Flavour Chemistry Overview

The combination of taste and odor perceived by our senses.

Chemicals in food that stimulate taste receptors on the tongue, leading to specific sensations.

The four primary taste sensations recognized by humans.

The sensation triggered by substances like vinegar or citrus fruits.

A complex sensation caused by a variety of compounds, often triggered by substances like coffee or dark chocolate.

A reduction in the sharpness or harshness of a taste, often achieved by lowering the acidity (pH).

Milk proteins binding to polyphenols in food, preventing them from interacting with proteins in the mouth, resulting in a smoother taste.

The sensation of burning or heat experienced in the mouth, often associated with spices.

Chemicals found in certain plants, like cabbage and mustard, that produce a pungent flavor when broken down.

The enzyme that breaks down glucosinolates in plants, producing pungent compounds.

A sugar substitute discovered by accident, it's 180 times sweeter than sucrose but unstable in high temperatures or outside pH range of 3-6. It must have a warning label for patients with PKU due to high phenylalanine content.

Derived from the bitter grapefruit, this sweetener is 1500-1800x sweeter than sucrose. It is costly, not used alone in food but masks bitterness in medicines.

The only artificial sweetener made from sucrose, it's 600 times sweeter than sucrose. It's safe, heat-stable and has a long shelf life.

This sweetener is 2000 times sweeter than sucrose and promotes Maillard browning reaction.

A naturally derived sweetener from the licorice root, it is 50-100 times sweeter than sucrose and used extensively in the Far East. It also has medicinal benefits, but may have side effects on kidneys and blood pressure.

Extracted from the leaves of Stevia rebaudiana, it's 300 times sweeter than sucrose and recently approved in the USA and EU.

Artificial sweeteners are chemical compounds that provide a sweet taste without the calories found in sugar. Some are made from natural ingredients, while others are synthetically produced.

The potential health effects of artificial sweeteners are still under investigation. Some studies suggest possible links to health issues, while others find them safe. It's crucial to consume these in moderation and consider individual health needs and sensitivities.

A protein extracted from the fruit of a West African tree, known for its intense sweetness - about 2000 times sweeter than sugar. It is also resistant to heat, making it suitable for use in various food products.

The ability to sense and perceive bitter flavors. This sensitivity stems from the need to avoid potentially toxic substances found in plants, which often contain bitter alkaloids.

Organic compounds found in various plants, often with a bitter taste, and often possessing nitrogen in a ring structure. Examples include nicotine, caffeine, cocaine, and quinine, some of which have medicinal properties.

A compound found in hops, responsible for the bitter taste in beer. It contributes a desirable and characteristic flavor component to the beverage.

A sensory experience characterized by dryness and constriction in the mouth, often a result of the interaction of proteins in saliva with polyphenolic compounds in food.

A taste sensation elicited by inorganic salts, predominantly sodium chloride. It's detected mainly on the side tip of the tongue. Adding salt enhances food flavor, but Na ions naturally present in food also play an important role.

A taste sensation attributed to the presence of acids, primarily organic acids like citric and malic acid. Foods rich in these acids include fruits, vinegar, and dairy products like yogurt.

A savory, delicious sensation associated with the compounds inosine monophosphate (IMP) and monosodium glutamate (MSG).

A breakdown product of adenosine monophosphate (AMP), which accumulates as ATP is used in muscle after death.

Naturally present in muscles at low levels, derived from protein breakdown during the aging process of meat.

A mixture of equal parts IMP and MSG tastes 20 times stronger than the same amount of either alone.

The sense of smell, providing detailed information about a potential foodstuff.

Three major groups of compounds contribute to the flavor of meat: MSG and IMP, dipeptides, and...

The ability to detect and differentiate between an overwhelming variety of substances in food and everyday life.

While taste provides a general assessment, it is odor that provides the specific details of our food experience.

The characteristic taste and aroma of a fruit is a combination of taste, which includes sweetness from sugars, sourness from acids, and sometimes astringency from polyphenolics, and smell, which is a complex mix of up to 200 volatile compounds.

The enzyme lipoxygenase is responsible for the flavor of many vegetables. When vegetables are damaged during harvesting, this enzyme reacts with unsaturated fatty acids in the cell membranes, producing off-flavors.

