Deepak MemoriAlAcADEMY SCHOOL
SAGAR(AFFLIATED TO C.B.S.E)
SESSION : 2016-2017CHEMISTRY- INVESTIGATORY
PROJECTON
Study of effect of Potassium bisulphite as a food preservative
Submitted to:- Submitted by:-Mr.P.N Tiwari HimanshuMourya
Chemistry Teacher, Class-12, Section-A*CLASS 12, DMA“Intelligence plus character-that is the goal
of true education.”
CERTIFICATE
This is to certify that the project work titled“Study of effectof Potassium bisulphite as a food preservative”submitted byHimanshuMourya(class XIIthA* - PCB group) in partial fulfilment of the credit for the chemistry project evaluation from “DEEPAK MEMORIAL SCHOOL, SAGAR” , is the bonafide work of the student done under the guidance and supervisionof Mr. P.N Tiwari,Chemistry Teacher,DMAduring session 2016-2017, as a project report.
INTERNALEXAMINER :- EXTERNAL EXAMINER :- Name- Mr. P.N Tiwari Name - Sign – Sign -
Remark - Remark - PRINCIPLE :- Name - Mrs.RituJaiswal Sign –Remark –
ACKNOWLEDGEMENTOur project can never begin without you, dear GOD.
Rather than saying “thank you” to you, you know that we feel like saying ‘I love you’, to you, always.
We must say thanks to our parents who provided us sufficient money and help in making of this project.
Mr. P.N Tiwari, you are the real foundation of the project done by us. Thank you very much. Special thanks to ourPrincipal, ourVicePrincipal and our chemistry teachers, Our Chemistry Teacher who gave support to us and library which provides all useful books related to this project.
Next on our thank list are ourfriends, teachers who really showered constructive feedbacks and suggestions without which this project would not have been in present form.
HIMANSHU MORYA CLASS – 12th, A*
DECLARATION
We hereby declare that the project work entitled“Study of effect of Potassium bisulphite as a food preservative”submitted to the“DEEPAK MEMORIAL ACADEMY , SAGAR ”is a record of original work done by us, except for quotations and summaries which have been duly acknowledged, under the guidance of‘‘Mr.P.N Tiwari’’ Chemistry Teacher,DMA".The project has not been accepted for any credits based on investigatory projects previously.
HIMANSHU MOURYACLASS – 12th , A*
INDEXSL.NO. TOPIC
PAGE NO.
1 OBJECTIVE 12 CONCENTRATION EFFECT 23 INTRODUCTION 3-43 AIM 54 APPARATUS REQUIRED 65 MATERIALS & CHEMICALS 76 THEORY 8-9 7 FOOD PRESERVATION 10
7.1PRINCIPLES OF FOOD PRESERVATION 11
7.2 METHODS OF FOOD PRESERVATION 128 PROCEDURE 139
EFFECT OF CONCENTRATION OF SUGAR 14
10EFFECT OF CONCENTRATION OF KHSO3 15
11 EFFECT OF TEMPERATURE 1612 EFFECT OF TIME 1713
RESULTS,CONCLUSIONS&SUGGESTIONS 17-18
14 BIBLIOGRAPHY 19
OBJECTIVE
The objective of this project is to study the effect of Potassium bisulphite as a food preservative under various conditions.
CONCENTRATION EFFECT
Effect of Concentration :-1)Sugar2)Temperature3)KHSO3
4)Time
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 human beings. Such chemical substances which are added to food materials to prevent their spoilage are known aschemical preservatives. In our country, two chemical preservatives which are permitted for use are:
1. Benzoic acid(orsodium benzoate)2. Sulphur dioxide(orpotassium
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.Potassium bisulphiteis used for the preservation of colourless food materials such as fruit juices, squashes, apple and raw mango chutney. This is not used for
preserving coloured food materials becauseSulphur dioxide produced from this chemical is a bleaching agent.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 stuffs and thus prevents it from getting spoilt.
