真空(kong)(kong)袋的(de)(de)(de)主(zhu)要(yao)作用(yong)是(shi)除氧(yang)(yang)，以有(you)利于(yu)防止食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)(bian)質(zhi)(zhi)，其原理也比(bi)較簡單，因食(shi)品(pin)(pin)(pin)霉(mei)腐(fu)變(bian)(bian)(bian)(bian)(bian)質(zhi)(zhi)主(zhu)要(yao)由微(wei)生(sheng)(sheng)物的(de)(de)(de)活動(dong)造成，而(er)(er)大(da)(da)多數微(wei)生(sheng)(sheng)物（如(ru)霉(mei)菌和(he)(he)酵(jiao)母菌）的(de)(de)(de)生(sheng)(sheng)存(cun)是(shi)需(xu)要(yao)氧(yang)(yang)氣(qi)的(de)(de)(de)，而(er)(er)真空(kong)(kong)包裝(zhuang)就(jiu)(jiu)是(shi)運(yun)用(yong)這個(ge)原理，把包裝(zhuang)袋內(nei)和(he)(he)食(shi)品(pin)(pin)(pin)細(xi)胞(bao)內(nei)的(de)(de)(de)氧(yang)(yang)氣(qi)抽(chou)掉，使(shi)微(wei)物物失(shi)去“生(sheng)(sheng)存(cun)的(de)(de)(de)環境”。實(shi)驗證明：當包裝(zhuang)袋內(nei)的(de)(de)(de)氧(yang)(yang)氣(qi)濃(nong)度≤1%時，微(wei)生(sheng)(sheng)物的(de)(de)(de)生(sheng)(sheng)長和(he)(he)繁(fan)殖(zhi)速(su)(su)度就(jiu)(jiu)急劇下(xia)降，氧(yang)(yang)氣(qi)濃(nong)度≤0.5%時，大(da)(da)多數微(wei)生(sheng)(sheng)物將受(shou)(shou)到抑(yi)(yi)制(zhi)(zhi)(zhi)而(er)(er)停(ting)止繁(fan)殖(zhi)。（注(zhu)：真空(kong)(kong)包裝(zhuang)不(bu)能抑(yi)(yi)制(zhi)(zhi)(zhi)厭氧(yang)(yang)菌的(de)(de)(de)繁(fan)殖(zhi)和(he)(he)酶反(fan)應引起(qi)的(de)(de)(de)食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)(bian)質(zhi)(zhi)和(he)(he)變(bian)(bian)(bian)(bian)(bian)色，因此(ci)還(huan)需(xu)與其它輔助方法結合(he)，如(ru)冷藏、速(su)(su)凍、脫水、高溫殺(sha)菌、輻照 滅菌、微(wei)波殺(sha)菌、鹽腌制(zhi)(zhi)(zhi)等。）真空(kong)(kong)除氧(yang)(yang)除了抑(yi)(yi)制(zhi)(zhi)(zhi)微(wei)生(sheng)(sheng)物的(de)(de)(de)生(sheng)(sheng)長和(he)(he)繁(fan)殖(zhi)外(wai)，另一個(ge)重要(yao)功能是(shi)防止食(shi)品(pin)(pin)(pin)氧(yang)(yang)化(hua)，因油脂類食(shi)品(pin)(pin)(pin)中含(han)有(you)大(da)(da)量不(bu)飽和(he)(he)脂肪酸，受(shou)(shou)氧(yang)(yang)的(de)(de)(de)作用(yong)而(er)(er)氧(yang)(yang)化(hua)，使(shi)食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)(bian)味、變(bian)(bian)(bian)(bian)(bian)質(zhi)(zhi)，此(ci)外(wai)，氧(yang)(yang)化(hua)還(huan)使(shi)維生(sheng)(sheng)素(su)A和(he)(he)C損失(shi)，食(shi)品(pin)(pin)(pin)色素(su)中的(de)(de)(de)不(bu)穩定物質(zhi)(zhi)受(shou)(shou)氧(yang)(yang)的(de)(de)(de)作用(yong)，使(shi)顏色變(bian)(bian)(bian)(bian)(bian)暗。所以，除氧(yang)(yang)能有(you)效地防止食(shi)品(pin)(pin)(pin)變(bian)(bian)(bian)(bian)(bian)質(zhi)(zhi)，保持(chi)其色、香、味及營養價(jia)值(zhi)。