真空充氣包裝(zhuang)的主要作(zuo)用除真空包裝(zhuang)所具備(bei)的除氧保質(zhi)功能外，主要還有抗(kang)壓(ya)、阻(zu)氣、保鮮等(deng)作用(yong)(yong)，能(neng)更有(you)效地(di)使食(shi)(shi)品(pin)長(chang)期(qi)保(bao)持原有(you)的色、香、味、形及營養(yang)價值。另外(wai)(wai)，有(you)許多(duo)食(shi)(shi)品(pin)不適宜采用(yong)(yong)真(zhen)(zhen)空(kong)包(bao)(bao)(bao)(bao)裝(zhuang)而必須(xu)采用(yong)(yong)真(zhen)(zhen)空(kong)充(chong)(chong)氣(qi)包(bao)(bao)(bao)(bao)裝(zhuang)。如松(song)脆易碎食(shi)(shi)品(pin)，易結塊食(shi)(shi)品(pin)，易變(bian)(bian)形走油食(shi)(shi)品(pin)，有(you)尖銳棱角或(huo)硬(ying)度較高會刺破包(bao)(bao)(bao)(bao)裝(zhuang)袋(dai)的食(shi)(shi)品(pin)等(deng)。食(shi)(shi)品(pin)經真(zhen)(zhen)空(kong)充(chong)(chong)氣(qi)包(bao)(bao)(bao)(bao)裝(zhuang)后(hou)，包(bao)(bao)(bao)(bao)裝(zhuang)袋(dai)內充(chong)(chong)氣(qi)壓強(qiang)(qiang)大于(yu)包(bao)(bao)(bao)(bao)裝(zhuang)袋(dai)外(wai)(wai)大氣(qi)壓強(qiang)(qiang)，能(neng)有(you)效地(di)防(fang)止食(shi)(shi)品(pin)受壓破碎變(bian)(bian)形并不影響包(bao)(bao)(bao)(bao)裝(zhuang)袋(dai)外(wai)(wai)觀及 印刷(shua)裝(zhuang)潢。真(zhen)(zhen)空(kong)充(chong)(chong)氣(qi)包(bao)(bao)(bao)(bao)裝(zhuang)在(zai)真(zhen)(zhen)空(kong)后(hou)再充(chong)(chong)入氮氣(qi)、二(er)氧化碳、氧氣(qi)單一氣體或二(er)(er) 三種(zhong)氣體的混合氣體。其(qi)(qi)氮氣是(shi)惰性(xing)氣體，起充(chong)填作(zuo)用(yong)，使(shi)袋(dai)內保(bao)持(chi)正壓 ，以防止袋(dai)外空氣進(jin)入袋(dai)內，對食品起到一個保(bao)護(hu)作(zuo)用(yong)。其(qi)(qi)二(er)(er)氧(yang)化(hua)碳能夠溶于(yu)各類脂肪(fang)或水(shui)，引成(cheng)酸性(xing)較弱的碳酸，有抑制(zhi)霉(mei)菌(jun)、腐敗細菌(jun)等(deng)微生(sheng)物(wu)的活(huo)性(xing)。其(qi)(qi)氧(yang)氣具有抑制(zhi)厭(yan)氧(yang)菌(jun)的生(sheng)長繁殖(zhi)，保(bao)持(chi)水(shui)果、蔬菜的新鮮及色(se)彩，高濃(nong)度氧(yang)氣可(ke)使(shi)新鮮肉(rou)類保(bao)持(chi)其(qi)(qi)鮮紅色(se)。