真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)中(zhong)重要(yao)的(de)其(qi)一環節是除氧(yang)(yang)(yang)，有(you)利于防止(zhi)(zhi)食(shi)品(pin)變(bian)質(zhi)，其(qi)原(yuan)理也比較簡(jian)單，因食(shi)品(pin)霉(mei)腐變(bian)質(zhi)主要(yao)由微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)的(de)活動造成， 而(er)大(da)多數(shu)微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)（如(ru)霉(mei)菌(jun)和(he)酵母菌(jun)）的(de)生(sheng)(sheng)(sheng)(sheng)(sheng)存是需要(yao)氧(yang)(yang)(yang)氣(qi)的(de)，而(er)真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang) 就(jiu)是運用這個原(yuan)理，把包(bao)裝(zhuang)(zhuang)袋(dai)內和(he)食(shi)品(pin)細胞內的(de)氧(yang)(yang)(yang)氣(qi)抽掉，使(shi)微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)失去“生(sheng)(sheng)(sheng)(sheng)(sheng)存的(de)環境(jing)”。實驗證明：當(dang)包(bao)裝(zhuang)(zhuang)袋(dai)內的(de)氧(yang)(yang)(yang)氣(qi)濃(nong)度(du)≤1%時(shi)， 微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)的(de)生(sheng)(sheng)(sheng)(sheng)(sheng)長和(he)繁殖(zhi)(zhi)速度(du)就(jiu)急劇下降(jiang)，氧(yang)(yang)(yang)氣(qi)濃(nong)度(du)≤0．5%，大(da)多數(shu)微(wei)(wei)(wei)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)將(jiang)受到抑(yi)制而(er)停(ting)止(zhi)(zhi)繁殖(zhi)(zhi)。（注(zhu)：真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)不能抑(yi)制厭氧(yang)(yang)(yang)菌(jun)的(de)繁殖(zhi)(zhi)和(he)酶反應引(yin)起的(de)食(shi)品(pin)變(bian)質(zhi) 和(he)變(bian)色，因此(ci)還(huan)需與其(qi)他輔(fu)助方法結合，如(ru)冷藏(zang)、速凍、脫水、高溫殺菌、輻照滅菌、微波殺菌、鹽腌制等。