HSO3–(aq) + H+
(aq) H2O(l) + SO2(g)
The advantage of this method is that no harmful chemical is left in the food. The Manitoba Agriculture, Food and Rural Initiatives reports that this product works to‘prevent the growth of mould, yeast and bacteria in foods. It is also an additive for homemade wine. Potassium bisulphite is found in some cold drinks and fruit juice concentrates. Sulphites are common preservatives in smoked or processed meats and dried fruits. In spray form, it may help prevent foods from discolouring or browning.
AIMThe aim of this project is to study the effect of potassium bisulphite as food preservative.
1. At different intervals of time
2. For different concentrations.
3. At different Temperature.
APPARATUS
MATERIALS AND CHEMICALS
THEORYFood materials undergo natural changes due to temperature, time and enzymatic actionand become unfit for consumption. These changes may be checked by adding small amounts of potassium bisulphite. Theeffectiveness of KHSO3 as preservative depends upon its concentration under different conditions which may be determined experimentally. An ideal method of food preservation has the following characteristics:-
1.It improves shelf-life and safety by inactivating spoilage and pathogenic microorganisms, 2. It does not change organoleptic (smell, taste, colour, texture, etc.) and nutritional attributes,3.It does not leave residues,
4.It is cheapand convenient to apply.5.It encounters no objection from consumers and legislators.
‘‘FOOD PROCESSING’’Food processing is the transformation of raw ingredients, by physical or chemical means into food, or of food into other forms. Food processing combines raw food ingredients to produce marketable food products that can be easily prepared and served by the consumer. Food processing typically involves activities such as mincing and macerating, liquefaction, emulsification, and cooking (such as boiling, broiling, frying, or grilling); pickling, pasteurization, and many other kinds of preservation; and canning or other packaging. (Primary-processing such as dicing or slicing, freezing or drying when leading to secondary products are also included.)
Benefits:-Benefits of food processing include toxin removal, preservation, easing marketing and distribution tasks, and increasing food consistency. In addition, it increases yearly availability of many foods, enables transportation of delicate perishable foods across long distances and makes many kinds of foods safe to eat by de-activating spoilage and pathogenic micro-organisms. Modern supermarkets would not exist without modern food processing techniques, and long voyages would not be possible.Processed foods are usually less susceptible to early spoilage than fresh foods and are better suited for long distance transportation from the source to the consumer. When they were first introduced, some processed foods helped to alleviate food shortages and improved the overall nutrition of populations as it made many new foods available to the masses.Processing can also reduce the incidence of food borne disease. Fresh materials, such as fresh produce and raw meats, are more likely to harbor pathogenic micro-organisms (e.g. Salmonella) capable of causing serious illnesses.
The extremely varied modern diet is only truly possible on a wide scale because of food processing. Transportation of more exotic foods, as well as the elimination of much hard labourives the modern eater easy access to a wide variety of food unimaginable to their ancestors.
Drawbacks:-Any processing of food can affect its nutritional density. The amount of nutrients lost depends on the food and processing method. For example, heat destroys vitamin C. Therefore, canned fruits possess less vitamin C than their fresh alternatives. The USDA conducted a study in 2004, creating a nutrient retention table for several foods.New research highlighting the importance to human health of a rich microbial environment in the intestine indicates that abundant food processing (not fermentation of foods) endangers that environment. Using food additives represents another safety concern. The health risks of any given additive vary greatly from person to person; for example using sugar as an additive endangers diabetics. In the European Union, only European Food Safety Authority (EFSA) approved food additives (e.g., sweeteners, preservatives, stabilizers) are permitted at specified levels for use in food products. Approved additives receive an E number (E for Europe), simplifying communication about food additives included in the ingredients' list for all the different languages spoken in the EU. As effects of chemical additives are learnt, changes to laws and regulatory practices are made to make such processed foods more safe.
Principles of food preservation
There are three basic objectives for the preservation of foods:-
1. Prevention of contamination of food from damaging agents.2. Delay or Prevention of growth of microorganisms in the food 3. Delay if enzymic spoilage, i.e. self – decomposition of the food by naturally
occurring enzymes within it.
