Food Additives

Any substances not normally consumed as a food and not normally used as a typical ingredients. There are approximately 300 food additives in use. Popular opinion suggests food additives are 'unnatural','unnecessary' and 'unhealthy'. They are often listed under their chemical name in the interest of consistency in the industry. E.g. citric acid is the chemical name for naturally occuring chemical in lemons, limes and oranges. Many of the subtances are added in small amounts to food.

Additives are used in food for a variety of reasons.

• To preserve foods so they are avilable all year around. • To enhance the microbiological safety of a particular food.• To add or restore to food colour that has been lost during processing.• To restore nutrients to their original levels and fortify (add nutrients)• To improve appearance or texture.

Food additives may be classified into the following groups;• colourings• preservatives• anti-oxidants• flavourings and flavour enhancers• artifical sweeteners• humectants

MSG = brings out flavours

Food ManufacturersWho are food manufacturers?Multinationals e.g. Coca Cola, McDonalds, Cadbury Schweepes.Smaller companies e.g. local bakery, pizza parlour.

Raw materials:Raw material: any product that goes into the manufacturing of another processed good. Raw materials used in food processing are:• product ingredients, such as fruit and vegies• processing materials such as steam and water• food additives, such as emulsifiers, starches, colours and flavours• packaging materials such as cans, bottles and fibreboard containersQuality control of raw materials:• raw materials are a large expenditure• time and effort ensuring raw materials entering manufacturing site of

very high standards• all raw materials must meet strict standards

• just one delivery of contaminated material can mean spoilage and rejection of complete production.

Food Additives:

• Flavourings: MSG= monosodium glutamate. Can be natural or synthetic. Must be labelled.

• Free flowing agents: anti-caking agents. Maintain the free-flowing characteristics of powdery foods such as salt.

• Colourings: Used to restore food to its normal colour range or used to enhance - e.g. confectionery.

• Vitamins and minerals: Restore nutrients lost. Vitamin C added to juice.• Emulsifiers, stabilisers and thickeners: General thickenings. Lecithin

found in egg yolk.• Antioxidants: to retard deterioration by oxidation• Antimicrobial additives (preservatives): Inhibit the growth of moulds,

yeasts and bacteria and were among the first additives.• Sweeteners: Sucrose is the main sweetening agent.• Humectants: able to absorb and retain moisture. A food additive is a chemical substance purposely added to food.E.g. asorbic acid (vitamin C), carotene (orange in carrot), cochineal (red colouring), caffeine and saltPreservatives protect food against moulds (e.g. anti-oxidants)

Quality Control and Quality AssuranceQuality = able to meet requirements. Quality assessed through eyes of user or consumer of that product.Control = process employed in order to meet standardsQuality control = process by which we measure characteristics, compare them to a standard and act on any differences that may occur. To achieve this all the separate parts of a company must co-operate.Quality asurance = cooperation to achieve quality control. The ultimate aim of quality control - all parts of a company working together to maintain the quality of the products produced.

Production systems• Production systems are the ways the processes of food production are

organised and applied.Production systems are classed as:• large scale• small scale• manual• automated• computerised• production line• roboticsProduction systems generally follow this format depending on the scale of

operation: manual>>automated>>computerised

Large scale production systemsThese are used within larger production operations such systems are based on a product on line which is a continual process. From the inspection of raw materials, through to the storage and distribution of the final product. A large scale system has the advantage of producing large volumes of products in a short time period.

Small scale production systemsThese systems are used on a domestic level and are smaller in scale and less complex.

Manual productionThis involves the operator physically adding food components eg filling pie cases

Automation processingThis is when machines handle and control processing from raw materials to the finished product

ComputerisationSensors enable large and complex operations to be undertake due to data being stored and compared to preset specifications. Computer programs have een dveloped to respond to variations in raw materials. Cheese-making is an example of this.

Automation and computerisation have the following benefits:• reduced labour• energy savings• consistent product quality• less wastage of materials• more consistent production levels

Unit OperationsUnit operations are the specific processes the food undergoes during production i.e. heating, mixing, transportation. Handling of raw materials is the first important unit operation performed in the food processing plant. Different handling systems are required depending on the characteristics of the raw material. Separation or grinding and milling are common processes in the raw material unit operation. Unit operations: are the specific processes food undergoes during production. Processes are:

Process used: Purpose:

Separation-filtration The process of passing a liquid through a filter so solid particles are removed.

Separation-sedimentation The use of gravitational or centrifugal forces to remove solids from liquids.

Separation-centrifuging The process used to separate food particles of different densities e.g. the separation of cream from whole milk

Grinding & milling The process of reducing raw material size which may be required to:*make raw materials easier to handle*make raw materials suitable for the final product*make a completely new product

Mixing The process used to evenly distribute ingredients through a product batch.The type of mixer used depends on the size batch to be produced.

Heating equipment The equipment used to heat raw materials during processing.The type of equipment used depends on the nature of the raw materials & the intensity of the heat treatment.

PROCESSING EQUIPMENTThe ability of a food industry to provide a continous supply of nutritious and safe food to the consumer depends on the processes and equipment used in all stages of handling, processing and distribution.

Separation can be:1. physical separation of components of food - for example, removing the skin from an orange2. chemical separation of components in foods - for example, adding chemicals for the separation of whey from the fat in the making of cheese.

