真空(kong)袋(dai)主(zhu)(zhu)要(yao)作用是(shi)除氧，以有利于防止食品變質(zhi)，其(qi)原理也比較簡單，因食品霉腐變質(zhi)主(zhu)(zhu)要(yao)由微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)的(de)(de)活動造(zao)成，而大(da)多數(shu)微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)（如霉菌(jun)和酵(jiao)母菌(jun)）的(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)存(cun)是(shi)需要(yao)氧氣(qi)的(de)(de)，而真空(kong)包(bao)裝就(jiu)是(shi)運用這個原理，把包(bao)裝袋(dai)內和食品細(xi)胞內的(de)(de)氧氣(qi)抽掉，使微(wei)(wei)物(wu)物(wu)失(shi)去“生(sheng)(sheng)(sheng)(sheng)(sheng)存(cun)的(de)(de)環境”。實(shi)驗證明：當包(bao)裝袋(dai)內的(de)(de)氧氣(qi)濃度(du)≤1%時，微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)的(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)長和繁(fan)(fan)殖(zhi)速度(du)就(jiu)急劇下降(jiang)，氧氣(qi)濃度(du)≤0.5%時，大(da)多數(shu)微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)將(jiang)受到抑制(zhi)而停(ting)止繁(fan)(fan)殖(zhi)。