The food preservation methods by which the microbial,decomposition of foods can be delayed or prevented include:- 1. Restrict access of microorganisms to foods (packaging and aseptic packaging), 2. Removal of microorganisms (by filtration orcentrifugation),
3. Slow or prevent the growth and activity of microorganisms (reduction in temperature, wateractivity and pH, removal of oxygen, modified atmosphere packaging and addition of preservatives).4. Inactivation of microorganisms (by heat, radiations, high hydrostatic pressures, ultra soundand pulsed electric fields).
These methods usually are also effective against enzymatic activity or chemical reactions in the food, responsible for its self-decomposition. Changes in the requirement of consumers in recent years have included a desire for foods which are more convenient, higher quality, fresher in flavor, texture and appearance, more natural with fewer additives and nutritionally healthier than hitherto. Food industry reactions to these changes have been to develop less severe or minimal preservation and processing technologies with less intensive heating or use of less chemical preservatives. However, minimal technologies tend to result in a reduction in the intrinsic preservation of foods, and may, therefore, also lead to a potential reduction in their microbiological safety.. A major trend is to applythese techniques in new combinations, in ways that minimize the extreme use of any one of them, and so improve food product quality.
‘‘Methods of Food Preservation”
1. Physical methods of preservation =>The foods to be preserved are physically processed or treated in such a way that the metabolic activity of microorganisms and their spores either slowed down or completely arrested. These various physical methods used for the preservation of foods are as follows.Asepsis Keeping quality of foods can be increased by introducing as few spoilage organisms as possible i.e., by reducing the amount of contamination. In nature, there are numerous examples of asepsis or removal of microorganisms as a protective factor. The presence of a protective covering surrounding some foods e.g. shells of nuts, shells of eggs, skin of fruits and vegetables and fat on meats and fish, prevents microbial entry and decomposition until it is damaged.
2.Chemical methods of preservation =>In food industries, contamination is prevented by packaging foods in a wide variety of artificial coverings ranging from a loose carton or wrapping to the hermetically sealed containers of canned foods. Moreover, practicing sanitary methods during the processing and handling of foods reduces total microbial load and thus improves the keeping quality of food. Both flexible. Many chemicals will kill micro-organisms or stop their growth but most of these are not permitted in foods; chemicals that are permitted as food preservatives are listed in Table 5.3.1. Chemical food preservatives are those substances which are added in very low quantities (up to 0.2%) and which do not alter the organoleptic and physico-chemical properties of the foods at or only very little. Preservation of food products containing chemical food preservatives is usually based on the combined or synergistic activity of several additives, intrinsic product parameters (e.g. composition, acidity, water activity) and extrinsic factors (e.g. processing temperature, storage atmosphere and temperature). This approach minimises undesirable changes in product properties and reduces concentration of additives and extent of processing treatments. The concept of combinations of preservatives and treatments to preserve foods is frequently called the hurdle or barrier concept. Combinations of additives and preservatives systems provide unlimited preservation alternatives for applications in food products to meet consumer demands for healthy and safe food.Chemical food preservatives are applied to foods as direct additives during processing, or develop by themselves during processes such as fermentation. Certain preservatives have been used either accidentally or intentionally for centuries, and include sodium chloride (common salt), sugar, acids, alcohols and components of smoke. In addition to preservation, these compounds contribute to the quality and identity of the products, and are applied through processing procedures such as salting, curing, fermentation and smoking.
PROCEDURE :
1)Take fresh fruits, wash them thoroughly with water and peel off their outer cover.
2)Grind it to a paste in the mortar with a pestle.
3)Mix with sugar and colouring matter.
4)The material so obtained is fruit jam. It may be used to study the effect of concentration of sugar and KHSO3, temperature and time.
(A)Effect of concentration of Sugar:-1. Take three wide mouthed reagent bottles
labeled as I II III.Put 100 gms of fruit jam in each bottle.
2. Add 5.0 gms, 10.0 gms and 15.0 gms of sugar to bottle No. I, II and III respectively.
3. Add 0.5 gm of KHSO3 to each bottle.4. Mix contents thoroughly with a stirring rod.5. Close the bottle and allow them to stand for
one week or 10 days at room temperature.
6. Observe the changes taking place in Jam every day.
BottleNo.