Filtration involves the process of passing a liquid through a filter to remove any solid particles. Filtering systems are used in the separation of cheese curd from water in the manufacture of cheese, and microbial air filters are used in dryers in the production of powdered products such as milk.

Sedimentation is the proces of removing solids from liquids, using gravitational or centrifugal forces. A centrifuge is based on the principle that if a liquid containing particles of different densities is placed in a rotating bowl, the heavier partices will move to the outside of the bowl as a result of the greater centrifugal force acting on them.

Mixing is a process that ensures all the ingredients are evenly distributed throughout a batch of the product. The type of mixer depends on the size of the batch and the materials being mixed. A computerised bread mixer, mixers used for dough will require different mixing arms.

Heating of food products using steam is probably the most frequently occurring process in the food production plant. For low-intensity heat transfer methods equipment such as blanching tanks are generally used. Two of the most commonly used include the tubular heat exchange and the plate exchanger. In a tubular heat exchanger the hot water or steam flows through the outer jacket, while the liquid product flows through the inside tube. E.g. chutneys and sauces. In a plate heat exchanger the product flows between two heated surfaces in a very thin film resulting in a rapid increase in temperature. The use of radiant heat in an oven is another method of heat processing used extensively in the food industry. The most commonly used type of oven for baking bread, cakes and biscuits is the tunnel oven.

Dehydration has a direct effect on the final volume of the food, providing both the consumer and the food manufacturer with a product that is convenient to use. Dehydration reduces moisture content of the product to a level that limits microbiological growth or other reactions. The moisture is removed by heating the product. E.g. tunnel dryers or vacuum dryers. Two other methods are freeze drying and spray drying. Freeze drying has a number of advantages as it is lighter and does not require cold storage. Spray drying is a technique in which the product being dried must be in the form of a liquid. The liquid food is forced through an atomiser. E.g. instant coffee, powdered milk.

Cooling equipment is used to slow down or stop the activity of microorganisms and enzymes and the spoilage of food. Cooling systems are commonly used in confectionery manufacture.

Freezing equipment involve 3 categores; air blast freezers, plate freezers and immersion freezers. The plate freezing involves bringing the food product into direct contact with plates. Immerision freezing brings the product into direct contact with a low-temperature refrigerant such as liquid nitrogen.

Grinding and milling is used to reduce size. A reduction in size may be necessary for a variety of reasons such as making the raw material easier to handle or to make a new product. Characteristics include machinery totally computerised and running 24/7.

Process = a step during manufacture

Flow process chartsAre diagrammatic representation of production process involved in the manufacture of a specific product. They are closely linked to quality assurance because;1. each step of the process can be analysed to determine how effective each step is and how it contributes to product standards, quality, yields and costs.2. new staff can quickly become familiar with each step of the process and assess the importance of that step to the overall production line.3. critical control points can be identifiedcritical control points are those points that could result in RISK to public health or significant financial cost. They are used to monitor and control variation in the process. They are checked to assure quality and consistency in a food product.

Storage = (triangle) occurs a when product is kept under controlled o permanent storage and protected against unauthorised removal.Transportation = (arrow) occurs when labour or equipment are used to move a material. Inspection = (square) occurs when a material is inspected, sampled, counted, examined, identified, measured or compared with a standard in terms of quantity quality and other characteristics.Inspection and processing = (circle and square) when two operations occur at the same time. Delay = (D) occurs when conditions o not allow the next step of the process to take placeOperation = (circle) occur when a material is deliberately changed in any of its physical, chemical or microbiological characteristics, assembled or dissembled from another material, arranged or prepared for another operation or prepared for transporation, inspection or storage.

Quality control and quality assurance are necessary in all levels of food manufacturing, regardless of the level of production or unit operation. • consumers expect all processed foods to be applealing, nutritious and

safe• the quality management system involves the planning and

management activities, that ensure a product meets the expectations indrectly by the consumer

Guidelines for quality assurance include;• a clear final product specification including level of quality that is

expected that can be achieved at the price the customer is prepared to pay

• methods for assessing and measuring the quality

• specifications for processing areas involved. • sampling and testing of the finished product, after packaging and

labelling to ensure that all specification standards are met.

Quality control: process by which we measure characteristics, compare them to a standard & act on any differences that may occur. Quality control consists of economically developing, designing, producing, marketing & servicing products that will satisfy consumers.

Quality assurance: refers to the cooperation to achieve quality control i.e. all separate parts of the company must work together.

Setting up a quality management system:• *A clear final product specification statement of the level of quality that is

expected & that can be achieved at the price the customer is prepared to pay.

• *Methods for assessing & measuring the quality of the material to the specification set out & agreed to by the supplier & purchaser.

• *Specifications for the processing areas involved.• *Sampling & testing of the final product, after packaging & labelling to

ensure that all specification standards were met.

HAACP: Hazard Analysis of Critical Control Points.

