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ACADEMY OF MARITIME EDUCATION AND TRAINING(AMET)

(Declared as Deemed to be University u/s 3 of UGC Act 1956)

135, EAST COAST ROAD, KANATHUR, CHENNAI - 603 112.

TAMILNADU, INDIA

Food Fermentation Process

A Report on Internship

In

Department of Food Processing Technology

By

AJAS MOHAMMED

AFP19001

APRIL 2020

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CONTENTS

LIST OF SYMBOLS AND NOTATIONS PAGE NO

1. ABSTRACT 4

2. INTRODUCTION 5

3. METHODOLOGY 6

4. CONCLUSION 7

5. LIST OF PHOTOGRAPHS 8

ABSTRACT

In this study I examine the self-life of some fermented food products (i) rice based idly

batter (ii) Yogurt. Idly batter is prepared by soaking polished parboiled rice and decorticated

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black gram for 4 hours at 30 ± 1oc in water. The soaked mass ground using a grinder with

adequate amount of water. The blend ratio of 5:1 was allowed to ferment for 7-8 hours with

addition of 2% salt. Meanwhile yogurt is prepared by the bacterial fermentation of full cream

milk (Fat-6.0%) were lactose is converted into lactic acid by several probiotic microorganisms. I

observed the acidic variation in both the products due to the growth of the microorganisms, this

may lead to the change in pH. The rate of fermentation is high in yogurt than the idly batter this

is due to the culture which is added to the milk.

INTRODUCTION

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In Human History, Fermented food is started in 7000-6600 BC. The Conversion of sugar

and other carbohydrates into alcohol or preservative organic acids and carbon dioxide is called

fermentation. In organic chemistry, it's narrowly outlined because the extraction of energy from

carbohydrates within the absence of atomic number 8. within the context of food production, it

should additional loosely see any method within which the activity of microorganisms brings a

few fascinating modifications to a foodstuff or potable. The science of fermentation is thought as

zymology.

In microorganisms, fermentation is that the first means of producing ATP (ATP) by the

degradation of organic nutrients anaerobically. Humans have used fermentation to supply

foodstuffs and beverages since the Neolithic Age. for instance, fermentation is employed for

preservation during a process that produces carboxylic acid found in such sour foods as pickled

cucumbers, kombucha, kimchi, and yogurt, also as for producing alcoholic beverages like wine

and beer. Inside the gastrointestinal tracts of all animals, including human's fermentation process

occurs.

IDLY/DOSA BATTER PREPARATION:

Maturation of idly batter brings about both raising brought about by the age of carbon

dioxide just as an expansion in sharpness. This maturation is performed by lactic corrosive

microorganisms particularly the heterofermentative strain Leuconostoc mesenteroides and the

homofermentative strain Enterococcus faecalis (some time ago named Streptococcus faecalis).

Heterofermentative lactic corrosive microorganisms, for example, L. mesenteroides produce both

lactic corrosives just as carbon dioxide though homofermentative lactic corrosive microscopic

organisms just create lactic corrosive. Both L. mesenteroides and E. faecalis are prevalently

conveyed to the player by the urad dal. The two strains begin increasing while the grains are

drenching and keep on doing as such in the wake of granulating. L. mesenteroides endures high

groupings of salt not at all like most other microscopic organisms. Thus, the salt in the player

and the continuous age of lactic corrosive both stifle the development of other bothersome

miniaturized scale living beings.

YOGURT PREPARATION:

Yogurt may be a foodstuff obtained by coagulating milk during a process called

yogurtling. The coagulation can be caused by adding rennet or any edible acidic substance such

as Citric acid or acetic acid, and then allowing it to coagulate. The increased acidity causes the

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milk proteins (casein) to tangle into solid masses, or yogurts. Milk that has been left to sour (raw

milk alone or milk with added carboxylic acid bacteria) also will naturally produce yogurts, and

sour milk cheeses are produced this manner.

METHODOLOGY

Process of Idly Batter Preparation:

▪ Idly batter is made with soaking and fermenting rice and urad dal in a 5:1 ratio as you can

see in the fig 1.1

▪ While the actual rice idly recipe takes only about 30 mins to cook, the process of

fermentation, for the batter, takes more than a day.

▪ Once the urad dal and rice is soaked overnight we need to grind it separately as shown in

the fig 1.2 & 1.4

▪ Once the graining of the Fermenting rice and urad dal is done. We need to mix both the

mixture together (fig 1.5) and keep it for fermentation in room temperature for 7-8 hrs.

Once its fermented store it in the refrigeration condition. To complete this process, it will

take more than a day.

▪ To compare the self-life of the batter I examined it in refrigerated condition and room

temperature.

