INTRODUCTION TO FOOD PROCESSING

GLOSSARY OF TERMS

The food industry has evolved its own terminology, which will not be familiar to those outside of the industry. This glossary has been prepared for those without any prior experience in the food industry - and who must feel that they "just landed in Greece with out a Greek dictionary" as they enter this course.

This listing is not complete. As terms arise that are unfamiliar to you, please bring them to the attention of the instructor so that they can be defined, and included in the next edition of this glossary

Governmental Agencies and Laws:

      FDA:  Food and Drug Administration

FD&C Act:  Food Drug and Cosmetic Act

FIFRA:  Insecticide, Fungicide and Rodenticide Act

EPA:  Environmental Protection Agency

OSHA:  Occupational Safety and Health Administration

USDA:  U.S. Department of Agriculture

Chemical Terms:

Amino acid:  organic compound compose of C, N, O which is the building block for proteins

Carbohydrate:  hydrate of carbon and hydrogen (CH₂O) including sugars, starch and polysaccharide

Lipids:  fats or oils, contain water insoluble components

Lipid Oxidation:   reaction of unsaturated fat with oxygen to produce undesirable flavors

Maillard browning:  reaction of reducing sugars with  amino groups to form brown colors.  Also produces a wide range of flavorful compounds that can have positive or negative effects on flavor acceptance.

Non-enzymatic browning:  chemical reaction (not catalyzed by enzymes) that produces a brown color in food - Maillard browning is an example

Rancidity:   there are two types, which can lead to confusion -

oxidative rancidity:  see lipid oxidation.  Most of the food industry uses the term  rancidity to  mean oxidative rancidity

hydrolytic rancidity:  hydrolytic cleavage of triglycerides to yield free fatty acids - associated with off flavors in dairy products.  When dairy people speak of rancidity they generally mean the off flavor resulting from lipolysis.  They use the term oxidized or tallowy to denote oxidative rancidity.

Cleaning and Sanitizing terms:

      Chelation:   complexing of metal ions with an organic compound - used to remove calcium and magnesium salts from water (water softening)

Chloramine:   an organic chlorine compound used as a sanitizer in the food industry

CIP (cleaned in place):  Circulation cleaning of food plant equipment without taking it apart.

COP (cleaned out of place):  Circulation of equipment parts in a tank washer after dissemble.  Generally the parts are placed in a tank and the parts are cleaned by circulation of the cleaning solution in the cleaning tank.

Emulsification:  dispersion of oil in water (or water in oil) generally requiring the adsorption of a molecule with solubilities in both (emulsifier) to achieve the dispersion

Iodophor:   a complex of iodine and an anionic surfactant to provide a sanitizer that is second in effectiveness to chlorine

Peptizing:  hydrolysis of the peptide bond

Saponification:  chemical hydrolysis of glycerides by the action of heat and sodium hydroxide

Sequestration:  conversion of insoluble salts (Ca/Mg) into soluble complexes through the addition of inorganic sequestrants - such as phosphates.

Surfactants:  a compound that reduces the surface tension of water

Sanitizing:   reducing the microbial population on the surface of equipment to a level where they do not contaminate the product

Sterilizing:  complete elimination of bacterial from the surface of equipment

Quaternary ammonium germicide:  a chemical compound used as a sanitizer, but not as effective as chlorine or iodine

Soil:  organic and inorganic deposits on equipment surfaces - may contain carbohydrates, proteins, fats/oils and/or mineral salts (primarily di-valent cations)

Wetting:   reducing the surface tension of the surface of soil to improve cleaning efficiency

Engineering terms:

 Drying:  removal of free water from a product - which may be accomplished by sun drying, oven drying, spray drying or freeze drying.

Unit Operations:  A single operation which is defined by physical principles:

Fluid flow:  the unit operation of moving liquid from one place to another.

Heat transfer:  the movement of energy in the form of heat into or out of a product.

      can be heating or cooling including boiling and freezing.

Mass transfer:  the transfer of mass into or out of a food system, generally requiring a change in state.  Does not refer to moving a product from one place to another.  example:  removal of water during drying; removal of whey from curds during cooking.

Mixing:   production of a homogenous mass.

Separation:  separation of components on the basis of size, density, etc.

