pengembangan cara/tehnik pengujian makanan yang mengandung pati/amilum (testing food for the...

7/25/2019 Pengembangan cara/tehnik pengujian makanan yang mengandung pati/amilum (Testing food for the presence of

1/23

TEACHING AID TUTORIAL

TESTING FOOD FOR THE PRESENCE OF STARCH

CREATED BY:

AHMAD ZUHUDY B

121 444 1020

ICP B

DEPARTMENT OF BIOLOGY

MATHEMATIC AND SCIENCE FACULTY

MAKASSAR STATE UNIVERSITY

2015


2/23

THE ORIGINAL EXPERIMENT

Ex!"#$!%& A%'()*#*

T+#, : Testing food for the presence of starch

P-"+*! : To determine the starch content in food to be tested

P"+.(!$ F+"$-(': How the contain of starch in food to be tested?

H)+&/!*#* : There are differences in the content of starch in foods that will be test.

Ex!"#$!%& V'"#'.(!

1. Free Variable: food ingredients used are: potatoes, onion, bread, bananas, apples, and milk,

2. ependent !ariable: the starch content of food ingredients used are: potatoes, onion, bread,

bananas, apples, and milk,

". #ontrol !ariable : a sample si$e of 1 cm cube, the addition of distilled 1%cm", heating time,addition iodine,

&perational definition of !ariables:

'ach material used is !aried

Tests conducted b( the method logul starch ) iodine solution

*o Variable &perational

1 Food sample 1. The use of + different t(pes of food, indicating the

difference in starch content of each t(pe of food. Food

samples are:

1. otatoes2. &nions

". -read

. -ananas

/. 0pples

+. r( ilk

2 tarch content tarch is the main ingredient that is produced b( plants to

store e3cess glucose 4as a product of photos(nthesis5 in

the long term.

tarch is composed of two kinds of carboh(drates,

am(lose and am(lopectin, in !ar(ing compositions.0m(lose gi!e tough nature 4pera5 whereas am(lopectin

cause stick( properties. 0m(lose pro!ide dense purple

color in the iodine test while am(lopectin did not react.

" 6odine test method tarch that binds with iodine to produce a blue color.

These properties can be used to anal($e the starch. This is

due to the molecular structure of iodine and forming a

blue color.


3/23

0fter a few drops of iodine starch solution 4pre7heated5

white translucent solution. Howe!er, after a heated white

color of the solution remains clear but there is a purple

precipitate the bottom of a test tube. This shows that the

h(drol(sis of starch upon heating. The precipitate which

appears at the bottom of the tube is caused b( starchh(drol(sis process is not perfect. These deposits

constitute the remainder of the starch grains.


4/23

EXPERIMENT UPGRADE

Ex!"#$!%& A%'()*#*

T+#, : Testing food for the presence of starch

P-"+*! :

1. To determine the starch content in food to be tested

2. To see the process of iodine to detect starch content

P"+.(!$ F+"$-(':

1. How the contain of starch in food to be tested?

2. How the wa(s working of iodine to detect starch content in different pH?

H)+&/!*#*:1. There are differences in the content of starch in foods that will be test.

2. There are influence of pH in process of iodine to detect starch content

Ex!"#$!%& V'"#'.(!

. Free Variable: food ingredients used are: potatoes, onion, bread, bananas, apples, and milk,

addition H#l, addition of *0&H./. ependent !ariable: the starch content of food ingredients used are: potatoes, onion, bread,

bananas, apples, and milk. #olor change of e3tract food in different H.

+. #ontrol !ariable : a sample weight / g, the addition of distilled 1% cm"or /% mm, heating

time, addition of / drops of iodine, addition of istilled water

O!"'+%'( !#%#+% + '"#'.(!*:

*o Variable &perational

1 Food sample The use of + different t(pes of food, indicating the

difference in starch content of each t(pe of food. Food

samples are:

1. otatoes

2. &nions". -read

. -ananas

/. 0pples

+. r( ilk

2 tarch content The starch content in 8uestion is starch. tarch or starch is


5/23

a comple3 carboh(drate which is insoluble in water,

tangible white powder, tasteless and odorless. tarch is

the main ingredient that is produced b( plants to store

e3cess glucose 4as a product of photos(nthesis5 in the

long term.

tarch is composed of two kinds of carboh(drates,am(lose and am(lopectin, in !ar(ing compositions.

