Food

FOOD

Food is any substance consumed to provide nutritional support for the body

It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals.

Most food has its origin in plants. Some food is obtained directly from plants; but

even animals that are used as food sources are raised by feeding them food derived from plants. 

Some foods not from animal or plant sources include various edible fungi, especially mushrooms.

Food chains and food webTaste Perceptions of food

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Food chains, food web and food supply

Food chains

Food web

Food chain pyramid

Pyramids of biomass

pyramids of numbers

Taste perception

Sweet Sour Salty Bitter Umami

Sweet

Generally regarded as the most pleasant taste, sweetness is almost always caused by a type of simple sugar such as glucose

Glucose

Sour Sourness is caused by the taste of acids Sour foods include citrus,

specifically lemons, limes, and to a lesser degree oranges.

Salty Saltiness is the taste of alkali metal ions such

as sodium and potassium. There are many different types of salt, with

each having a different degree of saltiness, including sea-salt, fleur de sel, kosher salt, mined salt, and grey salt. 

Bitter Bitterness is a sensation often considered

unpleasant characterized by having a sharp, pungent taste. 

Dark, unsweetened chocolate, caffeine, lemon rind, and some types of fruit are known to be bitter.

Umami Umami, the Japanese word for delicious, is

the least known in Western popular culture but has a long tradition in Asian cuisine.

Umami is the taste of glutamates, especially monosodium glutamate 

Cuisine Many cultures have a recognizable cuisine, a specific set

of cooking traditions using various spices or a combination of flavors unique to that culture, which evolves over time.

Some popular types of ethnic foods include Italian, French, Japanese, Chinese, American, Cajun, Thai, and Indian cuisine.

How we taste food

Food and Nutrition

Nutrition

CARBOHYDRATES PROTEINS FATS VITAMINS and MINERALS WATER

Nutrition ᴥ It is the scientific study of food and its relation

to health.ᴥ Food has been used to treat in conjunction

with or with or without medicine.ᴥ It is a combination of processes by which all

parts of the body receive and utilize materials.ᴥ Age, religion, economic status, agriculture,

education are some factors which affect human nutrition.

ᴥ Functions of nutrients include supplying energy to the body, building and repairing body tissues and regulating body processes.

• These are the body’s main source of energy

• a) Simple carbohydrates (sugar)This sugar is found naturally in some foods like fruits and milk . The sugar which we use is derived from these natural sugars .

CARBOHYDRATES

b) Complex carbohydrates (starch) These carbohydrates are found in foods

derived from plants like potatoes.

c) It is digested in the mouth and further by pancreatic and intestinal enzymes.

d) Sources include cereals, vegetables, jiggery etc.

PROTEINSa) Proteins help to repair and build the body

tissues. It also regulates body processes as hormones, antibodies, enzymes etc.

b) It is digested in the stomach and the small intestine.

c) Complete proteins contain all essential amino acids and are of animal origin.

d) Incomplete proteins are deficient in one or more amino acids

e) Protein deficiency results in impaired healing weight loss etc.

f) Sources include eggs, meat, fish, poultry, pulses, soybeans etc.

FATS• These are concentrated forms

of energy stores. It is present in different forms like cholesterol, omega fatty acids etc.

• They supply heat, insulation, padding for vital organs etc.

• It is digested by pancreas and the intestines.

• Plant sources include edible nuts and oilseeds.

• Animal sources include whole milk, eggs, lard, fish etc.

• Deficiency of Fats causes growth failure and skin problems.

VITAMINS• These are a group of chemicals which are

vital for the body. These chemicals are found in green leafy vegetables, fresh fruits etc. A deficiency  of these in our diet will cause certain diseases .

a) Fat soluble vitamins- A,D,E,K. These require fat for there absorption and are stored in the body.

b) Water soluble vitamins- B complex group, C. These are sensitive to environmental conditions and are not stored in the body.

c) Sources include vegetables, fruits, nuts etc.

Diseases caused by deficiency of certain vitamins 

Vitamin Disease caused by the deficiency of that vitamin

Treatment

Vitamin A Night blindness Include leafy vegetables , ripe yellow vegetables, carrots, papayas and milk in the diet

Vitamin B Redness of the tongue Roughness of the skin

Include pulses, leafy vegetables and milk in the diet

Vitamin C Bleeding of the gums

Include amla, lemons, oranges and sprouts in the diet

Vitamin D Bending of the bones of the legs Bending of the back

Expose the body to the early morning sun. Include milk in the diet

MINERALS

• These are inorganic elements occurring as salts.

• These help to build body tissues regulate body fluids.

