真(zhen)空充氣包裝(zhuang)的主要作用除(chu)(chu)真(zhen)空包裝(zhuang)所具備的除(chu)(chu)氧保質功能外，主要還有(you)抗壓、阻氣、保鮮(xian)等作用(yong)(yong)，能更(geng)有(you)效(xiao)地(di)使食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)長期保持(chi)原(yuan)有(you)的色、香、味、形(xing)及(ji)營養價值。另(ling)外，有(you)許(xu)多食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)不(bu)適(shi)宜采用(yong)(yong)真(zhen)空包(bao)裝(zhuang)(zhuang)而必須采用(yong)(yong)真(zhen)空充(chong)(chong)氣(qi)(qi)(qi)包(bao)裝(zhuang)(zhuang)。如(ru)松(song)脆易碎食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)，易結塊食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)，易變(bian)形(xing)走(zou)油(you)食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)，有(you)尖銳棱角(jiao)或硬度較高(gao)會刺(ci)破包(bao)裝(zhuang)(zhuang)袋的食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)等。食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)經(jing)真(zhen)空充(chong)(chong)氣(qi)(qi)(qi)包(bao)裝(zhuang)(zhuang)后，包(bao)裝(zhuang)(zhuang)袋內充(chong)(chong)氣(qi)(qi)(qi)壓(ya)(ya)強大(da)于包(bao)裝(zhuang)(zhuang)袋外大(da)氣(qi)(qi)(qi)壓(ya)(ya)強，能有(you)效(xiao)地(di)防止食(shi)(shi)(shi)(shi)品(pin)(pin)(pin)受壓(ya)(ya)破碎變(bian)形(xing)并(bing)不(bu)影(ying)響包(bao)裝(zhuang)(zhuang)袋外觀及(ji) 印刷裝(zhuang)(zhuang)潢。真(zhen)空充(chong)(chong)氣(qi)(qi)(qi)包(bao)裝(zhuang)(zhuang)在真(zhen)空后再充(chong)(chong)入氮氣(qi)(qi)(qi)、二氧化碳、氧氣(qi)(qi)(qi)單一氣體或二 三種氣(qi)(qi)體(ti)(ti)的(de)混合氣(qi)(qi)體(ti)(ti)。其(qi)氮氣(qi)(qi)是惰(duo)性(xing)氣(qi)(qi)體(ti)(ti)，起充填作(zuo)用(yong)，使袋(dai)內保(bao)(bao)持正壓 ，以防止袋(dai)外空氣(qi)(qi)進入袋(dai)內，對(dui)食(shi)品起到一個保(bao)(bao)護作(zuo)用(yong)。其(qi)二氧化碳能夠溶于各類脂(zhi)肪或水，引(yin)成酸(suan)性(xing)較弱的(de)碳酸(suan)，有抑制(zhi)霉菌、腐(fu)敗(bai)細菌等(deng)微生(sheng)物(wu)的(de)活(huo)性(xing)。其(qi)氧氣(qi)(qi)具有抑制(zhi)厭(yan)氧菌的(de)生(sheng)長繁殖，保(bao)(bao)持水果、蔬菜的(de)新(xin)鮮(xian)及色彩(cai)，高濃度氧氣(qi)(qi)可使新(xin)鮮(xian)肉類保(bao)(bao)持其(qi)鮮(xian)紅色。