Food Chemistry

Food Chemistry

The study of chemical processes and interactions of all biological and non-biological components of foods.

Water

The most abundant constituent of food and the most significant substance for food safety, occurring in solid, liquid, and gas states simultaneously.

Water

only substance on Earth that occurs in all three physical states simultaneously

Forms of Water in Foods

• Free Water

• Absorbed Water

• Bound Water

Free Water

Water in foods that is lightly entrapped and easily pressed out, acting as a dispersing agent and solvent.

Absorbed Water

Water that associates through intermolecular hydrogen bonds around hydrophilic food molecules.

Bound Water

Water in food that is unavailable as a solvent, varying in amount based on protein content.

• Appearance

• Boiling Point of Water

• Freezing Point of Water

• Density of Water

• Viscosity of Water

• Surface Tension of Water

• Refractive Index of Water

• Dielectric Constant of Water

• Compressibility of Water

Physical Properties of Water

Appearance

Water is colorless, odorless, and tasteless liquid in its natural state.

Boiling Point of Water

The temperature at which water changes from liquid to vapor.

Freezing Point of Water

The temperature at which water changes from liquid to solid.

Density of Water

The mass per unit volume of water, about 1 gm/cc.

Viscosity of Water

The resistance to deformation at a given rate.

Surface Tension of Water

The tendency of water to shrink to minimize surface area.

Refractive Index of Water

Describes how fast light travels through water.

Dielectric Constant of Water

Measures how easily water is polarized by an electric field.

Compressibility of Water

The change in volume of water with changes in temperature and pressure.

Function of temperature and pressure and its effect on the substance.

• Amphoteric Nature of Water

• Auto-protolysis of Water

Chemical Properties of Water

Amphoteric Nature of Water

Water can act as both an acid and a base.

Auto-protolysis of Water

The ionization of water where it deprotonates to form a hydroxide ion.

Water Hardness

The measure of the concentration of calcium and magnesium in water.

• Hard Water

• Soft Water

Two Types of Water Hardness

Hard Water

Water high in dissolved minerals like calcium and magnesium.

Hard Water

known as calcareous water.

• Temporary Hard Water

• Permanent Hard Water

Types of Hard Water

Temporary Hard Water

consists primarily of calcium and bicarbonate ions

Permanent Hard Water

consists of high concentrations of anions, like sulphate ion

Soft Water

Water with low concentrations of dissolved salts.

• Tap Water

• Spring Water

• Mineral Water

• Purified Water

• Distilled Water

• Sparkling Water

Types of Water

Tap Water

Water from the faucet, may or may not be suitable for drinking.

Mineral Water

Water naturally containing minerals.

Spring Water/Well Water

Water from underground sources that naturally surface.

Purified Water

Water that has undergone purification treatment.

Distilled Water

Water where all minerals and salts have been removed.

Sparkling Water

Water that has undergone carbonation to make it fizzy.

• Food ingredient

• Agricultural and Primary Production

• Cleaning and Sanitation

• Processing Operations

Uses of Water in Food Production and Processing

Food ingredient

When water is used as an ingredient in food, it must be free from undesirable taste, odor, color and impurities that could be harmful to consumers and product quality.

Agricultural and Primary Production

The biggest use of water is in primary crop production (e.g. vegetables and farming) where it is used for irrigation purposes

Cleaning

refers to washing of the equipment, instruments, containers, plants, associated machinery, and even the personnel who handle raw or processed food.

Sanitization

refers to the reduction of microorganisms to the level that is considered safe from a public health viewpoint.

Sterilization

is the statistical destruction and removal of all living organisms, whereas disinfection refers to inanimate objects and the destruction of all vegetative cells (not spores).

Processing Operations

Water are used on several food processes such as, but not limited to, heating and refrigeration

• Heat Transfer

• Universal Solvent

• Solution

• Colloidal Dispersion

Functions of Water in Food

Heat Transfer

Water transfers and moderates the effects of heat in food processing.

Universal Solvent

Water is considered the universal solvent on Earth.

Solution

A homogeneous mixture where solute molecules are completely dissolved in the solvent.

• Suspension

• Emulsion

Two Types of Dispersion

Suspension

Mixing cornstarch and water results in a suspension in which the starch grains float within the liquid.

Emulsion

Another type of colloidal dispersion involves water-in-oil (w/o) or oil-in-water (o/w) emulsions

Colloidal Dispersions

Particles that do not dissolve homogeneously in water, forming suspensions or emulsions.

21 CFR 113.10

Regulation specifying attendance at an approved school providing relevant instruction for preservation technology.

