Food Processing and Preservation Practice Flashcards

Vocabulary practice flashcards covering the fundamentals of food processing, thermal death kinetics (D, Z, F values), non-thermal technologies, and chemical preservatives.

Food Processing

The set of methods and techniques used to convert agricultural products into finished and semi-finished products for consumers.

NOVA Classification System

A system from the Food and Agriculture Organization (2019) that groups foods into four categories according to the nature, extent, and purposes of the industrial processes they undergo.

Group 4: Ultra-Processed Foods

Industrial formulations made from a series of processes including extraction and chemical modification, containing very little intact Group 1 foods (e.g., soda, chicken nuggets).

Low Acid Foods

Foods with a pH greater than $4.6$, such as peas, corn, lima beans, and eggs, which require strict process control like sterilization for safety.

High Acid Foods

Foods with a pH less than $3.7$, such as berries and sauerkraut, where high acid content naturally inhibits pathogen growth.

Thermal Preservation

Processes that employ heat to make food safe or extend shelf-life by reducing microbiological contamination and enzymatic activity (e.g., canning, pasteurization).

Asepsis

The principle of food preservation by keeping microorganisms out using natural barriers (like fruit peels) or artificial coverings (like packaging).

Phosphine

The most common fumigant used to prevent food damage caused by insects and rodents.

FAT TOM

An acronym representing the conditions necessary for microbial growth: Food, Acid ($pH\text{ }4.6-7.0$), Temperature ($5-60^\text{o}C$), Time ($>4\text{ hours}$), Oxygen, and Moisture ($a_w > 0.85$).

Blanching

A mild heat treatment where food is scalded in boiling water and then "shocked" in iced water to destroy enzymatic activity, specifically Polyphenol Oxidase (PPO).

Pasteurization

A mild heat treatment applied at temperatures below $100^\text{o}C$ to kill pathogens and extend shelf life without causing extensive chemical or physical changes.

Coxiella burnetti

One of the two primary reference microorganisms used to test the adequacy of the pasteurization process due to its high thermal resistance.

HTST (Flash Pasteurization)

A method where milk is heated to at least $72^\text{o}C$ and held for at least $15\text{ seconds}$, targeting resistant pathogenic bacterial spores.

Commercial Sterility

The destruction of all pathogenic and spoilage organisms that can grow in food under normal storage and handling conditions, though some thermophilic spores may survive.

Aseptic Processing

A method in which the product and packaging materials are sterilized separately and then combined in a sterile environment.

Incipient Spoilage

Microbial spoilage in canned products caused by an excessive delay between container sealing and retorting.

D-value

The decimal reduction time; the time in minutes needed to destroy 90\text{ %} (or $1\text{ log cycle}$) of a specific microorganism at a given temperature.

Z-value

The number of degrees the temperature must be increased to achieve a tenfold ($1\text{ log}$) reduction in the D-value.

F-value

The thermal death time; the number of minutes required to kill a known population of microorganisms in a food under specified conditions.

12D Concept

A processing requirement used for low acid canned foods designed to reduce the probability of $Clostridium ext{ }botulinum$ spore survival to $10^{-12}$, or 1 in 1 billion containers.

Psychrotrophs

Bacteria that grow best at $58^\text{o}F$ to $68^\text{o}F$ but can grow slowly at $40^\text{o}F$; $Clostridium ext{ }botulinum$ Type E is a concern in this group.

High Pressure Processing (HPP)

A non-thermal process using uniform isostatic pressure (up to $6000\text{ bar}$) to inactivate microorganisms while keeping taste close to fresh products.

Electroporation

The mechanism in Pulsed Electric Field (PEF) processing where high voltage ($20-80\text{ }kV/cm$) creates pores in microbial cell membranes, leading to inactivation.

Gray (Gy)

The unit used to measure the absorbed dose of ionizing radiation in food irradiation; defined as $1\text{ Joule}$ of energy absorbed per kilogram of matter.

Ozone Treatment ($O_3$)

A non-thermal disinfection method using a strong oxidizing agent that decomposes into oxygen, leaving no harmful residues.

GRAS

Acronym for "Generally Recognized As Safe," referring to substances intentionally added to food that experts consider safe under intended use conditions.

Propionic acid

An organic acid preservative used to inhibit mold and prevent "ropiness" in bread, which is a sticky condition often caused by $Bacillus ext{ }subtilis$.

Nisin

An antibiotic produced by $Lactococcus ext{ }lactis$ used to inhibit Gram-positive bacteria and prevent spoilage in cheese, milk, and canned products.