Wt. of jam
taken added
Wt. of sugar
Wt. of KHSO3
Observations (Days)1 2 3 4 5
I 100 gms 5.00 gms 0.5gm NOChan
ge
NOChang
e
NOChang
e
FewChang
e
FewMore
Change
II 100 gms 10.00 gms 0.5 gm NOChan
ge
NOChang
e
FewChang
e
SomeChang
e
Few moreChang
e
III 100 gms 15.00 gms 0.5 gm NOChan
ge
FewChang
e
FewChang
e
SomeChang
e
MoreChang
e
RECORD:-
Result: The increase in concentration of sugarcausesfast decaying
(B)Effect of concentration of KHSO3 :–1. Put 100 gm of Jam in each bottle.2. Add 5.0 gm of sugar to each bottle.3. Take bottles labeled as I, II, III.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:-
BottleNo.
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 2.0gm no no no no few
III 100 gms 5.00 gms 3.0gm no no no no no
Result: The increase in concentration of KHSO3increase more time of
preservation
(C)Effect of temperature:–1. Take 100 gm of Jam in three bottles labelled as
I, II and III.2. Add 10.0 gm of sugar and 2.0 gm of KHSO3 to
bottle No. I, II and III respectively.3. Mix the contents thoroughly with a stirring rod.4. 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:-
BottleNo.
Wt. of jam
taken added
Wt. of sugar
Wt. of KHSO3
Observations (Days)
1 2 3 4 5
I 100 gms
10.00 gms
2.0gm No change
No chang
e
No change
No change
No change
II 100 gms
10.00 gms
2.0gm No change
No chang
e
No change
No change
Slight change
III 100 gms
10.00 gms
2.0gm No change
No chang
e
Slight change
Some change
Some more
change
Result: The increase in temperature causes faster fermentation of jam.
(D)Effect of time: –1. Take three bottles and label them as I, II and III.2. To each bottle add 25 g of Jam and 1 g of
potassium bisulphite.3. Keep bottle I for 7 days, bottle II for 14 days
and bottle III for 21 days at room temperature.4. Note the changes taking place in each bottle
and record the observations.
Bottle No.Observations(Days)
7 14 21I No ****** ******
II No Taste changes
******
III No No Unpleasant smell develops
RECORD:-
Result: With increase of days, the quality of the jam deteriorates.
RESULTS,CONCLUSIONS AND SUGGESTIONS
From the experiment, we can conclude thatKHSO3 acts as a viable food preservative whose increased concentration can increase time forpreservation. But increase in concentration of sugar content in the food material causes fast decaying. Also, the experiment shows that rateof
fermentation of food stuffs is directly proportional to temperature conditions. On passage of time, even in the presence of KHSO3,the food gets spoiled. Though potassium bisulphite is a good food preservative (class II preservative), it can trigger lung irritation andasthma. So, our suggestion is that the usage of food preservatives must be reduced to the extent possible.Food containing more amountof sugar is not favorable to keep for a long time,Potassium bisulphite is a good preservative.Uses=>There are a number of uses for potassium bisulfite as a food preservative. The Manitoba Agricul-ture, Food and Rural Initiatives reports this
product works to prevent the growth of mold, yeast and bacteria in foods. It is also an additive for homemade wine.
Potassium bisulfate is found in some cold drinks and fruit juice concentrates. Sulfites are common preservat-ives in smoked or processed meats and dried fruits. In spray form, it may help prevent foods from discoloring or browning.
Availability =>Potassium bisulfite is primarily a commercial product. You might find this chemical compound at meat processing plants. Manufacturers of juice drinks and concentrate will use potassium bisulfite to increase the shelf life of their products. The preservative is also available for home use.Allergies =>Sulphites such as potassium bisulfite can trigger an attack for thosewith asthma. potassium bisulfite may cause lung irritation.
BIBLIOGRAPHYReference books:
NCERT CLASS 12 CHEMISTRY BOOKS- PART I, II
CONCISE INORGANIC CHEMISTRY -BY J.D.LEE
NCERT LABORATORY MANUAL - CLASS 12 CHEMISTRY
Reference websites: Google :-
Website- www.google.co.inWikipedia:-
www.ncert.nic.in www.livestrong.com
