即飲式高機能性苦瓜飲料之製備與貯存

Preparation and Storage of Functional Instant Bitter Melon Juice

本研究目的在製得具機能性成分且適口性與儲存性俱佳的苦瓜飲料。研究中，確立以HPLC分析苦瓜中血糖降低活性物苦瓜苷（charantin）的方法。其次，則利用田口法（Taguchi method）尋求即飲式苦瓜飲料加工製作的最適參數。最後則觀察產品之儲存穩定性。結果顯示，原料樣品中charantin的含量，以山苦瓜最高，白玉苦瓜最低。製成即飲式飲料後，該機能性成分約殘留30%。在飲料製作方面，以添加2%小蘇打，沸水殺菁5分鐘能有效降低原料苦瓜之苦味。殺菁過的苦瓜經榨汁、過濾後，以蔗糖調整糖度至10°Brix並添加0.1% CMC及0.1%蘋果酸，可得苦瓜飲料製備的最佳組合。將所製得的苦瓜汁，以沸水殺菌20分鐘後，將苦瓜汁儲存於4℃及25℃下12週，並就其果汁色澤與濁度等品質進行分析。結果顯示，L值、a值及果膠含量皆有明顯上升的趨勢，於4℃儲藏時，其變化較緩。殺菁具有安定性及去苦味之效果；經調整pH值或預熱的苦瓜汁，具有較佳的穩定性。 This research aimed to obtain a flavorable and stable bitter melon beverage with functional composition. Firstly, we establish the HPLC method of detecting the charantin contained in bitter melon, which is proved capable to decrease the blood sugar. Secondly, we try to find the best procedures of making the bitter melon juice through Taguchi Technique. The charantin content detected in green, white and wild varieties were 240.38, 148.14, 447.18ppm, respectively. However only remained as little as 73.17 and 47.63ppm for green and white juice respectively. Blanching with 2% Na2CO3 for 5min. showed the best effect in making the bitter taste of the sample juice. A favorable juice then can be acquired by adjusting the sample to 10 °Brix and pH 4.5 and by adding 0.1% CMC. After the procedure of sterilization in boiling water for 20min, the instant juice of bitter melon is produced. Finally ,the juice was stored at 4℃ and 25℃ for 12 weeks showed different stability in juice color and turbidity. The results showed that, the L value, a value and pectin content increased apparent during storage, but it changed less at 4℃ than at 25℃. Blanching decrease the bitter taste of the juice and increase its turbidity and stability. However the acidification and preheating process increase the turbidity and stability of the juice.