真(zhen)(zhen)空(kong)袋的(de)(de)(de)(de)(de)(de)主要(yao)作(zuo)用是除氧(yang)(yang)(yang)，以有(you)利于防(fang)止(zhi)(zhi)(zhi)食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)(bian)質(zhi)(zhi)(zhi)，其(qi)原理(li)也(ye)比較簡單(dan)，因食(shi)(shi)(shi)品(pin)(pin)霉腐變(bian)(bian)(bian)(bian)質(zhi)(zhi)(zhi)主要(yao)由微(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)(de)(de)(de)(de)活動(dong)造(zao)成，而(er)大多(duo)數(shu)微(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)（如(ru)(ru)霉菌(jun)(jun)(jun)和(he)(he)(he)(he)酵母菌(jun)(jun)(jun)）的(de)(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)存是需(xu)要(yao)氧(yang)(yang)(yang)氣(qi)的(de)(de)(de)(de)(de)(de)，而(er)真(zhen)(zhen)空(kong)包(bao)裝就是運用這個原理(li)，把包(bao)裝袋內和(he)(he)(he)(he)食(shi)(shi)(shi)品(pin)(pin)細胞(bao)內的(de)(de)(de)(de)(de)(de)氧(yang)(yang)(yang)氣(qi)抽掉，使(shi)微(wei)物(wu)(wu)物(wu)(wu)失去(qu)“生(sheng)(sheng)(sheng)(sheng)存的(de)(de)(de)(de)(de)(de)環境”。實驗證(zheng)明：當包(bao)裝袋內的(de)(de)(de)(de)(de)(de)氧(yang)(yang)(yang)氣(qi)濃(nong)度≤1%時，微(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)長和(he)(he)(he)(he)繁殖速(su)度就急劇下(xia)降(jiang)，氧(yang)(yang)(yang)氣(qi)濃(nong)度≤0.5%時，大多(duo)數(shu)微(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)將受(shou)到抑制(zhi)(zhi)而(er)停(ting)止(zhi)(zhi)(zhi)繁殖。（注(zhu)：真(zhen)(zhen)空(kong)包(bao)裝不(bu)(bu)能(neng)抑制(zhi)(zhi)厭氧(yang)(yang)(yang)菌(jun)(jun)(jun)的(de)(de)(de)(de)(de)(de)繁殖和(he)(he)(he)(he)酶反應引起的(de)(de)(de)(de)(de)(de)食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)(bian)質(zhi)(zhi)(zhi)和(he)(he)(he)(he)變(bian)(bian)(bian)(bian)色(se)(se)，因此還需(xu)與其(qi)它輔(fu)助方法(fa)結(jie)合，如(ru)(ru)冷藏、速(su)凍、脫水、高溫殺(sha)菌(jun)(jun)(jun)、輻照 滅菌(jun)(jun)(jun)、微(wei)波殺(sha)菌(jun)(jun)(jun)、鹽腌(a)制(zhi)(zhi)等。）真(zhen)(zhen)空(kong)除氧(yang)(yang)(yang)除了抑制(zhi)(zhi)微(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)長和(he)(he)(he)(he)繁殖外(wai)，另(ling)一(yi)個重要(yao)功能(neng)是防(fang)止(zhi)(zhi)(zhi)食(shi)(shi)(shi)品(pin)(pin)氧(yang)(yang)(yang)化(hua)(hua)，因油脂類食(shi)(shi)(shi)品(pin)(pin)中含(han)有(you)大量不(bu)(bu)飽和(he)(he)(he)(he)脂肪酸，受(shou)氧(yang)(yang)(yang)的(de)(de)(de)(de)(de)(de)作(zuo)用而(er)氧(yang)(yang)(yang)化(hua)(hua)，使(shi)食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)(bian)味(wei)、變(bian)(bian)(bian)(bian)質(zhi)(zhi)(zhi)，此外(wai)，氧(yang)(yang)(yang)化(hua)(hua)還使(shi)維生(sheng)(sheng)(sheng)(sheng)素A和(he)(he)(he)(he)C損失，食(shi)(shi)(shi)品(pin)(pin)色(se)(se)素中的(de)(de)(de)(de)(de)(de)不(bu)(bu)穩定(ding)物(wu)(wu)質(zhi)(zhi)(zhi)受(shou)氧(yang)(yang)(yang)的(de)(de)(de)(de)(de)(de)作(zuo)用，使(shi)顏色(se)(se)變(bian)(bian)(bian)(bian)暗。所以，除氧(yang)(yang)(yang)能(neng)有(you)效地防(fang)止(zhi)(zhi)(zhi)食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)(bian)質(zhi)(zhi)(zhi)，保持其(qi)色(se)(se)、香、味(wei)及營(ying)養價(jia)值。