真空(kong)(kong)(kong)袋(dai)的(de)(de)(de)(de)主(zhu)要作用(yong)是(shi)除氧(yang)(yang)，以有(you)利于防止(zhi)食(shi)品(pin)變(bian)(bian)質，其(qi)(qi)原(yuan)理也比較簡單，因(yin)食(shi)品(pin)霉(mei)腐變(bian)(bian)質主(zhu)要由微(wei)(wei)生(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)(de)活動(dong)造成，而大多數(shu)微(wei)(wei)生(sheng)(sheng)物(wu)(wu)(wu)（如霉(mei)菌(jun)(jun)和酵(jiao)母菌(jun)(jun)）的(de)(de)(de)(de)生(sheng)(sheng)存是(shi)需(xu)要氧(yang)(yang)氣的(de)(de)(de)(de)，而真空(kong)(kong)(kong)包(bao)裝就是(shi)運用(yong)這個原(yuan)理，把包(bao)裝袋(dai)內(nei)和食(shi)品(pin)細胞內(nei)的(de)(de)(de)(de)氧(yang)(yang)氣抽掉，使(shi)微(wei)(wei)物(wu)(wu)(wu)物(wu)(wu)(wu)失(shi)去“生(sheng)(sheng)存的(de)(de)(de)(de)環境”。實驗證(zheng)明：當包(bao)裝袋(dai)內(nei)的(de)(de)(de)(de)氧(yang)(yang)氣濃度≤1%時，微(wei)(wei)生(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)(de)生(sheng)(sheng)長(chang)和繁(fan)(fan)殖(zhi)速(su)度就急劇下降，氧(yang)(yang)氣濃度≤0.5%時，大多數(shu)微(wei)(wei)生(sheng)(sheng)物(wu)(wu)(wu)將(jiang)受到抑制而停止(zhi)繁(fan)(fan)殖(zhi)。（注：真空(kong)(kong)(kong)包(bao)裝不能(neng)抑制厭氧(yang)(yang)菌(jun)(jun)的(de)(de)(de)(de)繁(fan)(fan)殖(zhi)和酶反(fan)應引(yin)起(qi)的(de)(de)(de)(de)食(shi)品(pin)變(bian)(bian)質和變(bian)(bian)色(se)，因(yin)此(ci)還需(xu)與(yu)其(qi)(qi)它輔助方法結合(he)，如冷(leng)藏、速(su)凍、脫水(shui)、高溫(wen)殺(sha)菌(jun)(jun)、輻(fu)照 滅菌(jun)(jun)、微(wei)(wei)波殺(sha)菌(jun)(jun)、鹽腌制等(deng)。）真空(kong)(kong)(kong)除氧(yang)(yang)除了(le)抑制微(wei)(wei)生(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)(de)生(sheng)(sheng)長(chang)和繁(fan)(fan)殖(zhi)外(wai)(wai)，另(ling)一(yi)個重要功(gong)能(neng)是(shi)防止(zhi)食(shi)品(pin)氧(yang)(yang)化(hua)，因(yin)油脂(zhi)類食(shi)品(pin)中含(han)有(you)大量不飽和脂(zhi)肪(fang)酸，受氧(yang)(yang)的(de)(de)(de)(de)作用(yong)而氧(yang)(yang)化(hua)，使(shi)食(shi)品(pin)變(bian)(bian)味(wei)、變(bian)(bian)質，此(ci)外(wai)(wai)，氧(yang)(yang)化(hua)還使(shi)維生(sheng)(sheng)素(su)A和C損失(shi)，食(shi)品(pin)色(se)素(su)中的(de)(de)(de)(de)不穩(wen)定物(wu)(wu)(wu)質受氧(yang)(yang)的(de)(de)(de)(de)作用(yong)，使(shi)顏色(se)變(bian)(bian)暗(an)。所以，除氧(yang)(yang)能(neng)有(you)效地防止(zhi)食(shi)品(pin)變(bian)(bian)質，保持(chi)其(qi)(qi)色(se)、香、味(wei)及營(ying)養(yang)價值。