真空(kong)袋的(de)(de)(de)主要(yao)(yao)(yao)作(zuo)用(yong)(yong)是(shi)除(chu)氧(yang)(yang)(yang)(yang)(yang)(yang)，以有(you)利于(yu)防(fang)止(zhi)食(shi)(shi)(shi)品(pin)(pin)變(bian)質(zhi)，其(qi)原理(li)也比較簡單，因食(shi)(shi)(shi)品(pin)(pin)霉(mei)腐變(bian)質(zhi)主要(yao)(yao)(yao)由微(wei)生(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)(de)活動造成，而大(da)多數微(wei)生(sheng)(sheng)(sheng)物(wu)(wu)（如霉(mei)菌(jun)和(he)(he)酵母菌(jun)）的(de)(de)(de)生(sheng)(sheng)(sheng)存是(shi)需要(yao)(yao)(yao)氧(yang)(yang)(yang)(yang)(yang)(yang)氣(qi)的(de)(de)(de)，而真空(kong)包(bao)(bao)(bao)裝就是(shi)運用(yong)(yong)這個原理(li)，把包(bao)(bao)(bao)裝袋內(nei)(nei)和(he)(he)食(shi)(shi)(shi)品(pin)(pin)細胞(bao)內(nei)(nei)的(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)(yang)氣(qi)抽掉，使微(wei)物(wu)(wu)物(wu)(wu)失去(qu)“生(sheng)(sheng)(sheng)存的(de)(de)(de)環(huan)境”。實驗證明：當包(bao)(bao)(bao)裝袋內(nei)(nei)的(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)(yang)氣(qi)濃度≤1%時(shi)，微(wei)生(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)(de)生(sheng)(sheng)(sheng)長和(he)(he)繁(fan)殖(zhi)速度就急劇下降，氧(yang)(yang)(yang)(yang)(yang)(yang)氣(qi)濃度≤0.5%時(shi)，大(da)多數微(wei)生(sheng)(sheng)(sheng)物(wu)(wu)將受到(dao)抑制(zhi)而停止(zhi)繁(fan)殖(zhi)。（注(zhu)：真空(kong)包(bao)(bao)(bao)裝不能(neng)抑制(zhi)厭氧(yang)(yang)(yang)(yang)(yang)(yang)菌(jun)的(de)(de)(de)繁(fan)殖(zhi)和(he)(he)酶反應引起的(de)(de)(de)食(shi)(shi)(shi)品(pin)(pin)變(bian)質(zhi)和(he)(he)變(bian)色(se)(se)，因此(ci)還需與其(qi)它輔助方(fang)法結(jie)合，如冷藏、速凍、脫水(shui)、高(gao)溫殺菌(jun)、輻照 滅菌(jun)、微(wei)波殺菌(jun)、鹽腌制(zhi)等。）真空(kong)除(chu)氧(yang)(yang)(yang)(yang)(yang)(yang)除(chu)了抑制(zhi)微(wei)生(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)(de)生(sheng)(sheng)(sheng)長和(he)(he)繁(fan)殖(zhi)外(wai)，另(ling)一個重要(yao)(yao)(yao)功能(neng)是(shi)防(fang)止(zhi)食(shi)(shi)(shi)品(pin)(pin)氧(yang)(yang)(yang)(yang)(yang)(yang)化(hua)(hua)，因油脂(zhi)(zhi)類(lei)食(shi)(shi)(shi)品(pin)(pin)中(zhong)含有(you)大(da)量不飽和(he)(he)脂(zhi)(zhi)肪酸，受氧(yang)(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)作(zuo)用(yong)(yong)而氧(yang)(yang)(yang)(yang)(yang)(yang)化(hua)(hua)，使食(shi)(shi)(shi)品(pin)(pin)變(bian)味(wei)、變(bian)質(zhi)，此(ci)外(wai)，氧(yang)(yang)(yang)(yang)(yang)(yang)化(hua)(hua)還使維(wei)生(sheng)(sheng)(sheng)素A和(he)(he)C損失，食(shi)(shi)(shi)品(pin)(pin)色(se)(se)素中(zhong)的(de)(de)(de)不穩定物(wu)(wu)質(zhi)受氧(yang)(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)作(zuo)用(yong)(yong)，使顏色(se)(se)變(bian)暗。所以，除(chu)氧(yang)(yang)(yang)(yang)(yang)(yang)能(neng)有(you)效地防(fang)止(zhi)食(shi)(shi)(shi)品(pin)(pin)變(bian)質(zhi)，保持其(qi)色(se)(se)、香、味(wei)及營(ying)養(yang)價值。