真(zhen)(zhen)空袋(dai)的(de)主要(yao)作(zuo)用(yong)是(shi)除氧(yang)(yang)(yang)(yang)，以(yi)(yi)有(you)利于防止(zhi)食(shi)品(pin)(pin)變(bian)質(zhi)，其原(yuan)理也比較簡單，因食(shi)品(pin)(pin)霉腐變(bian)質(zhi)主要(yao)由微生(sheng)(sheng)(sheng)物(wu)(wu)的(de)活動造(zao)成，而(er)大(da)多(duo)(duo)數(shu)微生(sheng)(sheng)(sheng)物(wu)(wu)（如霉菌(jun)和(he)酵母菌(jun)）的(de)生(sheng)(sheng)(sheng)存(cun)是(shi)需要(yao)氧(yang)(yang)(yang)(yang)氣的(de)，而(er)真(zhen)(zhen)空包(bao)裝(zhuang)就是(shi)運(yun)用(yong)這個(ge)(ge)原(yuan)理，把(ba)包(bao)裝(zhuang)袋(dai)內和(he)食(shi)品(pin)(pin)細胞內的(de)氧(yang)(yang)(yang)(yang)氣抽掉，使(shi)微物(wu)(wu)物(wu)(wu)失(shi)去(qu)“生(sheng)(sheng)(sheng)存(cun)的(de)環境”。實(shi)驗證明：當包(bao)裝(zhuang)袋(dai)內的(de)氧(yang)(yang)(yang)(yang)氣濃度≤1%時，微生(sheng)(sheng)(sheng)物(wu)(wu)的(de)生(sheng)(sheng)(sheng)長和(he)繁(fan)殖(zhi)速(su)度就急劇下降(jiang)，氧(yang)(yang)(yang)(yang)氣濃度≤0.5%時，大(da)多(duo)(duo)數(shu)微生(sheng)(sheng)(sheng)物(wu)(wu)將受(shou)到(dao)抑(yi)(yi)制(zhi)而(er)停止(zhi)繁(fan)殖(zhi)。（注(zhu)：真(zhen)(zhen)空包(bao)裝(zhuang)不(bu)能(neng)(neng)抑(yi)(yi)制(zhi)厭氧(yang)(yang)(yang)(yang)菌(jun)的(de)繁(fan)殖(zhi)和(he)酶反(fan)應引(yin)起的(de)食(shi)品(pin)(pin)變(bian)質(zhi)和(he)變(bian)色，因此還需與其它輔助方法(fa)結(jie)合，如冷藏、速(su)凍、脫(tuo)水、高溫(wen)殺(sha)菌(jun)、輻(fu)照 滅菌(jun)、微波殺(sha)菌(jun)、鹽腌制(zhi)等。）真(zhen)(zhen)空除氧(yang)(yang)(yang)(yang)除了(le)抑(yi)(yi)制(zhi)微生(sheng)(sheng)(sheng)物(wu)(wu)的(de)生(sheng)(sheng)(sheng)長和(he)繁(fan)殖(zhi)外，另(ling)一個(ge)(ge)重(zhong)要(yao)功能(neng)(neng)是(shi)防止(zhi)食(shi)品(pin)(pin)氧(yang)(yang)(yang)(yang)化(hua)(hua)，因油脂(zhi)類食(shi)品(pin)(pin)中(zhong)(zhong)含有(you)大(da)量(liang)不(bu)飽和(he)脂(zhi)肪酸，受(shou)氧(yang)(yang)(yang)(yang)的(de)作(zuo)用(yong)而(er)氧(yang)(yang)(yang)(yang)化(hua)(hua)，使(shi)食(shi)品(pin)(pin)變(bian)味、變(bian)質(zhi)，此外，氧(yang)(yang)(yang)(yang)化(hua)(hua)還使(shi)維(wei)生(sheng)(sheng)(sheng)素A和(he)C損失(shi)，食(shi)品(pin)(pin)色素中(zhong)(zhong)的(de)不(bu)穩定物(wu)(wu)質(zhi)受(shou)氧(yang)(yang)(yang)(yang)的(de)作(zuo)用(yong)，使(shi)顏(yan)色變(bian)暗。所(suo)以(yi)(yi)，除氧(yang)(yang)(yang)(yang)能(neng)(neng)有(you)效地防止(zhi)食(shi)品(pin)(pin)變(bian)質(zhi)，保持其色、香(xiang)、味及營(ying)養價值。