Egg Albumin Powder Essay

2. Materials and methods

Egg albumin powder (minimum 80.5% protein) was obtained as a gift from SKM egg products, Erode, Tamil Nadu. Curcumin (minimum 95% purity) was obtained from Synthite Industries Ltd, Kolenchery, Kerala. All other reagents were of AR grade.

2.1 Experimental Design for preparation of curcumin loaded egg albumin powder

Based on through review egg albumin concentration, curcumin concentration and air inlet temperature were considered as the most important factors affecting the quality characteristics of curcumin loaded egg albumin powder. Egg albumin concentration of 2.5 to 7.5 (% w/v), curcumin concentration of 0.25 to 0.75 (%w/v) and air inlet temperature of 110 to 1300C were selected as low and high levels of independent

First step was the emulsification of curcumin and wall material using an emulsifier, followed by spray drying of the resultant emulsion. Curcumin-egg albumin emulsion was prepared by dissolving egg albumin (%w/v based on the total solution) in distilled water and subsequent addition of curcumin (%w/v based on total solution) into it according to the experimental design (Table 3). Emulsion has a continuous phase containing the film–forming carrier materials, and a discontinuous phase containing the curcumin. Prepared emulsion was stirred at 700 rpm for 10 min using magnetic stirrer. Two drops of Tween-80 was added to aid the emulsification process. Prepared emulsion was analysed for its quality characteristics before spray drying.

2.2.1 Quality Characteristics of Emulsion

2.2.1.1. Emulsion viscosity

Viscosity of emulsions was determined using rotational viscometer (M/s Fungi lab, Spain) at room temperature (28 ± 20C). It was measured by taking 50g emulsion in a beaker. The L2 spindles recommended for medium viscous foods was selected and fitted in the viscometer and the spindle was run at 100 rpm. After one minute of start at 100 rpm, the viscosity values attained a steady state and the values were recorded in terms of centipoise.

2.2.1.2. Total solids measurement

Total soluble solids (TSS) content of emulsion as °Brix was determined by a hand refractrometer (ATAGO INDIA Instruments Pvt. Ltd, Mumbai, India)

Spray drying was carried out in a lab model spray dryer (SprayMate, M/s JISL, Mumbai, India) with a spray nozzle of 0.7 mm. Emulsion was fed into the spray drier equipped with the two fluid nozzle atomizer using a peristaltic pump at the rate of 2 ml min-1. The pressure of compressed air for the flow of the spray was adjusted to 2 bar. The vacuum pressure was 50 kg/cm2 below atmospheric pressure. An air outlet temperature was maintained at 50 - 60°C. Inlet temperature of drying air was maintained according to the experimental design (Table 3). The microcapsules were collected from the drying chamber, collection bottle, cyclone separator and collection pot. Microencapsulated powders obtained from both the collection bottles were mixed and filled in airtight, self-sealable polyethylene pouches. Then these pouches were packed in aluminium foil pouches and sealed using the hand sealer (Make: Sevana, India) to protect it from light. Sealed bags were stored at refrigeration temperature (4±2ºC) until further