Study of effect of potassium bisulphite as a food preservative

Parmeshwari Devi Dhanuka Saraswati VidhyaMandir(Residential) Gaushala Nagar Vrindaban (Affiliated to C.B.S.E.)

Session :- 2012-13 Topic : Study of effect of Potassium bisulphite as a food preservative

Submitted To:

Submitted By:

Mr. G.K. Lawaniya

Ravindra Pratap Singh

H.O.D. Chemistry

12th Science Roll no. =

Certificate This is to certify that Ravindra Pratap Singh s/o Mr. Amar Singh is a bonafide student of class XIIth Science during session 2012-2013. He has completed his project on

Study of effect of

Potassium bisulphite as a food preservative successfully under my guidance and supervision.

Mr. Shishupal Singh (Head of the institution)

G.K. Lawaniya (H.O.D. Chemistry)

Acknowledgement Acknowledgement is the most beautiful page in any project’s final pages. More than a formality, this appears to me the best opportunity to express my gratitude. My project can never begin without you, dear GOD. Rather than saying “thank you” to you, you know that I feel like saying ‘I love you’, to you, always. I must say thanks to my parents who provide me sufficient money and help in making of this project. Mr. G.K. Lawaniya, you are real foundation of the project done by me. My project would never have been possible without your guidance. Thank you very much. Special thanks to my principal who gave support to me and library which provides me helpful books related to this project. Next on my thanks lists are my friends, teachers, students who really showered constructive feedbacks and suggestions without which this project would not have been in present form.

Ravindra Pratap Singh

INDEX

S. No.

Contents

Page no.

1.

Objective

1

2.

Introduction

2

3

Apparatus

4

4

Materials and Chemicals

5

5

Theory & Procedure

6

6

Effect of concentration of sugar

7

7

Effect of concentration of KHSO3

8

8

Effect of Temperature

9

9

Effect of Time

10

Objective: The objective of this project is to Study of effect of Potassium bisulphite as a food preservative under various conditions

Concentration

Conditions

Time

Temperature

1

Introduction Growth of microorganisms in a food material can be inhibited by adding certain chemical substances. However the chemical substances should not be harmful to the human beings. Such chemical substances which are added to food materials to prevent their spoilage are known as chemical preservatives. In our country, two chemical preservatives which are permitted for use are: 1. Benzoic acid(or sodium benzoate) 2. Sulphur dioxide(or potassium bisulphite) Benzoic acid or its sodium salt, sodium benzoate is commonly used for the preservation of food materials. For the preservation of fruits, fruit juices, squashes and jams sodium benzoate is used as preservative because it is soluble in water and hence easily mixes with the food product.

2

Potassium bisulphite is used for the preservation of colourless food materials such as fruit juices, squashes, apples and raw mango chutney. This is not used for preserving coloured food materials because Sulphur dioxide produced from this chemical is a bleaching powder. Potassium bisulphite on reaction with acid of the juice liberates Sulphur dioxide which is very effective in killing the harmful micro-organisms present in food and thus prevents it from getting spoiled.

HSO3–(aq) + H+ (aq)

H2O(l) + SO2(g)

The advantage of this method is that no harmful chemical is left in the food. The aim of this project is to study the effect of potassium bisulphite as food preservative. i. At different temperatures. ii. At different concentrations and iii. For different intervals of time.

3

Apparatus

Requirements

4

Materials and Chemicals

Requirements

5

Theory Food materials undergo natural changes due to temperature, time and enzymatic action and become unfit for consumption. These changes may be checked by adding small amounts of potassium bisulphite. The effectiveness of KHSO3 as preservative depends upon its concentration under different conditions which may be determined experimentally.

Procedure: 1. 2. 3. 4.

Take fresh fruits, wash them thoroughly with water and peel off their outer cover. Grind it to a paste in the mortar with a pestle. Mix with sugar and colouring matter. The material so obtained is fruit jam. It may be used to study the effect of concentration of sugar and KHSO3, temperature and time.

6

(A) Effect of concentration of Sugar: 1. 2. 3. 4. 5. 6. 7.

Take three wide mouthed reagent bottles labeled as I II III. Put 100 gms of fruit jam in each bottle. Add 5.0 gms, 10.0 gms and 15.0 gms of sugar to bottle No. I, II and III respectively. Add 0.5 gm of KHSO3 to each bottle. Mix contents thoroughly with a stirring rod. Close the bottle and allow them to stand for one week or 10 days at room temperature. Observe the changes taking place in Jam every day.

RECORD:

Bottle No. I

II

Wt. of jam taken added 100 gms

100 gms

Wt. of sugar 5.00 gms

10.00 gms

Wt. of KHSO3 0.5gm

0.5 gm

Observations (Days) 1

2

3

4

5

NO

NO

NO

Few

Change

Change

Change

Change

Few More Change

NO

NO

Few

Some

Few

Change

Change

Change

Change

more Change

III

100 gms

15.00 gms

0.5 gm

NO

Change

Few

Change

Few

Change

Result: The increase in concentration of sugar causes fast decaying

Some Change

More

Change

7

(B) Effect of concentration of KHSO3 :– 1.

Take bottles labeled as I, II, III.

2.

Put 100 gm of Jam in each bottle.

3.

Add 5.0 gm of sugar to each bottle.

4.

Add 1.0 gm, 2.0 gm and 3.0 gm of KHSO3 to bottle No. I, II and III respectively.

5.

Mix the contents thoroughly with a glass rod.

6.

Keep all the bottles at room temperature for about 10 days and observe the changes everyday.

RECORD:

Bottle No.

Wt. of jam taken added

Wt. of sugar

Wt. of KHSO3

Observations (Days) 1

2

3

4

5

I

100 gms

5.00 gms

1.0gm

no

no

no

few

some

II

100 gms

5.00 gms

1.0 gm

no

no

no

no

few

III

100 gms

5.00 gms

1.0 gm

no

no

no

no

no

Result: The increase in concentration of KHSO3 increase more time of preservation

8

(C) Effect of temperature: – 1. 2. 3. 4.

Take 100 gm of Jam in three bottles lebelled as I, II and III. Add 10.0 gm of sugar and 1.0 gm of KHSO3 to each bottle. Mix the contents thoroughly with a stirring rod. Keep bottle No. I in the refrigerator at 0˚C, bottle No. II at room temperature (25˚C) and bottle No. III in a thermostat at 50˚C. Observe the changes taking place in the jam for 10 days.

RECORD: Bottle No.

Wt. of jam taken added

Wt. of sugar

Wt. of KHSO3

Observations (Days) 1

2

3

4

5

I

100 gms

5.00 gms

2.0gm

no

no

no

no

no

II

100 gms

10.00 gms

2.0 gm

no

no

no

no

Few

III

100 gms

15.00 gms

2.0 gm

no

no

Few

Some

Some more

Ferme -nted

Ferme -nted

Ferme -nted

Ferme -nted

Result: The increase in Temperature causes fast fermentation of jam

9

(D) Effect of time: – 1. 2. 3. 4.

Take three bottles and label them as I, II and III. To each bottle add 25 g of Jam and 1 g of potassium bisulphite. Keep bottle I for 7 days, bottle II for 14 days and bottle III for 21 days at room temperature. Note the changes taking place in each bottle and record the observations.

RECORD: Observations(Days) 14 21 ****** ******

Bottle No. I

7 No

II

No

Taste changes

******

III

No

No

Unpleasant smell developes

Result: With increase of days, the quality of the jam deteriorates.

10