fermentation · web view“if we knew what it was we were doing, it would not be called research,...

MAHARISHI INTERNATIONAL RESIDENTIAL SCHOOL

FERMENTATION

Chemistry Investigatory Project Year: 2016-2017

ASWIN THAMBIRAN.T.S“If we knew what it was we were doing, it would not be called research, would it?”

― Albert Einstein

Bonafide Certificate

0| Chemistry Project

Certified That This Is A Bonafide Project Of Work Done By Master T.S.ASWIN THAMBIRAN, Reg.No Of Class XII , Maharishi International Residential School , Santhavelur , Sunguvarchatram , Sriperumbudur(t.k) , Kancheepuram(d.t) During The Year 2016-2017 .Date : Teacher Incharge :Submitted For AISSCE Practical Examination Held In The Chemistry Laboratory At MaharishiInternational Residential School , Santhavelur ,Sunguvarchatram ,Sriperumbudur(t.k) , Kancheepuram(d.t) .

Date : Principal : External Examiner


Seal :

Acknowledgements

I Express My Gratitude To Our Correspondent SHRI.S.NAMASHIVAYAM And My Gratitude To Our Principal, SMT.L.SARUMATHY And Our Vice Principal, SMT.D.LATHA Of Our Institution For Their Continuous Support And Encouragement . I Express My Sincere Thanks To My Chemistry Teacher MISS.VANITHA For Helping Me To Compete This Project Successfully .


I Also Thank My Chemistry Lab-Incharge MRS.LAKSHMI For Her Support .


CONTENTS

Title pageBonafide CertificateAcknowledgementIntroductionTheoryAimApparatus RequiredExperimentObservationResultPrecautions

Bibliography


FERMENTATION

What is Fermentation ???

Fermentation is a slow decomposition of complex organic compound into simpler compounds by the action of enzymes. Enzymes are generally protons example of fermentation are souring of milk curd, bread making wine making……

The word ‘Fermentation’ had been derived from latin (Ferver means to ‘boil’). As during fermentation there is lot of frothing of liquid due to the evolution of carbon dioxide, it gives the appearance as if it is boiling. Sugars like glucose, sucrose when fermented in presence of yeast cells are converted to ethyl


alcohol. During fermentation of, starch is first hydrolyzed to maltose by action of enzyme diastase.

Fermentation is carried out at a temperature of 4-16°C (40-60°F). This is slow for most kinds of fermentation, but is beneficial for cider as it leads to slower fermentation with less loss of delicate are ma. Apple based juices with cranberry also make fine ciders and many other fruit purees or flavorings can be used, such as grapes, cherry, raspherry. The cider is ready to drink after a three month fermentation period, though more after it is material in the vats for up to 2 to 3 years

Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol. It occurs in yeast and bacteria, and also in oxygen-starved muscle cells, as in the case of lactic acid fermentation.

Effect of oxygen

Fermentation does not require oxygen. If oxygen is present, some species of yeast (e.g., Kluyveromyces lactis or Kluyveromyces lipolytica) will oxidize pyruvate completely to carbon dioxide and water. This process is called cellular respiration. But these species of yeast will produce ethanol only in an anaerobic environment (not cellular respiration).

However, many yeasts such as the commonly used baker's yeast Saccharomyces cerevisiae, or fission yeast Schizosaccharomyces pombe, prefer fermentation to respiration. These yeasts will


produce ethanol even under aerobic conditions, if they are provided with the right kind of nutrition. During batch fermentation, the rate of ethanol production per milligram of cell protein is maximal for a brief period early in this process and declines progressively as ethanol accumulates in the surrounding broth. Studies demonstrate that the removal of this accumulated ethanol does not immediately restore fermentative activity, and they provide evidence that the decline in metabolic rate is due to physiological changes (including possible ethanol damage) rather than to the presence of ethanol. Several potential causes for the decline in fermentative activity have been investigated. Viability remained at or above 90%, internal pH remained near neutrality, and the specific activities of the glycolytic and alcohologenic enzymes (measured in vitro) remained high throughout batch fermentation. None of these factors appears to be causally related to the fall in fermentative activity during batch fermentation.