Process of yogurt Preparation:

▪ Bring the milk to boil and put aside to chill. The temperature to which it must cool is

vital. It should be warm – not lukewarm, not hot. an honest test is to insert your (clean!)

finger within the milk and see if you'll hold it there for 10 seconds without having to tug

it out because it’s too hot or feeling too comfortable because it’s too cold.

▪ Transfer the milk to the container.

▪ Add the yogurts to the milk. Yes, to form yogurt you would add yogurt as a starter. The

bacteria in our starter then acts on the remainder of the milk and turns it all to yogurt.

▪ Mix the yogurt and therefore the milk well together. This step is vital. the higher they're

mixed, the quicker and better the yogurt will set. employing a whisk may be a great idea

too.

▪ Once mixed, keep loosely covered during a warm place. Once the milk has completely

cooled down, you'll close the lid tighter (even airtight) but this is often not necessary.

▪ After about 6-8 hours, you see a wonderfully set batch of homemade yogurt.

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▪ To compare the self-life of the yogurt I examined it in refrigerated condition and room

temperature.

CONCLUSION

As the result of this study the self-life in the refrigerated condition is higher than the room

temperature in both the products. This is because in refrigerated condition the growth of the

microorganisms is inhibited but in room temperature the growth is rapidly increase which leads

to the spoilage of the products. This will give the side effect like digestive problems.

On the whole, This Internship was a useful experience. I have gained new knowledges. I

achieved several of my learning goals. Related to my study I had learned more about the

fermentation of food. This helped me to defined what skills and knowledge I have to improve in

the coming time. At last this Internship has given me new insight and motivation to pursue a

career in product development.

LIST OF PHOTOGRAPHYS

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IDLY/DOSA BATTER PREPARATION:

Fig 1.1: soaked rice and urad dal Fig 1.2: Grinding the soaked urad dal

Fig 1.3: Collecting the grinded urad dal Fig 1.4: Grinding the fermented rice

Fig 1.5: Collecting the grinded rice Fig 1.6:

Fermented idly/dosa batter

and mixed

YOGURT PREPARATION:

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Fig 2.1: Boiled milk Fig 2.1: Cultured milk

Fig 2.1: Yogurt

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ACADEMY OF MARITIME EDUCATION AND TRAINING(AMET)

(Declared as Deemed to be University u/s 3 of UGC Act 1956)

135, EAST COAST ROAD, KANATHUR, CHENNAI - 603 112.

TAMILNADU, INDIA

FOOD DRYING PROCESS

A Report on Internship

In

Department of Food Processing Technology

By

KAVI VARADHA RAJA

AFP19004

April 2020

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4

CONTENTS

LIST OF SYMBOLS AND NOTATIONS PAGE NO

1. ABSTRACT 4

2. INTRODUCTION 5

3. METHODOLOGY 7

4. CONCLUSION 10

5. LIST OF PHOTOGRAPHS, FLOW CHARTS &TABLES 11

ABSTRACT

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Drying is one of the oldest preservation processes available to the mankind, on that we can track since

prehistoric times. In today food market dried foods play an important role in the food supply chain. As for

fruits and vegetables it can be estimated that they constitute about 1% of the total drying in the food

industry, by large being the grains the most important. The main feature of this process consists on lowering

the water content in order to avoid or slow down food spoilage by microorganism. At this point some

understanding can arise derived from the vocabulary employed; common words found are " drying " or "

dehydration ", or even " dewatering ". There are various aspects that must be considered when drying small

fruits and vegetables, whether for the food or nutraceutical and functional food industries. A system which

minimizes exposure to light, oxidation and heat, (i.e. high heat 70 o C and shorter time duration) may help

conserve critical bioactive compounds.

Drying is the moisture removing process from the products. Drying reduces the bacterial growth in the

products. Tomatoes are commonly consumed fresh; over 80% of the tomato consumption comes from

processed products such as tomato juice, ketchup and sauce. Recent studies have indicated the potential

health benefits of a diet that is rich in tomatoes. It will helpful for preserving the products for long time.

Dehydration process was carried out using a cabinet tray dryer, solar dryer, freeze drying methods with

different thickness of tomato slices at same temperature of cabinet tray dryer, freeze dryer and solar dryer

according on atmosphere temperature conditions.

Key words: drying method, fruits and vegetables, sun drying, process of drying, dehydration.

INTRODUCTION

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In ancient times, the sun and wind would have naturally dried foods. Evidence shows that Middle East and

oriental cultures actively dried foods in the hot sun as early as 12,000 B.C. The Romans were particularly

fond of any dried fruit they could make.

