真空充(chong)(chong)氣(qi)(qi)(qi)包裝在真空后再充(chong)(chong)入氮氣(qi)(qi)(qi)、二(er)氧(yang)(yang)化碳(tan)(tan)、氧(yang)(yang)氣(qi)(qi)(qi)單一氣(qi)(qi)(qi)體或(huo)二(er) 三種氣(qi)(qi)(qi)體的混合(he)氣(qi)(qi)(qi)體。其氮氣(qi)(qi)(qi)是(shi)惰性(xing)氣(qi)(qi)(qi)體，起充(chong)(chong)填作用(yong)，使袋(dai)(dai)內(nei)保持正壓(ya) ，以防止(zhi)袋(dai)(dai)外空氣(qi)(qi)(qi)進入袋(dai)(dai)內(nei)，對食品起到一個保護(hu)作用(yong)。其二(er)氧(yang)(yang)化碳(tan)(tan)能(neng)夠(gou)溶于各類脂(zhi)肪或(huo)水，引成酸性(xing)較(jiao)弱的碳(tan)(tan)酸，有抑(yi)制霉菌(jun)(jun)、腐(fu)敗細菌(jun)(jun)等微(wei)生(sheng)(sheng)物的活性(xing)。其氧(yang)(yang)氣(qi)(qi)(qi)具有抑(yi)制厭氧(yang)(yang)菌(jun)(jun)的生(sheng)(sheng)長(chang)繁殖(zhi)，保持水果(guo)、蔬菜的新(xin)鮮(xian)(xian)(xian)及色彩，高濃(nong)度氧(yang)(yang)氣(qi)(qi)(qi)可(ke)使新(xin)鮮(xian)(xian)(xian)肉類保持其鮮(xian)(xian)(xian)紅色。水果(guo)蔬菜的新(xin)鮮(xian)(xian)(xian)可(ke)是(shi)營養不流失(shi)。