Bread baking

The formation of carbon dioxide — a byproduct of ethanol fermentation — causes bread to rise.

Ethanol fermentation causes bread dough to rise. Yeast organisms consume sugars in the dough and produce ethanol and carbon dioxide as waste products. The carbon dioxide forms bubbles in the dough, expanding it into something of a foam. 7| Chemistry Project

Nearly all the ethanol evaporates from the dough when the bread is baked.

History of Fermentation

Since fruits ferment naturally, fermentation precedes human history. Since ancient times, however, humans have been controlling the fermentation process. The Seven thousand years ago jars containing the remains of wine have been excavated in the Zagros Mountains in Iran, which are now on display at the University of Pennsylvania.There is also evidence of leavened bread in ancient Egypt circa1500 BC and of milk fermentation in Babylon circa 3000 BC.French chemist Louis Pasteur was the first known zymologist, when in 1854 he connected yeast to fermentation. Pasteur originally defined fermentation as “respiration without air”.

Louis Pastuer in 1860 demonstrated that fermentation is a purely physiological process carried out by living microorganism like yeast. This view was abandoned in 1897 when Buchner


demonstrated that yeast extract could bring about alcoholic fermentation in the absence of any yeast cell. He proposed that fermenting activity of yeast is due to active catalysts of biochemical origin. These biochemicals are called enzymes. Enzymes are highly specific compound or a closely related group of compounds.

Fermentation has been utilized for many years in the preparation of beverages. Materials from Egyption tombs demonstrated the procedures used in making beer and leavened bread. The history of fermentation, whereby sugar is converted to ethanol by action of yeast, is also a history of chemistry. Van Helmont coined the word iogaslt in 1610 to describe the bubble produced in fermentation.

Leeuwenhoek observed anddescribed the cell of yeast with his newly invented microscope in 1680. The fruit and vegetable juices contain sugar such as sucrose, glucose, and fructose. These sugars of fermentation in presence of enzyme invert are and zymose give with the evolution of [CO]_2. Maltose is converted to glucose by enzyme maltose, glucose to ethanol by another enzyme zymose.

Pasteur's Experiment

The steps of Pasteur's experiment are outlined below:

1. First, Pasteur prepared a nutrient broth similar to the broth one would use in soup.


2. Next, he placed equal amounts of the broth into two long-necked flasks. He left one flask with a straight neck. The other he bent to form an "S" shape.

3. Then he boiled the broth in each flask to kill any living matter in the liquid. The sterile broths were then left to sit, at room temperature and exposed to the air, in their open-mouthed flasks.

4. After several weeks, Pasteur observed that the broth in the straight-neck flask was discolored and cloudy, while the broth in the curved-neck flask had not changed.

5. He concluded that germs in the air were able to fall unobstructed down the straight-necked flask and contaminate the broth. The other flask, however, trapped germs in its curved neck, preventing them from reaching the broth, which never changed color or became cloudy.




http://science.howstuffworks.com/question235.htm




10. If spontaneous generation had been a real phenomenon, Pasteur argued, the broth in the curved-neck flask would have eventually become reinfected because the germs would have spontaneously generated. But the curved-neck flask never became infected, indicating that the germs could only come from other germs.

Pasteur's experiment has all of the hallmarks of modern scientific inquiry. It begins with a hypothesis and it tests that hypothesis using a carefully controlled experiment. This same process -- based on the same logical sequence of steps -- has been employed by scientists for nearly 150 years. Over time, these steps have evolved into an idealized methodology that we now know as the scientific method.

Importance of Fermentation

Enrichment of the diet through development of a diversity of flavors, aromoas and textures in food substances. Preservation of substantial amounts of food through lactic



acid alcohol, acetic acids and alkaline fermentation. Biological enrichment of food substances with proteins, essential aminoacids, falty acids and vitamins. Elimination of anti nutrients. A decrease in cooking times and fuel requirements.