Advantages of HACCP:• *the business makes more profit because it wastes less product & has to

redo less work• *the product has an edge over the competition• *problems are prevented than responded to when they happen• *consumers feel confidence in the safety of the product• *employees feel more in control of the work environment & job security is

improved

1. HACCP involves the following steps:1) Examine production stages & analyse potential hazards2) Identify the critical control points3) Specify control measures & set critical limits4) Establish a system to monitor control points5) Specify corrective action when monitoring indicates that control measures

have not been met6) Regular review of system effectiveness7) Make & keep suitable records

1. The first step involves:*listing all the operations in the production process from delivery of raw

materials to the finished product.

*conducting a hazard analysis to identify potential risks for each operation in the process such as physical, chemical or biological contamination.

2. The second step identifies any production steps where hazards can be controlled. These steps are known as the critical control points (CCP). They include all processes where a failure of controls could comprise food safety. E.g. CCPs occur during storage & transport, cooling, chilling or freezing, heating for blanching, pasteurisation, sterilisation, cooking, cleaning & sanitising, packaging & sealing.

3. The third step establishes control measures for CCPs & sets critical limits. Control measures to ensure safety will vary depending on the severity & type of hazard. Critical limits specify standards to ensure food safety.

4. The fourth step involves determining procedures for systematically monitoring critical control points & critical limits. There procedures indicate the tests of checks which must be applied to procedures & food samples to ensure that the food is safe. Monitoring can either be quantitative or qualitative. Quantitative monitoring are things you can’t see e.g. temperature acidity levels. Qualitative monitoring are things you can see and relies on visual inspection of characteristics such as colour and texture.

5. The fifth step involves specifying corrective action if the monitoring procedure indicates an operation is outside the critical limits. Corrective action involve adjusting the process to prevent future failure & either rejecting or reprocessing the food to ensure the safety of the product.

6. The sixth step involves regular onsite review to ensure that the program is working as it should and that it is adequate & effective.

7. The seventh step involves keeping records of all reviews, tests & procedures. Records provide evidence of safety procedures & identity areas for improvement. Documentation also identifies each batch of product, allowing quick identification if food contamination occurs & product recall is necessary.

HACCP = HAZARD ANALYSIS OF CRITICAL CONTROL POINTS• best known technique used to deal with hazards• wastage is less• problems are prevented• consumers fell confidence in the safety of the product

The 7 principles of HACCP are:

• assessment of hazards• identificatio of critical control poits• setting of standards for each of these crtical control points• monitoring of critical control points• description of clear procedures for prompt action if standards are not

met• keeping accurate records to identify variations from the standards• vertification of the system

Occupational Health and Safety• instruction or training should be done about safety issues• Occupational Health and Safety Act 1983• Occupational Health and Safety Act 2000 (NSW)

Occupational health & safety:

Accidents are most often caused by the worker being unskilled at the job, the worker being rushed during very busy times or the equipment being poorly maintained.

The employer in the food industry must by law provide basic working conditions. These include: *instruction of training about safety issues*equipment that operates correctly when used in the right way*a safe environment according to the Occupational Health & Safety Act 1983

1. An O&H committee must be established if there are 20plus employees in an origination. They:

*prepare a plan or checklist of areas prone to accidents.*devise an accident report form*decide an accident report form*decide on a course of action when an accident occurs.

2. Employees are to:*take reasonable care for eh heath& safety of others in the workplace.*use equipment as instructed & in a safe manner.*notify the employer in writing of accidents that occur*wear necessary protective clothing.

Five causes of food spoilage:• 1. Microbial activity i.e. bacteria, yeast, mould. Microbial activity

includes the effects of bacteria, mould and viruses. Given the corect conditions i.e. food source, warmth and moisture, such micro-organisms will multiply and cause food spoilage

• 2. Living organisms. Organisms such as insects and rodents can cause

spoilage of food e.g. weevils in flour• 3. Enzyme changes. Enzymes are found in meats, fruits and vegies.

Even when food sources are slaughtered or harvested, enzymes continue to work and so overripening can occur, causing food tissue composition.

• 4. Physical changes. Physical changes are those changes that alter the physical state of a food in some way. Examples of physical changes include size, surface damage or colour change. Causes of such changes can come from bruising, movement of food, freezing, burning and pressure.

• 5. Chemical reactions. Chemical breakdown of food is caused by chemical reactions ithin the food becomes chemically contaminated from such sources as agricultural chemicals.

Environmental Factors:- Infestation: An infestation of ants, weevils or any other insect can

get into foods. This spoils the food causing it to be unsuitable for consumption. Flys also land on food and contaminate it. Rodents such as rats or mice can nibble and spoil food. These are all spoilage agents.

- Oxygen: Oxidant reactions can spoil food.1. Enzymatic browning occurs when cut surfaces are

exposed to oxygen and they turn brown e.g. Pears.1. Rancidity occurs when oxygen reacts with fats to

create a “ranc” smell and the fat structure deteriorates.

1. Souring of milk occurs when oxygen or heat react with the lactose (milk sugar) and it’s converted into lactic acid which sours the milk and creates a curd texture. i.e. pH decreases.

- Light: Can spoil food by changing the colour of the food or the texture. Light can also break down the cell structure of food.

- Water: Food spoilage can be caused either by the addition or the removal of water. Water gain causes some food to become inedible and it will attract microbes. Water loss causes food to become stale which makes the food spoiled thus inedible. Although the foods can still be eaten water loss/gain makes them undesirable to eat.

