真空袋(dai)的(de)(de)主(zhu)要(yao)作用(yong)(yong)是除(chu)氧(yang)(yang)，以有(you)利(li)于防(fang)止(zhi)(zhi)(zhi)食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)質(zhi)(zhi)，其(qi)原理也比較簡單，因(yin)食(shi)品(pin)(pin)(pin)霉(mei)腐變(bian)(bian)(bian)(bian)質(zhi)(zhi)主(zhu)要(yao)由微(wei)(wei)(wei)生(sheng)(sheng)物(wu)(wu)的(de)(de)活動造成，而大(da)多數微(wei)(wei)(wei)生(sheng)(sheng)物(wu)(wu)（如(ru)霉(mei)菌(jun)和(he)(he)酵母菌(jun)）的(de)(de)生(sheng)(sheng)存是需要(yao)氧(yang)(yang)氣的(de)(de)，而真空包(bao)裝(zhuang)就是運(yun)用(yong)(yong)這個(ge)(ge)原理，把包(bao)裝(zhuang)袋(dai)內(nei)和(he)(he)食(shi)品(pin)(pin)(pin)細胞內(nei)的(de)(de)氧(yang)(yang)氣抽掉，使(shi)微(wei)(wei)(wei)物(wu)(wu)物(wu)(wu)失(shi)去“生(sheng)(sheng)存的(de)(de)環境”。實驗證明：當包(bao)裝(zhuang)袋(dai)內(nei)的(de)(de)氧(yang)(yang)氣濃度(du)≤1%時(shi)，微(wei)(wei)(wei)生(sheng)(sheng)物(wu)(wu)的(de)(de)生(sheng)(sheng)長(chang)和(he)(he)繁(fan)殖(zhi)速度(du)就急劇下(xia)降，氧(yang)(yang)氣濃度(du)≤0.5%時(shi)，大(da)多數微(wei)(wei)(wei)生(sheng)(sheng)物(wu)(wu)將受到抑制(zhi)而停止(zhi)(zhi)(zhi)繁(fan)殖(zhi)。（注：真空包(bao)裝(zhuang)不(bu)能(neng)抑制(zhi)厭氧(yang)(yang)菌(jun)的(de)(de)繁(fan)殖(zhi)和(he)(he)酶反應引(yin)起的(de)(de)食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)質(zhi)(zhi)和(he)(he)變(bian)(bian)(bian)(bian)色(se)，因(yin)此還需與(yu)其(qi)它輔助方(fang)法結合，如(ru)冷藏、速凍、脫水、高溫(wen)殺菌(jun)、輻照 滅菌(jun)、微(wei)(wei)(wei)波殺菌(jun)、鹽腌制(zhi)等(deng)。）真空除(chu)氧(yang)(yang)除(chu)了抑制(zhi)微(wei)(wei)(wei)生(sheng)(sheng)物(wu)(wu)的(de)(de)生(sheng)(sheng)長(chang)和(he)(he)繁(fan)殖(zhi)外，另(ling)一個(ge)(ge)重要(yao)功能(neng)是防(fang)止(zhi)(zhi)(zhi)食(shi)品(pin)(pin)(pin)氧(yang)(yang)化，因(yin)油脂類食(shi)品(pin)(pin)(pin)中含(han)有(you)大(da)量不(bu)飽和(he)(he)脂肪(fang)酸，受氧(yang)(yang)的(de)(de)作用(yong)(yong)而氧(yang)(yang)化，使(shi)食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)味、變(bian)(bian)(bian)(bian)質(zhi)(zhi)，此外，氧(yang)(yang)化還使(shi)維生(sheng)(sheng)素A和(he)(he)C損失(shi)，食(shi)品(pin)(pin)(pin)色(se)素中的(de)(de)不(bu)穩定(ding)物(wu)(wu)質(zhi)(zhi)受氧(yang)(yang)的(de)(de)作用(yong)(yong)，使(shi)顏色(se)變(bian)(bian)(bian)(bian)暗(an)。所以，除(chu)氧(yang)(yang)能(neng)有(you)效地防(fang)止(zhi)(zhi)(zhi)食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)質(zhi)(zhi)，保持其(qi)色(se)、香、味及營養價值。