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)(hua)機是(shi)通(tong)過水(shui)分(fen)、熱能、機械剪切和(he)壓力等(deng)綜合作(zuo)用(yong)對食(shi)品(pin)進(jin)行膨(peng)化(hua)(hua)的(de)一種技(ji)術，是(shi)高溫(wen)(wen)(wen)、高壓的(de)短時(shi)(shi)加(jia)工過程。當含有(you)一定(ding)水(shui)分(fen)的(de)原料(liao)(liao)通(tong)過供料(liao)(liao)器進(jin)入套筒后，隨著螺桿的(de)轉(zhuan)動而向前輸(shu)送，當物(wu)(wu)料(liao)(liao)逐漸受到機頭的(de)阻力作(zuo)用(yong)時(shi)(shi)而被(bei)壓縮，通(tong)過壓延(yan)效應和(he)吸(xi)收(shou)機筒外部所加(jia)熱量(liang)，以及物(wu)(wu)料(liao)(liao)在(zai)螺桿與套筒間(jian)的(de)強烈(lie)攪拌、混合、剪切等(deng)作(zuo)用(yong)而產生的(de)高溫(wen)(wen)(wen)、高壓，使物(wu)(wu)料(liao)(liao)在(zai)擠壓腔內成(cheng)熔(rong)融(rong)狀態(tai)(tai)，淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen)組織中排列(lie)緊密的(de)膠(jiao)束被(bei)破壞，淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen)由生淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen)(β一淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen))轉(zhuan)化(hua)(hua)為熟淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen)(α一淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen))，即形成(cheng)了淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen)糊化(hua)(hua)，此時(shi)(shi)物(wu)(wu)料(liao)(liao)中的(de)水(shui)分(fen)仍處于液體狀態(tai)(tai)。當熔(rong)融(rong)態(tai)(tai)物(wu)(wu)料(liao)(liao)進(jin)入成(cheng)型模(mo)(mo)頭前的(de)高溫(wen)(wen)(wen)高壓區(qu)時(shi)(shi)，呈完全的(de)流(liu)體狀態(tai)(tai)，隨模(mo)(mo)孔被(bei)擠出(chu)(chu)到達常溫(wen)(wen)(wen)常壓狀態(tai)(tai)，物(wu)(wu)料(liao)(liao)中的(de)溶膠(jiao)淀(dian)(dian)(dian)(dian)粉(fen)(fen)(fen)體積也瞬間(jian)膨(peng)化(hua)(hua)，致使食(shi)品(pin)內部爆裂出(chu)(chu)許多微孔，體積迅速膨(peng)脹(zhang)，從而形成(cheng)質構疏松的(de)膨(peng)化(hua)(hua)食(shi)品(pin)。