真空(kong)(kong)充氣(qi)(qi)(qi)包裝在真空(kong)(kong)后再充入(ru)氮氣(qi)(qi)(qi)、二(er)氧化碳(tan)、氧氣(qi)(qi)(qi)單一氣(qi)(qi)(qi)體(ti)(ti)或(huo)二(er) 三(san)種氣(qi)(qi)(qi)體(ti)(ti)的(de)混合氣(qi)(qi)(qi)體(ti)(ti)。其(qi)(qi)氮氣(qi)(qi)(qi)是惰性(xing)氣(qi)(qi)(qi)體(ti)(ti)，起充填作用(yong)(yong)，使(shi)袋內(nei)保持(chi)正壓(ya) ，以防止袋外(wai)空(kong)(kong)氣(qi)(qi)(qi)進入(ru)袋內(nei)，對食品起到一個保護作用(yong)(yong)。其(qi)(qi)二(er)氧化碳(tan)能夠溶于各類(lei)脂(zhi)肪或(huo)水，引成酸性(xing)較弱的(de)碳(tan)酸，有抑制霉菌、腐(fu)敗細(xi)菌等微(wei)生(sheng)物的(de)活(huo)性(xing)。其(qi)(qi)氧氣(qi)(qi)(qi)具有抑制厭氧菌的(de)生(sheng)長(chang)繁(fan)殖(zhi)，保持(chi)水果(guo)(guo)、蔬菜(cai)的(de)新鮮(xian)(xian)(xian)及色(se)彩，高濃度氧氣(qi)(qi)(qi)可(ke)使(shi)新鮮(xian)(xian)(xian)肉類(lei)保持(chi)其(qi)(qi)鮮(xian)(xian)(xian)紅色(se)。水果(guo)(guo)蔬菜(cai)的(de)新鮮(xian)(xian)(xian)可(ke)是營養(yang)不流失。