真(zhen)空充氣包(bao)裝(zhuang)的主(zhu)要作(zuo)用除真(zhen)空包(bao)裝(zhuang)所具(ju)備的除氧保質功(gong)能(neng)外，主(zhu)要還有(you)抗壓、阻氣、保鮮等作用(yong)，能更有(you)效地(di)使食(shi)(shi)(shi)品(pin)(pin)(pin)長(chang)期保(bao)持原有(you)的色、香、味(wei)、形(xing)及營養(yang)價值。另外(wai)，有(you)許多食(shi)(shi)(shi)品(pin)(pin)(pin)不適宜采用(yong)真空(kong)(kong)包(bao)裝(zhuang)(zhuang)(zhuang)而必(bi)須采用(yong)真空(kong)(kong)充(chong)(chong)氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)。如(ru)松脆易(yi)(yi)碎食(shi)(shi)(shi)品(pin)(pin)(pin)，易(yi)(yi)結塊食(shi)(shi)(shi)品(pin)(pin)(pin)，易(yi)(yi)變(bian)形(xing)走油食(shi)(shi)(shi)品(pin)(pin)(pin)，有(you)尖(jian)銳棱角或硬(ying)度(du)較高會刺(ci)破包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)的食(shi)(shi)(shi)品(pin)(pin)(pin)等。食(shi)(shi)(shi)品(pin)(pin)(pin)經(jing)真空(kong)(kong)充(chong)(chong)氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)后(hou)(hou)，包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)內充(chong)(chong)氣(qi)壓強(qiang)大于包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)外(wai)大氣(qi)壓強(qiang)，能有(you)效地(di)防止食(shi)(shi)(shi)品(pin)(pin)(pin)受壓破碎變(bian)形(xing)并不影響(xiang)包(bao)裝(zhuang)(zhuang)(zhuang)袋(dai)外(wai)觀及 印(yin)刷裝(zhuang)(zhuang)(zhuang)潢。真空(kong)(kong)充(chong)(chong)氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)在真空(kong)(kong)后(hou)(hou)再(zai)充(chong)(chong)入氮氣(qi)、二氧化碳(tan)、氧氣(qi)單一氣體或二 三種氣(qi)(qi)體的混合(he)氣(qi)(qi)體。其(qi)(qi)氮氣(qi)(qi)是惰性氣(qi)(qi)體，起充填(tian)作用，使袋(dai)內(nei)保持(chi)(chi)正壓 ，以防止袋(dai)外空氣(qi)(qi)進入袋(dai)內(nei)，對食品起到一個保護作用。其(qi)(qi)二氧化碳能夠溶(rong)于各類脂肪或水(shui)，引成(cheng)酸性較(jiao)弱的碳酸，有抑制(zhi)霉菌、腐敗(bai)細菌等微生物的活性。其(qi)(qi)氧氣(qi)(qi)具有抑制(zhi)厭氧菌的生長(chang)繁殖，保持(chi)(chi)水(shui)果、蔬(shu)菜的新鮮(xian)及色(se)(se)彩，高濃(nong)度氧氣(qi)(qi)可使新鮮(xian)肉類保持(chi)(chi)其(qi)(qi)鮮(xian)紅色(se)(se)。