KITCHEN CHEMISTRY PROJECT 2011

TITTLE: BEST PICKLED

NINA ALLYZA BINTI KEPOL (D20091035080)

NUR AYUNI BINTI ROZAKI (D20091035084)

NOR ASMALIZA BINTI BAKAR (D20091035095)

NUR ‘ALIA AFIFAH BINTI HAMDAN (D20091035076)

ABSTRACT:

Some food only long lasting if it is stored in a different way from its original form such as

preservations. One of the preservations methods is pickling. Pickling is the process of preserving

food by anaerobic fermentation in brine (a solution of salt in water) to produce lactic acid,

or marinating and storing it in an acid solution, usually vinegar (acetic acid). We chose mango

for our best pickled because it is easily found in Malaysia. This experiment is conducted to find

the best method to obtain the best pickled including to study how lime water effect the condition

of pickled and also to study how the concentration of solution affect the texture of pickled. First

thing that we need to do was cleaned and sterile the container that going to be used as well as the

mango itself. After that, the cut mango was divided into three parts which are soaked in lime

water for 5 minutes, 30 minutes and 60 minutes. Each of these parts then will be divided into

another three parts which are different in the amount of ingredient. The observation was first

made on the effect of lime water on the crunchiness of the mango. The crunchiest was then

selected from the first observation for the second observation, where the color, crunchiness, and

taste were considered to be observed. After that, the best pickled was concluded. From the result

obtained, we found that the, the crunchiest and best mango pickled was the mango that soaked

into the lime water for 60 minutes and contain sugar and salt only as its ingredients. So we

conclude that, the longer the mango is soaked into the lime water the crunchier it will be and the

combination of salt and sugar give the best pickled.

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KITCHEN CHEMISTRY PROJECT 2011

INTRODUCTION

Pickling is a global culinary art. If

you were to go on an international food-

tasting tour, you’d find pickled foods just

about everywhere.  There are two basic

categories of pickles. The first type includes

pickles preserved in vinegar, a strong acid in

which few bacteria can survive. Most of the

bottled kosher cucumber pickles available in

the supermarket are preserved in vinegar. 

The other category includes pickles soaked

in a salt brine to encourages fermentation—

the growth of "good" bacteria that make a

food less vulnerable to "bad" spoilage-

causing bacteria. Common examples of

fermented pickles include kimchi and many

cucumber dill pickles. In chemical pickling,

the jar and lid are first boiled in order to

sterilize them. The fruits or vegetables to be

pickled are then added to the jar along with

brine and/or vinegar as well as spices and

are then allowed to ferment until the desired

taste is obtained. In commercial pickling, a

preservative like sodium benzoate or EDTA

may also be added to enhance shelf life. In

fermentation pickling, the food itself

produces the preservation agent, typically by

a process that produces lactic acid. Pickling

is not only an international food-

preservation technique, it’s also an ancient

one. For thousands of years, our ancestors

have explored ways to pickle foods,

following an instinct to secure surplus food

supplies for long lasting. Here we also try to

test what is the best way in making pickle.

Another thing that we must take note, pickle

cannot be too much consumed because the

World Health Organization has listed

pickled vegetables as a possible carcinogen

and the British Journal of Cancer released

an online 2009 review of research on pickles

as increasing the risks of esophageal cancer

METHODOLOGY

1. Cut the mango into small pieces of

the same size. (Almost the same)

2. Divide the mango into three parts.

3. Soak the first sample into lime water

for 5 minutes, the second sample for

30 minutes and the third sample for

60 minutes.

4. Remove the mangoes from lime

water, and then rinse with tap water.

5. Divide the first sample into four and

add into the container that labeled A,

B, C and D.

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KITCHEN CHEMISTRY PROJECT 2011

container Contents

A 26.06 g of sugar +

250 ml of water

B 25.37 g of salt + 250

ml of water

C 25.37 g of salt +

26.06 g of sugar +

250 ml of water

D 26.06 g of sugar +

6 pieces of asamboi

+ 250 ml of water

6. Leave the labeled containers at a dry

place for six days.

