真(zhen)(zhen)空(kong)(kong)袋的(de)(de)(de)(de)(de)主要作用是除(chu)氧(yang)(yang)(yang)(yang)(yang)，以有利于防止(zhi)食(shi)品(pin)變質(zhi)(zhi)(zhi)，其原(yuan)理也(ye)比較簡(jian)單，因食(shi)品(pin)霉腐變質(zhi)(zhi)(zhi)主要由微(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)的(de)(de)(de)(de)(de)活動造成，而大(da)多(duo)數(shu)微(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)（如(ru)霉菌和(he)酵母菌）的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)存(cun)(cun)是需(xu)要氧(yang)(yang)(yang)(yang)(yang)氣的(de)(de)(de)(de)(de)，而真(zhen)(zhen)空(kong)(kong)包裝(zhuang)(zhuang)就是運用這個原(yuan)理，把(ba)包裝(zhuang)(zhuang)袋內(nei)和(he)食(shi)品(pin)細(xi)胞(bao)內(nei)的(de)(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)氣抽掉，使(shi)微(wei)物(wu)(wu)(wu)(wu)物(wu)(wu)(wu)(wu)失去“生(sheng)(sheng)(sheng)(sheng)(sheng)存(cun)(cun)的(de)(de)(de)(de)(de)環境”。實(shi)驗(yan)證明：當包裝(zhuang)(zhuang)袋內(nei)的(de)(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)(yang)氣濃度(du)≤1%時，微(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)長和(he)繁(fan)(fan)殖(zhi)速(su)(su)度(du)就急劇下降，氧(yang)(yang)(yang)(yang)(yang)氣濃度(du)≤0.5%時，大(da)多(duo)數(shu)微(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)將受(shou)到抑制(zhi)(zhi)而停止(zhi)繁(fan)(fan)殖(zhi)。（注：真(zhen)(zhen)空(kong)(kong)包裝(zhuang)(zhuang)不能抑制(zhi)(zhi)厭(yan)氧(yang)(yang)(yang)(yang)(yang)菌的(de)(de)(de)(de)(de)繁(fan)(fan)殖(zhi)和(he)酶反應引(yin)起的(de)(de)(de)(de)(de)食(shi)品(pin)變質(zhi)(zhi)(zhi)和(he)變色，因此(ci)還(huan)需(xu)與其它輔助方法結合，如(ru)冷(leng)藏、速(su)(su)凍(dong)、脫水、高溫殺(sha)菌、輻照 滅菌、微(wei)波殺(sha)菌、鹽腌制(zhi)(zhi)等。）真(zhen)(zhen)空(kong)(kong)除(chu)氧(yang)(yang)(yang)(yang)(yang)除(chu)了抑制(zhi)(zhi)微(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)長和(he)繁(fan)(fan)殖(zhi)外(wai)，另一個重要功(gong)能是防止(zhi)食(shi)品(pin)氧(yang)(yang)(yang)(yang)(yang)化(hua)，因油脂類食(shi)品(pin)中(zhong)含有大(da)量不飽和(he)脂肪酸，受(shou)氧(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)(de)(de)作用而氧(yang)(yang)(yang)(yang)(yang)化(hua)，使(shi)食(shi)品(pin)變味、變質(zhi)(zhi)(zhi)，此(ci)外(wai)，氧(yang)(yang)(yang)(yang)(yang)化(hua)還(huan)使(shi)維生(sheng)(sheng)(sheng)(sheng)(sheng)素A和(he)C損失，食(shi)品(pin)色素中(zhong)的(de)(de)(de)(de)(de)不穩定物(wu)(wu)(wu)(wu)質(zhi)(zhi)(zhi)受(shou)氧(yang)(yang)(yang)(yang)(yang)的(de)(de)(de)(de)(de)作用，使(shi)顏(yan)色變暗。所(suo)以，除(chu)氧(yang)(yang)(yang)(yang)(yang)能有效地防止(zhi)食(shi)品(pin)變質(zhi)(zhi)(zhi)，保持其色、香、味及營養價值(zhi)。