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Introduction to Food

History of Food

Food Pyramid

Fruits and Vegetable: Health Aspects

Food Supplements

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Food Sources

Food can be obtained from almost any part of the world, except at certain extreme regions, such as in the very deep bottom of the ocean, or the highest peak of snowy mountains. Yet, many organisms are found to thrive in such extreme conditions using the metabolism system which is adapted to such conditions in a way that the organisms living in that habitat may find the suitable food sources. Human being, on the other hand, is a species of organism that can only survive under a non-extreme habitat, that is at a temperature, humidity, and oxygen level suitable for human survival. Human lung consumes oxygen at a level of 5 - 6 ml of oxygen per minute at an esophageal temperature of 28 degrees C, that is about 5% of whole-body oxygen uptake, according to a study carried out by Loer, Scheeren, and Tarnow (1997) as published in the journal of Anesthesiology, 86 (3):532-537. In a simpler figure, a person uses about 550 liters of pure oxygen per day. On the other hand, many microorganisms are capable of living anaerobically, no oxygen is required for their living. Human being also requires food, in a complex form, unlike many microorganisms that can metabolise simple forms of nutrition such as nitrate or ammonium. In general, human being can only use food in the organic chemical form, such as carbohydrate from plant sources, protein from plant and animal sources, fat or lipid from plant or animal oil. In this website, we will only discuss food sources, and anything about food, from the human being point of view, that is: we are, the creatures who live on earth and is positioned at the highest level of evolutionary hierarchy.

Vegetables

Food come from several sources, mainly from plants, animals, and as a result of microbial activities (fermentation). Plants and animals have become the main sources of food since the early pre-historic age when human being obtained food through hunting and gathering. Foods from plants contain nutritional compounds that are not found in the food originated from animals. Several nutrients specifically come from plants are: (1) vitamin C, (2) flavonoids (oxidants), (3) dietary fiber, (4) starch. Phytochemicals are some other compounds found only in plants. However, food from animals also complement the food from plants, such as several esential amino acids that can only be synthesised in animals. Therefore, a balanced diet should contain food of plant and animal origin.

Food from Plants

Tomato

The biggest part of our food may come from plants or the derivative products of plants. Food from plants may come from the seed, tuber, fruits, stem, leaves, and practically almost from any part of the plant. Plants contain carbohydrate, protein and lipid in their tissues. Carbohydrate mainly comes from the plant, either in the form tuber, fruits, seeds or any other form of plant carbohydrates. Sago plant (Metroxylon sagu) is a tropical palm tree which becomes the staple food for the people of New Guinea, including Papua (Indonesia), and Molucca (Indonesia). Its spongy stem contains carbohydrate, called sagu (or sago) which can be extracted from the centre of the stem and processed to become a sago flour used as the source of carbohydrate.

Carbohydrates are also abundant in many food sources, particularly in plants. Rice, potato, corn, cassava, sweet potato are some common examples of carbohydrate sources used as staple food in many countries. In addition to the use of such carbohydrate sources as staple food, as the source of carbon compound for body metabolism, carbohydrate is also processed for the production of food derivatives in the food industry.

 

Fruits and vegetables are the major sources of macronutrients, such as fiber, and micronutrients, such as minerals and vitamin C, thiamin, riboflavin, B-6, niacin, folate, vitamin A and E. In addition, many phytochemicals present in vegetableas and fruits, such as polyphenolic compounds, carotenoids, glucosinolate, are also of importance for metabolism as they also function as micronutrients. Fruits are not only the sources of carbohydrate, but also the source of many vitamins and metabolites required by human body. A good balanced human diet should consist of fruits as it contains macro- and micronutrients, such as sugar, vitamin, minerals, organic acids, water soluble pigments and many phytochemicals. Fruits are considered as a paramount importance part of the diet as low intake of fruits and vegetables is among top 10 risk of mortality, according to World Health Report in 2003. Fruits can be obtained from almost any part of the world, except from certain extreme regions such as the north and south pole.

Table 1. Macronutrients Composition of Some Vegetables and Fruits

Vegetable/Fruits

Water
(g/100g)

Protein
(g/100g)

Total Fat
(g/100g)

Carbohy-drate
(g/100g)

Energy
(kcal/100g)

Total sugars
(g/100g)

Vegetables

 

 

 

 

 

 

Potatoes, new,
Boiled, flesh and skin

78.1

1.9

0.1

19.6

82

0.9

Carrots, old, raw

89.0

0.5

0.4

7.7

34

7.2

Broccoli, raw

88.2

4.3

0.6

3.2

34

1.9

Cabbage, green, raw

88.4

2.4

0.2

4.1

24

4.8

Cauliflower, raw

91.1

1.5

0.9

4.4

30

2.9

Beans, green, raw

91.3

2.1

0.4

3.1

102

2.2

Tomatoes, raw

94.6

0.5

0.1

3.0

61

3.0

Lettuce, raw

96.1

1.2

0.1

1.4

11

1.4

 

 

 

 

 

 

 

Fruits

 

 

 

 

 

 

Bananas, raw

75.0

1.2

0.1

20.3

81

18.1

Apples, raw

86.2

0.6

0.5

9.7

40

9.7

Pears, raw

85.2

0.3

0.1

10.9

43

10.9

Grapes, green

82.7

0.7

0.2

15.2

62

15.2

Grapes, red

81.1

0.6

0.1

17.0

67

17.0

Strawberries

91.6

0.6

0.5

6.1

30

6.1

Oranges, flesh only

87.0

0.8

0.2

8.2

36

8.2

 

