Food Science Terms - G

Galactose: Monosaccharide occurring in both levo (L) and dextro (D) forms as a constituent of plant and animal oligosaccharides (lactose and raffinose) and polysaccharides (agar and pectin). Galactose is the sugar derived from digesting lactose (‘milk sugar”). 

Galacturonic acid: Constituent of the pectin molecule. 

Ganache: Ganache is a chocolate mixture made by boiling cream and combining chopped semisweet chocolate then stirring until smooth. Ganache can be used as a cake glaze or beaten until fluffy and used as a filling or as the base for truffles and other chocolate confections. 

Glucono-delta-lactone: Transforms slowly into gluconic acid and thus retards the lowering of the pH and of gelation respectively. 

Gel: network formation of long-chain molecules which trap water to form a semi-solid material

Gel power: Measure of the ability of the pectin to gel a sugar solution. 

Gelatin: protein derived from collagen, which dissolves in water and forms a gel on cooling, then melts at body temperature. Alternative spelling is gelatin

Gelatinization: when protein or carbohydrates turn a liquid into a gelatin or jelly. The swelling and rupturing of starch grains due to heat and moisture

Gellan: vegan gelling agent (gelatin substitute) produced by the bacterium Sphingomonas elodea; used in milk 

Gelling agents: Used to form a jelly so providing texture to a product. 

Gelling speed: Time after which the gelation starts at a defined temperature. 

Gelling sugar: For producing jams and jellies in the household. Composition: sugar, pectin, acid. 

Gelling temperature: Temperature at which the gelling starts during cooling. 

Genetic modification: alteration of genetic material to artificially produce a desired characteristic, outcome, resistance or novel trait

Glazes: Glazes are used to give desserts a smooth and/or shiny finish. Cake glazes can be water icing, melted chocolate in combination with cream, butter and/or sugar syrup, or fondant. 

Glucogenesis: Synthesis of glucose from non-carbohydrate sources such as fats or proteins. This occurs when the glycogen supply in the liver is exhausted. 

Glucose: simple sugar (Monosaccharide sugar) originating in plants and used in animals to carry energy throughout the body, just as sucrose is the main carrier of energy throughout the plant. It is the main source of energy in the body, and the preferred fuel in the brain. It is prepared industrially by the hydrolysis of starch. (See Sucrose). 

Glucose syrup: Decomposed starch syrup, containing various types of sugar. 

Glutamate: An amino acid. It is necessary for metabolism and brain function, and is manufactured by the body. Glutamate is found in virtually every protein food we eat. In food, there is "bound" glutamate and "free" glutamate. Glutamate serves to enhance flavors in foods when it is in its free form and not bound to other amino acids in protein. Some foods have greater quantities of glutamate than others. Foods that are rich in glutamate include tomatoes, mushrooms, parmesan cheese, milk and mackerel. 

Gluten: protein found in wheat, responsible for elastic qualities in dough and chewy texture in bread. Also responsible for the characteristic crumb structure to bread

Glycemic Index: Ranks foods on how they affect blood glucose levels in the two or three hours after eating. Carbohydrates with high GI numbers increase blood sugar rapidly. Carbohydrates that produce a lower more constant insulin response within the body are termed low GI foods and usually possess numbers under 60. 

Glycerin: Syrupy type of alcohol derived from sugar which is used in food flavorings to maintain desired food consistency. 

Glycerol: Colorless, odorless, syrupy liquid chemically, an alcohol, that is obtained from fats and oils and used to retain moisture and add sweetness to foods. 

Glycogen: Like starch, this is a polysaccharide of glucose, but found in animals instead of plants. This is the form in which glucose is stored in muscles and in the liver. 

GMO (Genetically Altered Organism): The transfer of genetic material from one organism to another. Can include transgenic, but also refers to genes altered within the same species. 

Good Manufacturing Practices (GMP, GMPs): System of ensuring a safe environment in which to carry out the processing of food. This includes: ensuring that rodents, birds and insects cannot enter the facility, ensuring that light bulbs are not exposed, ensuring that open vats cannot be contaminated from overhead, etc. 

Grading: Sorting of unlike lots of the same product into uniform categories, according to quality standards. 

Granulated Sugar: Used to describe ordinary table sugar as it is most commonly used in the household and in industry. This particular sugar is a disaccharide sucrose, produced in all green plants. 

GRAS - Generally Recognized as Safe: Substances added to foods that have been shown to be safe based on a long history of common usage in food. 

Gray: Unit that measures the radiation dose (Gy). International health and safety authorities have endorsed the safety of irradiation for all foods up to a dose level of 10,000 Gy (10 kGy). One gray equals one joule of energy absorbed per kilogram of food being irradiated. 

Guar gum: Substance made from the endosperm of seeds of the guar plant which acts as a stabilizer in food systems. Is found as a food additive in cheese, including processed cheese, ice cream and dressings. Provides products with high viscosities. 

Gumming: Formation and accumulation of a fat insoluble sticky material resulting from continued heating of fats and oils. The gummy material is produced by oxidation and polymerization of the fat and represents fat breakdown products which collect on heating surfaces. 

Gustatory system: system responsible for sense of taste and flavor; it includes the mouth, tongue and taste buds

Gypsum: Common mineral sometimes added to water to make it simulate high-quality British brewing water. 

Gyrofrequency: Frequency at which the ions revolve in a magnetic field. 



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