- Impact damage: Foods can be either crushed or bruised due to poor handling, which makes the food spoiled.

- Freezer burn: Caused by exposure to cold air dehydrates foods leaving the spoiled.

Enzymatic Activity:Is involved in the ripening and eventual breakdown of fruits and vegetables, and the decomposition of meats. Enzymes naturally exist in all both plants and animals and have important functions while the organism

is still alive. Once the organism is dead the enzymes continue to work which causes spoilage.

Microbial Contamination:- Bacteria: Are pathogenic (cause food poisoning). Different strains of

bacteria thrive at different temps and different pH levels. Food manufacturers’ must ensure that all precautions are taken to deny bacteria a suitable environment for growth. Flesh foods are extremely vulnerable to bacteria. Anaerobic bacteria don’t require O2 for growth so food manufacturers must be very careful. Bacteria grow best in the danger zone between 5oC and 60oC.

- Moulds: Grow in warm moist conditions and create a green/gray mass over the surface of the food. Moulds aren’t usually pathogenic but AFGOTOXIN mould is an exception. Mould spores spread easily from one food to another e.g. bread, cheese etc. High temps. Deactivate/kill mould.

- Yeast: Wild yeast lands on sweet liquids and causes undesirable fermentation of the liquid e.g. OJ. Characteristic ‘gas’ bubbles appear in the liquid and a strong/undesirable alcohol taste develops.

Microbial spoilage can be air borne; it is constantly around us and can land on open or uncovered food. Microbes can also be present in soil, on animals and their faeces, insects and bodily fluids i.e. viruses. Cross-contamination can cause microbial spoilage. Conditions for microbe growth:

H2OO2

Sufficient nutrients in foodTemperature (above 70oC for pasteurization)TIME AND TEMP. ARE CRITICAL

· Other Spoilage Agents:- Addition of contaminants wither intentionally or accidentally e.g.

farm chemicals.- Intentional adulteration of foods may occur illegally e.g. adding

water to milk.- Deliberate sabotage of food for extortion threats e.g. poisoning of Arnott’s biscuits

Main methods used for preserving foodexclusion of air: this means not allowing the product to come in contact with

micro-organisms in aseptic condition. The container must be sterile.removal of micro-organisms: e.g. by filtrationuse of high temperatures: canning to destroy microbes and enzymesuse of low temperature: refridgeration or freezing to slow down microbial

growth

drying: freeze drying. Addition of sugar or salt makes water unavailable to microbes

use of chemical preservatives: adding sorbic acid, sulfur dioxideirradiation: electromagnetic radiations to retard and kill harmful micro-

organisms.

Principles of preservation:water availabilityaddition of chemicalstemperaturethe pH leveloxygen level

Principles behind food preservation techniques:

· The aim of food preservation is to render microbes inactive i.e. kill or control the conditions. The principles of food preservation are to control:

Temperature – Increase above 100o and kill microbes or decrease below 4oC (refrigeration) which slows/retards growth or -18oC (freezing) and microbes lay dormant.

Water Availability – Microbes can’t multiply w/o water, they cease to grow.

Oxygen Levels – Microbes and enzymes can’t exist w/o O2. No oxidation reactions either.

pH Levels – With pH<4 it is impossible for microbes to grow.Addition of Chemicals – It is impossible for microbes to grow by adding salt, sugar or other additives.

Techniques of preserving foods:Freezing (Snap Freezing): Happens at -40oC with liquid nitrogen in a

couple of seconds. Only small ice crystals form which reduces cell damage. Domestic freezing has large which damages food cells. Microbes lay dormant and can’t access the liquid but enzymes are still active. TEMP down

- Accelerate Freeze Drying (AFD): The product is snap frozen then dried through sublimation. TEMP down and H2O down

- Cook-Chill (Sous Vide): Used in hospitals, hotels and restaurants. Food is pasteurized and crash cooled via blast chilling, then vacuum packed and refrigerated. Cold chain is imperative of C.C.P. TEMP down and O2 down

- Dehydration/Drying: Involves the partial or complete removal of H2O from food e.g. semi dried tomatoes have 25% moisture content while dried milk has no moisture content. 100% moisture removal means a long stable shelf life. Barrier packaging is critical to prevent H2O entry into the V.A product. H2O down

- Pasteurization: Liquids are heated to 72oC for 15 seconds to kill

some of the harmful pathogens e.g. milk and juice. Cold chain storage is essential as the product IS NOT STERILE/ASEPTIC. TEMP up

- Ultra-Heat Treatment (UHT): Liquids are heated to 1300C to 140oC for 2 – 3 seconds. This renders the product ASEPTIC and with an aseptic package the product has a 1 – 2 year shelf-life e.g. Berri juices. Doesn’t need cold chain so it’s cheaper to store/distribute. TEMP up

- Canning: Food is placed in a laminated triplated can with a liquid (syrup, brine, oil, vinegar or springwater) and then it hermetically sealed and heat sterilized above 100oC. This creates a vacuum seal on the lid. Cans have got thinner and cheaper to transport. TEMP up and O2 down

- Salting/Curing/Corning: Salt is added in a solid or liquid form to create an environment unsuitable for microbes. Osmosis occurs as moisture is removed. H2O down and pH<4

- Irradiation: Food is passed by Gamma Rays which sterilizes any spoilage agents. It’s not permitted in Australia.

