真(zhen)(zhen)(zhen)空(kong)(kong)袋(dai)的(de)(de)主(zhu)要(yao)(yao)作(zuo)用(yong)是除(chu)氧(yang)(yang)(yang)(yang)，以(yi)有利于防止食(shi)(shi)品(pin)(pin)變(bian)(bian)質(zhi)(zhi)，其(qi)(qi)原(yuan)理(li)也(ye)比較簡單，因(yin)食(shi)(shi)品(pin)(pin)霉腐變(bian)(bian)質(zhi)(zhi)主(zhu)要(yao)(yao)由微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)活(huo)動造成，而大多數微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)（如霉菌和(he)酵母菌）的(de)(de)生(sheng)(sheng)(sheng)(sheng)存是需要(yao)(yao)氧(yang)(yang)(yang)(yang)氣的(de)(de)，而真(zhen)(zhen)(zhen)空(kong)(kong)包裝(zhuang)就(jiu)是運用(yong)這個原(yuan)理(li)，把包裝(zhuang)袋(dai)內和(he)食(shi)(shi)品(pin)(pin)細胞(bao)內的(de)(de)氧(yang)(yang)(yang)(yang)氣抽掉(diao)，使(shi)微(wei)(wei)(wei)物(wu)(wu)物(wu)(wu)失去“生(sheng)(sheng)(sheng)(sheng)存的(de)(de)環(huan)境(jing)”。實驗證明：當包裝(zhuang)袋(dai)內的(de)(de)氧(yang)(yang)(yang)(yang)氣濃度(du)≤1%時，微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)生(sheng)(sheng)(sheng)(sheng)長和(he)繁(fan)殖速度(du)就(jiu)急劇(ju)下降，氧(yang)(yang)(yang)(yang)氣濃度(du)≤0.5%時，大多數微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)將(jiang)受到抑(yi)制而停止繁(fan)殖。（注：真(zhen)(zhen)(zhen)空(kong)(kong)包裝(zhuang)不能抑(yi)制厭(yan)氧(yang)(yang)(yang)(yang)菌的(de)(de)繁(fan)殖和(he)酶反應(ying)引起的(de)(de)食(shi)(shi)品(pin)(pin)變(bian)(bian)質(zhi)(zhi)和(he)變(bian)(bian)色(se)，因(yin)此(ci)還需與其(qi)(qi)它輔(fu)助方法結合，如冷(leng)藏(zang)、速凍、脫水、高溫殺(sha)菌、輻照 滅菌、微(wei)(wei)(wei)波殺(sha)菌、鹽腌制等。）真(zhen)(zhen)(zhen)空(kong)(kong)除(chu)氧(yang)(yang)(yang)(yang)除(chu)了(le)抑(yi)制微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)物(wu)(wu)的(de)(de)生(sheng)(sheng)(sheng)(sheng)長和(he)繁(fan)殖外，另一個重要(yao)(yao)功能是防止食(shi)(shi)品(pin)(pin)氧(yang)(yang)(yang)(yang)化，因(yin)油脂類食(shi)(shi)品(pin)(pin)中含有大量不飽和(he)脂肪酸，受氧(yang)(yang)(yang)(yang)的(de)(de)作(zuo)用(yong)而氧(yang)(yang)(yang)(yang)化，使(shi)食(shi)(shi)品(pin)(pin)變(bian)(bian)味、變(bian)(bian)質(zhi)(zhi)，此(ci)外，氧(yang)(yang)(yang)(yang)化還使(shi)維生(sheng)(sheng)(sheng)(sheng)素(su)A和(he)C損失，食(shi)(shi)品(pin)(pin)色(se)素(su)中的(de)(de)不穩(wen)定物(wu)(wu)質(zhi)(zhi)受氧(yang)(yang)(yang)(yang)的(de)(de)作(zuo)用(yong)，使(shi)顏色(se)變(bian)(bian)暗。所以(yi)，除(chu)氧(yang)(yang)(yang)(yang)能有效地防止食(shi)(shi)品(pin)(pin)變(bian)(bian)質(zhi)(zhi)，保持其(qi)(qi)色(se)、香、味及營養價值。