7. Repeat step 4 until 6 by replacing the

first sample with the second and third

sample.

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KITCHEN CHEMISTRY PROJECT 2011

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KITCHEN CHEMISTRY PROJECT 2011

RESULTS

SAMPLES TIME

(MIN)

OBSERVATION

ON

CRUNCHINESS

A 5 Less crunchy

30 Moderately

crunchy

60 Very crunchy

B 5 Less crunchy

30 Moderately

crunchy

60 Very crunchy

C 5 Less crunchy

30 Moderately

crunchy

60 Very crunchy

D 5 Less crunchy

30 Moderately

crunchy

60 Very crunchy

After the time with best result has

been selected (60 minutes), the

second comparison is done.

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container observation

A (60) Brown in color

Quite taste

The least

crunchy

B (60) The original

color is

remained

Not delicious

at all (too

salty)

The most

crunchy

pickled

C (60) Very delicious

The original

color is

preserved

very crunchy

D(60) Bubbles

formed in the

solution

Reddish

orange in color

Quite tasty

Less crunchy

KITCHEN CHEMISTRY PROJECT 2011

DISCUSSION

Ingredients

In the experiment, a different

substance was added in each container.

Container A was added with sugar and

water, container B was added with salt and

water, container C was added with water,

sugar and salt while container D was added

with water, sugar and ‘asamboi’.

The pickled in container A was

quite tasty because it tasted sweet which

came from the sugar. Sugar plays an

important role in the food preservation. This

is because sugar is able to form hydrogen

bond with water molecules in which will

reduce the water activity and make the water

less favourable for microbial growth. From

the reading, it was found that the winter

radish root will appear bright yellow in color

that occurs naturally after the pickling

process. The condition for the formation of

yellow pigment is the same as the reaction

between thioglucosidase and ascorbic acid

that stimulate the production of yellow

pigment (Ozawa et al., 1993). However, in

this case the yellowing or browning of the

pickled might be caused by some errors that

were done during conducting the study. The

mango might be not soaked fully in the

sugar solution which caused it be exposed to

oxygen and oxidized. The enzyme that

responsible for the browning of the mango is

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KITCHEN CHEMISTRY PROJECT 2011

polyphenol oxidase. This enzyme caused the

formation of oxidized pigment which is

brown in color and contributed to the color

changes in the mango.

The addition of salt in the container

B has promoted the growth of bacteria

known as Lactobacillus plantarum.

However salt must be added at a correct

proportion. If too much salt was added, the

good bacteria will not function properly and

too little salt will promote the growth of less

beneficial bacteria.

The pickled in container C has the

best taste because it has a balance taste. It

was not too sweet and does not too salty, in

fact it has both of the combination of the

tastes.

The solution in container D was

quite different from the others, it was added

with ‘asamboi’ which gave the solution an

orange color. The solution was orange in

color because the paticles in ‘asamboi’

which was orange in color has diffused

throughout the water in the container via

simple diffusion. The orange solution has

stained the pickled with an orange color.

Lime Water

Processing is necessary for

all pickles and relishes to destroy the yeasts,

molds and bacteria that may cause the

product to spoil and also to inactivate

enzymes that could affect color, flavour and

texture of the pickled product.

Calcium hydroxide, traditionally

called slaked lime, is an inorganic

compound with the chemical formula Ca

(OH) 2. It is a colorless crystal or white

powder and is obtained when calcium

oxide (called lime or quicklime) is mixed, or

"slaked" with water. It has many names

including hydrated lime, builders lime, slack

lime, cal, or pickling lime. It is of low

toxicity and finds many applications,

including for food. Because of its low

toxicity and the mildness of its basic

properties, it is widely used in the food

industry. But here in this experiment we

were studying the effects of this substance

on the crunchiness of the pickles. Time for

the mango to be soaked on the lime water

was varied; this is to determine the effect of

time of mango soaked in lime water and the

crunchiness of the pickles. From the result

obtain we found out that the mango that

soaked into the lime water for 1 hour more

crunchy followed by 30 minutes and 5

minutes. Alum may be safely used to firm

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KITCHEN CHEMISTRY PROJECT 2011