Size adjustment:  reducing the size of particles in the food - such as by grinding, cutting or slicing.

Unit Process:  A combination of unit operations, generally encompassed in the single piece of equipment, to achieve a specific objective in food processing; examples:  Spray drying - combination of fluid flow, heat transfer and mass transfer; Pasteurization - combination of fluid, flow and heat transfer; Evaporation – combination of fluid flow, heat transfer and mass transfer

 Microbiological terms:

      Aerobic:   refers to an organism that requires air to grow 

Anaerobic:  refers to an organism that grows only the absence of air

Bacteria:  single cell prokaryotic organisms.  examples are Streptococcus, Bacillus, Salmonella

Bacteriophage:  a virus which destroys bacteria - of particular concern for fermented foods, where bacteriophages destroy starter organisms needed to make cheese and yogurt

Colony forming unit (CFU):  term used to enumerate bacteria by the plate count method.  Colonies on a plate may arise from more than one colony, which makes CFU more correct that "number of organisms".

D-value:   The time required to reduce the microbial population by one log cycle at a specified temperature.

Facultative anaerobe:  can grow under both aerobic and anaerobic conditions

Germination:  process which converts a spore into a vegetative state capable of reproducing

Mesophile:  an organism that grows at temperatures between 15-40 F

Mesophilic:  adjective for mesophile

Microaerophilic:  grows at reduced levels of oxygen - example is the growth lactobacilli in cheese

Mold:  micelled fungi like Rhizopus (black bread mold) or Penicillium (green bread mold or blue cheese mold)

Obligate anaerobe:  an organism must have complete anaerobic conditions to grow

Pathogen:  an organism capable of causing an infection (disease) or intoxication

Psycrhophylic:  likes to grow under refrigeration conditions

Psychrotrophic:  grows slowly under refrigerated conditions, but prefers to grow under mesophilic conditions

Spore:  a heat resistant, dormant body capable of germinating to produce vegetative cells

Spore former:  bacteria capable of forming spores

Sporulation:   the act of forming spores

Thermophylic:  an organism that required high temperature for growth (usually > 45 C)

Thermoduric:  Survive high heat treatment, but does not grow under such conditions - generally a spore-forming organism.

 Yeast:  a single cell fungi like Saccharomyces or Torula

Z-value:  the temperature required to reduce the D value by one log cycle.

Physical Terms: 

Colligative property:  a physical property that is dependent upon the number of molecules in the product, rather that the type of molecule - dictates freezing point depression, boiling point elevation.

Boiling point elevation:  increase in boiling point over that of water and dependent on the number of molecules in solution - important in drying and evaporation.

Freezing point depression:  a colligative property dependent upon the number of molecules present and is the degree to which the freezing point is lowered in respect to water - important in the processing of frozen desserts and frozen foods.

Glass transition temperature:  is the temperature at which a food product changes from a rubbery state to a solid glassy state.

Newtonian:  term used to describe the viscous behavior of a fluid - where the viscosity is independent of  both time and shear stress.

Non-Newtonian:  describes a fluid where the viscosity changes as a function of either shear stress or time.

Viscosity:  a measurement of the resistance of flow of a fluid product

Water activity:  an expression of the free water content of a food and expressed as the relative humidity of the product - important in defining chemical changes in food and in determining the ability of microorganisms to grow in food

Processing equipment terms: 

Centrifugal pump:  The rotation of an impeller forces the product into and out of the pump cavity - in which the fluid is accelerated centrifugally until it attains the tangential velocity close to the impeller tip.  The flow is controlled by the choice of impeller diameter and rotary speed of the pump drive.  For animated function diagram click here or here.

Clarifier:  generally a disc-type centrifuge that employs forces of 5 to 10 thousand times gravity and forcing the denser material to the outside.

Cream separator:  a disc type centrifuge in which the fluid  is separated into low and high density fluid streams that permits the separate collection of cream and skimmilk.

Evaporator:  a heated chamber under vacuum in which product is introduced  and water vapor is "flashed Off".  The water vapor is then cooled to condense it to water and removed from the system.  The product is concentrated within the chamber until it reaches the desired solids content.