- Smoking: Food can be exposed to smoke which permeates the cells and reduces the pH as well as partially drying the food. H2O down and pH<4

- Fermentation: The controlled use of yeast to create alcohol to preserve food. The eventual build-up of alcohol stops the yeast, common in Salami and alcohol.

The main reasons of preserving foods are to:promote safetykeep foods in a form acceptable to the consumer and therefore prevent wasteretain the nutritional value of the foodmake perishable foods available all year roundachieve economies for the production company

Enzymes are chemical substances that cause food deterioration by: hastening the ripening and decay of fruit when ethylene gas is present and carbon dioxide and oxygen levels are suitable, causing enzymic browning when exposed to oxygen.

If there is a protective covering around food, microbial action and enzymic browning is delayed or prevented.

Vacuum packing involves placing the food in a plastic or aluminium laminated foil pouch and removing all air.

Cooking a food by heating is probably the simplest and most commonly used method of food preservation.

Canning involves two preservation principles: the sealed container prevents micro-organisms from reaching the food inside and the heating of the food inide the container creates a temperature that will destroy all icro-organisms and their spores.

Chilling slows the growth and activity of enzymes and the growth of micro-organisms. Thus chilling is probably the most often usd preservative method for storing perishable food.

Dehydration is one of the oldest methods. Moulds and bacteria will grow in a food when there is as little as 13-20 per cent moisture content in the food. For this reason, manufacturers aim to dry products to the point where moisture content is 5-6 per cent.

Chemical preservative: Anti-oxidants - reduce the level of oxidation of fats. Often added to margarine, oil and cooking fats.

Notes: Food Safetyfoods need to be checked for contaminationcook thoroughly to reduce micro-organismsHACCP- identify problemseach batch has a codecontaminants e.g. pesticidesHygiene: strict regulations on clothes, checked regularly for illness, boots are

disinfected, liquid soap used, coats are laundered. Before each batch, tubs need to be cleaned. - Preclean, Main clean (hot h20

and detergent), Rinse, Disinfectant, rinse and dryingimportant to mix properly to ensure ingredients are evenly spread throughout

the producthigh risk - cooked meat, milk, eggslow risk - raw meatbacteria are most common type of contaminant- salmonella, listeria (like the

flu), E.Coli, staphylococcuslaboratory samplingbacteria loves food, moisture, ph, temperature, and oxygenprobes are used to ensure proper temperaturestorage - minus 5C - no micro-organisms can multiplyrapid chilledprinted use by date

Review Questions:Food preservation has become a necessity as consumers want a variety of

food all year around, includig foods that are out of season ca be preserved for a suplly all year. It preserves nutritional value.

Five causes of food spoilage - physical, enzymes, chemicals, living, microbial.Water availability - addition of sugar and saltTemperature: high temperatures reduce micro-organismsChilling: microbial growth slows when it is below -5CCanning seals off micro-organismsdehydration below 13% reduces water availability

Preservation ProcessesLowering temperature: chilling, freezingRaising temperature: canning/bottling, blanching, pasteurisation, UHTReducing water activity: Spray drying, vacuum dehydration, binding of H20,

freeze dryingChemical methods: Use of additives, smoking, salting and curing.Biological methods: Fermentation

Canning:conventional canning involves two preservation principles: the sealed

container prevents micro-organisms from reaching the food inside (packaging) and the heating of the food insie the container creates a temperature that will destroy al micro-organisms and their spores (heating).

Conventional canning combines both cooking and vacuum packing.the filled cans are then heated in large pressure cookers (called retorts)some cooking times need to be fairly long to make sure that the heat has

penetrated to the centre of the food, and that sterility has been achieved. Certain foods are not suitable for canning, because their quality suffers in terms of texture and colour in the canning process.

for high acidic foods can are lacquered to stop any reaction between food and the can

if the end of the can bulges, one of three scenrios could have happened: mcrobial action, physical action (space left in the can called head space) or chemical action.

Pasteurisation:Pasteurisation refers to a secific type of heat treatment of a food. The process

will either kill all specific heat-sensitive micro-organisms, or simple reduce the numer present to an acceptable level. Howeer, this process does not completely sterilise the food.

Many products such as fruit juices, beer, wine and dried fruits are pasteurised.HTST (high temperature, short time) method is used comonly where the milk

is heated very quickly to 72 degrees Celsuis and held at that temperature for 15 seconds, then cooled rapidly to 10C.

it is a procss which kills pathogenic micro-organisms which are not heat resistant

UHT:

Ultra-high temperature treatmentthis process gives us UHT milk which does not require refrigeration for

storage. The milk is heated to about 140 degrees celsuius for a few seconds to kill all heat-resistant bacteria, but some cooked flavour may be detected in the product.

packaged in aseptic packagingused - fruit juice, cream, custard suaces, stock, soupfood product and container are sterilised separately

Chilling:chilling slows the growth of micro-organismsrefrigeration 4C or lesschilling is most probably often used preservative method for storing perishable

foodthe lower the temperature is, the slower the chemical changes occur in the

food and the slower the microbial growth happensChilling or cooling a food has no effect on the number of bacteria present.