Blanching, a short-heat treatment, deactivates lipoxygenase in vegetables, preventing the development of off-flavors.

Onions and garlic contain odorless compounds when they're whole but release strong flavors when crushed or sliced. This is because the enzyme alliinase is activated, which reacts with the compounds to produce volatile aroma molecules.

Thiopropionaldehyde S-oxide, a compound produced when onions are sliced, is responsible for the lachrymatory (tear-inducing) effect.

Garlic, consumed daily for a few months, has been shown to reduce blood cholesterol levels. Allicin, a sulfur compound in garlic, is known for its antibacterial, antithrombotic, and anticancerogenic properties.

The increasing demand for diverse flavorings in the food industry has led to the development of synthetic flavorings, which are typically chemically-synthesized compounds that mimic the flavor of natural ingredients.

Sulfides and pyrazines are key contributors to the natural flavor of chocolate. A patented chocolate-flavoring formulation containing these compounds is commercially available.

Natural flavors are derived from natural sources like spices, fruits, vegetables, or fermentation products, and their primary function is to provide flavor. Artificial flavors are made from components that don't meet this definition, meaning they are not derived from natural sources.

The Maillard reaction is a chemical process between sugars and amino acids that occurs during cooking, particularly in browning food. It produces hundreds of flavorful compounds, contributing to the taste and aroma of cooked food.

Nitrite reacts with the iron in muscle myoglobin, oxidizing it to the iron(III) state, creating metmyoglobin (MMb) and nitrogen oxide as byproducts. This reaction is represented by the equation: Fe2+ + NO2- + H+ → Fe3+ + NO + OH-

The nitrogen oxide produced by the nitrite reaction further interacts with metmyoglobin (MMb), forming nitrosyl metmyoglobin (MMbNO).

Nitrosyl metmyoglobin (MMbNO) is quickly reduced by muscle tissue to nitrosyl myoglobin (MbNO), the characteristic red/pink pigment seen in uncooked bacon and ham.

The gas phase of wood smoke contains formaldehyde (HCHO), which has antimicrobial properties. It was traditionally used for preserving meat and fish but is rarely used today due to the presence of carcinogens in wood smoke.

Sulfur dioxide (SO2) is used in winemaking to control the growth of unwanted microorganisms. A typical level of 100 ppm is used to maintain the desired wine quality.

Sodium chloride (NaCl) was the first antimicrobial substance used in food preservation. It was primarily used as a preservative and flavoring agent.

Nitrates or nitrites are essential components of salt mixtures used in curing and preserving meat products, like bacon and ham. They contribute to the characteristic red/pink color in preserved meat.

Adding ascorbic acid to the curing-salt mixture helps reduce the formation of carcinogenic nitrosamines during meat preservation.

Preserving food using only one antimicrobial method is rare. Combining multiple mild methods like salting, adding nitrites, and heat processing is common to maximize microbial inhibition while minimizing adverse effects on food quality.

Microorganisms require similar nutrients to humans, often thriving in moderate pH and temperatures found in many food products.

Preservatives are chemicals used to deter unwanted microbial activity in food. They help extend shelf life and ensure food safety, often used in combination with other preservation methods.

Canning and refrigeration have reduced the reliance on salting as a primary preservation method. However, salt remains crucial for flavoring and influencing water activity in food.

Food science aims to ensure food safety through various methods, including antimicrobial procedures. Microbiologists contribute significantly to this field, particularly by addressing concerns regarding pathogenic bacteria and toxin production.

Sulfur dioxide is recognized as an allergy trigger, particularly for asthmatics, inducing allergic reactions in some individuals.

Sulfur dioxide reacts with thiamin (vitamin B1), depleting its levels in food products, particularly in vegetables exposed to sulfite solutions prior to processing.

Sodium benzoate, a more soluble form of benzoic acid, is commonly used as a food preservative. It's generally considered safe at standard levels (0.05-0.1%), with no adverse effects documented in humans.

Sorbic acid effectively prevents the growth of mold, a common food spoilage threat.

Acetic acid, a natural component of vinegar, is increasingly used to control mold growth in bread, serving as an effective inhibitor.