真空(kong)充氣包裝的主要作(zuo)用(yong)除真空(kong)包裝所(suo)具備的除氧保質功(gong)能外，主要還有抗壓、阻(zu)氣、保鮮等作用(yong)，能(neng)(neng)更有(you)(you)(you)效地(di)使食(shi)(shi)(shi)品(pin)長期保(bao)持原有(you)(you)(you)的色、香(xiang)、味、形(xing)(xing)及營養價值。另外(wai)，有(you)(you)(you)許多(duo)食(shi)(shi)(shi)品(pin)不適宜采(cai)用(yong)真(zhen)(zhen)(zhen)空(kong)包(bao)(bao)裝而必須采(cai)用(yong)真(zhen)(zhen)(zhen)空(kong)充(chong)氣(qi)包(bao)(bao)裝。如(ru)松脆易碎食(shi)(shi)(shi)品(pin)，易結(jie)塊食(shi)(shi)(shi)品(pin)，易變(bian)形(xing)(xing)走油(you)食(shi)(shi)(shi)品(pin)，有(you)(you)(you)尖銳棱角或(huo)硬度較高會刺破包(bao)(bao)裝袋(dai)的食(shi)(shi)(shi)品(pin)等。食(shi)(shi)(shi)品(pin)經(jing)真(zhen)(zhen)(zhen)空(kong)充(chong)氣(qi)包(bao)(bao)裝后(hou)，包(bao)(bao)裝袋(dai)內充(chong)氣(qi)壓(ya)(ya)強大于包(bao)(bao)裝袋(dai)外(wai)大氣(qi)壓(ya)(ya)強，能(neng)(neng)有(you)(you)(you)效地(di)防止食(shi)(shi)(shi)品(pin)受壓(ya)(ya)破碎變(bian)形(xing)(xing)并(bing)不影響包(bao)(bao)裝袋(dai)外(wai)觀及 印刷裝潢。真(zhen)(zhen)(zhen)空(kong)充(chong)氣(qi)包(bao)(bao)裝在真(zhen)(zhen)(zhen)空(kong)后(hou)再充(chong)入氮(dan)氣(qi)、二(er)氧化碳(tan)、氧氣(qi)單一氣體或二 三(san)種氣(qi)(qi)體(ti)的混合氣(qi)(qi)體(ti)。其(qi)(qi)氮氣(qi)(qi)是惰性(xing)氣(qi)(qi)體(ti)，起充填作(zuo)用，使袋內保持正壓 ，以防止(zhi)袋外(wai)空氣(qi)(qi)進入袋內，對(dui)食品(pin)起到一個(ge)保護作(zuo)用。其(qi)(qi)二氧化(hua)碳能夠溶(rong)于各類脂肪或水(shui)，引成酸性(xing)較弱(ruo)的碳酸，有(you)抑(yi)制霉菌、腐敗(bai)細(xi)菌等微生物的活性(xing)。其(qi)(qi)氧氣(qi)(qi)具有(you)抑(yi)制厭氧菌的生長(chang)繁殖，保持水(shui)果、蔬菜的新(xin)鮮(xian)及(ji)色(se)彩，高濃度氧氣(qi)(qi)可使新(xin)鮮(xian)肉類保持其(qi)(qi)鮮(xian)紅(hong)色(se)。