Once a foodstuff has een returned to room temperature, the micro-organisms will reactivate and will speed up the spoilage of that food.

Freezing:enzyme reaction rates are muh slower in frozen foods, the water in the food is

changed to ice, and is no longer available to react with micro-organisms.

foods need to be stored at -18 degrees Celsuius or below to ensure minimum microbial activity

the quality of a frozen food is determined by the amount of time that the food spends in the critical temperature zone (0-5 degrees celsuis). The reason is that the time spent in this zone will determine the size of the ice crystals, that are formed, - the longer the time in this zone, the larger he crystals, and therefore the greater the damage to the structure on thawing.

Freeze drying is not commonly used. It is expensive. e.g. tea, instant coffee, soup, dried milk and dried meat.

Commercial freezing:immersion freezing was one of the first methods generally employed for

freezing foods. It is aslow method with little control. Brines were prepared from salt and ice. As more and more ice was added the temperature fell to suitable level for freezing. This method is little used.

Plate freezing the food is prepared in the normal way and is packed into a flat container, usually a cardobard based container, often with a polythene or wax lining. Disadvantage of this method is that they cannot easily freeze irregular shaped food materials.

Blast freezers consist of a large cabinet in whic a fan has been introduced to move the air over the product. The air should have a temperature of -

25C or lower. Fluidised-bed freezers are blast freezers with a vertical air blast with enough

velocity to 'fluidise' the product in the air stream.Cryogenic freezing uses very old liquefied gases, such as nitrogen and

carbon dioxide. Liquid nitrogen at -196 is sprayed onto foods on a conveyed belt. Liquid carbon dioxide works at the higher temperature of -78 degrees celsius

Chemical preservatives:chemical preservatives are food additives that are added to food to prevent

deterioration or decomposition of the food. Factors that influence the effectiveness of chemical preservatives are: the

concentration of the chemical, the type and number of micro-organisms present in the food, temperature, time and the characteristcs of the food (for example, moisture content, pH level, sugar content, protein content)

If the level of a chemical preservative is high enough, the micro-organism will bekilled. Lower concentrations will only retard or slow the grwoth.

The addition of chemicals to food is controlled by food legislation. (FSANZ)e.g. benzoic acid - added to fruit juices, james and some high-acid foods,

used to inhibit moulds

Fermentation:Preservation of a food by fermentation uses alcohol or acid produced bythe

action of micro-organisms.Alcohol type fermentation (in wine making) - Grapes + Yeast = Alcohol and

Carbon DioxideAcid-type fermentation - Cabbage + 2.3% salt + Acid producing bacteria =

Sauerkrautthe salt prevents the growth of undesirable organismse.g.s cheese, yoghurt, salami, wine and beer

Dehydration:evaporation of H20 - dryingdecreases h20 activity in food - drying e.g. salting, jamesmould and bacteria can grow when 13-20% moisture. Drying aims for 5-6%

moisture content

Packaging:Packaging is an integral part of the food manufacturing processMany changes over the years, mainly because of technoloy and consumer

demandsAll areas of the food distribution chain depend on packaging to produce a

good quality productGovernment bodies control the information found on packaging so tha the

consumer is protected from false information

Packaging has a significant impact on the environment. o keep pollution to a minimum, packaging must be a concern of the consumer as well as the manufacturer.

Functions of Packaging:provide a container in which food is carried (transported)provide efficiency and flow on the production line in food manufactureprotect the food from; physical damage (impact of mechanical damage, pests,

moisture exchange, flavour exchange in tranpsort and storage ; chemical damage - caused by oxygen, ethlyene gas and light ; contamination frommiro-organisms and other contaminants

unitise food into easily handled, readily recognised and pre-measured quantities for transport, storage and sales

provide consumer convenience in food selection, storage and useprovide merchandising facilities for identification, information, display and

appealincrease consumer preference by appealing to trends and coerns such as

avoidance of over-packaging or the use of recyclable materials, or by a cost advantage.

Types of Packaging Materialthe food must suit the type of packaging e.g. eggs in cartonsthe food must be protected and preserved e.g. baby food in vaccum sealed

jarspackaging must be easily identifiable to the consumers e.g. sauce in a bottlethe food must not react with the packaging materialit must be convenient to use. It must be a suitable shape, size and weight for

handling and stroage.

Main types of material used in food industry:cansglass containersrigid plastic containers (plastic bottles)flexible plastic packaging (plastic films)paper and board products (moulded packaging, cardboard boxes, composite

containers)aluminium foil and laminates (many layers)

Cans:the metal can is one of the cheapest and most widely used types of packaging

in Australiaadvantages include that it provides good protection for the contents and

prevents undesirable gains or losses in moisture contentcans are relatively easy to handle

high speeds can be achieved during productioncans can be displayed easily and stacked neatlycan be stored for long periodsmost common types are the steel can and the aluminium canthe barrier is not completely inert = chemically inactive material (inert)at times, a coating of lacquer or plastic is needed on top of the tin to stop the

chemical reaction between the food and the tin coating. steel alloys developed over the past 10 years have allowed the production of

cans with thinner walls. Thus ring pull lids became possible for products such as canned vegetables, fruis and soups.

the air above the product is removed through steam or a vacuum, the can is sealed, and the can is heated.