Theory

There are two types of respiration:

Aerobic respiration – which needs oxygen Anaerobic respiration – which does not need oxygen

Fermentation or Anaerobic Respiration

Fruit juices contain various sugars like glucose, fructose etc. When juices are treated with yeast and it converts sugar into glucose and fructose. These monosccharides are further converted into ethyl alcohol by another enzyme known as zymase.


The relative rates of fermentation can be established with fillings solution A and B. Since glucose in an aldose gives red precipitate with Fehling’s solution. When all the quantity of glucose is converted to ethanol, the mixture will not give red colour.

Invertase: Invertase (systematic name: beta-fructofuranosidase) is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose. Related to invertases are sucrases. Invertases and sucrases hydrolyze sucrose to give the same mixture of glucose and fructose. Invertases cleave the O-C (fructose) bond, whereas sucrases cleave the O-C (glucose) bond. For industrial use, invertase is usually derived from yeast. It is also synthesized by bees, who use it to make honey from nectar. Optimum temperature at which the rate of reaction is at its greatest is 60 0 C and an optimum pH of 4.5.Saccharomyces cerevisiae commonly called baker's yeast is the chief strain used for the production and purification of the enzyme. Invertase in nature exists in different isoforms. In yeasts, it is present either as extracellular Invertase or intracellular Invertase. In plants, there are three isoforms each differing in biochemical properties and subcellular locations. Invertase in plants is essential not only for


metabolism but also help in osmoregulation, development and defence system. In humans, the enzyme acts as an immune booster, as an anti-oxidant, an antiseptic and helpful for bone cancer or stomach cancer patients in some cases.

Zymase: Zymase is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide. It occurs naturally in yeasts. Zymase activity varies among yeast strains.Zymase is also the brand name of the drug pancrelipase.Zymase is an enzyme complex (“mixture”) which catalyzes the fermentation of sugar into ethanol and carbon dioxide. They occur naturally in yeasts. Zymase activity varies among yeast strains.

ADDITION OF YEAST

Yeasts can grow in the presence or absence of air. Anaerobic growth, growth in the absence of oxygen, is quite slow and inefficient. For instance, in bread dough, yeast grow very little.


Instead, the sugar that can sustain either fermentation or growth is used mainly to produce alcohol and carbon dioxide. Only a small portion of the sugar is used for cell maintenance and growth. In contrast, under aerobic conditions, in the presence of a sufficient quantity of dissolved oxygen, yeast grow by using most of the available sugar for growth and producing only negligible quantities of alcohol.This means that the baker who is interested in the leavening action of carbon dioxide works under conditions that minimize the presence of dissolved oxygen. On the other hand, a yeast manufacturer that wants to produce more yeast cell mass, works under aerobic conditions by bubbling air through the solution in which the yeast is grown.The problem posed to the yeast manufacturer, however, is not as simple as just adding air during the fermentation process. If the concentration of sugar in the fermentation growth media is greater than a very small amount, the yeast will produce some alcohol even if the supply of oxygen is adequate or even in abundance. This problem can be solved by adding the sugar solution slowly to the yeast throughout the fermentation process. The rate of addition of the sugar solution must be such that the yeast uses the sugar fast enough so that the sugar concentration at any one time is practically zero. This type of fermentation is referred to as a fed-batch fermentation.

The role of yeast in winemaking is the most important element that distinguishes wine from grape juice. In the absence of oxygen, yeast converts the sugars of wine grapes into alcohol and carbon dioxide through the process of fermentation. The more sugars in the grapes, the higher the potential alcohol level


of the wine if the yeast are allowed to carry out fermentation to dryness. Sometimes winemakers will stop fermentation early in order to leave some residual sugars and sweetness in the wine such as with dessert wines. This can be achieved by dropping fermentation temperatures to the point where the yeast are inactive, sterile filtering the wine to remove the yeast or fortification with brandy to kill off the yeast cells. If fermentation is unintentionally stopped, such as when the yeasts become exhausted of available nutrients, and the wine has not yet reached dryness this is considered a stuck fermentation.

