Cinética de secagem da gema do ovo de codorna em camada de espuma (foam-mat drying)

Abstract

The egg is a food with high biological value, in its composition there are a variety of proteins, vitamins and minerals, like any product of animal origin, the egg is perishable and begins to lose its nutritional value moments after the posture if not taken appropriate methods for conservation. The major causes of loss of quality are: microbiological contamination, high moisture content and incorrect refrigeration. Drying is a way to conserve food, preserve nutrients and ensure longer shelf life; the foam layer drying method is even more advantageous in that it provides faster dewatering because of the larger area exposed to the air, the possibility of working with low temperatures and ease of rehydration. The objective of this work was to study the drying kinetics of egg yolk in foam layer (foam-mat drying) to obtain the yolk powder. Drying tests were carried out in a greenhouse with air circulation, the production of foam was given from the vigorous stirring of the yolk, adding a percentage of clear, in common beater. Foam stability analysis was performed by verifying the volume fraction drained in funnel with nylon cloth. The determination of the moisture content was performed by gravimetric method at 105ºC for 24 hours. Protein content was determined by the Kjeldhl method. The lipid content was obtained by Folch method. From the analyzes carried out, it was determined that the addition of clarified egg quail as foaming agent, presented satisfactory results. By analyzing the results of the drying tests, it can be concluded that the best result was presented in experiment 5, whose tag = 4 min, C = 7% and T = 70 ºC, because it presented better characteristics in relation to the foam, being more stable and thus better for the drying process.