真(zhen)(zhen)空(kong)(kong)袋(dai)的(de)(de)(de)(de)主要(yao)作(zuo)用是(shi)除氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)，以有利于防止(zhi)(zhi)食(shi)(shi)品(pin)變(bian)(bian)(bian)質(zhi)，其原(yuan)理也比較簡單，因食(shi)(shi)品(pin)霉(mei)腐變(bian)(bian)(bian)質(zhi)主要(yao)由微(wei)生(sheng)(sheng)(sheng)(sheng)物的(de)(de)(de)(de)活動(dong)造成，而(er)(er)大多(duo)數微(wei)生(sheng)(sheng)(sheng)(sheng)物（如(ru)霉(mei)菌(jun)和(he)(he)(he)酵母菌(jun)）的(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)存(cun)是(shi)需要(yao)氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)氣的(de)(de)(de)(de)，而(er)(er)真(zhen)(zhen)空(kong)(kong)包(bao)裝就是(shi)運用這個原(yuan)理，把包(bao)裝袋(dai)內和(he)(he)(he)食(shi)(shi)品(pin)細(xi)胞內的(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)氣抽掉，使(shi)(shi)(shi)微(wei)物物失(shi)去“生(sheng)(sheng)(sheng)(sheng)存(cun)的(de)(de)(de)(de)環境”。實驗證明：當包(bao)裝袋(dai)內的(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)氣濃(nong)度≤1%時，微(wei)生(sheng)(sheng)(sheng)(sheng)物的(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)長和(he)(he)(he)繁(fan)(fan)殖(zhi)速度就急劇下降(jiang)，氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)氣濃(nong)度≤0.5%時，大多(duo)數微(wei)生(sheng)(sheng)(sheng)(sheng)物將受到抑(yi)制(zhi)(zhi)而(er)(er)停止(zhi)(zhi)繁(fan)(fan)殖(zhi)。（注：真(zhen)(zhen)空(kong)(kong)包(bao)裝不(bu)能(neng)抑(yi)制(zhi)(zhi)厭氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)菌(jun)的(de)(de)(de)(de)繁(fan)(fan)殖(zhi)和(he)(he)(he)酶反應引起的(de)(de)(de)(de)食(shi)(shi)品(pin)變(bian)(bian)(bian)質(zhi)和(he)(he)(he)變(bian)(bian)(bian)色(se)，因此還需與其它輔助方法結合，如(ru)冷藏、速凍、脫水、高(gao)溫殺菌(jun)、輻照 滅菌(jun)、微(wei)波殺菌(jun)、鹽(yan)腌制(zhi)(zhi)等。）真(zhen)(zhen)空(kong)(kong)除氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)除了抑(yi)制(zhi)(zhi)微(wei)生(sheng)(sheng)(sheng)(sheng)物的(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)長和(he)(he)(he)繁(fan)(fan)殖(zhi)外，另一個重要(yao)功(gong)能(neng)是(shi)防止(zhi)(zhi)食(shi)(shi)品(pin)氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)化，因油脂(zhi)類食(shi)(shi)品(pin)中含有大量不(bu)飽和(he)(he)(he)脂(zhi)肪(fang)酸，受氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)(de)作(zuo)用而(er)(er)氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)化，使(shi)(shi)(shi)食(shi)(shi)品(pin)變(bian)(bian)(bian)味、變(bian)(bian)(bian)質(zhi)，此外，氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)化還使(shi)(shi)(shi)維生(sheng)(sheng)(sheng)(sheng)素(su)A和(he)(he)(he)C損失(shi)，食(shi)(shi)品(pin)色(se)素(su)中的(de)(de)(de)(de)不(bu)穩定(ding)物質(zhi)受氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)(de)作(zuo)用，使(shi)(shi)(shi)顏色(se)變(bian)(bian)(bian)暗。所(suo)以，除氧(yang)(yang)(yang)(yang)(yang)(yang)(yang)能(neng)有效地防止(zhi)(zhi)食(shi)(shi)品(pin)變(bian)(bian)(bian)質(zhi)，保持其色(se)、香、味及營養價值。