哪些因素會影響植物油脂的煙(yan)點

         油(you)脂(zhi)(zhi)(zhi)(zhi)的(de)(de)煙點(dian)(dian)是(shi)油(you)脂(zhi)(zhi)(zhi)(zhi)質量指(zhi)標之一。煙點(dian)(dian)高的(de)(de)油(you)脂(zhi)(zhi)(zhi)(zhi)熱穩定(ding)性(xing)在一定(ding)時期(qi)內較好,油(you)炸食(shi)品(pin)(pin)及(ji)烹飪操作環境衛生(sheng)條(tiao)件(jian)較好,食(shi)品(pin)(pin)風味好,但一味追(zhui)求高煙點(dian)(dian)的(de)(de)油(you)脂(zhi)(zhi)(zhi)(zhi)產(chan)品(pin)(pin),必將(jiang)受(shou)加工(gong)過(guo)程高溫的(de)(de)影(ying)響,若(ruo)工(gong)藝(yi)條(tiao)件(jian)控制不(bu)(bu)當,不(bu)(bu)但使(shi)(shi)油(you)脂(zhi)(zhi)(zhi)(zhi)發生(sheng)雙鍵的(de)(de)異(yi)構化及(ji)聚合,熔點(dian)(dian)升高,降低(di)消化吸收率和營養價值,而且使(shi)(shi)油(you)中的(de)(de)天然抗氧(yang)化劑大大減少,儲存安定(ding)性(xing)降低(di),含油(you)食(shi)品(pin)(pin)貨架期(qi)縮短。因此(ci), 上(shang)海(hai)頎高儀(yi)器(qi)有限公(gong)司(si)生(sheng)產(chan)的(de)(de)HSY-20795D全自(zi)動油(you)脂(zhi)(zhi)(zhi)(zhi)煙點(dian)(dian)測定(ding)儀(yi)必須綜合考慮油(you)脂(zhi)(zhi)(zhi)(zhi)產(chan)品(pin)(pin)的(de)(de)各(ge)項質量指(zhi)標,選好工(gong)藝(yi)并(bing)把握好油(you)脂(zhi)(zhi)(zhi)(zhi)精(jing)煉(lian)各(ge)工(gong)序(xu)的(de)(de)工(gong)藝(yi)條(tiao)件(jian),才能得到既品(pin)(pin)質良好,又有較長(chang)儲存期(qi)的(de)(de)食(shi)用(yong)油(you)脂(zhi)(zhi)(zhi)(zhi)產(chan)品(pin)(pin)。

影(ying)響煙點的因(yin)素：

主(zhu)要內因。由于游(you)離脂(zhi)(zhi)(zhi)肪酸(suan)(suan)(suan)比(bi)甘(gan)油(you)(you)酯容易揮(hui)發，精煉程度不同(tong)的(de)油(you)(you)脂(zhi)(zhi)(zhi)，游(you)離脂(zhi)(zhi)(zhi)肪酸(suan)(suan)(suan)含(han)(han)量(liang)不同(tong)，其煙(yan)點(dian)(dian)測定(ding)值(zhi)不同(tong)。游(you)離脂(zhi)(zhi)(zhi)肪酸(suan)(suan)(suan)含(han)(han)量(liang)相(xiang)同(tong)的(de)油(you)(you)脂(zhi)(zhi)(zhi)，以高碳酸(suan)(suan)(suan)為(wei)主(zhu)的(de)油(you)(you)脂(zhi)(zhi)(zhi)煙(yan)儀點(dian)(dian)高，以低(di)碳酸(suan)(suan)(suan)為(wei)主(zhu)的(de)油(you)(you)脂(zhi)(zhi)(zhi)煙(yan)點(dian)(dian)低(di)。如(ru)，椰(ye)子(zi)油(you)(you)比(bi)菜籽(zi)油(you)(you)的(de)煙(yan)點(dian)(dian)低(di)。皂(zao)(zao)化(hua)值(zhi)徊E甘(gan)三酯平(ping)均(jun)相(xiang)對分子(zi)質(zhi)量(liang)）相(xiang)近的(de)油(you)(you)脂(zhi)(zhi)(zhi)，在相(xiang)同(tong)酸(suan)(suan)(suan)值(zhi)條(tiao)件下，碘值(zhi)高的(de)比(bi)碘值(zhi)低(di)的(de)油(you)(you)脂(zhi)(zhi)(zhi)煙(yan)點(dian)(dian)低(di)。如(ru)；棉籽(zi)油(you)(you)（皂(zao)(zao)化(hua)值(zhi)9l一199，碘值(zhi)103—115）比(bi)花生油(you)(you)（皂(zao)(zao)化(hua)值(zhi)188：197，碘值(zhi)94一_9B1的(de)煙(yan)點(dian)(dian)低(di)，這是由于脂(zhi)(zhi)(zhi)肪酸(suan)(suan)(suan)的(de)末飽和度越高，空氣中加熱越易氧化(hua)分解出(chu)低(di)分子(zi)易揮(hui)發性(xing)組分。

目(mu)(mu)前國內各檢測(ce)(ce)(ce)機構和企業均采用國家標準(zhun)GB/T20795-2006《植物油脂(zhi)煙(yan)(yan)點(dian)(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)(ding)》推薦(jian)的煙(yan)(yan)點(dian)(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)(ding)方法。其中，一法是(shi)采用自(zi)動測(ce)(ce)(ce)定(ding)(ding)(ding)儀(yi)方法（上海頎高儀(yi)器有限公司生產的HSY-20795D全自(zi)動油脂(zhi)煙(yan)(yan)點(dian)(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)(ding)儀(yi)），第(di)二法是(shi)目(mu)(mu)測(ce)(ce)(ce)法。目(mu)(mu)測(ce)(ce)(ce)法通過肉跟觀察得到測(ce)(ce)(ce)定(ding)(ding)(ding)結果。測(ce)(ce)(ce)定(ding)(ding)(ding)人(ren)員眼睛(jing)觀察煙(yan)(yan)霧和溫度計讀(du)數不，測(ce)(ce)(ce)定(ding)(ding)(ding)結果穩(wen)定(ding)(ding)(ding)性(xing)差(cha)。同時，樣品加熱(re)速度控制不準(zhun)確。因(yin)(yin)此，目(mu)(mu)測(ce)(ce)(ce)法受人(ren)為(wei)的因(yin)(yin)素影響較大，煙(yan)(yan)點(dian)(dian)(dian)測(ce)(ce)(ce)定(ding)(ding)(ding)誤差(cha)較大。