0m(lose gi!e tough nature 4pera5 whereas am(lopectin

cause stick( properties. 0m(lose pro!ide dense purple

color in the iodine test while am(lopectin did not react.

" 6odine test method tarch that binds with iodine to produce a blue color.

These properties can be used to anal($e the starch. This is

due to the molecular structure of iodine and forming a

blue color.

0fter a few drops of iodine starch solution 4pre7heated5

white translucent solution. Howe!er, after a heated whitecolor of the solution remains clear but there is a purple

precipitate the bottom of a test tube. This shows that the

h(drol(sis of starch upon heating. The precipitate which

appears at the bottom of the tube is caused b( starch

h(drol(sis process is not perfect. These deposits

constitute the remainder of the starch grains.

. 0ddition of H#l 0ddition of H#l in the test carboh(drates ha!e the same

function with other reagents such as, H&. -oth ser!e to

h(drol($e pol(saccharides into monosaccharide9s

constituent. tarch which has been coupled with

h(drochloric acid when tested with iodine solution,

indicating a negati!e result, it can be concluded that the

starch has been h(drol($ed to perfection

/ 0ddition of *0&H odium h(dro3ide 4*a&H5, also known as caustic soda

l(e. The addition of *a&H is to pro!ide alkaline

conditions the iodine test. 6n testing the starch and iodine

solution, *a&H pre!ent a reaction between starch with

iodine. This is because the iodine reacts with a base that

does not undergo reaction with the starch. This situation

occurs because the e3isting *a&H solution first reacts

with iodine to form compounds *a6 and *aoi, so the testwith the addition of *a&H ha!e been no changes in the

starch solution.

+. 0ddition of istilled

water

istilled water is neutral and so can not h(drol($e

glucose though accompanied b( heating. istilled water

onl( ser!es as a sol!ent. istilled watert not a reagent,

and distilled water has a pH neutral, acidic and not

alkaline. o that mi3ing distilled water will not inhibit the


6/23

reaction of h(drol(sis of starch.


7/23

3+" P"+,!-"!

The work in this lab procedure, namel(:

1. The samples were then washed peeled, crushed and weighed / grams.

2. The sample is inserted into a measuring cup and add /% ml of distilled water.

". amples were put into " reaction tubes, each " ml then treated and obser!ed the color change.

0s for treatment, namel(:

7 2 drops of distilled water

7 " H#l solution 2 drops

7 + *a&H solution 2 drops

. The iodine solution is added as much as / drops on each sample and then obser!e the color

change.

/. The sample is heated for / minutes and obser!ed changes

+. amples were cooled for 1% minutes and then obser!e the color change.

O.*!"'+% &'.(!

Table 1.1 0ddition with istilled water

%+ F++ S'$(!

T"!'&$!%&

D#*((!

6'&!"

I+#%!

*+(-+%

C/'%7!

8*/'!9

,+(+" '&!"

/!'&!

C/'%7!

8*/'!9

,+(+" '&!"

,++(!

1 otato

2 &nion

" -read -anana

/ 0pple

+ ried milk

Table 1.2 0ddition with H#l

%+ F++ S'$(!

T"!'&$!%&

HC( I+#%!

*+(-+%

C/'%7!

8*/'!9

,+(+" '&!"

/!'&!

C/'%7!

8*/'!9

,+(+" '&!"

,++(!

1 otato

2 &nion

" -read

-anana

/ 0pple

+ ried milk


8/23

Table 1." 0ddition with *0&H

%+ F++ S'$(!

T"!'&$!%&

NAOH I+#%!

*+(-+%

C/'%7!

8*/'!9

,+(+" '&!"/!'&!

C/'%7!

