Importance of Food Chemistry

• Food is essential for humans, especially with population increase and climate change.
• Providing enough good quality food is a major challenge for agricultural and food scientists.
• Efforts are focused on increasing food quantities, reducing spoilage, and meeting consumer needs based on age, income, habits, and health.
• Food industry science relies on chemistry, microbiology, and machinery engineering.
• Food chemistry studies the chemical composition, properties, and interactions of food components.
• Food chemistry is related to chemistry, biochemistry, botany, zoology, and microbiology.
• Food chemists need knowledge of these sciences to effectively study and control biological materials as human food.

Importance of Food Chemistry

• Identify the chemical composition and nutritional value of food components.
• Study the properties of different foods and their relationship to quality standards.
• Considered a part of quality assurance programs in all stages of food product manufacturing.
• Study the chemical changes of food products from raw materials to the final product.
• Estimate the extent to which a food product conforms to standard specifications.
• Determine the suitability and safety of food for human consumption.
• Detecting food adulteration and contamination, and monitoring the proportions of additives.
• Study the stability of food during storage to choose appropriate preservation methods.
• Develop food products using technological transactions in food production.

Food Nutrients Classification

• Six main categories of nutrients: water, fat, protein, vitamins, minerals, and carbohydrates.
• Nutrients are split into four groups: macro and micro nutrients.
• Also split into four groups: essential and non-essential nutrients.
• Also split into four groups: energy generating and non-energy generating nutrients.
• Also split into four groups: organic and inorganic nutrients.

Water

• Humans can only live a few days without water but can live weeks without other nutrients.
• Water is about 60% of the human body.
• The average person in a moderate climate needs 2-3 liters per day.
• Sources of water for the human body include drinking water (1-1.5 liters per day).
• Food water (900 ml per day).
• Metabolic water (300-350 ml per day).
• Water exits the body as sweat (700 ml), urine (1.5 liters), breathing (300 ml), and stool (100 ml).
• Thirst occurs with a 2% water loss, and a deficiency exceeding 10% is dangerous.
• A deficiency exceeding 20% leads to dehydration and death.
• Water serves as a solvent for dry food materials like sugar and salt in food production.
• Water is used to reconstitute dry materials like dried milk.
• Water extracts flavor compounds from drinks like tea.
• Water washes raw materials like vegetables and fruits for manufacturing.
• It is used during cooking.
• Water helps eliminate harmful substances and reduce cooking time for legumes and grains.
• Water is used to classify food products based on moisture content, such as soft, semi-hard, and hard cheeses.
• Also based on perishing speed (fast, medium, slow).
• Water aids in digesting food and transports nutrients within cells.

Macronutrients

• Carbohydrates are organic substances made up of carbon, hydrogen, and oxygen.
• They are widespread in plants.
• Carbohydrates are a primary energy source, constituting 40-80% of daily energy intake.
• They are found in cereals, bread, pasta, and grain-based foods.
• Sugars, dextrins, polysaccharides, cellulose, hemicellulose, gum, and pectin are basic carbohydrates that serve as a source of fiber.
• Scientific data shows that carbohydrates make up 1% of the human body.
• Divided into three main types based on polymerization degree: basic (mono- and disaccharides), oligo-saccharides, and poly-saccharides.

Simple Carbohydrates

• Simple or basic carbohydrates are known as monosaccharides (5-6 carbon atoms) and disaccharides (2 monosaccharide molecules).
• Di-saccharides and monosaccharides are sugars that digest quickly, taste sweet, and provide energy.
• Excessive consumption can be harmful, as they only provide a source of calories alone.
• "Mono" means "one," and "saccharide" means "sugar," forming "monosaccharide".
• Examples of monosaccharides are galactose, fructose (fruit sugar), and glucose (grape sugar).
• When measured against sucrose (cane/table sugar, sweetness level 100), glucose is 74, fructose is 173.
• Galactose = 32.
• Lactose = 16.

Oligo-saccharides

• Oligo- means "few".
• An oligo-saccharide carbohydrate contains 3-10 monosaccharide molecules and has a slightly sweet taste.
• Raffinose (galactose, glucose, and fructose) and stachyose (glucose, fructose, and two galactose units) are examples.
• Humans cannot digest these sugars, so they ferment in the lower digestive tract causing bloating.
• Naturally found in legumes, mallow and arugula.
• Can be used as texture enhancers, thickeners, or fat substitutes to improve food appearance.

Poly-saccharides

• Poly-saccharides have glycosidic linkages between several monosaccharides of up to 2000 units.
• Starch is a prevalent carbohydrate in cereals (wheat, rice, corn, oats, barley) and potatoes.
• Produced by green plants during photosynthesis as an energy reserve in the form of starch.
• Enzymes break down starch into glucose.
• Glycogen is animal starch, stored in small proportions in animals.
• Plant cell wall components (cellulose, hemicellulose, pectin, gums) are classified as dietary fibers due to their indigestibility.
• Consumable plant materials or carbohydrates resistant to digestion in the small intestine but fermented in the large intestine are also called dietary fibers.
• Fibers support bowel movements, lower blood lipids and glucose levels.
• Dietary fiber contains 10+ monomeric units not broken down by human enzymes.
• Includes: edible carbohydrate polymers naturally in food
• Including carbohydrate polymers produced physically, enzymatically, or chemically from food raw materials
• Shown to improve physiological health which in turn has a physiological benefit.

Sources of carbohydrates

• Sugars are found in natural and processed foods.
• Honey, fruit drinks, jam, jelly, sweets, and fruits are popular.
• Most people can tolerate complex carbohydrates like grains, legumes, and starchy vegetables in their diet.

