Nutrition: Nutritional Value and Hygienic Features of Food Groups

Nutrition: Nutritional Value and Hygienic Features of Food Groups

# Food Classification

Food can be classified in many ways, with two common methods being:

• Classification by origin:

• Plant-based foods

• Animal-based foods

• Processed foods from natural ingredients

• Classification by nutritional value: This is a more common method, based on the content of major nutrients:

• Group 1: Foods rich in carbohydrates: Rice, corn, potatoes, cassava,…

• Group 2: Foods rich in protein: Meat, fish, eggs, milk, beans,…

• Group 3: Foods rich in lipids: Oils, butter, peanuts,…

• Group 4: Foods rich in vitamins and minerals: Vegetables, fruits,…

# Non-nutritious substances in food

Besides nutrients, food also contains non-nutritious substances with different effects:

• Non-nutritious substances with medicinal effects:

• Garlicin in garlic: Enhances immunity, reduces lipids, lowers blood pressure,…

• Polysaccharide in mushrooms: Improves resistance, prevents cancer,…

• Black fungus: Reduces cholesterol, detoxifies the body,…

• Non-nutritious substances with harmful effects:

• Antitrypsin, hemaglutin in soybeans: Causes food poisoning, affects digestion,…

• Avidin in raw egg white: Inhibits biotin absorption, causing vitamin deficiency,…

# Nutritional value and hygienic features of some main food groups

Meat

• Nutritional value:

• Warm-blooded animal meat (pork, beef, chicken, duck,…) contains many essential amino acids, minerals, lipids, vitamins,…

• White meat has a higher nutritional value than red meat.

• Protein digestibility of meat is 96%.

• Water accounts for 70-75% of meat weight.

• Protein accounts for 15-20%.

• Protein quality in meat:

• Contains a full range of essential amino acids, but Methionine content is not high.

• Collagen, elastin (found in meat, belly meat) are low-nutritional value proteins, poorly absorbed.

• Lipids in meat account for 1-30%, depending on the animal type, fat content, and location of the meat piece. Most of them are saturated fatty acids, so eating too much meat can increase the risk of cardiovascular disease, and increase blood lipids.

• Carbohydrates in meat account for 1%.

• Meat extracts (creatine, creatinine, carnosine) have a delicious flavor but very little nutrition, stimulating digestive juice secretion. Should not be used for the elderly, children, and people with gastric ulcers.

• Vitamins in meat: Rich in B vitamins (pork contains a lot of B1).

• Factors affecting meat quality:

• Type of meat

• Meat location

• Animal age

• Diet

• Storage, preservation

• Slaughter

• Transportation process

Fish

• Nutritional value:

• Protein accounts for 16-17%.

• Lipids account for 0.3-30.8%.

• Protein characteristics in fish:

• Low tissue bonding and loose connective tissue.

• No Elastin: easy to absorb, assimilate but not as tough and delicious as meat.

• Contains all essential amino acids but Methionine content is lower than meat and Lysine is in excess => Sailors who eat fish exclusively for a long time may develop Beri Beri (due to lack of vitamin B1), lack of Met.

• Lipid characteristics in fish:

• Contains 2 valuable nutrients: EPA and DHA.

• Unsaturated fatty acids account for over 90% => better than lipids in meat.

• Vitamin characteristics in fish:

• Rich in vitamins A, D, B but B1 is lower than meat => Sailors who eat fish for a long time may lack B1 (Beri-Beri disease).

• Extract characteristics in fish:

• Lower content than meat.

• Less stimulatory effect on gastric juice than meat.

• Fish preservation characteristics:

• High water content.

• Loose connective tissue, low tissue bonding.

• Unsaturated fatty acids over 90% -> easily oxidized.

• There is a mucous membrane of mucin, a polysaccharide -> Environment helps bacteria grow favorably.

• Easy penetration through many routes and from many different sources.

Fish is difficult to preserve and easily spoiled because:

• Bacteria that cause decay grow fastest at 15-20 degrees Celsius.

Shrimp

• Nutritional value:

• Protein content is high at 18-20%, lipid and carbohydrate content is not high, rich in vitamins and minerals.

• Hygiene properties:

• Crab lungs have many fungal species.

• Crab bodies have a lot of histidine -> When crabs die, they decompose into histamine, causing food poisoning.

• Crabs can be infected with parasites such as lung flukes -> Need to be boiled for half an hour.

Milk

• Nutritional value:

• The best way to supplement calcium is by drinking milk because Ca binds to casein -> easy to absorb.

• Breast milk is a food that lacks Fe => In the 5th month, babies need to eat more fruits and vegetables.

• For children, animal milk is of poor quality because it contains a lot of lactoglobulin, a high-allergy protein, unfamiliar to children -> Can cause allergies.

• Breast milk is better for babies because it contains IgA -> You should breastfeed your baby immediately after birth.

• Assessment of hygiene quality:

• Milk density: Is an expression of the nutritional components in milk.

• Acidity: Reflects the freshness of the milk.

Eggs

• Nutritional value:

• A golden food that provides nutrition, is the best protein source because it contains all the essential amino acids.

• Lipids in eggs contain a significant amount of cholesterol, but lecithin is more abundant -> regulates cholesterol, prevents cardiovascular disease and excretes cholesterol.

• Note:

• Do not eat raw egg whites because they contain the enzyme antitrypsin (affects the digestive system and protein absorption) and Avidin (deactivates biotin, long-term consumption will lead to biotin deficiency).

• Eggs should be heated to 80 degrees Celsius to decompose antitrypsin and separate the Avidin-Biotin complex.

Peanut oil

• Note on storage:

• 80% is unsaturated fatty acids -> easily oxidized -> When storing, it should be added with vitamin E.

Cashews

• Nutritional value:

• Provide many types of protein with high biological value (equivalent to eggs, milk) -> Good for diabetics.

Rice

• Storage:

• Maximum rice storage time is no more than 3 months.

Potatoes

• Nutritional value:

• Contains a lot of Lysine -> very good, especially for young children.

• Note:

• Solanin is a toxic substance in sprouted potatoes.

Vegetables

• Nutritional value:

• Vegetables have low protein content but high Lysine and Met -> Good combination with grains.

• Dietary fiber in vegetables:

• Soluble fiber: slows down blood sugar increase, reduces blood lipids.

• Insoluble fiber: prevents constipation (cellulose-pectin complex), detoxifies.

• The minimum amount of vegetables required in each daily diet is 300g.

Fruits

• Nutritional value:

• Fruits provide more intact vitamin C than vegetables because they do not contain the arcorbinase enzyme, so vitamin C is not lost when the fruit is bruised or cut into pieces.

# Conclusion

A balanced diet with a variety of food groups is essential for maintaining health. It is important to consider the nutritional value, hygienic characteristics, and storage methods of each food to maximize health benefits.