食品膨化機由供料系統、擠壓系統、加熱系統、傳動系統、旋切系統和控制系統等幾部分組成。將物料由喂料機喂入，機筒經過高溫、高壓、高剪切，使物料膨化以達到所需的組織狀態等品質要求。

食(shi)品(pin)膨(peng)化(hua)機是(shi)通過(guo)水(shui)分、熱能(neng)、機械剪切和壓(ya)(ya)力等綜合(he)作用(yong)(yong)對(dui)食(shi)品(pin)進(jin)(jin)行(xing)膨(peng)化(hua)的(de)(de)一種技(ji)術，是(shi)高(gao)(gao)溫(wen)、高(gao)(gao)壓(ya)(ya)的(de)(de)短時加(jia)(jia)工過(guo)程。當(dang)含有(you)一定水(shui)分的(de)(de)原料(liao)(liao)通過(guo)供料(liao)(liao)器進(jin)(jin)入(ru)套(tao)筒(tong)(tong)后，隨(sui)著(zhu)螺桿的(de)(de)轉(zhuan)動而(er)向前(qian)輸送，當(dang)物(wu)料(liao)(liao)逐漸(jian)受到機頭(tou)的(de)(de)阻力作用(yong)(yong)時而(er)被(bei)壓(ya)(ya)縮(suo)，通過(guo)壓(ya)(ya)延效(xiao)應和吸(xi)收機筒(tong)(tong)外部所加(jia)(jia)熱量，以及物(wu)料(liao)(liao)在(zai)螺桿與套(tao)筒(tong)(tong)間的(de)(de)強烈攪拌、混合(he)、剪切等作用(yong)(yong)而(er)產生(sheng)的(de)(de)高(gao)(gao)溫(wen)、高(gao)(gao)壓(ya)(ya)，使物(wu)料(liao)(liao)在(zai)擠壓(ya)(ya)腔內成(cheng)(cheng)熔融(rong)(rong)狀(zhuang)態，淀(dian)(dian)(dian)粉(fen)(fen)組織中(zhong)(zhong)排(pai)列緊(jin)密的(de)(de)膠束被(bei)破壞，淀(dian)(dian)(dian)粉(fen)(fen)由(you)生(sheng)淀(dian)(dian)(dian)粉(fen)(fen)(β一淀(dian)(dian)(dian)粉(fen)(fen))轉(zhuan)化(hua)為熟淀(dian)(dian)(dian)粉(fen)(fen)(α一淀(dian)(dian)(dian)粉(fen)(fen))，即形成(cheng)(cheng)了淀(dian)(dian)(dian)粉(fen)(fen)糊化(hua)，此時物(wu)料(liao)(liao)中(zhong)(zhong)的(de)(de)水(shui)分仍處于液(ye)體狀(zhuang)態。當(dang)熔融(rong)(rong)態物(wu)料(liao)(liao)進(jin)(jin)入(ru)成(cheng)(cheng)型模(mo)頭(tou)前(qian)的(de)(de)高(gao)(gao)溫(wen)高(gao)(gao)壓(ya)(ya)區時，呈完全的(de)(de)流體狀(zhuang)態，隨(sui)模(mo)孔(kong)(kong)被(bei)擠出到達常溫(wen)常壓(ya)(ya)狀(zhuang)態，物(wu)料(liao)(liao)中(zhong)(zhong)的(de)(de)溶膠淀(dian)(dian)(dian)粉(fen)(fen)體積也(ye)瞬(shun)間膨(peng)化(hua)，致(zhi)使食(shi)品(pin)內部爆裂出許多微(wei)孔(kong)(kong)，體積迅速(su)膨(peng)脹，從(cong)而(er)形成(cheng)(cheng)質構疏松的(de)(de)膨(peng)化(hua)食(shi)品(pin)。