fermented pickles. However, it is

unnecessary and is not included in the

recipes. The calcium in lime definitely

improves pickle firmness. Food-

grade lime may be used as a lime-

water solution for soaking fresh mango

before pickling them. The calcium in the

lime reacts with the pectic acid in the fruit to

form calcium pectate, which adds to

'crunchiness'. There is already some calcium

pectate in mango and other vegetables. The

longer the time it was soaked, the

probability for the calcium in lime reacts

with pectic acid also high.

Excess lime absorbed by the mango

must be removed to make safe pickles. To

remove excess lime, drain the lime-

water solution, rinse, and then resoak the

mango in fresh water for 1 hour. Repeat the

rinsing and soaking steps two more times.

To further improve pickle firmness, the

mango pickles can be process for 30 minutes

in water at 180°F. This process also prevents

spoilage, but the water temperature should

not fall below 180°F. Use a candy or jelly

thermometer to check the water temperature.

But this process was not done for this time

experiment. But the crunchiness of the

pickles not only depends on this factors but

the concentration of the solution also affect.

In order to determine this we were observing

the crunchiest mango within the samples A,

B and C. Once we got the crunchiest one,

the comparison between the crunchiest 5

minute, 10 minute and 1 hour was made. We

found that the longer the mango soaked into

the lime water crunchier it will be.

Temperature

Temperature is one of the factors

affecting the pickling process. Pickling

process is also known as fermentation

process. The optimum temperature for

fermentation is around 21 oC. A change of

just a few degrees from this temperature

modifies the activity of the microbial

process and affects the quality of the final

product. Therefore, temperature control is

one of the most important factors in the

pickling process. A temperature of 18 oC to

22 oC is most appropriate for initiating

fermentation since this is the optimum

temperature range for the growth and

metabolism of L. mesenteroides.

Temperatures above 22 oC favor the growth

of Lactobacillus species. When temperature

is low, Leuconostoc

mesenteroides dominates, producing a mix

of acids, alcohol, and aroma compounds. At

higher temperatures Lactobacillus

plantarum dominates, which produces

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KITCHEN CHEMISTRY PROJECT 2011

primarily lactic acid. Many pickles start with

Leuconostoc, and change

to Lactobacillus with higher acidity.[

Otherwise, the temperature above 30 oC will provide pickles become too soft

during fermentation. It is also will cause the

excess of microbial growth in the pickle and

formation of bubble will occur. Actually,

bubbling in pickles is the feedback from

fermentation process. During fermentation,

cultures transform the fresh fruits into

pickles by converting sugars to lactic acid,

acetic acid, carbon dioxide, and other

beneficial substances. The bubbling formed

in pickles is the carbon dioxide that released

from fermentation process. To reduce the

excessive bubbling formed, pickles can store

under refrigerator to slow the fermentation.

A very low temperature makes process of

fermentation become more slowly compared

at room temperature. As we mentioned

above, the optimum temperature for

fermentation process is around 21 oC, hence

when pickles are kept in refrigerator which

is in very low temperature under 21oC, the

microbial process will become slow, and

process converting sugar to lactic acid and

carbon dioxide also become slow, this will

reduce the formation of bubbles in pickle.

There are some precaution steps during

making the pickles. Make sure that using the

different spoon to stir salt or sugar with

water and fruit in order to avoid pickles

from being contaminated. Furthermore, we

should use boiled water instead of pipe

water to make pickle. Do not use the pipe

water because there are microorganisms that

might be caused the growth of bad bacteria

and contaminate the pickles.