21 CFR 113.40(i)

Regulation detailing equipment and procedures for thermal processing of foods considering critical factors like water activity.

21 CFR 113.81(f)

Regulation outlining additional factors to control to prevent the growth of microorganisms surviving thermal processes.

21 CFR 113.100(a) (6)

Regulation specifying record-keeping requirements for water activity (aw) determinations.

Moisture Content

is a measurement of the total amount of water contained in a food, usually expressed as a percentage of the total weight.

Carbohydrates

Biomolecules known as carbs or saccharides, the primary energy storage compounds in nature.

Monosaccharides

The monomers of carbohydrates, simple sugars like glucose and fructose.

Disaccharides

Carbohydrates formed by the dehydration synthesis of two monosaccharides.

Polysaccharides

Long chains of monosaccharides linked by glycosidic bonds, serving as energy storage compounds.

Starch

A carbohydrate mixture of amylose and amylopectin, the main form of stored sugars in plants.

Cellulose

A carbohydrate component of plant cell walls and a major part of wood and paper.

Chitin

A carbohydrate forming the exoskeleton of arthropods and a component of fungal cell walls.

Simple Carbs

Carbohydrates composed of one or two sugar molecules, found in refined sugars and natural sources like fruits.

Complex Carbs

Carbohydrates containing three or more sugar molecules, including starches and fiber-rich foods.

Refined Carbs

Processed carbohydrates with removed or altered natural fiber content.

Source of Energy

Carbohydrates are the primary energy source for the body, including sugars, starches, and dietary fiber.

Biological Recognition Processes

Sequences of carbohydrates linked to amino acids in immunoglobulins and peptide hormones for biological recognition.

Glycogen

The stored form of glucose primarily found in the liver and muscle.

Soluble Fiber

Draws in water and forms a gel-like substance while passing through the body.

Insoluble Fiber

Adds bulk to stools and helps alleviate constipation by moving things quicker through the digestive tract.

Triglycerides

Lipids that can increase with a sugar-rich diet, elevating the risk of heart disease.

Lipids

Molecules containing hydrocarbons, essential for the structure and function of living cells.

Fatty Acids

Made of a hydrocarbon chain ending with a carboxylic acid group, with a polar and nonpolar end.

Glycerolipids

Composed of mono-, di-, and tri-substituted glycerols, including triglycerides.

Glycerophospholipids

Key components of cell membranes, involved in metabolism and cell signaling.

Sphingolipids

Compounds with a sphingoid base backbone, involved in various cellular functions.

Sterols

Important components of membrane lipids, including bile acids and cholesterol derivatives.

Prenol lipids

Synthesized from five-carbon isoprene units, used in the production of natural products.

Saccharolipids

Compounds where fatty acids are linked to a sugar backbone, compatible with membrane bilayers.

Polyketides

Synthesized by polymerization of acetyl and propionyl subunits, with features similar to fatty acid synthases.

Triacylglycerols

Esters derived from glycerol and three fatty acids, commonly known as triglycerides.

Trans Fats

Form of unsaturated fat, occurring naturally in meat and dairy or artificially.

Omega Fatty Acids

Polyunsaturated fats, such as Omega-3 and Omega-6, essential for the body.

Omega-3 Fatty Acids

Include Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), important for health.

Alpha-linolenic acid (ALA)

A type of essential omega-3 fatty acid.

Phospholipids

Lipids that are major components of the plasma membrane and have both hydrophobic and hydrophilic parts.

Lipid Soluble Vitamins

Vitamins that are classified as "fat soluble" and include vitamins A, D, E, and K.

Lipids Metabolism

The process of synthesizing, degrading, and utilizing lipids in the body.

Emulsification of Fats

The breakdown of dietary fats into small particles to increase the surface area for enzyme action.

Pancreatic lipase

An enzyme that breaks down triglycerides into 2-monoglycerides during fat digestion.

Lipid peroxidation

The oxidative degradation of lipids by reactive oxygen species.

Protein

A macronutrient essential for building muscle mass, composed of amino acids.

Complete Proteins

Protein foods that contain all essential amino acids.

Incomplete Protein

Proteins that lack one or more essential amino acids.

Denaturation

Physical changes in a protein due to abnormal environmental conditions.

Amino acids

The building blocks of proteins, consisting of an amino group, a carboxyl group, a hydrogen atom, and an R group.

Zwitterion

A molecule with both positive and negative electrical charges, resulting in a net charge of zero.

Essential Amino Acid

Amino acids that cannot be synthesized by the body and must be obtained from the diet.

Nonessential Amino Acid

Amino acids that the body can produce even if not obtained from food.