• These are required in small quantities and are vital to the body.

• Major minerals like calcium sodium are required in large amounts.

• Minor minerals like iron, sulphur are required in small amounts.

• Trace elements like iodine, zinc, fluorine are required in micro amounts.

• Sources include vegetables, water etc.• Deficiency symptoms are varied.

WATER

a) 65% of an adults body consists of water.

b) It is found as intracellular, extra cellular and intercellular fluid.

c) It acts as a solvent, transports nutrients and acts as a lubricant. It also regulates body temperature.

d) Sources include food , metabolic water, ingested water

e) Deficiency (dehydration) causes fatigue, headache etc.

Sweetschocolate

Butter Oil margarine

Meat, BeansEggs, Nuts

Milkyogurt

Fruits Vegetables

Bread Pasta, Rice

SafetyFoodborne illness, commonly called "food

poisoning", is caused by bacteria, toxins, viruses, parasites, and prions.

Some people have allergies or sensitivities to foods which are not problematic to most people. This occurs when a person's immune system mistakes a certain food protein for a harmful foreign agent and attacks it.

Human diet was estimated to cause perhaps around 35% of cancers in a human epidemiological analysis by Richard Doll and Richard Peto in 1981

Important Organisms Norwalk-like viruses Campylobacter Salmonella E. coli O157:H7 Clostridium botulinum Shigella spp Toxoplasma Emerging organisms

Norwalk-like Viruses Norovirus; Caliciviridae

familyMost common foodborne agent23 million cases annually

SourcesPerson-to-person

Shed in human feces, vomitusOutbreaks in daycares, nursing homes, cruise ships

Contaminated shellfish

Small infectious dose Signs

12-48 hours post-exposureNausea, vomiting, diarrhea, abdominal crampsHeadache, low-grade feverDuration: 2 days

Food handlers should not return to work for 3 days after symptoms subside

Campylobacteriosis Leading cause of bacterial

diarrhea Sources

Raw or undercooked poultry Non-chlorinated water Raw milk Infected animal or human feces

Poultry, cattle, puppies, kittens, pet birds

Clinical signs Diarrhea, abdominal cramps,

fever, nausea Duration: 2-5 days

Salmonellosis* Gram negative bacteria* Many serotypes can

cause disease* S. enteritidis and

typhimurium 41% of all human cases Most common species in

U.S.

* 1.4 million cases annually 580 deaths

* Signs Onset: 12-72 hours Diarrhea, fever, cramps Duration: 4-7 days

* Sources* Raw poultry and

eggs* Raw milk* Raw beef* Unwashed fruit,

alfalfa sprouts* Reptile pets: Snakes,

turtles, lizards

E. coli O157:H7

Sources• Undercooked or raw

hamburger; salami• Alfalfa sprouts; lettuce• Unpasteurized milk, apple

juice or cider• Well water• Animals: Cattle, other

mammals

Sequela• Hemolytic Uremic Syndrome

(HUS)Acute kidney failure in childrenLife threatening

Enterohemorrhagic Escherichia coli (EHEC)

Surface proteins; toxin

Signs• Watery or bloody diarrhea,

nausea, cramps• Onset: 2-5 days• Duration: 5-10 days

Toxoplasmosis

Toxoplasma gondii- intracellular protozoan 112,500 cases annually Pregnant women/immunocompromised at

greatest risk Sources

Infected cats, soil, undercooked meat Signs

Fever, headache, swollen lymph nodes

On Farm Strategies At the Slaughter Plant In the Home

Prevention and Control of Diseases

On Farm Strategies Testing and removal for Salmonella

Serologic, fecal culture, hide culture

Vaccinating Many serotypes Varying effectiveness

Minimize rodents, wild birds Isolation of new animals

decrease the chance of spread

At the Slaughter Plant FSIS (Food Safety Inspection Service)

identified target organisms Salmonella and E. coli

Control points Removal of internal organs Minimize contact between carcasses Proper movement through facilities Chilling Cooking processes (proper time,

temperature)

In the Home

Drink pasteurized milk and juices

Wash hands carefully and frequently After using the bathroom Changing infant’s diapers Cleaning up animal feces

Wash hands before preparing food

In the Home

Wash raw fruits and vegetables before eating

After contact with raw meat or poultry Wash hands, utensils and kitchen

surfaces Hot soapy water

Defrost meats in the refrigerator

In the Home Cook beef/beef products thoroughly

Internal temperature of 160oF

Cook poultry and eggs thoroughly Internal temperature of 170-180oF

Eat cooked food promptly

Refrigerate leftovers within 2 hours after cooking

Store in shallow containers