Drying is the oldest method of preserving food. Throughout history, the sun, the wind, and a smoky fire was

used to remove water from fruits, meats, grains, and herbs. By definition, food dehydration is the process of

removing water from food by circulating hot air through it, which prohibits the growth of enzymes and

bacteria. Dried foods are tasty, nutritious, lightweight, easy-to- prepare, and easy-to-store and use. The

energy input is less than what is needed to freeze or can, and the storage space is minimal compared with

that needed for canning jars and freeze containers.

The nutritional value of food is only minimally affected by drying. Vitamin A is retained during drying;

however, because vitamin A is light sensitive, food containing it should be stored in dark places. Yellow and

dark green vegetables, such as peppers, carrots, winter squash, and sweet potatoes, have high vitamin A

content. Vitamin C is destroyed by exposure to heat, although pre-treating foods with lemon, orange, or

pineapple juice increases vitamin C content. Dried fruits and vegetables are high in fiber and carbohydrates

and low in fat, making them healthy food choices.

In the early 1900s, natural draft dehydrators were created to dry fruits, vegetables and herbs in areas that did

not have enough strong sunlight for drying. These early dehydrators were designed with fire pits on the

bottom and exhaust vents at the top. As the fire heated the air, it was carried upwards creating the critical air

flow and low humidity that is essential for dehydration.

Freezing was an obvious preservation method in the appropriate climates. Any geographic area that had

freezing temperatures for even part of a year made use of the temperature to preserve food. Less than

freezing temperatures were used to prolong storage times. Cellars, caves and cool streams were put to good

use for that purpose.

In America, estates had icehouses built to store ice and food on ice. Soon the “icehouse” became an

“icebox”. In the 1800s mechanical refrigeration was invented and was quickly put to use. Also, in the late

1800s, Clarence Birdseye discovered that quick freezing at very low temperatures made for better tasting

meats and vegetables.

How Drying Preserves Food

* Drying removes the moisture from the food so bacteria, yeast and mould cannot grow and spoil the food.

* Drying also slows down the action of enzymes (naturally occurring substances which cause foods to

ripen), but does not inactivate them. Because drying removes moisture, the food becomes smaller and lighter

in weight.

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* Foods can be dried in the sun, in an oven or in a food dehydrator by using the right combination of warm

temperature, low humidity and air current.

* In drying, warm temperatures cause the moisture to evaporate. Low humidity allows moisture to move

quickly from the food to the air. Air current speeds up drying by moving the surrounding moist air away

from the food.

How to dry food safely

By using the right combination of warmth, low humidity and air current, we can safely dry foods. To

dry foods successfully we need

• Low humidity - Low humidity allows moisture to move from the food to the air.

• A source of low heat - The warm temperature allows the moisture to evaporate.

• Air circulation - Air currents speed up drying.

SUN DRYING

Sun drying has been used for centuries as a means to dry out foods, removing the natural moisture of the

food and in a sense dehydrating that foods.

ADVANTAGES

• Save energy and no need to purchase a dehydrator.

• Accomplish similar functions to dehydrating.

• A timeless process that has worked for centuries.

• A great “dehydration” method if you need an alternative to the oven or dehydrator.

METHODOLOGY:

1.DRIED TOMATO PREPARATION BY SUN DRYING:

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Sun dried tomatoes are the ripe tomatoes that lose most of their water content after spending a majority of

drying time in the sun. They have a sweet taste and can last far longer than fresh tomatoes. Drying tomatoes

doesn’t change any of the nutritional benefits of the fruit with the exception of the loss of some Vitamin C.

It will loss 88% of their initial weight during the process.

PROCESS OF DRIED TOMATOES PREPARATION:

STEP 1: SELECT TOMATOES:

Select fresh plum and oval shaped tomatoes with no rotten spot and insects damage. Wash tomatoes

well under clean running water then cut into pieces.

STEP 2: LAYOUT THE TOMATOES:

Arrange tomatoes in a single layer with a space between the pieces so hot air can circulate between the

slices.

STEP 3: BEGIN THE PROCESS:

Place tomatoes on a sun drying surface and sprinkle them lightly with a salt (for a preservation

purpose). It should be placed in an area that gets steady sunshine throughout the day. This process

could be taken up to 2 weeks. They need to be fully dry but not crispy in order to be done. The final

product may contain up to 2-5% of salt and could provide a significant contribution to the daily’s

intake.

WHAT TO USE TO STORE DRIED TOMATOES

• Select airtight containers like zipped plastic freezer bags, jars, or plastic containers with tightly-fitting lids.

Decorative jars work especially well.

