The Development and quality evaluation of mixed drum-hot air dried egg flakes

• Main Authors: Lee, Chien-Ho, 李建和
• Other Authors: Sheng-Chin Yang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/35173490856855572422

碩士 === 靜宜大學 === 食品營養學系 === 85 === In order to increase the utilization of liquid egg and provide theconsumers the choice of new type egg product, the development ofdrum-dried flavored egg flakes was conducted. Chicken egg yolk andegg white were mixed with a ratio of 1:1 of 1:2, and formulated intovarious flavored liquid eggs. The flavored liquid egg was subjectedto drum drying, followed by hot air drying to remove residual moisture of dried egg product. Experiments included (1) mixeddrum-hot air drying conditions (2) establishment of moistureabsorption isotherm curve (3) the addition of textural stabilizers(4)the addition of cereal flours and (5) the addition of carrot residuum.Suitable drying conditions, as selected from the result of texturaland sensory analysis were drum drying at 135℃ for 39 sec, followed byhot air drying at 50℃ for 30 min. The dried egg product was flake inshape. Optimum moisture content of the egg flakes was 4.1-8.3%,andwater activity was 0.20-0.45 according to the curve of moisturesorption isotherm. Result showed that the moisture content of the eggflakes was higher with a ratio of egg yolk : egg white = 1:2, when drum drying at 125℃ and hot air drying at 50℃. Under the samedrying condition, water contnet of egg flakes with egg yolk : eggwhite = 1:2 was higher than that with the ratio of 1:1. Egg flakesmade with a ratio of egg yolk : egg white = 1:1 was brighter, when drum drying at 60℃ rather than 50℃, however, contrast resultwas found for egg flakes with an egg yolk : egg white = 1:2. The higher the drum drying temperature, the larger the Hunter'sa value. The lower the contnet of the egg white, the more intensive of the egg flakes yellowness.The addition of textural stabilizers increased the viscosity of liquidflavored eggs and moisture absorption capacity of egg flakes, butthe water activity of egg flakes was decrease(p< 0.05). The moistureabsorption capacity of egg flakes was highest with the addition of 0.5%xanthan gum. Egg flakes with textural stabilizers were brighter thancontrol, but no effect on the yellwoness was found.The moisture contentand water activity of egg flakes with or without txtural stabilizersdecreased as storage time increased at 25℃ for 8 weeks, while TBA valuesof egg flakes remained constant until 7th week of storage. During storagetimes, the total plate counts of egg flakes was less than 1.0 × 10 cfu/g,and mold and yeast count were cultured negative.The addition of cereal flours and carrot residuum increased the viscosityof liquid flavored eggs while the water activity of egg flakes were decreased significantly(p<0.05). Egg flakes with green bean flour had thehighest moisture absorption capacity. In general, there was no improvementon sensory acceptability of dried and rehydrated egg flakes with the additionof cereal flours or carrot residuum. Instead, the main benefit of additioncereal flours or carrot residuum was the supplementation of nutrient anddietary fiber to gee flakes.