Production Optimization of Fortified Foam-Mat Dried Yoghurt

Abstract

• This experimental study examines the effect of different production parameters such as moringa seed flour, ginger extract, forming agent, mixing time and drying temperature on the selected proximate and microbiological qualities of foam-mat dried yoghurt. The design and analysis of the experiment were conducted with the central composite design technique of the Design Expert statistical software. The study aimed at fortifying and optimizing the production of foam-mat dried yoghurt, which involves powdered milk, water, starter culture and flavour which are kept constant and followed by the addition of moringa seed flour, ginger extract and forming agent (egg white). Twenty-five experimental runs with the control experiment inclusive were carried out based on the mixture-process design matrix and the nutritional properties evaluated include moisture content, crude protein, fat content, ash content, carbohydrate content, total lactic acid, bacteria and fungi. Numerical optimization, via the desirability approach, was utilized to determine the optimum production parameters for the fortified foam-mat dried yoghurt. Graphical optimization was also used to display the prediction of all responses in the mixture-process factors space. Results got revealed that foam-mat dried yoghurt with 10.79 % moisture content, 12.115% crude protein, 0.552% ash content, 2.196% fat and 16.409% carbohydrate could be produced from 80% of fresh yoghurt, 5.466% of moringa seed flour, 7.534% of ginger extract, 7% of foaming agent, mixing duration 2.53mins, drying temperature at 50oC and 0.721 desirability index gave the optimum quality. The results of this work are of great use to the food and beverage industries as they provide a basis for selecting process parameters for optimal foam-mat dried yoghurt production. Prospects for more studies were suggested.

Keywords

• Foam-mat drying, fortification, quality factors, numerical optimization, yoghurt