真(zhen)空(kong)(kong)袋的(de)主(zhu)要(yao)作(zuo)用(yong)是(shi)(shi)除(chu)氧(yang)(yang)(yang)(yang)，以有(you)利于防止(zhi)食(shi)(shi)(shi)品(pin)(pin)變(bian)質(zhi)(zhi)(zhi)，其(qi)原理(li)也比(bi)較簡單，因食(shi)(shi)(shi)品(pin)(pin)霉(mei)腐(fu)變(bian)質(zhi)(zhi)(zhi)主(zhu)要(yao)由(you)微(wei)(wei)生(sheng)(sheng)物的(de)活動造(zao)成，而大(da)多數微(wei)(wei)生(sheng)(sheng)物（如霉(mei)菌(jun)(jun)和(he)酵母菌(jun)(jun)）的(de)生(sheng)(sheng)存是(shi)(shi)需要(yao)氧(yang)(yang)(yang)(yang)氣(qi)的(de)，而真(zhen)空(kong)(kong)包(bao)(bao)裝就是(shi)(shi)運用(yong)這個原理(li)，把包(bao)(bao)裝袋內(nei)(nei)和(he)食(shi)(shi)(shi)品(pin)(pin)細胞內(nei)(nei)的(de)氧(yang)(yang)(yang)(yang)氣(qi)抽掉，使(shi)(shi)微(wei)(wei)物物失去“生(sheng)(sheng)存的(de)環(huan)境”。實驗證明：當包(bao)(bao)裝袋內(nei)(nei)的(de)氧(yang)(yang)(yang)(yang)氣(qi)濃度≤1%時(shi)，微(wei)(wei)生(sheng)(sheng)物的(de)生(sheng)(sheng)長(chang)和(he)繁(fan)(fan)殖速度就急劇(ju)下降，氧(yang)(yang)(yang)(yang)氣(qi)濃度≤0.5%時(shi)，大(da)多數微(wei)(wei)生(sheng)(sheng)物將受到抑制(zhi)(zhi)而停止(zhi)繁(fan)(fan)殖。（注：真(zhen)空(kong)(kong)包(bao)(bao)裝不(bu)能(neng)抑制(zhi)(zhi)厭(yan)氧(yang)(yang)(yang)(yang)菌(jun)(jun)的(de)繁(fan)(fan)殖和(he)酶反應引(yin)起(qi)的(de)食(shi)(shi)(shi)品(pin)(pin)變(bian)質(zhi)(zhi)(zhi)和(he)變(bian)色(se)(se)，因此還需與其(qi)它輔助方(fang)法結(jie)合，如冷藏、速凍、脫(tuo)水、高溫殺菌(jun)(jun)、輻照 滅菌(jun)(jun)、微(wei)(wei)波殺菌(jun)(jun)、鹽(yan)腌(a)制(zhi)(zhi)等。）真(zhen)空(kong)(kong)除(chu)氧(yang)(yang)(yang)(yang)除(chu)了抑制(zhi)(zhi)微(wei)(wei)生(sheng)(sheng)物的(de)生(sheng)(sheng)長(chang)和(he)繁(fan)(fan)殖外(wai)，另一個重要(yao)功(gong)能(neng)是(shi)(shi)防止(zhi)食(shi)(shi)(shi)品(pin)(pin)氧(yang)(yang)(yang)(yang)化，因油脂(zhi)類食(shi)(shi)(shi)品(pin)(pin)中(zhong)含有(you)大(da)量不(bu)飽(bao)和(he)脂(zhi)肪酸，受氧(yang)(yang)(yang)(yang)的(de)作(zuo)用(yong)而氧(yang)(yang)(yang)(yang)化，使(shi)(shi)食(shi)(shi)(shi)品(pin)(pin)變(bian)味、變(bian)質(zhi)(zhi)(zhi)，此外(wai)，氧(yang)(yang)(yang)(yang)化還使(shi)(shi)維生(sheng)(sheng)素A和(he)C損失，食(shi)(shi)(shi)品(pin)(pin)色(se)(se)素中(zhong)的(de)不(bu)穩定物質(zhi)(zhi)(zhi)受氧(yang)(yang)(yang)(yang)的(de)作(zuo)用(yong)，使(shi)(shi)顏(yan)色(se)(se)變(bian)暗。所(suo)以，除(chu)氧(yang)(yang)(yang)(yang)能(neng)有(you)效地防止(zhi)食(shi)(shi)(shi)品(pin)(pin)變(bian)質(zhi)(zhi)(zhi)，保持其(qi)色(se)(se)、香、味及(ji)營(ying)養價值(zhi)。