Development of egg yolk powder using a small-scale double drum dryer: Influence of steam pressure on physical properties

Abstract

Egg yolk powder is a versatile and widely used food ingredient. Double drum dryers have been widely used in the food industry for many years, but no report was found that utilize drum dryer to produce powdered eggs. This study aimed to investigate double drum drying process conditions, especially steam pressures which consisted of three different conditions: 2.5, 3, and 3.5 bar with drum rotation of 2 revolutions per minute (rpm) to produce chicken egg yolk powder. Once egg yolk powder resulted, the products were evaluated in terms of yield, moisture content (MC), water activity (aw), bulk densities (ρB) and tapped densities (ρT), and color (L*/a*/b* coordinates). Results showed that steam pressures affected several parameters including yield, MC, aw and color properties of egg yolk powder but did not affect ρB and ρT. The egg yolk powder yielded was in range of 48–52%. MC and aw of egg yolk powder were in a range of 3.6– 5.1% and 0.38–0.43, respectively. In terms of density, the egg yolk powders had 0.40-0.43 g/cm3 and 0.46-0.48 g/cm3, for ρB and ρT, respectively. Regarding color, egg yolk powder was medium bright (59–62), less red (5–6), and yellowish (26-28). The double drum dryer is a promising technology for producing chicken egg yolk powder and prolonging its shelf life.