Formulation and characterization of food grade water-in-oil emulsions encapsulating mixture of essential amino acids

The present study was conducted to study the encapsulation properties of a mixture of four amino acids (AAs) in the disperse phase of water-in-oil (W/O) emulsions. Four different AAs (methionine, lysine, threonine, and tryptophan) at 1% (w/w) each AA concentration was used in dispersed phase, while the continuous phase constitutes vegetable oils with 5% (w/w) tetraglycerin monolaurate condensed ricinoleic acid esters as an emulsifier. The optimized conditions include homogenization at 7000rpm for 5min using soybean oil as a continuous phase medium. The average droplet diameter of the W/O emulsions ranged between 4 and 5m with a coefficient of variation between 20 and 23%. The W/O emulsions were found to be stable over a period of 30 days at 4 degrees C with slight phase separation at 25 degrees C after 30 days of storage. The W/O emulsions retain about 10.5mg/mL (encapsulation efficiency 79.8%) of amino acids after 30 days of storage at 4 and 25 degrees C. The methionine and lysine have encapsulation efficiency of over 80% in comparison to threonine (79%) and tryptophan (60%) after 30 days of storage at 4 and 25 degrees C. Practical applications: Multiple studies have emphasized the benefits to human health of including amino acids in the diet and as special nutrient formula for sport persons. For this reason, the study was proposed to formulate a stable emulsion system that could later be able to formulate high energy food or energy drinks. The optimization of formulation parameters is necessary for industrial production and the methodology pointed in this research is far easily to apply and helps in designing new nutraceuticals and functional foods. Successful encapsulation of mixture of amino acids (methionine, lysine, threonine, and tryptophan) at (4% (w/w)) in the W/O emulsions. The W/O emulsions have encapsulation efficiency over 70% after 1 month of storage.