真(zhen)空(kong)充氣包(bao)裝(zhuang)的主(zhu)要(yao)作用除真(zhen)空(kong)包(bao)裝(zhuang)所(suo)具備(bei)的除氧保質功能(neng)外，主(zhu)要(yao)還有(you)抗壓、阻(zu)氣、保(bao)鮮(xian)等作用(yong)，能(neng)更有(you)(you)效地使食(shi)(shi)品長期保持原(yuan)有(you)(you)的色、香(xiang)、味、形(xing)(xing)及營(ying)養價值(zhi)。另外，有(you)(you)許多(duo)食(shi)(shi)品不(bu)適宜(yi)采用(yong)真(zhen)(zhen)(zhen)(zhen)空(kong)包(bao)裝(zhuang)(zhuang)(zhuang)而(er)必(bi)須采用(yong)真(zhen)(zhen)(zhen)(zhen)空(kong)充(chong)(chong)(chong)氣(qi)(qi)(qi)包(bao)裝(zhuang)(zhuang)(zhuang)。如松脆易碎(sui)(sui)食(shi)(shi)品，易結塊(kuai)食(shi)(shi)品，易變(bian)形(xing)(xing)走油食(shi)(shi)品，有(you)(you)尖銳(rui)棱角或硬度較(jiao)高會刺破(po)包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)的食(shi)(shi)品等。食(shi)(shi)品經真(zhen)(zhen)(zhen)(zhen)空(kong)充(chong)(chong)(chong)氣(qi)(qi)(qi)包(bao)裝(zhuang)(zhuang)(zhuang)后，包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)內(nei)充(chong)(chong)(chong)氣(qi)(qi)(qi)壓強(qiang)大于包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)外大氣(qi)(qi)(qi)壓強(qiang)，能(neng)有(you)(you)效地防止食(shi)(shi)品受(shou)壓破(po)碎(sui)(sui)變(bian)形(xing)(xing)并不(bu)影響包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)外觀及 印刷裝(zhuang)(zhuang)(zhuang)潢。真(zhen)(zhen)(zhen)(zhen)空(kong)充(chong)(chong)(chong)氣(qi)(qi)(qi)包(bao)裝(zhuang)(zhuang)(zhuang)在真(zhen)(zhen)(zhen)(zhen)空(kong)后再(zai)充(chong)(chong)(chong)入氮氣(qi)(qi)(qi)、二氧(yang)化(hua)碳、氧(yang)氣(qi)(qi)(qi)單一氣體或二 三種氣體的(de)混合氣體。其(qi)(qi)氮氣是惰(duo)性氣體，起充(chong)填作用(yong)(yong)，使袋(dai)內保持正壓 ，以防(fang)止袋(dai)外空氣進(jin)入袋(dai)內，對食(shi)品(pin)起到一個(ge)保護作用(yong)(yong)。其(qi)(qi)二氧(yang)化碳能夠溶于各類脂肪或水(shui)，引(yin)成(cheng)酸性較弱的(de)碳酸，有抑制(zhi)霉菌(jun)、腐敗細菌(jun)等(deng)微生物的(de)活性。其(qi)(qi)氧(yang)氣具有抑制(zhi)厭氧(yang)菌(jun)的(de)生長繁殖，保持水(shui)果、蔬(shu)菜的(de)新鮮(xian)及色彩(cai)，高濃度氧(yang)氣可使新鮮(xian)肉(rou)類保持其(qi)(qi)鮮(xian)紅色。