Aseptic canning method: the cooked and/or sterilised product is placed in a sterilised can, then airabove the product is removed by a vacuum and the can is sealed.

Glass containers:inertnon-poroushygenictransparentstrongeasily opened and resealedwide varietylong shelf liferecycled and reusedretain pressurevacuum packedsecureresealabletamper prooflow acid foods such as fish, meat and baby food products need to undergo

sterilisation and are required to be heated to much higher temperatures, so all the micro-organisms are destroyed.

Aluminium foils and laminationsmost of the foils used for packaging today are made from aluminiumthey are light, fleible, add value to the product.foil is often combined with plastic and paper (lamination)e.g. muesli-bar wrapper which uses paper, foil and plastic combined into the

one wrapped material.

Rigid Plastic Packaging two most commonly used in food packaging: polyvinyl chloride (PVC) and

polyethylene terephthalate (PETP). PVC are used to hold edible oils and cordials

PETP is used in the sof drink industryflexible plastics/plastic films used for cereal liners, cling wrap, chips and

biscuits

Flexible plastic packagingsome common plastics used to make plastic films are: low-density polyethlene

(LDPE) and linear low-density polyethlene (LIDPE) used for cake and cereal liners

polypropylene (PP) used for packaging of snak oodspolyvinyl chloride (PVC) - used for meat and vegetable wrapping

LaminationsLamination involves the combination of two or more materials from separate

reels which are stuck together with the use of an adhesive or heat. Most plastic packaging material is a lamination.

retortable plasticsshrinkable bagsfilm for vacuum packagingmodified atmosophere packaging

Paper and cardboardpaper can be treated to suit the productgreaseproff papers are used because they offer a barrier to unwanted odours

and moisture. Waxed papers are tasteless, odourless, non-toxic and inert and can be used

for most foods.

Sous Vide Processsometimes called the cook-chill process.the perishable food was cooked, rapidly chiled vacuum packed and stored at

0-3 degrees celsius to extend its shelf-life. when required the bag was placed in boiling waternot biodegradable

Active packagingif the food has been processed, active packaging will keep the oxygen level

low. Thus the packaging slows discolouration of cured meats and powdered milk, and prevents rancidity in nuts and ther high-fat foods.

not only provides a barrier to outside influences but can also control and react to the environment inside the packaging.

Modified atmosphere packagingthe starting atmosphere in the modified atmosphere package is adjusted to

produce a gas mix that will maximise shelf life. one form of MAP has a headspace filled with a gas or gases that will extend

shelf life.

nitrogen can be used to replace the air in potato crips packages. a combination of carbon dioxide (70%) and nitrogen (30%) keeps baked

products fresh especially bread. ethylene, oxygen or carbon dioxide scavengers can be used. another form of MAP uses a packaging film that allows the movement of

gases and water into and out of the package

Policy and legislation on packagingthe food industry could not function without packaging. Correct packaging

keeps products safe, prevents waste and is more convenient for the consumer. The Food standards code determines types of packaging, labelling requirements along with laws determining packaging used.

Final choice of packaging depends:1. the cost in time, energy and money2. ease of production3. consumer appeal4. environmental impactIn July 1991 the Australian and New Zealand Environemnt and Conservation

Council and the National Environment Protection Council jointly drew up the National Packaging Covenant.

Food manufacturing companies need to show how their packaging follows laws.

Food labellingNational Health and Medical Research council (NHMRC) provides

recommendations to determine the Australia Food Standards that control food labelling.

The control of food labelling focuses on the 3 categories1. statements or words that MUST appear on the label2. statements or words that MUST NOT appear on the labe3. statements or words that may appear on a label under certain circumstances. Statements that are required to appear on a food label:1. A prescribed name e.g sour cream, apple juice2. The name and business address of the manufacturer and packer or importer3. Details of the country of oriin e.g. made in ... Product of... 4. Some form of identification about where the food was produced, and the production lot or batch number.5. List of ingredients. Must appear in descending order according to weight.6. A dat when packaged or a 'use by' date7. A barcode; identifies each product individually8. A statement of quantity; weight of volume of food without packaging weight9. A nutrition information panel. A warning must be given if caffeine or phenylalanine has been added.

10. Alcohol content and number of standard drinks11. Printing on labels must be in English, uniform size, permanent and distinct.

National Packaging CovenantThis was formed by the Australian New Zealand Environment and

conservation council and the National Environment Protection council in 1999. The National Packaging Convenant is based on the principle that packaging and its final destination is the producer's overall responsibility. It is a five year convenant that has national undertaking. Producers are required to sign a convenant that shows their undertaking to monitor all aspects of the packaging supply chain, from raw materials to kerbside recycling.

Storage and Distribution (Transport)During manufacturing, raw materials, semiprocessed and processed foods

need to be efficiently and hygienically stored and/or transported to prevent spoilage, maintain quality of the product and allow easy and cost-effective movement of the manufactured foods.

Food will arrive at the factory in a fresh (fruit), frozen (fish), chilled (milk) or dry (flour) state.

The manufacture of foods involves the transportation of all the ingredients to the factory.