8*/'!9

,+(+" '&!",++(!

1 otato

2 &nion

" -read

-anana

/ 0pple

+ ried milk


9/23

PERCOBAAN A3AL

T+# :u;i kandungan pati pada makanan

T-;-'% : untuk mengetahui kandungan pati pada makanan (ang akan diu;i

R-$-*'% $'*'('/ :-agaimanakah kandungan pati pada makanan (ang akan diu;ikan?

H#+&!*#* :Terdapat perbedaan kandungan pati pada makanan (ang akan di u;ikan.

V'"#'.!( Ex!"#$!%&

1. Variaberl bebas : bahan makanan (ang digunakan (aitu : kentang, bawangg, roti, pisang,

apel, dan susu2. Variable terikat : kandungan pati dari bahan makanan (ang digunakan (aitu: kentang,

bawangg, roti, pisang, apel, dan susu". Variable control : ukuran sampel berbentuk kubus 1 cm, penambahan a8uades 1%cm",

lama pemanasan, penambahan / tetes iodium

D!!%#*# +!"'*#+%'( '"#'.(!:

*o Variabel &perasional

1 Food sample enggunaan + ;enis makanan (ang berbeda,

mengindikasikan adan(a perbedaan kandungan pati dari

setiap ;enis makanan. Food sample (ang dimaksud adalah

:

1.


10/23

amilopektin tidak bereaksi.

" etode >;i 6odin ati (ang berikatan dengan iodin akan menghasilkan

warna biru. ifat ini dapat digunakan untuk menganalisis

adan(a pati. Hal ini disebabkan oleh struktur molekul

iodin dan terbentuklah warna biru.

arutan amilum setelah ditetesi iodium 4sebelum

dipanaskan5 larutan berwarna putih bening. *amun,

setelah dipanaskan warna larutan tetap putih bening tetapi

ada endapan berwarna ungu didasar tabung reaksi. Hal ini

menun;ukkan bahwa ter;adi hidrolisis pati pada saat

pemanasan. 0dapun endapan (ang muncul di dasar

tabung ini disebabkan karena proses hidrolisis pati (ang

tidak sempurna. 'ndapan ini merupakan sisa dari butir7

butir amilum.


11/23

PENGEMBANGAN PRAKTIKUM

T+# :u;i kandungan pati pada makanan

T-;-'% :

1. >ntuk mengetahui kandungan pati pada makanan (ang akan diu;i2. >ntuk melihat cara ker;a iodin dalam mendeteksi kandungan pati

R-$-*'% $'*'('/ :

1. -agaimanakah kandungan pati pada makanan (ang akan diu;ikan?2. -agaimana cara ker;a iodine pada pH (ang berbeda dalam mendeteksi kandungan pati

pada makanan

H#+&!*#* :

1. Terdapat perbedaan kandungan pati pada makanan (ang akan di u;ikan.

2. Terdapat pengaruh pH terhadap cara ker;a iodine dalam mendeteksi kandungan pati pada

makanan.

V'"#'.!( Ex!"#$!%&

1. Variaberl bebas : bahan makanan (ang digunakan (aitu : kentang, bawangg, roti, pisang,

apel, dan susu, penambahan H#l, penambahan *0&H

2. Variable terikat : kandungan pati dari bahan makanan (ang digunakan (aitu: kentang,

bawangg, roti, pisang, apel, dan susu

". Variable control : ukuran sampel berbentuk kubus 1 cm, penambahan a8uades 1%cm",lama pemanasan, penambahan iodium

D!!%#*# +!"'*#+%'( '"#'.(!:

*o Variabel &perasional

1 Food sample enggunaan + ;enis makanan (ang berbeda,

mengindikasikan adan(a perbedaan kandungan pati dari

setiap ;enis makanan. Food sample (ang dimaksud

adalah :

1.


12/23

dalam air, berwu;ud bubuk putih, tawar dan tidak berbau.

ati merupakan bahan utama (ang dihasilkan oleh

tumbuhan untuk men(impan kelebihan glukosa 4sebagai

produk fotosintesis5 dalam ;angka pan;ang.

ati tersusun dari dua macam karbohidrat, amilosa dan

amilopektin, dalam komposisi (ang berbeda7beda.