Freeze dryer:  frozen product is placed in a high vacuum environment and water is removed by sublimation

Homogenizer:  a high shear positive pump that forces fluid though a very small orifice at very high pressure to form or reduce the size of an emulsion. The positive pump uses pistons or rotary lobes.  The fluid forms the seal between the rotating parts. 

Hydraulic cooker:  a continuous sterilizer, where the cans are rotating during the sterilization process

Microfiltration (MF):  a membrane process similar to UF, but with larger pores in the membrane than for UF - used to remove bacteria from fluids such as milk

Multiple effect evaporators:  2 or more evaporators placed in series to provide a means for the continuous concentration of a fluid product.

Pasteurizer:  equipment which provides a means of heating the product at a specific temperature for a specific time to kill all but the most heat resistant pathogenic organisms

HTST (high temperature short time): - used to define a continuous method of pasteurization, which for milk is 161.5°F for 15 seconds.  Times and temperatures for other products varies as a function of their viscosity.

UHT (ultra-high temperature):  used to define a very short time pasteurization or sterilization process when the temperature exceeds 190°F.

Plate heat exchanger:  A heat exchanger constructed of plates so that the heating medium and  product are located on opposite sides of the same plate and flow in counter-current.

Positive pump:  Consists of a reciprocating or rotating cavity between two lobes or gears and a rotor.  Fluid enters by gravity or a difference in pressure and the fluid forms the seals between the rotating parts.  The rotating move of the rotor produces the pressure to cause the fluid to flow.  For more information click: animated lobe pump 1, animated lobe pump 2, lobe pump diagram, lobe pumps, or progressing cavity pump.

Reverse osmosis (RO):  a membrane process than removes very small molecules, such as water - used to concentrate fluids as an alternative to evaporation

Still Retort:  A type of batch sterilizer used for canning food, where the cans are not in motion during the sterilization process

Spray dryer:  Equipment where product is sprayed into heated air to remove moisture

Sterilizer:   Equipment used to eliminate all microorganisms in the food

Tubular heat exchanger:  Two or more tubes are placed inside of each other, so that the heating media and product are flowing in opposite directions.

Ultrafiltration (UF):  a membrane process which separates on the basis of size - used to concentrate proteins from small molecular weight soluble compounds

Product Abbreviations: 

NFDM:  not fat dry milk

SS (serum solids): generally used in ice cream formulation calculations;  the solids in milk that are not fat

SNF:  solids not fat in dairy products

WPC:  whey protein concentrate (whey protein content >34%)

WPI:  whey protein isolate (whey protein content > 90%

Quality terms: 

HACCP (hazard analysis critical control point):  process of quality control mandated by the FDA

ISO 9000:  Certification procedure for TQM, monitored by an agency outside of the organization being certified

Quality control (QC):  Establishment of acceptable standards for a product with standards enforced after production

Quality assurance (QA):  Expanding QC to try to implement systems that correct problems before they arise

Total quality management (TQM):  Management system that gets all of the employees involved with QA, with the goal of producing  Zero defect products.

Total Quality Implementation (TQI):  TQM + ISO 9000 (registration verification system for TQI

Environmental and Waste Management Terms: 

BOD  (biological oxygen demand):  The amount of oxygen required by microorganisms to convert organic material in a fluid waste into microbial cell mass.  May be expressed in terms of mg/l (ppm) of is mass/unit mass (lbs/lb, kg/kg, etc.).

BOD₅:   biological oxygen demand (mg/l) after 5 days at 21 C.  The value used by environmental agencies to express the organic matter in fluid wastes.

BOD_U:   the ultimate amount of oxygen utilized (mg/l) by microorganisms to convert organic material in fluid waste to microbial cell mass.  This generally requires from 20-40 days depending upon the nature of the organic matter and the microorganisms involved.

COD:  chemical oxygen demand.  The amount of oxygen required  (mg/l)to chemically oxidize the organic matter in fluid wastes.  Based on titration with an oxidant.  It is faster and more convenient than BOD - but does not always correlate to biological treatability of the waste.

FOG:  fats, oils and grease present in a fluid waste.  Originally designed to express the material in petroleum wastes.

N:  nitrogen

P:  phosphorous

SS:  suspended solids

TSS:  total suspended solids

VSS:  volatile suspended solids

05/26/00
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