortified maize-mushroom porridge were investigated using standard analytical techniques and Pearson's correlations. The maize flour was replaced with mushroom flours at different levels; a control sample (0%), 10%, 20%, 30%, 40% and 50% of mushroom flour. Increasing mushroom content resulted in increasing of protein, ash, fiber, zinc and iron content in both composite flours and fortified maize-mushroom porridges. Furthermore, the fortified maize-mushroom porridges in vitro-protein digestibility increased with increasing the mushrooms content. Adding P. ostreatus flour resulted in increasing of the pH and decreasing of the total titratable acidity (TTA). On the other hand, increasing the A. bisporus flour content resulted in decreasing of the pH and increasing of the TTA. A strong significant (p<0.05) linear correlation (-0.73) was observed between the in vitro-protein digestibility and the viscosity in maize-mushroom porridges. Besides, increasing mushroom content resulted in decreasing of the fat, carbohydrates and energy content in both composite flours and fortified maize-mushroom porridges. The fortified maize-mushrooms viscosity also decreased with increasing mushroom flour content. In addition, a positive significant linear effect (p<0.05) in the composite flours on foaming capacity, foam stability, fat absorption capacity, water retention capacity, water absorption capacity, solubility index and swelling capacity was observed, while a negative linear effect on compact density, bulk density and syneresis was found. However, the gelation capacity, emulsifying activity and emulsions stability in the blend were not affected with adding P. ostreatus, while a slight decrease was observed with adding A. bisporus. Increasing mushroom flours content resulted in decreasing of the lightness (L*) value and increasing of redness (a*) and yellowness (b*) in both composite flours and porridge. Based on the colour as well as the consumer acceptability, porridge and maize flour supplemented with 10% and 20% P. ostreatus flours were found to be the best. The information provided in this study increases the attractiveness of the mushroom flours as a novel food fortification due to their nutritional attributes that are associated with numerous health-promoting benefits.

Keywords: Consumer acceptability, food fortification, fortified porridge, maize flour, mushroom, physicochemical properties

Contact Address: R.M. Ishara Jackson, Université Evangélique en Afrique (UEA), Food Science and Technology, 3323 Bukavu, DR Congo, e-mail: jackishara17uea.ac.cd