There are two main types of Fermentation:

Alcoholic fermentation Acid fermentation

ALCOHOLIC FERMENTATION:

It is a biological process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as a side-effect. Because yeasts perform this


conversion in the absence of oxygen, alcoholic fermentation is considered an anaerobic process.

Ethanol fermentation has many uses, including the production of alcoholic beverages, the production of ethanol fuel, and bread baking.

1. ACID FERMENTATION :Lactic acid fermentation is a biological process by which glucose and other six-carbon sugars (also, disaccharides of six-carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactate. It is an anaerobic fermentation reaction that occurs in some bacteria and animal cells, such as muscle cells. Sometimes even when oxygen is present and aerobic metabolism is happening in the mitochondria, if pyruvate is building up faster than it can be metabolized, the fermentation will happen anyway.In homolactic fermentation, one molecule of glucose is ultimately converted to two molecules of lactic acid. Heterolactic fermentation, in contrast, yields carbon dioxide and ethanol in


addition to lactic acid, in a process called the phosphoketolase pathway.


Experiment

Aim:

To determine the rate of fermentation of various fruit juices.

Apparatus Required

Fruits such as pineapple, apple, orange, grape, lemonYeast powderAmmonium sulphate Fehling's solutionsBeaker Round bottom flaskThermometerTest TubesDropper StandHot Water BathConical FlaskDistilled Water


Fruits Yeast Powder

Ammonium Sulphate Fehling’s Solution

Beaker Round Bottom Flask


Thermometer Test Tubes

Dropper Stand Hot Water Bath

Conical Flask Distilled Water


Procedures :-

Step 1 : Take approximately 1g of yeast powder in beaker, add 20ml distilled water and 3 -4ml of saturated solution of ammonium sulphate and stir the solution by a glass rod.

Step 2: Pour 2ml of fruit juice a clean round bottom flask and add 20ml of distilled water.

Step 3: Now transfer the content of the beaker into a round bottom flask and shake the mixture.

Step 4: Place the round bottomed flask into a hot water bath containing water at 35 - 45°C and shake the solution after each minute.

Step 5: After keeping the round bottomed flask for 10 min, take out 10 drops of the mixture in a test tube and add 1 ml of "Fehling's solution -B". Heat the test tube in a hot water both for few minutes observe. The change in color and the fermentation of red precipitate. Perform this test after internal of five minutes until the mixture gives red precipitate with Fehling's reagent.

Step 6: Repeat the procedure in the same way taking other samples of fruit juices.

Observation

All fruit juices do not undergo fermentation at the same rate. The increasing order of the rate of fermentation.


Result

The rate of fermentation is Apple <Pine apple juice = orange juice <Grape juice < Lemon Juice.

Applications of fermentation

Fermentation has a number of commercial applications beyond those described thus far. Many occur in the food preparation and processing industry. A variety of bacteria are used in the production of olives, cucumber pickles, and sauerkraut from the raw olives, cucumbers, and cabbage, respectively. The selection of exactly the right bacteria and the right conditions (for example, acidity and salt concentration) is an art in producing food products with exactly the desired flavors. An interesting line of research in the food sciences is aimed at the production of edible food products by the fermentation of petroleum.In some cases, antibiotics and other drugs can be prepared by fermentation if no other commercially efficient method is available. For example, the important drug cortisone can be prepared by the fermentation of a plant steroid known as diosgenin. The enzymes used in the reaction are provided by the mold Rhizopus nigricans.

