WJEC Level 3 Diploma In Food Science And Nutrition
53 6WDUFK LV GHULYHG IURP SODQWV DQG LV D SURGXFW RI SKRWRV\QWKHVLV ,W LV VWRUHG LQ YDULRXV SODFHV LQ SODQWV LQFOXGLQJ ⦁ Amyloplasts ZKLFK DUH FHOO RUJDQHOOHV IRXQG LQVLGH SODQW FHOOV Ŝ WKHVH DUH VRPHWLPHV referred to as starch granules . ⦁ 3ODQW URRWV DQG WXEHUV H J \DPV SRWDWRHV SDUVQLSV ⦁ 6HHGV 8VLQJ WKH H[DPSOH RI VDXFH PDNLQJ ZLWK VWDUFK DV WKH WKLFNHQLQJ DJHQW JHODWLQLVDWLRQ RFFXUV LQ WKH IROORZLQJ ZD\ ⦁ :KHQ VWDUFK JUDQXOHV DUH LQ SXW LQWR D cold liquid WKH\ VLQN WR WKH ERWWRP RI WKH ERZO or pan. ⦁ :KHQ VWDUFK JUDQXOHV DQG WKH OLTXLG DUH KHDWHG at about 60°C WKH JUDQXOHV VWDUW WR absorb WKH OLTXLG ZKLFK FDXVHV WKHP WR swell DQG HQODUJH WKUHH GLPHQVLRQDOO\ 3D). ⦁ This makes the sauce start to thicken EHFDXVH WKH JUDQXOHV WDNH XS PRUH VSDFH DQG WKHUH LV OHVV URRP IRU WKHP WR PRYH DURXQG ⦁ &RQWLQXRXV VWLUULQJ RI WKH VDXFH DV LW LV KHDWLQJ SUHYHQWV WKH VWDUFK JUDQXOHV IURP VWD\LQJ DW WKH ERWWRP RI WKH OLTXLG ZKHUH WKH\ ZRXOG VZHOO XS VWLFN WRJHWKHU DQG FDXVH WKH VDXFH WR GHYHORS D OXPS\ WH[WXUH ⦁ At about 80°C WKH VWDUFK JUDQXOHV DUH VR VZROOHQ WKDW WKH\ VWDUW WR leak, which causes starch (i.e. amylose and amylopectin molecules WR EH UHOHDVHG LQWR WKH VXUURXQGLQJ liquid. ⦁ These released starch molecules gelatinise, i.e. the amylose molecules form a 3-dimensional (3D) network that traps water molecules and slows down the PRYHPHQW RI WKH VZROOHQ VWDUFK JUDQXOHV ⦁ At boiling point (100 r& WKH VDXFH FRPSOHWHO\ JHODWLQLVHV ⦁ ,W LV QRUPDO SUDFWLFH WR FRQWLQXH WR heat the sauce for a few minutes to make sure all WKH VWDUFK LV FRRNHG DQG SUHYHQW D ŞUDZş flDYRXU ⦁ 6RPH VWDUFK EDVHG VDXFHV DUH VLPPHUHG IRU D ORQJ WLPH DIWHU JHODWLQLVDWLRQ WR JUDGXDOO\ WKLQ DQG SURGXFH D YHU\ ʐQHO\ WH[WXUHG VDXFH 7KLV KDSSHQV EHFDXVH FRQWLQXHG KHDWLQJ DQG RFFDVLRQDO EULVN VWLUULQJ RI WKH VDXFH FDXVHV WKH UHPDLQLQJ VZROOHQ DQG GHOLFDWH VWDUFK JUDQXOHV LW FRQWDLQV WR EUHDN XS LQWR YHU\ VPDOO SDUWLFOHV and many of the amylose and amylopectin molecules break into smaller sections. ⦁ As the cooked sauce cools down WKH VWDUFK PROHFXOHV VWDUW WR OLQN XS DQG IRUP longer chains DQG WKH ZDWHU PROHFXOHV VWD\ WUDSSHG LQVLGH WKHP VR WKH FRROHG VDXFH JUDGXDOO\ EHFRPHV D solid 3 dimensional (3D) gel . ⦁ *HODWLQLVDWLRQ DOVR WDNHV SODFH ZKHQ IRRGV FRQWDLQLQJ VWDUFK DUH FRRNHG H J ZKHQ ERLOLQJ ULFH DQG SDVWD RU ZKHQ XVLQJ SRWDWRHV WR WKLFNHQ D VRXS ⦁ ,I WKHVH W\SHV RI IRRG DUH ERLOHG IRU WRR ORQJ D ORW RI WKH VWDUFK JUDQXOHV WKH\ FRQWDLQ ZLOO OHDN DQG WKH VWDUFK WKDW FRPHV RXW ZLOO FDXVH WKH JUDLQV RI ULFH RU SLHFHV RI SDVWD WR VWLFN WRJHWKHU ZKLFK FDQ PDNH WKHP GLʒFXOW WR VHUYH DQG HDW ⦁ 6RPH W\SHV RI ULFH XVHG LQ UHFLSHV IURP $VLD DUH QDWXUDOO\ VWLFN\ EHFDXVH RI WKH SDUWLFXODU FRPSRVLWLRQ DQG DPRXQW RI VWDUFK WKH\ FRQWDLQ H J 7KDL VWLFN\ ULFH VXVKL rice. Amyloplasts (stained blue) inside plant cells 60˚C 60˚C 80˚C 100˚C The properties of foods and how they are changed
Made with FlippingBook
RkJQdWJsaXNoZXIy Nzc1OTg=