Differentiating E jiao, Deer Antler Gelatin (lu jiao jiao) and Pigskin Gelatin
阿膠﹐鹿角膠﹐豬皮膠的區別 按此看中文
translated by: Joe Hing Kwok Chu （in English and Chinese 中英文)
E jiao is also known as donkey skin glue. It is the gelatin of the hide of donkeys. The gelatin extract of the hide is rendered until it becomes a solid glue block when it is cold. The commercial glue block is rectangular or square in shape, dark brown, shiny, translucent and amber colored. It is hard and brittle, with a slightly sweet flavor. Take a small amount of this product, and add about 3 times that amount of boiling water, and stir for 10 to 60 minutes until completely dissolved. The solution will be transparent like tea color, clear and not muddy. After cooling, it becomes a watery tan color, somewhat opaque; the surface shows some specks of fatty oil. It does not congeal when let sit for some time. It has a slight fishy smell.
Pigskin gelatin is called the 'new gelatin.' It is the extract of pigskins. The commercial products are in square blocks. The surface is brown, and it is opaque, not translucent at all. When you break off a piece, the cross section is rough and it does not reflect light. Take a small amount of this product and stir to dissolve in boiling water. After cooling, the solution becomes a watery tan color, somewhat opaque, and there is a layer of fatty oil on the surface. It has a strong flavor of skin broth and a slightly sweet taste. Its medical efficacy is similar to that of e jiao.
Deer antler gelatin (lu jiao jiao) is made by rendering the antlers with water into concentrated glue. The commercial product is in square shapes, yellow-brown or reddish brown and translucent. Sometimes the commercial product has a yellow-white foam on the upper layer. It is brittle and fragile. When broken, the surface reflects light. Take a small amount of this product and add 3 times the amount of boiling water. It dissolves in 2 to 5 minutes. After cooling, the solution becomes a light red liquid, with floating droplets of oil. Deer antler gelatin (lu jiao jiao) is warm, sweet, and salty.
UV spectroscopy may be used to identify e jiao, deer antler gelatin (lu jiao jiao), pigskin gelatin as follow:
Take small amount of samples. Weigh them accurately and add 50% ethanol solution and then filter the solution. The sample preparation should contain 1 mg per ml of the solution. Use UV spectrophotometer and scan for measurement.
E jiao will show 270 ~ 280 nm spectrum and has a maximum absorption peak at 290 nm.
Deer antler gelatin (lu jiao jiao) will show maximum absorption peak,
Pigskin gelatin will show no significant absorption peaks.
The Chinese article is written by Shi Ya Fang, Traditional Chinese Medicine Medical Journal.
阿膠﹐鹿角膠﹐豬皮膠的區別
阿膠又稱驢皮膠，為馬科動物驢的皮經煎熬濃縮而成的干燥膠塊。呈長方形或方形膠塊，黑褐色，有光澤，對光透視顯琥珀色半透明狀。質硬而脆，斷面光亮。氣微，味微甘。取本品少許加沸水約3倍攪拌10∼60分鐘溶解，溶液呈透明的紅茶色，清而不濁，冷卻後，液面可見少數油滴，放置不凝集，微帶腥氣。
豬皮膠又稱新膠，系豬皮熬制而成，呈方塊狀，表面棕褐色，對光透視不透明，斷面不光亮。取本品少許加入沸水溶解，水溶液棕褐色，混濁不透明，冷卻後表面有一 層脂肪油，有強烈的肉皮湯味，味微甜，功效同阿膠。
鹿角膠為鹿角經水煎熬濃縮制成的固體膠，呈扁方塊，黃棕色或紅棕色，半透明，有的上部有黃白色泡沫層。質脆，易碎，斷面光亮。取本品少許加入3倍量沸水，2∼5分 鐘可溶解，溶液呈淺紅色液體，液面有較多油滴。鹿角膠性溫，味甘 ﹐咸。
阿膠，鹿角膠，豬皮膠也可採用紫外光譜法鑒別，方法為：
分別取樣品少許，精密稱定，加50%的乙醇溶解過濾，配制成每毫升含樣品1mg的溶液，置紫外分光光度計掃描測定。阿膠270∼280nm有最大吸收峰，鹿角膠290nm處有最大吸收峰，而豬皮膠則無明顯吸收峰。
史亞芳，中國中醫藥報
