真(zhen)空袋的(de)(de)(de)(de)主要(yao)(yao)作用(yong)是(shi)除(chu)氧(yang)(yang)(yang)(yang)(yang)，以有利于防(fang)(fang)止食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)質(zhi)(zhi)(zhi)，其(qi)原理也比較簡單，因食(shi)(shi)(shi)品(pin)(pin)霉腐變(bian)(bian)(bian)質(zhi)(zhi)(zhi)主要(yao)(yao)由微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)(de)活動造成，而大(da)多數(shu)微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)（如霉菌(jun)和(he)酵母菌(jun)）的(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)存是(shi)需要(yao)(yao)氧(yang)(yang)(yang)(yang)(yang)氣的(de)(de)(de)(de)，而真(zhen)空包(bao)裝(zhuang)(zhuang)就是(shi)運用(yong)這個原理，把(ba)包(bao)裝(zhuang)(zhuang)袋內和(he)食(shi)(shi)(shi)品(pin)(pin)細(xi)胞內的(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)氣抽(chou)掉，使(shi)微(wei)(wei)(wei)物(wu)(wu)(wu)物(wu)(wu)(wu)失去“生(sheng)(sheng)(sheng)(sheng)(sheng)存的(de)(de)(de)(de)環境”。實驗證明(ming)：當包(bao)裝(zhuang)(zhuang)袋內的(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)氣濃(nong)度≤1%時，微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)長(chang)和(he)繁(fan)殖(zhi)速度就急劇下降，氧(yang)(yang)(yang)(yang)(yang)氣濃(nong)度≤0.5%時，大(da)多數(shu)微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)將受(shou)到(dao)抑(yi)(yi)(yi)制而停(ting)止繁(fan)殖(zhi)。（注：真(zhen)空包(bao)裝(zhuang)(zhuang)不(bu)(bu)能抑(yi)(yi)(yi)制厭氧(yang)(yang)(yang)(yang)(yang)菌(jun)的(de)(de)(de)(de)繁(fan)殖(zhi)和(he)酶反應(ying)引起的(de)(de)(de)(de)食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)質(zhi)(zhi)(zhi)和(he)變(bian)(bian)(bian)色(se)，因此(ci)還需與其(qi)它輔助方(fang)法結合，如冷藏(zang)、速凍、脫水、高溫殺(sha)(sha)菌(jun)、輻照 滅菌(jun)、微(wei)(wei)(wei)波殺(sha)(sha)菌(jun)、鹽腌(a)制等。）真(zhen)空除(chu)氧(yang)(yang)(yang)(yang)(yang)除(chu)了抑(yi)(yi)(yi)制微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)長(chang)和(he)繁(fan)殖(zhi)外(wai)，另一個重要(yao)(yao)功能是(shi)防(fang)(fang)止食(shi)(shi)(shi)品(pin)(pin)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)，因油脂類食(shi)(shi)(shi)品(pin)(pin)中含有大(da)量不(bu)(bu)飽和(he)脂肪酸，受(shou)氧(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)(de)作用(yong)而氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)，使(shi)食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)味(wei)、變(bian)(bian)(bian)質(zhi)(zhi)(zhi)，此(ci)外(wai)，氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)還使(shi)維(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)素A和(he)C損(sun)失，食(shi)(shi)(shi)品(pin)(pin)色(se)素中的(de)(de)(de)(de)不(bu)(bu)穩(wen)定物(wu)(wu)(wu)質(zhi)(zhi)(zhi)受(shou)氧(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)(de)作用(yong)，使(shi)顏色(se)變(bian)(bian)(bian)暗。所以，除(chu)氧(yang)(yang)(yang)(yang)(yang)能有效地(di)防(fang)(fang)止食(shi)(shi)(shi)品(pin)(pin)變(bian)(bian)(bian)質(zhi)(zhi)(zhi)，保持其(qi)色(se)、香、味(wei)及營(ying)養價值(zhi)。