One of the most successful commercial applications of fermentation has been the production of ethyl alcohol for use in gasohol. Gasohol is a mixture of about 90% gasoline and 10% alcohol. The alcohol needed for this product can be obtained from the fermentation of agricultural and municipal wastes. The use of gasohol provides a promising method for using 23| Chemistry Project

http://science.jrank.org/pages/407/Antibiotics.html

http://science.jrank.org/pages/5126/Petroleum.html

http://science.jrank.org/pages/5948/Salt.html

http://science.jrank.org/pages/714/Bacteria.html

renewable resources (plant material) to extend the availability of a nonrenewable resource (gasoline).used for the treatment of wastewater.

Uses of fermentation

The alcoholic beverages that can be produced by fermentation vary widely, depending primarily on two factors—the plant that is fermented and the enzymes used for fermentation. Human societies use, of course, the materials that are available to them. Thus, various peoples have used grapes, berries, corn, rice, wheat, honey, potatoes, barley, hops, cactus juice, cassava roots, and other plant materials for fermentation. The products of such reactions are various forms of beer, wine or distilled liquors, which may be given specific names depending on the source from which they come. In Japan, for example, rice wine is known as sake. Wine prepared from honey is known as mead. Beer is the fermentation product of barley, hops, and/or malt sugar.

Ethyl alcohol is not the only useful product of fermentation. The carbon dioxide generated during fermentation is also an important component of many baked goods. When the batter for bread is mixed, for example, a small amount of sugar and yeast is added. During the rising period, sugar is fermented by enzymes in the yeast, with the formation of carbon dioxide gas. The carbon dioxide gives the batter bulkiness and texture that would be lacking without the fermentation process.

Fermentation used in industries24| Chemistry Project

http://science.jrank.org/pages/2677/Fermentation-Uses.html


http://science.jrank.org/pages/1107/Cactus.html

http://science.jrank.org/pages/751/Barley.html

http://science.jrank.org/pages/7378/Wheat.html

http://science.jrank.org/pages/5875/Rice.html

http://science.jrank.org/pages/3099/Grapes.html

http://science.jrank.org/pages/5277/Plant.html



Fermentation is used in bakeries

PRECAUTION

The type of hazards that might occur can be classified into the following areas:

Microbiological hazardsChemical hazardsPhysical hazardsElectrical hazards

1. MICROBIOLOGICAL HAZARDS:

In the fermentation industries or laboratories, we are dealing and always exposed to very high concentrations of microorganisms. If taken care and proper control these high concentration microorganisms are always contained in the bioreactor where they are purpose grown.Depending on the type of fermentation process, the microorganisms used may or may not be pathogenic. Any danger of release of pathogenic microorganisms would be a real threat to the surroundings

The risk of mirobial hazards can occur at all stages of the fermentation activity right up from upstream, mid stream and down stream. Of course the most crucial stage will be the period the microorganisms are grown in the fermentor. There are billions and billions of microorganisms "swimming" in the fermentation broth!Microorganisms can only escape due to poor handling procedures that is poor microbiological


techniques. They can also be released by accidental discharge or poor containment of the microorganisms in the fermentor.

In aerobic fermentors, air or oxygen is actively supplied into the broth of the fermentor for the use of the aerobic microorganisms. Most of the air will be released through the exhaust outlet to the environment. If the exhaust air is not sterilized or filtered, there is the danger that aerosols carrying the microorganisms from the fermentor will be released.

The fermentor is usually operated skightly under high pressure of about two bars. Any sudden release of the pressure through any of the valves risk releasing and spreading the microbes.

The presence of aerosols released from the pressured fermentor will exacerbate the problem of microbial dispersion and transmission. Not only will the aerosols be the "carrier" for the microbes but it will even protect the microbes from premature dessication and even provide nutrients for the microbes.

2.CHEMICAL HAZARD:

There are a few possible chemical hazards that may arise in operating the fermentor or in the fermentation plant. Chemicals that may be used in the fermentation plant are from a few sources:-

Calibration gasesGases used in fermentation such as nitrogen, oxygen,

hydrogen, carbon dioxide, NH3 gas


Solvents such as alcoholsSurfactantsChemicals used as substratesAcids and AlkalinesDisinfectants

Some of these chemicals are toxic, flammable, corrosive and may be dangerous if not used properly.