Concentration

            Now, we move to the other factors

that make the pickles crunchier which is

concentration of the solution that the pickles

were soaked. There are four different of

concentration in making these pickles. The

four solutions that we prepared are:

 

1. Solution of water and sugar only

2. Solution of water and salt only

3. Solution of water, salt and sugar only

4. Solution of water, sugar and asam boi

only

All of the solutions have different

concentration. The lowest concentration is

the concentration of sugar solution (syrup),

the middle one is sugar and salt solution and

the highest concentration is the solution of

salt (brine).  Based on the results, it showed

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KITCHEN CHEMISTRY PROJECT 2011

that the solution of sugar give the most

crunchy texture compare to the other. This

means that the lowest the concentration of

pickling solution, the crunchy the pickles. 

The process that involved to makes the food

more crispy was osmosis. Osmosis is the

movement of water molecules through a

selectively-permeable membrane. Water will

move from an area of high solute

concentration to an area of low solute

concentration. This process does not require

any energy so it occurs naturally and goes

on until equilibrium is achieved. This is the

essence of osmosis and is life critical in the

cells of all living organisms. All plants,

fruits consist of cells, surrounded by a cell

wall that gives strength to the plant. The

fluid in the cell is under pressure, providing

a crisp and fresh texture.

Osmosis

When pickling, water will be extracted from

the fruit by osmosis, resulting in a

concentration of solutes in the food product

and make the fruit less crispy or crunchy.

Meanwhile, diffusion will cause the fruit to

enrich itself with solutes in the brining

solution or syrup. It is also possible that

substances in the fruit leach out to the

brining solution.

          

 Different concentrations contribute to

different texture of pickles. The

concentrated solution contains high amount

of solute which made the lots of water from

fruit to move out to the outer membrane.

When water from fruit move outs, it makes

the fruit less crunchy. For dilute solution,

the amount of water loss is less compare to

the concentrated solution and hence made

the fruit crispier. Thus, the dilute the

solution, the less amounts of water move out

from the fruit and the crunchier the pickles.

The effect can again be reversed by washing

the pickles afterwards in clean ice water.

Now the pickles will take up water since the

concentration of solutes is higher in the cells

than in the ice water.

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KITCHEN CHEMISTRY PROJECT 2011

Pickling will preserve food

microbiologically. It will actually make

water unavailable for any living organism in

the brine or brined food product. Since the

concentration of solutes is far greater outside

the cell of any bacteria or other harmful

organisms than inside (food’s cell), hence

the result is that bacteria will not be able to

uptake water, which is essential to remain

alive, on the contrary, water will be forced

out of the cell, causing the bacteria to

dehydrate and eventually  die. The same

happens in a pickling solution, with added

pH effects.

In this kitchen project also, we add few

asam boi in 4th solution for better taste.

Asam boi is to make the pickles taste sourer.

It is quite tasty but not as tasty as the pickles

that was soaked in 3rd solution

CONCLUSION

The longer the mango is soaked into the

lime water the crunchier it will be. This is

because the calcium in the lime reacts with

the pectic acid in the fruit to form calcium

pectate, which adds to 'crunchiness'. When

concentration of solution increase, the

texture of mango pickled become crunchier

due to the process of osmosis. This process

occurs because of the tendency of substance

to move through membrane from high

concentration water molecule to low

concentration of water molecule. In this

case, water molecule inside mango flows out

to the solution since it has lower water

molecule concentration than the water

molecule concentration inside mango. The

flowing out of water molecule from mango

makes the pickled become crunchier.

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9-05/how-make-quick-pickles

Peter S. Murano, understanding Food

Science and Technology, United States

of America, Thomson Learning, Inc.,

2003

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KITCHEN CHEMISTRY PROJECT 2011

Alev Bayindirli, Enzymes in Fruit and

vegetable Processing: Chemistry and

Engineering Application, United States

of America, Taylor & Francis Group,

2010

Retrieved October 22,2011,from

http://www.chemtutor.com/soluti

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env211/lesson8_3.htm

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