包裝液態食品脫氧膜之研究

Abstract

氧氣是造成食品劣變的主要因素之一，氧氣的存在會影響其儲存安定性。活性包裝，如脫氧劑（oxygen scavenger）的使用，可以減少氧氣對食品品質得不良影響，本實驗擬開發可應用於液體食品包裝之脫氧膜，並進一步以溶出實驗、拉力實驗及儲藏實驗瞭解所研發之脫氧膜之應用性。 脫氧膜主要為高分子聚合物（polymer）、可被氧化之物質（oxidizable compounds）與催化劑（catalyst）之組合，本研究利用脫氧膜在水中的脫氧量及脫氧速率為指標，發現以聚乙烯（PE）加上4%異抗壞血酸鈉與0.1% EDTA螯合銅離子鹽類所製備之脫氧膜，具有較佳的脫氧效能，在300ml水中，儲存第一天及第十天分別可達到0.02及0.065 mg/cm2/day之脫氧速率。以實驗室規模的熱壓成形機及商業生產用之押出機所製備之上述脫氧膜，在脫氧效能上並無太大差別。沸石的添加在本實驗中發現，並無法增加其脫氧效能。 以萬能拉力機對脫氧膜進行物性分析，結果發現異抗壞血酸鈉的添加會減低脫氧膜之抗張強度，推測配方與塑膠會有相容性問題。在重金屬溶出試驗中，銅離子的溶出量符合標準規範。應用儲藏試驗中，將柳橙汁分裝於PET瓶中，以研究製備之脫氧膜或商業脫氧膜做為柳橙汁的瓶蓋內襯，儲存於4℃中10天；結果發現與控制組相比，在溶氧值方面，有明顯之降低。

Oxygen is one of the major factors of the deterioration of foods. The presence of oxygen may decrease the shelf-life of the foods. Using oxygen scavengers on foods can reduce the harmful effects caused by oxygen. The purpose of this study was to develop the oxygen scavenger film for liquid foods. The major components of oxygen scavenger films are polymer, oxidizable compounds, and catalyst. In this study, the oxygen scavenging capacity and oxygen scavenging rate of the oxygen scavenger film in water were determined for evaluating the performance of the films. The results showed that the film composed of polyethylene, 4% sodium erythorbate, and 0.1% EDTA cupric salt had the best oxygen scavenging efficiency. On the 1st and 10th day, the oxygen removed rate of the film was 0.02 and 0.065 mg/cm2/day, respectively, from 300 ml water. The oxygen scavenging efficiency of films produced by thermal compresser was less than that made by the extruder. Addition of aluminosilicate in the films did not elevate the oxygen scavenging efficiency. The physical properties analyses conducted by Instron indicated that addition of sodium erythorbate decreased the tensile strength of the PE film. On the other hand, the migration test showed that the amount of cupric ion dissolved from film to the solution conformed to the official standard. We filled the PET bottle with orange juice, and the oxygen scavenger film or the commercial film was used as the cap gasket. After storage at 4℃ for 10 days, the dissolved oxygen contents of the orange juice were significantly lower than that of the control groups.