Table 2. Micronutrients Composition of Some Vegetables and Fruits

Vegetable/Fruits

Vit A
(µg/100g)

Potassium
(mg/100g)

Thiamin
(µg/100g)

Riboflavin
(µg/100g)

Vit C
(mg/100g)

Folate (µg/100g)

Vegetables

 

 

 

 

 

 

Potatoes, new,
Boiled, flesh and skin

N/A

377

0.13

0.01

7

21

Carrots, old, raw

1961

178

0.13

0.01

2

8

Broccoli, raw

N/A

397

0.15

0.12

79

95

Cabbage, green, raw

N/A

227

0.33

0.04

48

45

Cauliflower, raw

<4

252

0.06

0.09

56

55

Beans, green, raw

42

286

0.12

0.09

8

58

Tomatoes, raw

58

223

0.04

0.01

22

23

Lettuce, raw

10

222

0.14

0.05

1

60

 

 

 

 

 

 

 

Fruits

 

 

 

 

 

 

Bananas, raw

4

330

0.15

0.04

9

14

Apples, raw

2

100

0.04

0.04

6

<5

Pears, raw

2

105

0.03

0.04

3

6

Grapes, green

<4

217

0.04

0.01

2

6

Grapes, red

2

213

0.09

0.01

3

6

Strawberries

<4

170

0.02

0.02

57

61

Oranges, flesh only

9

122

0.22

0.03

52

33

Source: ©Crown copyright, Department of Health, United Kingdom (2013), read the full list: https://www.gov.uk/government/publications/nutrient-analysis-of-fruit-and-vegetables

 

Food from Animal

Cow

Food from animals complement food from plants. Meat, for example, provides energy, high quality protein, and essential micronutrients, such as iron, zinc, vitamin A, vitamin B-12. In general, it is known that meat, poultry, fish, eggs, and dairy products are complete protein sources and provide more protein (per gram) than vegetables, fruits, and grain, except some leguminous plant, such as lentils, beans, peas, and peanuts which contain plenty of proteins and thus become the sources of protein from plant. Plant products, on the other hand, are incomplete protein sources. For example, corn protein is low in lysine and tryptophan, and so is wheat which also provides only a small amount of lysine. Protein of animal product is considered as a high quality protein source and the best protein for human nutrition. Animal protein contains the full complement of essential amino acids and most resembles of amino acids present in human body.

Table 3. Macronutrient Composition of Some Animal Food Products

Name of food

Measure
(g)

Energy (kcal)

Protein (g)

Saturated fat (g)

Polyunsaturated fat (g)

Cholesterol (mg)

 

 

 

 

 

 

 

Beef, tenderloin

75

170

709

3.2

0.3

59

Lamb, American, fresh, ground, cooked

75

212

19

6.1

1.1

73

Chicken, broiler, breast, meat, roasted

75

119

25

0.4

0.3

64

Turkey, dark meat, roasted

75

139

19

1.6

1.0

82

Goat, roasted

75

107

20

0.7

0.2

56

Egg, fried

2 large

173

12

3.6

2.7

367

Cod fish, Atlantic, baked or broiled

75

79

17

0.1

0.2

41

Salmon, Atlantic, farmed, baked or broiled

75

155

17

1.9

3.3

47

Shrimp, boiled or steamed

30

30

6

0.1

0.1

59

Crab, canned, drained

71

71

15

0.2

0.3

63

Oysters, boiled or steamed

42

58

6

0.6

0.8

44

Source: Nutrient Value of Some Common Foods, Minister of Health, Canada, 2008. Read the full list: http://www.hc-sc.gc.ca/fn-an/nutrition/fiche-nutri-data/nutrient_value-valeurs_nutritives-eng.php

 

Table 4. Micronutrients Composition of Some Animal Food Products

Name of food

Measure
(g)

Vit A (RAE)*

Vit D (µg)

Vit B-12 (µg)

Folate
(DFE)

Vit E (mg)

 

 

 

 

 

 

 

Beef, tenderloin

75

0

0.5

2.04

5

0.2

Lamb, American, fresh, ground, cooked

75

0

0.6

1.96

14

0.1

Chicken, broiler, breast, meat, roasted

75

5

0.2

0.26

3

0.2

Turkey, dark meat, roasted

75

0

0.2

0.29

8

N/A

Goat, roasted

75

0

N/A

0.89

4

0.3

Egg, fried

92

236

1.9

1.62

54

2.7

Cod fish, Atlantic, baked or broiled

75

11

0.5

0.79

N/A

0.6

Salmon, Atlantic, farmed, baked or broiled

75

11

5.1

2.1

N/A

N/A

Shrimp, boiled or steamed

30

20

N/A

0.45

N/A

0.4

Crab, canned, drained

71

1

N/A

0.33

N/A

1.3

Oysters, boiled or steamed

42

23

3.4

14.71

N/A

0.7

RAE: Retinol Activity Equivalent
DFE: Dietary Folate Equivalent
N/A: data not available

Source: Nutrient Value of Some Common Foods, Minister of Health, Canada, 2008. Read the full list: http://www.hc-sc.gc.ca/fn-an/nutrition/fiche-nutri-data/nutrient_value-valeurs_nutritives-eng.php

 

 

Backgrounds

The quest for food has risen along with the increase of human population and dramatically changed the preference for food.