Acid foods - foods with enough natural acid, or with enough additional acid such as vinegar to allow processing in a boiling water canner. Includes all fruits except figs; most tomatoes; fermented and pickled vegetables; relishes; and jams, jellies, and marmalades.

Additive - a chemical substance intentionally added to food (as during processing).

Anti-darkening agent - a substance that keeps certain fruits and vegetables from turning dark when it is cut and exposed to air.

Ascorbic acid - the chemical name for vitamin C; lemon juice contains large quantities of ascorbic acid and is commonly used to prevent browning of peeled, light colored fruits and vegetables.

Blanching - heating food, such as raw vegetables, for a certain length of time to stop the action of enzymes.

Boiling water canner - a large standard-sized lidded kettle with jar rack, designed for heat-processing 7 quarts or 8 to 9 pints in boiling water.

Canning - a method of preserving food in air-tight vacuum-sealed containers and heat processing sufficiently to enable storing the food at normal home temperatures.

Carbon dioxide - a colorless gas that helps make batter fluffy and rise during baking.

Citric acid - a form of acid that can be added to canned foods; increases the acidity of low acid foods and may improve the flavor and color.

Cross-contamination - refers to the mixing of cooked food with raw meat or its juices, allowing bacteria to be transferred from the raw food or its juices to the cooked food.

Cut across the grain - cut perpendicular to meat fibers.

Cut in - to mix fat, such as shortening or butter, into a flour mixture using a pastry blender or two knives in a scissor-like manner.

Double boiler - two pans with one sitting inside the other so that contents in the pan on top are heated by the boiling water in the pan on the bottom.

Dry pack - fruit frozen with no sugar or liquid added.

Enzyme - a special protein found in small amounts in all plants; promotes ripening in fruits and vegetables.

Fermentation - changes in food caused by intentional growth of bacteria, yeast, or mold. Good bacteria ferment natural sugar to lactic acid; sauerkraut, dill pickles, vinegar, yogurt, and cheese are fermented products.

Food industry - all business operations that are involved in getting the food produced in the farmer's field to the consumer's dinner plate.

Foodborne illness - an illness caused by eating food contaminated by microorganisms due to improper storage, handling, or cooking of the food; characterized by vomiting and diarrhea.

Food scientist - develops new food products that satisfy the consuers' wants and needs.

Freezer burn - the loss of moisture from food during freezing, resulting in surface texture changes on the food; dry, grainy-textured whitish or brownish spots are visible and the food's flavor decreases in quality.

Fruit browning - the darkening of light-colored fresh fruit that is caused by a reaction between the oxygen in air and enzymes in the fruit.

Gluten - a protein in flour which, when a dough is kneaded, helps hold in the gas bubbles formed by the leavening agent so the dough will rise.

Head space - the unfilled space above food or liquid in jars; allows for food expansion as jars are heated, and for forming vacuums as jars cool.

Heat processing - treatment of jars with sufficient heat to enable storing food at normal home temperatures; sterilizing jars and the food they contain in a pressure or boiling water bath canner to destroy microorganisms.

Hot pack - heating of raw food in boiling water or steam and filling it hot into jars.

Jam - made from crushed or ground fruit, it tends to hold its shape but generally is less firm than jelly.

Jelly - a clear fruit juice product that is soft and somewhat elastic, yet firm enough to hold its shape when turned out of its container.

Knead - to work dough with hands by folding and pressing.

Low-acid foods - foods which contain very little acid; acidity is insufficient to prevent the growth of bacterium Clostridium botulinum. Jars of low-acid foods must be heat processed in a pressure canner.

Moisture- and vapor-resistant - a material for freezing that does not let moisture or flavor escape.

Pastry blender - blends fat and flour; two knives can be used.

Pectin - a natural substance in ripe fruits, such as apples, that gels when in the right concentration with sugar and acid; available commercially in powdered and liquid forms.

Pickling - the practice of adding enough vinegar or lemon juice to a low-acid food to make it more acid; preserving food, especially cucumbers, in a solution of brine or vinegar, often with spices added.

Pressure canner - a specifically designed metal kettle with a lockable lid used for heat processing low-acid foods. These canners have jar racks, one or more safety devices, systems for exhausting air, and a way to measure or control pressure.

Prick - to make small holes in the surface of a food with the tines of a fork; an unfilled pie dough is pricked all over so it bakes without blistering or rising.

Raw pack - the practice of filling jars with raw, unheated food; acceptable for canning low-acid foods, but allows rapid quality losses in acid foods heat processed in boiling water.

Recyclable - a product that can be recycled by a commonly available industrial process; by practical definition, products can be recycled only where facilities exist to handle them. Usually designated by the "chasing arrows" on packaging.

Saute - to cook briefly in a small amount of fat in a skillet until soft and glossy.

Sensory evaluation - evaluating a food by means of a taste panel to rate how a food looks, smells, tastes, and feels in a tester's mouth.

Sugar pack - a method of freezing fruit using dry sugar.

Unsweetened pack - fruit frozen with no added sugar.

Vacuum - reflects how thoroughly air is removed from within a jar of processed food; the higher the vacuum, the less air is left in the jar.

Venting - forcing air to escape from a jar by applying heat, or permitting air to escape from a pressure canner before closing the vent or putting on the weighted gauge. Also called exhausting.


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