哪(na)些(xie)因(yin)素會影響植物油脂的煙(yan)點

         油(you)(you)(you)脂(zhi)(zhi)的(de)(de)煙點(dian)是(shi)油(you)(you)(you)脂(zhi)(zhi)質量指標(biao)之一(yi)。煙點(dian)高的(de)(de)油(you)(you)(you)脂(zhi)(zhi)熱(re)穩(wen)定性(xing)在一(yi)定時(shi)期內較好(hao),油(you)(you)(you)炸食(shi)品(pin)(pin)及烹(peng)飪操作環境(jing)衛生(sheng)條(tiao)件(jian)較好(hao),食(shi)品(pin)(pin)風味(wei)好(hao),但一(yi)味(wei)追求高煙點(dian)的(de)(de)油(you)(you)(you)脂(zhi)(zhi)產品(pin)(pin),必將受加工(gong)過程高溫的(de)(de)影響,若工(gong)藝(yi)(yi)條(tiao)件(jian)控(kong)制不(bu)(bu)當,不(bu)(bu)但使油(you)(you)(you)脂(zhi)(zhi)發生(sheng)雙(shuang)鍵的(de)(de)異(yi)構(gou)化(hua)及聚合,熔(rong)點(dian)升高,降(jiang)低(di)(di)消化(hua)吸收率和營養(yang)價值(zhi),而且(qie)使油(you)(you)(you)中的(de)(de)天然抗氧化(hua)劑(ji)大大減少,儲(chu)(chu)存安定性(xing)降(jiang)低(di)(di),含油(you)(you)(you)食(shi)品(pin)(pin)貨架期縮短。因此, 上海頎高儀器有(you)限公司(si)生(sheng)產的(de)(de)HSY-20795D全自動油(you)(you)(you)脂(zhi)(zhi)煙點(dian)測定儀必須(xu)綜合考慮油(you)(you)(you)脂(zhi)(zhi)產品(pin)(pin)的(de)(de)各項質量指標(biao),選(xuan)好(hao)工(gong)藝(yi)(yi)并(bing)把握(wo)好(hao)油(you)(you)(you)脂(zhi)(zhi)精煉各工(gong)序的(de)(de)工(gong)藝(yi)(yi)條(tiao)件(jian),才(cai)能得到既品(pin)(pin)質良好(hao),又有(you)較長儲(chu)(chu)存期的(de)(de)食(shi)用(yong)油(you)(you)(you)脂(zhi)(zhi)產品(pin)(pin)。

影響(xiang)煙點的因素：

主(zhu)要內(nei)因。由于(yu)游離脂(zhi)(zhi)肪(fang)酸(suan)(suan)比甘(gan)油(you)酯(zhi)容(rong)易(yi)揮(hui)發(fa)(fa)，精煉(lian)程度不同(tong)的(de)(de)油(you)脂(zhi)(zhi)，游離脂(zhi)(zhi)肪(fang)酸(suan)(suan)含(han)量不同(tong)，其煙(yan)點(dian)(dian)測定值(zhi)(zhi)(zhi)不同(tong)。游離脂(zhi)(zhi)肪(fang)酸(suan)(suan)含(han)量相(xiang)同(tong)的(de)(de)油(you)脂(zhi)(zhi)，以高碳酸(suan)(suan)為(wei)主(zhu)的(de)(de)油(you)脂(zhi)(zhi)煙(yan)儀點(dian)(dian)高，以低(di)(di)(di)碳酸(suan)(suan)為(wei)主(zhu)的(de)(de)油(you)脂(zhi)(zhi)煙(yan)點(dian)(dian)低(di)(di)(di)。如(ru)，椰子油(you)比菜籽油(you)的(de)(de)煙(yan)點(dian)(dian)低(di)(di)(di)。皂(zao)化(hua)(hua)(hua)值(zhi)(zhi)(zhi)徊E甘(gan)三酯(zhi)平均相(xiang)對(dui)分子質(zhi)量）相(xiang)近的(de)(de)油(you)脂(zhi)(zhi)，在相(xiang)同(tong)酸(suan)(suan)值(zhi)(zhi)(zhi)條件下，碘值(zhi)(zhi)(zhi)高的(de)(de)比碘值(zhi)(zhi)(zhi)低(di)(di)(di)的(de)(de)油(you)脂(zhi)(zhi)煙(yan)點(dian)(dian)低(di)(di)(di)。如(ru)；棉籽油(you)（皂(zao)化(hua)(hua)(hua)值(zhi)(zhi)(zhi)9l一(yi)199，碘值(zhi)(zhi)(zhi)103—115）比花生(sheng)油(you)（皂(zao)化(hua)(hua)(hua)值(zhi)(zhi)(zhi)188：197，碘值(zhi)(zhi)(zhi)94一(yi)_9B1的(de)(de)煙(yan)點(dian)(dian)低(di)(di)(di)，這是由于(yu)脂(zhi)(zhi)肪(fang)酸(suan)(suan)的(de)(de)末飽和(he)度越(yue)(yue)高，空(kong)氣(qi)中加熱越(yue)(yue)易(yi)氧化(hua)(hua)(hua)分解出低(di)(di)(di)分子易(yi)揮(hui)發(fa)(fa)性組分。

目(mu)(mu)(mu)前國內各檢測(ce)(ce)(ce)機構和企(qi)業均采(cai)用(yong)國家標(biao)準GB/T20795-2006《植物油脂煙點(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)》推(tui)薦的(de)煙點(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)方法(fa)。其中，一法(fa)是(shi)采(cai)用(yong)自(zi)動(dong)測(ce)(ce)(ce)定(ding)(ding)儀(yi)方法(fa)（上(shang)海頎高儀(yi)器有限公司生產的(de)HSY-20795D全自(zi)動(dong)油脂煙點(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)儀(yi)），第二(er)法(fa)是(shi)目(mu)(mu)(mu)測(ce)(ce)(ce)法(fa)。目(mu)(mu)(mu)測(ce)(ce)(ce)法(fa)通(tong)過肉(rou)跟觀察(cha)得到測(ce)(ce)(ce)定(ding)(ding)結(jie)果(guo)。測(ce)(ce)(ce)定(ding)(ding)人(ren)員眼睛觀察(cha)煙霧和溫度計讀(du)數不(bu)，測(ce)(ce)(ce)定(ding)(ding)結(jie)果(guo)穩定(ding)(ding)性差(cha)。同時，樣品加熱速(su)度控(kong)制(zhi)不(bu)準確。因此(ci)，目(mu)(mu)(mu)測(ce)(ce)(ce)法(fa)受人(ren)為的(de)因素影響較大，煙點(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)誤差(cha)較大。