At the manufacturing plant or factory the raw produce needs to be temporarily stored before it is manufactured into value-added foods. For e.g. in the manufacture of cream-style corn, the corn and other additives need to be stored separately, prior to use, in a manner that will maintain quality. Storage of these items will occur in one of three environments: chilled, frozen or dry stored at room temperature.

Every stage in the process requires products to be package so that they can be stord and transported with minimal damage.

After harvesting, e.g. tomatoes are placed in bulk pallets and stored in refrigerated conditions.

Packaging individual packets, cans and bottles into cartons and then the cartons onto pallets facilitates the stacking and storing of the product and the moving and distribution of large volumes of product..

Once the cartons are stacked onto pallets they are covered with a strong film which is shrink-wrapped to increase both the stability of the pallet and the protection of the cartons.

These pallets are then transported to a central warehouse where they are often reassemble with cartons of a variety of produts for distribution to individual supermarkets (re-palletisation)

Milk is transported in specially developed refrigeration tanksEnclosed semitrailers are used to transport non-perishable foods that do not

require special environments. Also freight trains.

If a product defrosts, ice crystals form and will diminish the product quality.

Review Questions:Packaging has five major functions: contain to product, to protect, packaging

preserves and informs the consumer and markets the product.Requirements that need to be met by food label: prescribed name, name and

business address of the manufacturer and packer or importer, country of origin, identifcation about where the food was produced, list of ingredients, date (use by date), barcode, statement of quantity, nutrition information panel, alcohol content and the number of standard drinks and labels must be in English, of uniform size and permanent + distinct.

Moulded cartons are dense and hard which can be moulded in a size to suit the container (egg cartons).

Composite containers use more than one material e.g. paper body and metal lid (Milo Containers)

Packaging preserves food by: decreasing the chances of, or preventing contamination by micro-organisms, prevent moisture entering, prevent loss of water, allow products to respire, prevent rancidity and protect light-sensitive products.

Impact of Food ManufacturingTechnologies -EnvironmentalSocial implications (society)Nutritional implications

To respond to environmental concerns to cut costs, food manufacturers are now using lighter and more environmentally friendly packaging.

Recycling: recycling of broken glass does save energy, but alot of energy is used in shaping the glass.

Re-use: glass containers have to be reused 10 times to be environmentally friendly as laminated or plastic packaging.

'Cradle to grave' - Cost analysis shows that large amounts of energy are used to shape glass bottles and handle their heavy weight.

Coca Cola: the feel and shape of the bottle is an important product symbol.Australian Food Standards: if packaging of a particular food satisfies the

Australia Food Standards, the manufacturer choose packaging materials and shape.

Production TechniquesFood companies to promote ecological sustainability - that is, to use the least

amount of natural resources necessary to make their products.Aspects of food manufacture that require energy: heating, cooling and

freezing, maintaining corect storage conditions and moving ingredients and products through the production process.

Large machines --- more energyOlder machines --- less power efficientThe State Environmental Protection Agency ensures manufacturers don't

pollute the environmentMain energy used in food manufacture is non-renewable resources e.g. coal

and oilgases released into the atmosphere during the production of packaging

products such as glass contain more carbon dioxide than is released during the plastic packages - and plastic products are also recyclable.

Some solutions: Reusing waste materials and recycling. Production of lighter and more efficiently shaped packages so that more can be transported at the same time.

Australian packaging industry has eliminated chlorofluorocarbons (CFC's) and replaced them with hydrocarbons.

Waste ManagementWaste management: Trucking, shipping or railed to an appropriate

destination.Use of inedible portions of food e.g. Orange juice --- Orange peel --- Used in

cattle feed " " " e.g. Packaged peanuts --- Shells ---

Mulch for mushroom growingIdeal situation: Food would be completely used or recycled, and there would

be no need for waste removal and waste water treatment.Biodegradable: able to be broken down by the action of living organisms such

as bacteria.Bacteria to treat waste water - The bacteria break down harmful semisolid and

solid waste in sediment tanks in harmless gases and clean water.Recycle: changing the form of an already used product into a new formsome food manufacturers are employing waste management companies such

as Pacific Waste Management to manage their waste.

Packaging WasteSanitary landfill: Involves filling natural depressions and quarries with

successive layers of waste and soil.Domestic waste - 35.4%Food waste - 10.9%

Social implications Lifestyle ChangesProduction of convenience packaging and convenience foods has enabled

Australians to enjoy increased leisure timeworking women has led to more convenience foodfamily members have clashes in schedules so all family members may not be

present for meal - led to microwaveable and already prepared mealshealth and fitness - low fat/high fibre foods are made due to the awareness of

healthnumber of family meanls has decreased, thus self-service has increasedfood manufacturers do alot of preparation, so consumers only have to do

basic steps. some residential units are being made without a kitchen due to lack of

preparation. developments in scientific research and production of food have led to an

increase in the production of organic foodstuffs.

Employment opportunitiesThe food industry employes 1 in 5 of the manufacturing work force small level operations: tends to be more labour intensive because of the cost

of machinery is hightype of product being produce: a large number of butchers are needed in a

meat processing plant because deboning meat and preparing speciality racks of lamb required skilled people. Few people are needed in an automated flour mill.

Goodman Fielder: produces ingredients. Employs 13000 people. Employment opportunities also exist in product development, materials

research, package design, labelling, waste management, marketing and food processing.