3. PHYSICAL HAZARDS:

Physical dangers that lurked in the fermentation laboratory or plant may include:-

HeatPressureSlips and fallsKnocksFire and burn hazardsCuts and bruises

Dangers from high heat source occur in such activities as sterilizing the fermentors or from the use of autoclaves. High pressure accidents too can occur by improper use of fermentors and autoclaves. Slippery fermentation plant floors could easily lead to slips and injuries.


Cuts and bruises are common during handling of the fermentor. Equipments and tools left haphazardly could lead to unwanted accidents and falls. Improper use of flaming during aseptic procedures could lead to accidental burnings and personal injuries.

4. ELECTRICAL HAZARDS:

Electrical accidents such as electric shocks is common in any fermentation laboratory. Short circuits are common. High voltage and high amps current are often used regularly in the fermentation operation.Fermentation operatives should be trained to identify all the possible danger points and steps taken should accidents happen. This will be discussed in future blogs.

Benefits of consuming fermented food:

Fermented foods have been around for thousands of years; the process helped our ancestors preserve food long before refrigerators and canning systems were available. When a food is fermented, it’s left to sit and steep (sometimes for months!) until the sugars and carbs are digested by lactic-acid producing bacteria. It sounds kind of scary that bacteria is left to run rampant through your food, but it’s actually a good thing — for your health and your tastebuds. Thanks to the acidic environment produced by the bacteria, no unwanted bacteria can grow, and the food itself (think yogurt, kimchi, or sauerkraut) is left to take on a delicious, tangy flavor.28| Chemistry Project

The main reasons for consuming fermented foods are :

1. Boosts immune system:

The live bacteria in fermented foods strengthens the immune system by upping the amount of antibodies fighting infectious disease in your body. Having more healthy bacteria in your gut — the largest immune organ in our bodies — also helps reduce chronic inflammation, a major factor in diseases like asthma, Crohn’s, diabetes and high blood pressure.

2. Improve digestive function:

When the balance of good and bad bacteria in our digestive tract is off, it can lead to a weak digestive system, which has repercussions past spending too much time in the bathroom. Irritable bowel syndrome, heartburn and Celiac’s disease are all related to digestive health. Eating fermented foods helps maintain the bacteria ecosystem in our guts, ensuring things run (ahem) smoothly.

3. Creates better skin:

You might be staring at an imbalance of gut bacteria face-on. If you suffer from eczema, acne, rashes, or other skin issues, adding more fermented foods to your diet can ease symptoms. That’s because the healthy bacteria these foods add to your body will reduce inflammation, improving your skin condition. Lay off the makeup and load up on the sauerkraut.

4. Absorbs more nutrients:


During the fermentation process, nutrients have been pre-digested by beneficial bacteria. This means when it’s time to chow down, your body is able to extract the minerals and nutrients from foods more easily. Plus, anti-nutrients (stealth compounds that interfere with your body’s ability to extract the good stuff from foods) are also broken down during fermentation, leaving your body free to absorb what it needs.

5. Brightens your mood:

Recent studies show that when there’s havoc in your gut — your body’s “second brain” — it can manifest itself in your mood.


Bibliography

•Practical Chemistry Comprehensive - XII • Class XII Chemistry Text Book•Internet

www.google.com

http://fermentationtechnology.blogspot.com

https://en.wikipedia.org/wiki/Fermentation

articles.mercola.com/fermented-foods.aspx

draxe.com/fermented-foods/

www.morethanorganic.com/fermentation

Referred From BooksThe Art Of Fermentation – by Sandor Ellix Katz


https://en.wikipedia.org/wiki/Fermentation

http://fermentationtechnology.blogspot.com/

http://www.google.com/

fermentation · web view“if we knew what it was we were doing, it would not be called research,...

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