0milosa memberikan sifat keras 4pera5 sedangkan

amilopektin men(ebabkan sifat lengket. 0milosa

memberikan warna ungu pekat pada tes iodin sedangkan

amilopektin tidak bereaksi.

" etode >;i 6odin ati (ang berikatan dengan iodin akan menghasilkan

warna biru. ifat ini dapat digunakan untuk menganalisis

adan(a pati. Hal ini disebabkan oleh struktur molekul

iodin dan terbentuklah warna biru.

arutan amilum setelah ditetesi iodium 4sebelumdipanaskan5 larutan berwarna putih bening. *amun,

setelah dipanaskan warna larutan tetap putih bening

tetapi ada endapan berwarna ungu didasar tabung reaksi.

Hal ini menun;ukkan bahwa ter;adi hidrolisis pati pada

saat pemanasan. 0dapun endapan (ang muncul di dasar

tabung ini disebabkan karena proses hidrolisis pati (ang

tidak sempurna. 'ndapan ini merupakan sisa dari butir7

butir amilum.

enambahan H#l enambahan H#l pada pengu;ian karbohidrat memiliki

memiliki fungsi (ang sama dengan pereaksi lainn(aseperti, H&.


13/23

ter;adi perubahan pada larutan amilum 4raandesk(, 2%115.

+ enambahan 08uades 08uadest bersifat netral sehingga tidak dapat

menghidrolisa glukosa walaupun disertai pemanasan.

08uadest han(a berfungsi sebagai pelarut. 08uadest

bukanlah reagen, dan a8uadest memiliki pH netral, tidak

asam serta tidak basa. ehingga pencampuran a8uades

tidak akan menghambat reaksi hidrolisis pati 4utri,

2%125

P"+*!-" K!";' L'.

0dapun prosedur ker;a pada praktikum ini, (aitu:

1. ampel dikupas kemudian dicuci, dihaluskan dan ditimbang seban(ak / gram.

2. ampel dimasukkan kedalam gelas ukur dan ditambahkan a8uades /% ml.

". ampel dimasukkan ke dalam " tabung reaksi, masing7masing " ml kemudian diberi

perlakuan dan diamati perubahan warna (ang ter;adi. 0dapun perlakuann(a (aitu :

7 a8uades 2 tetes

7 larutan H#l " 2 tetes

7 larutan *a&H + 2 tetes

. larutan iodium ditambahkan seban(ak / tetes pada setiap sampel kemudian amati

perubahan warna (ang ter;adi./. ampel dipanaskan selama / menit dan diamati perubahan (ang ter;adi

+. ampel didinginkan selama 1% menit kemudian amati perubahan warna (ang ter;adi.


14/23

T'.!( O.*!"'*#

Table 1.1 enambahan 08uades

no Sampel Makanan

Perlakuan

+ Aquades+ Larutan

Iodin

Perubahan

(bentuk,warna)

yang

teradi

setelah

dipanaska

n

Perubahan

(bentuk,warna)

yang

teradi

setelah

didinginka

n1 Kentang2 Bawang3 Roti4 Pisang5 Apel6 Susu uu!

Tale 1"2 Pena#a$an %&l

no Sampel Makanan

Perlakuan

+ !"l+ Larutan

Iodin

Perubahan

(bentuk,

warna)

yang

teradi

setelah

dipanaska

n

Perubahan

(bentuk,

warna)

yang

teradi

setelah

didinginka

n1 Kentang2 Bawang3 Roti4 Pisang5 Apel6 Susu uu!

