真空充氣包(bao)裝的主要作用除真空包(bao)裝所(suo)具備(bei)的除氧保(bao)質功能外，主要還有(you)抗壓、阻氣、保鮮等作用，能更有(you)(you)(you)效地使食(shi)(shi)品(pin)長期保持原有(you)(you)(you)的色、香、味、形(xing)(xing)及營養價值。另外(wai)(wai)，有(you)(you)(you)許多食(shi)(shi)品(pin)不(bu)適宜(yi)采(cai)用真(zhen)空(kong)包(bao)裝(zhuang)(zhuang)(zhuang)而必須(xu)采(cai)用真(zhen)空(kong)充(chong)(chong)氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)。如松脆(cui)易碎食(shi)(shi)品(pin)，易結塊食(shi)(shi)品(pin)，易變(bian)形(xing)(xing)走(zou)油(you)食(shi)(shi)品(pin)，有(you)(you)(you)尖銳棱角或硬度(du)較高會(hui)刺破包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)的食(shi)(shi)品(pin)等。食(shi)(shi)品(pin)經真(zhen)空(kong)充(chong)(chong)氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)后，包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)內充(chong)(chong)氣(qi)壓(ya)(ya)強大于包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)外(wai)(wai)大氣(qi)壓(ya)(ya)強，能有(you)(you)(you)效地防止食(shi)(shi)品(pin)受壓(ya)(ya)破碎變(bian)形(xing)(xing)并(bing)不(bu)影響(xiang)包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)外(wai)(wai)觀及 印刷裝(zhuang)(zhuang)(zhuang)潢。真(zhen)空(kong)充(chong)(chong)氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)在真(zhen)空(kong)后再充(chong)(chong)入氮(dan)氣(qi)、二(er)氧化碳、氧氣(qi)單一氣體或二(er) 三種(zhong)氣(qi)(qi)(qi)體(ti)的混合氣(qi)(qi)(qi)體(ti)。其氮氣(qi)(qi)(qi)是惰(duo)性(xing)(xing)氣(qi)(qi)(qi)體(ti)，起充(chong)填(tian)作用(yong)，使袋內保持正壓 ，以防止袋外空氣(qi)(qi)(qi)進入袋內，對食品起到(dao)一個保護(hu)作用(yong)。其二(er)氧化碳(tan)能夠溶(rong)于各類脂肪(fang)或水(shui)，引成酸性(xing)(xing)較弱的碳(tan)酸，有(you)抑制(zhi)霉(mei)菌、腐敗細菌等微生物(wu)的活性(xing)(xing)。其氧氣(qi)(qi)(qi)具有(you)抑制(zhi)厭氧菌的生長(chang)繁殖，保持水(shui)果(guo)、蔬菜的新(xin)鮮(xian)(xian)及色(se)彩，高濃度氧氣(qi)(qi)(qi)可使新(xin)鮮(xian)(xian)肉類保持其鮮(xian)(xian)紅色(se)。