真空(kong)袋主要作用是(shi)除氧，以(yi)有利于防止食(shi)(shi)品(pin)變質(zhi)，其原理也比較簡單，因食(shi)(shi)品(pin)霉腐變質(zhi)主要由微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的活動造成，而大多數(shu)微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)（如霉菌(jun)和酵母菌(jun)）的生(sheng)(sheng)(sheng)(sheng)存是(shi)需要氧氣(qi)(qi)的，而真空(kong)包(bao)裝(zhuang)(zhuang)就(jiu)是(shi)運(yun)用這個原理，把(ba)包(bao)裝(zhuang)(zhuang)袋內和食(shi)(shi)品(pin)細胞內的氧氣(qi)(qi)抽掉，使微(wei)(wei)物(wu)(wu)物(wu)(wu)失去“生(sheng)(sheng)(sheng)(sheng)存的環境”。實驗證明：當包(bao)裝(zhuang)(zhuang)袋內的氧氣(qi)(qi)濃度(du)≤1%時(shi)，微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的生(sheng)(sheng)(sheng)(sheng)長和繁(fan)殖速度(du)就(jiu)急(ji)劇(ju)下(xia)降(jiang)，氧氣(qi)(qi)濃度(du)≤0.5%時(shi)，大多數(shu)微(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)將受(shou)到抑制而停止繁(fan)殖。