WJEC Level 3 Diploma In Food Science And Nutrition

52 Mechanical agitation 7KH HʏHFWV RI PHFKDQLFDO DJLWDWLRQ ZKLVNLQJ EHDWLQJ RQ SURWHLQ PROHFXOHV LV EHVW LOOXVWUDWHG E\ FRQVLGHULQJ HJJV ⦁ (JJ \RONV DQG HJJ ZKLWHV DUH ERWK FDSDEOH RI SURGXFLQJ foams of air cells (bubbles) WUDSSHG LQVLGH D WKLQ OLTXLG SURWHLQ ŞZDOOş VWUXFWXUH ⦁ (JJ \RONV ZLOO SURGXFH D GHQVH IRDP LI ZKLVNHG ZLWK VXJDU ⦁ :KROH HJJV ZLOO WUDS DLU LI ZKLVNHG EXW WKH DLU ZLOO JUDGXDOO\ HVFDSH ZKHQ ZKLVNLQJ stops. ⦁ :KROH HJJV ZKLVNHG ZLWK VXJDU ZLOO WUDS DQG KROG D ODUJH DPRXQW RI DLU DQG ZKHQ PL[HG ZLWK flRXU DQG EDNHG ZLOO SURGXFH D OLJKW VSRQJH IRDP ⦁ (JJ ZKLWH SURWHLQV DUH FDSDEOH RI KROGLQJ ODUJH YROXPHV RI DLU ZKLFK PDNHV WKHP XVHIXO DV D PHWKRG RI OLJKWHQLQJ D PL[WXUH VXFK DV D PHULQJXH VRXʓ« RU PRXVVH ⦁ (JJ ZKLWHV FDQ WUDS EHWZHHQ 6 and 8 WLPHV WKHLU RZQ YROXPH RI DLU ⦁ The PHFKDQLFDO DFWLRQ RI ZKLVNLQJ HJJ ZKLWHV FDXVHV WKH FRPSDFW VWUXFWXUH RI WKH proteins (mainly ovotransferrin and ovoglobulins suspended in a watery liquid) to XQIROG DV PDQ\ RI WKH ERQGV WKDW KROG WKHP WRJHWKHU DUH EURNHQ ⦁ 7KH GHQDWXUHG SURWHLQV KDYH hydrophilic ZDWHU ŞORYLQJş VHFWLRQV DQG hydrophobic ZDWHU ŞKDWLQJş VHFWLRQV ⦁ $LU EHFRPHV WUDSSHG DV FHOOV DV WKH XQIROGHG SURWHLQV DUUDQJH WKHPVHOYHV LQ DQ XQEURNHQ QHWZRUN VXUURXQGLQJ WKH DLU FHOOV DV IROORZV • Their hydrophilic VHFWLRQV EHFRPH VXEPHUJHG LQ WKH liquid ZDWHU\ SDUW RI WKH HJJ ZKLWH SURWHLQ ŞZDOOş • Their hydrophobic VHFWLRQV JR LQWR WKH DLU FHOOV ⦁ :KLVNLQJ VKRXOG EH FDUULHG RXW DW D PRGHUDWH VSHHG WR DOORZ HYHQ VL]HG DLU FHOOV WR IRUP UDWKHU WKDQ ODUJH FHOOV WKDW HDVLO\ EUHDN DQG WKH SURWHLQV WR GHQDWXUH DQG FRDJXODWH HYHQO\ ⦁ ,I RYHU ZKLVNHG WKH DLU FHOOV PD\ EXUVW UHOHDVH WKH ZDWHU WKH\ KROG DQG FDXVH WKH collapse of the foam. ⦁ 7KH DGGLWLRQ RI DQ DFLG H J YLQHJDU HWKDQRLF DFLG OHPRQ MXLFH FLWULF DFLG RU FUHDP RI WDUWDU SRWDVVLXP K\GURJHQ WDUWUDWH >WDUWDULF DFLG@ WR DQ HJJ ZKLWH IRDP ZLOO HQKDQFH GHQDWXUDWLRQ DQG FRDJXODWLRQ RI WKH SURWHLQ DQG VWDELOLVH LW ⦁ :KHQ EDNHG HJJ ZKLWH IRDP ZLOO VHW EHFDXVH WKH RYDOEXPLQ SURWHLQ LW FRQWDLQV GHQDWXUHV DQG FRDJXODWHV ZLWK KHDW PXFK RI WKH ZDWHU LV GULYHQ RXW DQG WKH IRDP becomes solid. ⦁ 6XJDU DGGHG WR HJJ ZKLWH IRDPV GLVVROYHV LQ WKH ZDWHU DQG UHGXFHV WKH VSHHG RI ZDWHU HYDSRUDWLRQ GXULQJ EDNLQJ ZKLFK VWUHQJWKHQV WKH ZDOOV RI WKH DLU FHOOV DQG DOORZV PRUH WLPH IRU WKH SURWHLQV WR FRDJXODWH Gelatinisation 7KH SRO\VDFFKDULGH starch consists of thousands of glucose molecules MRLQHG WRJHWKHU either in long straight chains (called amylose ) and short chains with branches (called amylopectin ). :KHQ VWDUFK LV KHDWHG LQ D OLTXLG LW gelatinises . *HODWLQLVDWLRQ LV D SURFHVV WKDW LV XWLOLVHG LQ D QXPEHU RI IRRG SURGXFWLRQ WHFKQLTXHV usually to thicken a food. Hydrophilic section of protein Air cell (bubble) Hydrophobic section of protein Air cells (bubbles) surrounded by denatured and coagulating proteins Hydrophilic section of protein Air cell (bubble) Hydrophobic section of protein Air cells (bubbles) surrounded by denatured and coagulating proteins Amylopectin Glycogen Amylose Amylopectin Glycogen Chapter 5: The scientific properties of food Unit 3: Experimenting to solve food production problems (LO1)

RkJQdWJsaXNoZXIy Nzc1OTg=