低溫常壓電漿殺菌對葡萄汁品質的影響

Abstract

在近幾年的食品市場中，食物的營養品質越來越受到重視，因此儘量減少加工製程對食材的破壞成為主流。葡萄汁因含有豐富的花青素及其他酚類化合物對人體健康有許多益處。傳統的熱加工會加速花青素的降解，嚴重影響到食品的營養品質及口感。為此，尋找替代熱處理的新型加工技術已經成為食品科技的重要方向。低溫電漿技術應用於食品中可以有效地抑制微生物，延長食品的儲藏期限。另外低溫可以減少花青素等熱敏性化合物在處理過程中的損失從而更好地保留蔬果製品的品質。本研究旨在評估低溫電漿技術對葡萄汁品質的影響，探討運用低溫電漿技術替代熱加工對其進行殺菌的可行性。比較不同電漿解離功率及處理時間對葡萄汁pH值、可溶性固形物、顏色、總花青素含量和總酚含量及微生物抑制的效果。結果顯示，隨著電漿功率的升高，葡萄汁中的總花青素會逐漸下降，並且造成樣品顏色發生明顯變化。然而在50 W之電漿解離功率下，不會對葡萄汁顏色產生明顯的影響，且電漿處理組花青素和酚類的保留率均高於熱處理組。低溫電漿對葡萄汁中的大腸桿菌也有很好的抑制效果，在解離功率50 W處理20分鐘後可使大腸桿菌數量下降2.5個對數值。綜合上述，低溫常壓電漿既可以有效地抑制微生物又可以較好地保留葡萄汁的品質，極有潛力應用到果汁的生產中作為巴士德殺菌的替代或與之結合使用。

In recent years, nutritional quality and minimal processing have gained much more attention in food market. Grape juice benefits human health owing to abundant anthocyanins and other polyphenolics. However, traditional thermal pasteurization can accelerate degradation of anthocyanins. To solve this problem, it’s a crucial topic that develop non-thermal technology to take place of thermal processing. Atmospheric cold plasma technology has been widely used in fruit products to prevent contamination, while room temperature can lower the loss rate of anthocyanin, improve the quality of fruit by-products . The aim of this study was to evaluate the effect of cold plasma treatment on the quality of grape juice, to discuss the potential of cold plasma pasteurization in fruit juice processing. After cold plasma/thermal processing, samples were measured pH, total soluble solids (TSS), color index, total phenols content (TPC), total anthocyanin content (TAC), microbe inactivation. With the increasing of plasma power, TAC in grape juice significantly decreased, which resulted in visually color difference.50 W plasma treating didn’t affect the color of grape juice, and the anthocyanin and phenols content were higher than thermal-treated group. 50 W cold plasma treated for 20 min led to 2.5 log reduction of Escherichia coli in grape juice. In a word, atmosphere cold plasma effectively inactivate microbe in grape juice, while improve nutritional quality and marketing value. In the future, cold plasma pasteurization can be applied to juice processing as a candidate of thermal treated.