Introduction to food science and technology.

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3.1. FOOD PRESERVATION IN THE ANCIENT TIMES
 Food science - Oldest science in the world.
 Primitive man - gathered food as early as
1,00,000 years ago
 Palaeolithic Period (before 15,000 BC), or the
"Old Stone Age“ - man dried, roasted and
pounded some of his farm produce
 Used back of the cave to store food
 Mesolithic Period (Middle Stone Age, 15,000 BC)
- variety of food gathered much more diversified
 Food processing techniques also diversified - dry
fish, boil food and store for later use discovered.

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FOOD PRESERVATION IN THE ANCIENT TIMES contd....
 Neolithic Period (New Stone Age - 9,000 BC) -
man settled in villages, used tools to cultivate
 Alcoholic and acetic fermentations, extraction of
oil from plant materials started
 Baking of leavened bread introduced in
Northern Iran around 6,000 BC.

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FOOD PRESERVATION IN THE ANCIENT TIMES contd....
 Bronze Period (3,500 BC) - man started settling in cities
 Egyptian tombs left details of cultural and food habits of
that period
 Egyptians baked bread from cereals, prepared cakes
and pastries, fermented grapes to produce wine
 Brewed beer from cereals, especially barley, millet and
corn
 Butter and cheese making discovered probably in Iraq at
about 2,500 BC
 Bronze Period man learnt techniques of filtration, floatation
alcoholic, acetous, and lactic fermentations, developed
more types of flavourings.

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FOOD PRESERVATION IN THE ANCIENT TIMES contd....
 Iron Age (1,500 BC) - Sea and land trade
flourished
 Developments took place in agriculture, especially
in the Roman Empire (600-400 AD)
 Romans used brine to preserve vegetables and
sugary liquors for fruits
 Brewed wines, produced vinegar, baked bread,
prepared cheese and extracted oil from olives
 Food adulteration - rampant during the Roman
period
 Greeks - prepared and preserved fish and fish
products in different forms, prepared sausages.

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3.2. LAYING SCIENTIFIC FOUNDATIONS OF FOOD
PRESERVATION contd....
 Late in 18th century, during the French wars,
foundations laid for food processing industry to
start on strong scientific footing
 French forces making gains on war front
 Losing grounds to hunger
 France's governing body, the Directory, announced
prize of 12,000 Francs for:
 Discovery of satisfactory method of food
preservation by which it could be transported to
fighting army over long distance without
spoilage.

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3.2. LAYING SCIENTIFIC FOUNDATIONS OF FOOD
PRESERVATION contd....
 Nicolas Appert, a Paris confectioner and
distiller, emerged as winner
 Solved the problem and won the promised prize
on January 30, 1810
 In June, first ever book on food processing
published by Appert in French, titled
 "The Book of All Household: or the Art of
Preserving Animal and Vegetable Substances
for Many Years".

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3.2. LAYING SCIENTIFIC FOUNDATIONS OF FOOD
PRESERVATION contd....
 Appert discovered principle of sterilisation by
heat
 He described four important steps in his method
of food preservation as: -
 Place food to be preserved in bottles
 Close the bottles with utmost care
 Subject these bottles to the action of boiling
water for a certain length of time depending
upon the nature of food
 Remove the bottles from water bath at the end
of the prescribed period.

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3.2. LAYING SCIENTIFIC FOUNDATIONS OF FOOD
PRESERVATION contd....
 Today Appert's method of food preservation known
as canning
 Appert called the "father of canning".
 In his honour, canning sometimes referred to as
Appertising.

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3.3. DEVELOPMENTS IN OTHER TECHNIQUES
3.3.1. Cold Storage and Freezing Technology
 Cold storage and freezing - among oldest food
preservation techniques
 Chilling and ice storage known to Chinese since
800 BC
 Romans built cold storage warehouses and
supplied refrigerated foods as luxury items
 Freezing food in mountains and near the Arctic
Circle
 Vikings and Scandinavians preserved game and
fish on ice
 In mid 1800 ice-salt mixture found to freeze foods
more efficiently than plain ice.

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Cold Storage and Freezing Technology contd....
 Mechanical refrigeration system invented in late
19th century
 Provided basis for commercialisation of freezing as
food preservation technique
 Clarence Birdseye (USA) revolutionized freezing
industry by inventing and developing quick freezing
process and equipment in 1929
 Home refrigerator manufactured in 1913
 Fridge with a separate freezer compartment
appeared in 1939.

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3.3.2. Drying and Dehydration
 Drying practised for centuries using sun's energy
and air
 Development of dehydration equipment in
beginning of 19th century, moved inside factories
 Use of dehydration equipment with vacuum
enabled removal of moisture from delicate foods
without loss in quality
 Freeze-drying involves sublimation of ice from
frozen food
 Very helpful discovery for preservation of delicate
and heat sensitive foods e.g. instant tea, coffee
and fruit juices.

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3.3.3 Flour Milling
 Cereals contribute about half of all food produced
worldwide - Wheat mainstay of temperate climate
 Flour milling passed through numerous stages
from pounding, grinding between stones to the use
of pestle and mortar followed by roller mills
 Flour milling first food industry to be modernised
 Development of Ramelli's hand mill in 1588 for
grinding grains to produce flour, revolutinized this
industry
 By 1849, roller mills employed in Hungary
 Old stone mills (chakki), driven by animal power or
water, still visible in rural areas in Pakistan.

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3.3.4. Dairy Industry
 Process for producing evaporated milk patented in
1835
 Gale Borden in 1853 improved it by use of vacuum
 He initiated first process for condensing milk and
sealing it hermetically in 1856
 In 1878 Dr. Gustaf de Laval invented continuous
centrifugal cream separator in Sweden
 Had a far-reaching effect on dairy industry
 Developments in refrigeration and pure culture
techniques, a variety of better quality dairy
products started flooding the markets.

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3.3.5 Irradiation
 Artificially produced radiations like X-rays and
radioactivity of natural materials discovered by
Wilhelm Roentgen in 1895 and Henri Bacquerel in
1896
 In the middle of the 20th century these were
considered useful tools in food processing
 Earliest patent on application of X-rays to prolong
storage life of foods awarded in France in 1930.