Functions of carbohydrates

• Abundant sources of stored energy in the body.
• Support body processes and add sweetness to food.
• Act as dietary fibers.
• Non-digestible carbohydrates, whole grains, vegetables, and fruits reduce the risk of diabetes, colon issues, constipation, cancer, and obesity.
• Ribose pentose sugar (Carbohydrates) is also a component of cell compounds like nucleic acids and vitamin B2 (riboflavin).

Proteins

• Proteins are complex organic polymers containing nitrogen, carbon, hydrogen, and oxygen, while some contain phosphorus and sulfur.
• Each protein contains hundreds to thousands of amino acids.
• 20 naturally occurring amino acids make up proteins in the human body linked by peptide bonds.
• Protein properties are determined by the type and amount of amino acids.
• Amino acids consist of an R group, an acidic carboxylic group (-COOH), and a basic amine group (-NH2).
• The nature of the R group is what largely manages amino acid reactions.
• Amino acids are split into essential (the body cannot synthesize, include lysine, threonine, methionine, phenylalanine, leucine, isoleucine, tryptophan, valine, histidine and arginine in children) and non-essential (synthesized by the body, include alanine, glycine, cysteine, glutamic, aspartic, cysteine, serine, proline, tyrosine, and hydroxyproline).
• The nutritional value of dietary protein depends on its content of essential amino acids.
• Complete proteins contain all essential amino acids (eggs, meat, fish, milk, and poultry).
• Incomplete proteins don't contain all essential amino acids.

Protein Sources

• Proteins in the diet may be animal (eggs/meat/fish/milk/poultry and its products) or plant (legumes, grains and seeds).
• Adults need about 0.81 gram per kilogram of body weight per day.

Functions of Protein

• When carbohydrates run out, proteins provide energy and help transport and store molecules.
• Essential for growth and repair of body tissues (cartilage, nails, muscles, and hair).
• Many hormones, enzymes, and antibodies are also proteinaceous materials.

Lipids

• Lipids are organic compounds with carbon, hydrogen, and oxygen that don't dissolve in water.
• Dissolve in non-polar solvents - alcohols.
• Lipids form by the union of fatty acids (20) with glycerol and called glycerides.
• Acids differ in carbon chain length and number of double bonds.
• Fats differ according to the type of fatty acids present in the triglyceride.
• During esterification, the alcohol group of glycerol and the carboxyl group of the fatty acids form an ester bond and release a water molecule.

Fatty Acids Divided

• Saturated fatty acids (single bonds between carbon atoms such as butyric acid (4 carbon atoms)) palmitic acid (16 carbon atoms) and stearic acid (18 carbon atoms).
• Unsaturated fatty acids (double bonds between carbon atoms such as oleic acid (one double bond)).
• Linoleic acid is essential and has two double bonds.
• Linolenic acid has three double bonds.
• The higher the percentage of unsaturated fatty acids, the more fluid the fat or the lower the melting point.
• Oil is liquid at room temperature, and fat is solid. Fat may be called saturated fat.
• Cholesterol is a fat-like substance and an animal sterol (ergosterol is a plant sterol).
• Important in brain cells, hormones, and precursor of vitamin D.
• The liver produces bile salts necessary for fat absorption using cholesterol.
• Daily cholesterol consumption should not exceed 300-500 mg.
• Maintain the blood at 200 mg/100 ml.
• Increases may cause heart and artery diseases.

Functions of Lipids

• Lipids are essential to human health.
• The body absorbs humans consumes most fat (3.3% of stool).
• Fats and oils have a high energy density and contain fat-soluble vitamins (A, D, E, and K) and provide twice as many calories as carbohydrates and proteins.
• Fats provide essential fatty acids, act as energy storage, protect internal organs, and give food flavor.

Micronutrients

• Minerals are inorganic substances remaining as ash after burning food.
• Found in hard and soft tissues and represent about 4% of the human body.
• Obtained mainly through the diet in very small quantities.
• Minerals regulate water balance inside/outside cells (sodium and potassium).
• Minerals regulate the balance between bases/acids (sodium, potassium, calcium, chlorine, sulfur, phosphorus).
• Minerals regulate muscle contraction (calcium controls muscle tension, while sodium, potassium and magnesium control muscle relaxation).
• Important in hormone composition (iodine in thyroid hormone thyroxine).
• Enzyme composition (iron and copper in proteases).
• Vitamin composition (cobalt in vitamin B12).
• Minerals are divided based on importance to the human body.
• Major elements: Sodium, potassium, calcium, chlorine, sulfur, phosphorus, and magnesium.
• Minor elements: iron, zinc, selenium, copper, manganese, iodine, cobalt and fluorine.
• Elements present in small quantities such as barium bromine cadmium.
• Elements whose importance has not been proven (silver, aluminum, and lead).
• Food sources of minerals are most foods.
• Mineral deficiency symptoms do not occur except in cases of increased body needs (pregnancy and breast feeding).
• Factors that affect the extent to which the body benefits from minerals: phytic acid, oxalic acid, phosphates, tannins, and the chemical state of iron.

Vitamins

• Vitamins are complex organic nutrients needed in small quantities.
• Classified as water-soluble or fatsoluble vitamins.
• Although in very small quantities, vitamins are essential for normal body growth and continuity of life.
• The body cannot synthesize them except for vitamin D, so they must be obtained from food.
• Vitamins act as co-enzymes.
• Water-soluble vitamins are diverse and necessary for red blood cells, protein metabolism, and energy transfer.
• Include biotin, riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), cyanocobalamin (vitamin B12), thiamine (vitamin B1), and ascorbic acid (vitamin C).
• Fat-soluble vitamins include A, D, E, and K, obtained through fats.
• Foods like eggs, green leafy vegetables, and whole grains contain a variety of vitamins and minerals, but a variety of nutritious foods are needed.