• Use the smallest possible container for the amount of prepared dried tomatoes. The less air exposure, the

better.

• When using zipped plastic, freezer bags squeeze out excess air before sealing. If possible, vacuum seal

bags.

WHERE TO STORE DRIED TOMATOES:

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To store in the pantry or on a shelf:

* Place sealed containers in a cool, dry, dark place, maintained at about 60-70ºF. If completely moisture-

free, dried tomatoes will keep flavour and texture for up to a year.

However, most dried tomatoes will have remnants of moisture that will permit mould to develop.

Tomato Dirt’s best recommendation: store dried tomatoes in refrigerator or freezer as a precaution.

To store in refrigerator or freezer:

✓ Seal tightly to prevent freezer burn. Label with date.

✓ Dried tomatoes can be stored in the freezer or refrigerator and maintain flavour and texture for about 18

months.

2. DRIED FISH BY CURING METHOD

CURING METHOD:

Curing reduces water activity through the addition of chemicals, such as salt, sugars, or acids. There are two

main types of salt-curing used in the fish industry: dry salting and pickle-curing. In dry salting the butchered

fish is split along the backbone and buried in salt (called a wet stack). Brine is drained off until the water

content of the flesh is reduced to approximately 50 percent (the typical water content of fresh fish is 75 to 80

percent) and the salt content approaches 25 percent. In heavy or hard-cure salting, an additional step is taken

in which warm air is forced over the surface of the fish until the water content is reduced to about 20 percent

and the salt content is increased to approximately 30 percent. Most dry-salted fish products are consumed in

warm, humid countries or in areas that have few means of holding products in refrigeration or cold storage.

Fish preservation by drying means preserving fish by removing water from its body through heating them Sun

drying and solar drying are used for preserving the fish.

PROCESS OF DRIED FISH PREPARATION

STEP 1: Select fish size it may be small sized or big sized which can be preserved through drying in

sunlight.

STEP 2: In small fish, no need to remove innards and scale from their body. But sometimes if needed

remove those from the fish by slightly pressing on their body .

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STEP 3: Wash the fish property by using clean and fresh water. Apply salt over the fish then keep them

on the bed and make it to dry by sunlight.

STEP 4: It takes about 3-5 days to make the fishes fully dry. We should keep the fish free from worms,

insects and birds while drying.

For drying the fish fast turn over those several times a day.

IMPORTANCE OF FISH DRYING:

* Generally huge amount of fish caught from the internal water reservoir like pond, lake etc. If it not

possible to consume or sell the fish then drying is the suitable way for preserving.

* Fish is very for rotten being. So, drying is must to keep them free from rotten.

* Drying fish has the demand in the market. It also helps to meet up protein or fish demand.

* Drying of fish is also being used a nutritious protein food for poultry.

* Dried fish stays for long time. As the drying weights less so, it costs less while transporting .

CONCLUSION:

• Advances in dehydration techniques and development of novel drying methods have in recent years

enabled the preparation of a wide range of dehydrated products and convenience foods from fruits and

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vegetables meeting the qualityn, stability and functional requirements coupled with economy. This has been

made possible by the sustained experimental studies over the years to understand the theoretical and

fundamental aspects of the process and optimization of the techniques to achieve a favourable combination

of cost and quality. This process reviews and highlights the developments in the dehydration of fruits and

vegetables and their products during the last decade covering theoretical aspects and practical applications

with major emphasis on techniques that have received the maximum.

• The method of preservation through sun drying is not a new one.

• The process of preserving food is something mankind is familiar with since the days of yore. Several

folklores recount the methods of preserving foods in one way or another in accordance with the local and

cultural traditions.

• The idea was to prevent food from spoiling and helps make it last longer while keeping it fit for

consumption. Though there are various ways of preserving food, drying and fermentation are said to be one

of the oldest methods of preservation. The idea was to eliminate the water content in the fruit and vegetables

thus preventing bacteria, yeast or fungi from growing on them.

• Drying as a method of preservation has numerous advantages. Food becomes lightweight and easy to carry

due to the reduced water content in it.

• The energy input is less than what is needed to freeze or can, and the storage space is minimal compared

with that needed for canning jars and freeze containers. The nutritional value of food is only minimally

affected by drying.

LIST OF PHOTOGRAPHS, FLOWCHARTS & TABLES:

Drying of tomatoes (flow chart):

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Dried tomato preparation:

FIG 1: Select fresh tomatoes and then

cut into pieces

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Dried fish preparation:

FIG 2: After a day, tomato started drying.

FIG 3: Washed clean fish with salt

as preservative

FIG 4: After a day fish was dried

partially

FIG 5: After 5 days fish was

completely dried