台灣雞隻屠宰業每年約有800公噸砂囊內膜，卻未能有效利用而遭廢棄。砂囊內膜在中醫藥學《本草綱目》被稱為「雞內金」，屬上品中藥材，具有改善消化不良等腸胃疾病，甚至用於減少膽結石等功能。本研究以砂囊內膜萃取高利用價值成分為實驗目的，探討國產商業白肉雞、烏骨雞與土雞砂囊內膜之一般成分分析、酸鹼值、色差值、胺基酸與蛋白質體組成分析，以蛋白質二維電泳結合基質輔助雷射游離-飛行時間質譜儀進行蛋白質身分鑑定，以了解其蛋白質成分種類，並比較三者砂囊內膜成分。在一般成分分析方面，發現白肉雞水分含量最高，而烏骨雞蛋白質、必需胺基酸與脂肪含量則最高；蛋白質體組成分析顯示，砂囊內膜中主要功能性蛋白質為胃竇黏膜蛋白AMP-18、血清白蛋白、NF-X1型鋅指蛋白等，以土雞含量最高，故蛋白質方面是以烏骨雞與土雞優於白肉雞。但白肉雞在屠宰市場占有率，價格方面與上市週齡皆具優勢。若在實際應用上，以量產萃取收集高利用價值物質，白肉雞為較佳之選擇。本研究結果發現，AMP-18蛋白在砂囊內膜中為比例最高的功能性蛋白，且已被前人研究確認具有胃部保護和生理活性，這項發現使我們推測AMP-18是保護砂囊免於胃酸與碎石等傷害，且在中藥裡為具有改善消化不良等腸胃疾病的功能性蛋白之一。

Chicken (Gallus gallus) gizzard is a popular food, but the gizzard inner lining is not currently processed for direct human consumption, and approximately 22.5 million kg of gizzard inner lining is wasted annually in the slaughter industry. Thus, useful conversion of wasted gizzard inner lining into industrially beneficial products can provide some economic merits. According to the book of Compendium of Materia Medica, a classical Chinese medicine book, gizzard inner lining is called “endothelium corneum gigeriae galli,” which is purported to help maintain the integrity of the stomach lining and is believed to produce effects that improve indigestion and reduce gallstones. The aims of this study were to analyze the chemical components of gizzard inner lining and investigate their functional roles. This study analyzed the proximate components of gizzard inner lining, its pH, color, and amino acid composition. This study also conducted a proteomic analysis via biochemical and instrumental analyses to identify and quantify the major and bioactive proteins from the broiler, silkier, and native chicken gizzard inner lining. The results showed that broiler has the highest moisture content; silkier has the highest essential amino acids, protein and fat content. The proteomic analysis data showed that gizzard inner lining major proteins were 18 kDa antrum mucosa proteins (AMP- 18), NF-X1zinc finger protein and serum albumin precursor, native chicken has the highest content. In protein composition, silkier and native chicken is more than the broiler. However, broilers have advantages in slaughter market share, price, and listing age. If the practical application, the need for a large number of extraction and collection of active ingredients, it is recommended to choose broiler. Our results indicate that AMP-18 protein, which has been reported to exhibit gastroprotective and physiological activities, might be one of the most important components of gizzard inner lining.