半凝固性卵黃鴨蛋滷蛋之製作及其品質性狀之研究

為開發多元化鴨蛋製品，以提高鴨蛋之加工利用性及拓展鴨蛋的消費市場，本研究旨在利用鴨蛋以探討半凝固性卵黃鴨蛋滷蛋之製作及其品質性狀，以供業者參考應用。試驗時分別進行探討不同加熱時間、滷汁浸漬時間及二次殺菌時間對半凝固性卵黃鴨蛋滷蛋品質性狀之影響，而後於4±1℃保存8週，以探討保存期間製品之品質變化情形其結果摘要如下： 1.生鮮鴨蛋在90℃之加熱時，其蛋白及卵黃之凝固性有隨加熱時間愈長而愈硬化，在5~13分鐘加熱時，其蛋白及卵黃中水分含量並無顯著變化，蛋白之pH值有因加熱後而較高，其結果以90℃加熱7分鐘可得蛋白已完全凝固，而卵黃呈金黃色之黏稠膠狀性，是為本研究之加熱條件。 2.經上述所得以90℃加熱7分鐘後之半凝固卵黃鴨蛋，浸漬於5℃下的滷汁中，分別浸漬0、1、2及3天，其總生菌數約在3.07~3.85 log CFU/g，且有隨浸漬時間的延長而總生菌數也隨之增加之趨勢(p<0.05)，當浸漬2天時之外觀、風味皆可，而菌數也較浸漬3天為低，此以浸漬2天為供浸漬條件。 3.經浸漬二天之製品以真空包裝在85 ℃加熱0、6、8及10分鐘之二次殺菌時，蛋中水分含量約61.62~64.11(%)之間，pH值約在6.96~7.17之間，有隨加熱時間之增加而pH值較低些。然總生菌數有隨加熱時間之增加而降低，但當加熱至10分鐘時其卵黃已呈固化現象，在加熱8分鐘時，其卵黃仍呈金黃色黏稠之膠狀性，此供為二次殺菌之條件。 4.以90℃加熱7分鐘後，在滷汁中浸漬2天，並以真空包裝經85℃熱水加熱8分鐘及未二次殺菌製品分別於4±1℃進行8週的保存試驗，結果顯示在保存期間兩組之水分皆呈穩定而無顯著之變化，保存初期其pH值兩組皆有微些降低至第二週呈平穩趨勢至第五週後則微有上升的變化。整個保存期間其pH值以二次殺菌組較未二次殺菌組稍高。VBN值隨保存時間呈平穩而緩慢微許上升的趨勢，至7週後轉較明顯的增加現象。總生菌數在8週之保存期間，未殺菌組皆比殺菌組高(p<0.05)，未殺菌組保存至7週後其總生菌數由初期的103 CFU/g則增加達104 CFU/g，但以二次殺菌組則皆維持在103 CFU/g間。製品分別以0、4及8週進行品評結果，其外觀、組織質地、風味及總接受性無顯著變化，皆維持在良好品評分數，且風味良好，並無腐敗變質之現象。綜上所述將鴨蛋以90℃加熱7分鐘，於冷藏(5±1℃)在滷汁中浸漬2天後經真空包裝再以85℃熱水加熱8分鐘之二次殺菌，並於4±1℃保存8週時其質地、風味及總接受仍保良好，可供為本凝固性卵黃鴨蛋滷蛋加工製作之參考應用。

關鍵字

半凝固；卵黃；滷鴨蛋；風味

並列摘要

In order to develop the multiple products of duck eggs and to further advance the processing utility of duck eggs and expand the consumption market, duck eggs were utilized in this study to investigate the production of the marinated duck eggs with half-coagulated yolk, the quality, and the characteristics for the reference and application of the manufacturers. In the test, the influence of respectively difference heating time, marinating time, and the time for the second sterilization on the quality and characteristics of the marinated duck eggs with half-coagulated yolk, and, later, these eggs were preserved in 4±1℃ for eight weeks to investigate the changes of the quality during the preservation period. The result was summarized as follows: 1.When fresh duck eggs were heated in 90℃, the coagulation of egg white and yolk became harder as the heating time increased. During the heating time between the fifth and thirteenth minute, the water content in the egg white and yolk did not change significantly, but the pH value of the egg white increased due to heating. After being heated in 90℃ for seven minutes, the egg white completely coagulated, and the yolk became golden, sticky, and colloidal, which was employed as the heating condition in this study. 2.The duck eggs with half-coagulated yolk, which were heated in 90℃ for 7 minutes, were marinated in the marinade in 5℃ for respectively 0, 1, 2, and 3 days. The total bacterial counts were approximately 3.07~3.85 log CFU/g, and as the time of being marinated increased, the total bacterial counts increased (p<0.05). After being marinated for two days, the appearance and flavor of the eggs were both fair, and the bacterial counts were less than those being marinated for three days. Therefore, being marinated for two days was applied as the condition for immersion. 3.When the products after being marinated for two days were packed in vacuum packages and heated at 85 ℃ for 0, 6, 8, and 10 minutes for second sterilization, the water content in the eggs was between 61.62% and 64.11%, and the pH value was between 6.96 and 7.17, which became higher as the heating time increased. However, the total bacterial counts reduced as the heating time increased, but the yolk became solidified when they were heated for the ten minutes whereas the yolk was still golden, sticky, and colloidal when they were heated for the eight minutes, which was taken as the condition for second sterilization. 4.The products which were heated in 90℃ for seven minutes, marinated for two days, packed in vacuum packages, and finally heated 85 ℃ water for eight minutes and the products which did not have second sterilization were respectively placed at 4±1℃ for the eight-week preservation test. The result indicated that during the preservation period, the water content of the two groups was stable and did not have significant changes. In the beginning of the preservation period, the pH values of the two groups both decreased slightly. In addition, the values became stable since the second week, and they increased slightly since the fifth week. In the entire preservation period, the pH value of the products with second sterilization was slightly higher than that of the products without second sterilization. As the preservation time passed, the VBN values tended to be stable and increase slowly and slightly, and the values increased more significantly since the seventh week. During the eight-week preservation period, the total bacterial counts of the unsterilized group were higher than those of the sterilized group (p<0.05). After the seventh week, the total bacterial counts of the unsterilized group increased from 103 CFU/g to 104 CFU/g, but those of the group with second sterilization maintained at approximately 103 CFU/g. The products were evaluated after respectively 0, 4, and 8 weeks. The appearance, quality, flavor, and overall acceptance of the products did not change significantly, the evaluation grades were all good, the flavor was fine, and there was not any decay. 　　In summary, the products which were heated in 90℃ for seven minutes, marinated in the marinade in the freezer (5±1℃) for two days, packed in the vacuum packages, heated in the 85℃ hot water for eight minutes for second sterilization, and preserved in 4±1℃ for weeks still had good quality, flavor, and overall acceptance. This can be employed as the reference for the processing and production of the marinated duck eggs with half-coagulated yolks.