WBCHSE HS Vocational Food Processing flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Food processing definition

Any deliberate operation that transforms raw agricultural produce into a stable, safe, edible and transportable form, including cleaning, milling, heating, drying, freezing and packaging.

Water activity

Ratio of the vapour pressure of water in a food to that of pure water at the same temperature. Pure water is 1.00; most spoilage bacteria need values above 0.90.

Unit operation

A single discrete physical step such as size reduction, mixing, heating, separation or drying, treated as a common building block that can be analysed and scaled across different foods.

Perishable food

A food that spoils within days without special preservation, such as milk, meat, fish, and fresh fruits and vegetables, because of high moisture and nutrient content.

Maillard reaction

Non-enzymatic browning between reducing sugars and amino groups of proteins, favoured by heat and intermediate moisture. It creates brown colour and flavour but can destroy lysine.

Enzymatic browning

Browning of cut fruits and vegetables caused by polyphenol oxidase acting on phenolic compounds in the presence of oxygen. Blanching or acid treatment prevents it.

Essential amino acids

Nine amino acids the adult body cannot make and must obtain from food: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

Protein denaturation

Unfolding of a protein's three-dimensional structure by heat, acid or shear without breaking peptide bonds, altering solubility and texture but not nutritional value.

Energy values

Usable energy per gram of macronutrient: carbohydrate 4 kcal, protein 4 kcal, fat 9 kcal, and alcohol 7 kcal. Dietary fibre is carbohydrate but yields little energy.

Danger zone temperature

The range of roughly 5 to 60 degrees Celsius in which bacteria grow fastest. Foods are kept below 5 or above 60 degrees Celsius to control growth.

HACCP principles

Seven principles: conduct hazard analysis, determine critical control points, set critical limits, monitor, establish corrective actions, verify, and maintain records for a food safety management system.

Clostridium botulinum

An anaerobic spore-forming bacterium whose toxin is destroyed by boiling but whose spores survive, so low-acid canned foods need a 12-D heat process such as 121 degrees Celsius for at least 3 minutes.

Aflatoxin

A toxic compound produced by moulds such as Aspergillus flavus in poorly stored groundnuts, cereals and oilseeds. Its presence is a food safety hazard and a quality rejection criterion.

Sanitising versus cleaning

Cleaning removes visible soil with detergent and water; sanitising then reduces microorganisms with heat or a chemical sanitiser such as 100-200 ppm chlorine. Clean before sanitising.

Pasteurisation

A mild heat treatment, typically 63 degrees Celsius for 30 minutes or 72 degrees Celsius for 15 seconds for milk, which destroys vegetative pathogens and extends shelf life.

Blanching

Brief hot water or steam treatment of fruits and vegetables for 1-5 minutes that inactivates enzymes, fixes colour, expels tissue gases and shrinks tissue before freezing or drying.

Commercial sterility

Condition in which a food is free of viable pathogens and of spoilage microorganisms capable of growing under normal storage conditions, achieved by heat processing such as canning.

Osmotic preservation

Preservation by adding high concentrations of sugar or salt, as in jam, jelly, pickle and murabba, which lowers water activity and inhibits microbial growth.

Freezing preservation

Holding food at -18 degrees Celsius or below, which stops microbial growth and greatly slows enzymes. Constant cold chain prevents large ice crystals damaging texture.

Plate heat exchanger

Equipment made of stacked plates that transfers heat between fluids with high efficiency and easy cleaning, widely used for milk and juice pasteurisation.

Spray dryer

Drying equipment that atomises a liquid feed into a hot air stream so droplets dry into powder quickly, used for milk powder, coffee and instant beverages.

Spray drying

A continuous drying method in which a liquid food is atomised into fine droplets in hot air, evaporating water rapidly to produce a free-flowing powder such as milk powder.

Evaporator effects

Number of evaporation stages that reuse vapour. A triple-effect evaporator uses roughly one-third the steam of a single-effect unit for the same water removal.

Modified atmosphere packaging

Packaging in which the internal gas mixture is changed, usually by lowering oxygen and raising carbon dioxide or nitrogen, to slow respiration and microbial growth of fresh or processed foods.

Aseptic packaging

Filling a commercially sterile product into pre-sterilised packaging in a sterile environment, giving shelf-stable milk and juice that need no refrigeration until opened.

FEFO stock rotation

First-Expired-First-Out: the stock nearest its expiry date is dispatched first. It is preferred over FIFO for perishable and dated food products in storage.

Water vapour transmission rate

A measure of how much water vapour passes through a packaging film per unit area and time. Low values are needed for moisture-sensitive foods such as biscuits and powders.

FSSAI

The Food Safety and Standards Authority of India, the apex regulator under the Food Safety and Standards Act, 2006, which licenses food businesses and sets standards and labelling rules.

Codex Alimentarius

International food standards and codes of practice established jointly by FAO and WHO, used as the reference for national food standards and international trade.

Break-even quantity

The number of units that must be sold for total revenue to equal total cost, calculated as fixed cost divided by selling price per unit minus variable cost per unit.

Working capital

Money needed for day-to-day operations such as raw material, wages and stock until payment is received; food businesses often need two to three months of operating cost.

Brix measurement

Total soluble solids of a juice or syrup measured with a refractometer and corrected to 20 degrees Celsius, approximating the percentage of sucrose in solution.