Tale 1"3 Pena#a$an Na'%

no Sampel Makanan

Perlakuan

+ #a$!+ Larutan

Iodin

Perubahan

(bentuk,warna)

yang

teradi

setelah

dipanaska

n

Perubahan

(bentuk,warna)

yang

teradi

setelah

didinginka

n1 Kentang


15/23

2 Bawang3 Roti4 Pisang5 Apel6 Susu uu!

%&periment '* esting ood or the presen-e o star-h

PRE&A(TI'N" E)pe*i#ent 3 s$owe+ t$at t$e sta*,$ test is a sensiti-e one. so i/ 0ou

use a

testtue /o* #o*e t$an one e)pe*i#ent. #a!e su*e it is t$o*oug$l0 ,leane+ out

ea,$ ti#e o*

else t*a,es o/ sta*,$ /*o# one /oo+ sa#ple #a0 *e#ain on t$e si+es an+ gi-e a

positi-e

*esult /o* a sa#ple w$i,$. in /a,t. ,ontains no sta*,$" o* t$e sa#e *eason. t$e#o*ta* an+ pestle #ust e was$e+ etween ea,$ test"

(a)Lael si) testtues 16"

&op0 t$e tale gi-en elow into 0ou* noteoo!"

(b)&*us$ a 1 ,# ,ue. o* eui-alent uantit0. o/ t$e *st /oo+ sa#ple in a #o*ta*

wit$

aout 1 ,#3wate* 75## in a testtue8"

(-)Pou* t$e #i)tu*e into a ,lean testtue an+. using a testtue $ol+e*. $eat t$e

#i)tu*e

in a s#all 9a#e o/ a Bunsen u*ne* till it oils /o* a /ew se,on+s. s$a!ing t$e tue

gentl0 all t$e ti#e"

(d)&ool t$e tue un+e* a *unning tap"

(e)A++ -e +*ops o/ io+ine solution"

()Re,o*+ 0ou* *esults in t$e tale in 0ou* noteoo! an+ *epeat t$e e)pe*i#ent wit$

t$e ne)t /oo+ sa#ple"

06=0*

2.1

&'*T

Food sample Colour change with iodine Interpretation of result

1 Potato

2 'nion

3 B*ea+

4 Banana

5 Apple

6 :*ie+

#il!


16/23


17/23

%&periment '. /is-ussion

1< 6f a food sample, e3tracted and tested as abo!e, gi!es a blue colour with iodine solution,can (ou assume that starch is present in the sample?

2< oes the result indicate that the onl( food present is starch?

=< oes the result mean that starch will be present in all samples of the same food?

4< 6f the food sample, when tested, gi!es no blue colour, does it mean in!ariabl( that no

starch is present?

5< Ahat difficulties are there in tr(ing to answer the 8uestion, Bo apples contain starch?B

If you did experiment 5, answer questions 6 and 7.

6. 6f, with (our sample of potato, (ou obtained a blue colour that corresponded closel( to(our 1 result in e3periment /, wh( would (ou not be ;ustified in sa(ing that 1 of

the potato sample was starch? 4There are se!eral reasons.5

>< 6f the blue colour had corresponded to the %.1 result and the potato sample had beena one centimetre cube, what would (ou be prepared to sa( about the concentration of

starch in the potato?

Ahat reser!ations would (ou make in gi!ing (our answer?


18/23

Ex!"#$!%& ?


19/23

Ex!"#$!%& ?


20/23

P!",+.''% ?


21/23

P!",+.''% ?


22/23

1. 0salkan semua tindakan pencegahan (ang dilakukan sesuai dengan prosuder dan $at dari

suatu sampel tidak saling bercampur , maka wa;ar untuk mengatakan bahwa sampel

makanan tersebut mengandung pati.2. Hasil penelitian ini untuk menun;ukkan kehadiran pati tapi tidak menutup kemungkinan

mungkin ada kandungan $at lain ;uga.

". #ontoh lain mungkin tidak berisi ati, misaln(a kacang polong tua berisi ati, tapikacang polong muda mungkin tidak. Guga, berbagai belahan buah atau sa(uran (ang sama

mungkin memiliki ;umlah pati (ang berbeda , misaln(a bagian embrio dan endosperm

benih..


23/23

P!",+.''% ?

pengembangan cara/tehnik pengujian makanan yang mengandung pati/amilum (testing food for the...

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