Cold chain consists of cold storage, cold transport, value addition and preservation infrastructure to provide an integrated cold chain without any break from the farm gate to the consumer. It covers pre-cooling facilities at production sites, reefer vans, mobile cooling units as well as value addition centres which include infrastructural facilities like Processing/ Multi-line Processing/ Collection Centres, etc. for horticulture, organic produce, marine, dairy, meat and poultry etc. Cold Chain Management is much needed for maintaining it’s quality and safety in food processing industries.
IMPORTANCE OF COLD CHAIN
Cold chain is vital to preserve the safety and quality of refrigerated foods and comply with legislative directives and industry ‘codes of practice’. The ultimate goal for cold chain management is to deliver perishable foods and food products in a timely fashion while maintaining the quality of the products and increasing their shelf life.
Cold Chain Management
MAINTAIN THE QUALITY AND SAFETY OF COLD CHAIN
Maintaining the quality and safety of cold chain is not an easy task. Special care has to be taken from the point of origination to the point of delivery. Each stage has its own problems which need to be maintained properly for efficient results.
For this, we have compiled up some important factors that need to be taken care off and they are:
Temperature should be controlled for chilled foods as they are highly susceptible to the growth of microbes. The minimum growth temperature of some susceptible bacteria are:-
Ice in frozen foods keeps them safe while ensuring quality while in chilled foods temperature control is crucial for the initial low bacterial count. Temperature control also preserves both sensory and nutritional qualities. The various attributes of freeze damage after thawing are freezer burn, discoloration, mechanical damage etc. evident after cooking.
How ice and water can damage foods?
Unfrozen Water-10% unfrozen water below-180C can take part in physical and biochemical reactions.
Freezing Damage- Expansion of water to ice causes large voids and excessive drip loss in frozen foods after thawing. Hence the food should be frozen rapidly and constant low temperature should be maintained during frozen storage.
Ostwald ripening causes freeze damage where large ice crystals grow on the expense of small ice crystals. Accretion is joining of two ice crystals to form a large crystal and freeze damage. Both are minimised by maintaining a constant temperature.
Vapour migration is building of ice on the interior of packaging and on food surfaces caused by the temperature gradient between the surface and centre of the product. The freezer burn caused can be minimised by maintaining a constant temperature.
Solute concentration and osmotic dehydration– Ice formation increases solute concentration in unfrozen water and leading to inconsistency through the product and damage to cell membranes. Drip loss causes loss of turgor and cell damage minimised by maintaining a constant temperature.
2.Role Of Packaging in cold chain management
Packaging plays a key role in protecting the product from contamination by external sources and from damage during its passage from the food producer to the consumer and portrays high quality and responsible food production to consumers.
The primary function of food packaging is to protect the food from external hazards. Package barrier properties protect the food from moisture loss, ingress of gas, light, and water vapour, each of which can result in deterioration of colours, oxidation of lipids and unsaturated fats, denaturation of proteins and a general loss of characteristic sensory qualities.
Laminates have ideal packaging properties and hence board and paper packages are laminated with synthetic plastic to improve barrier properties. Food packaging should be stable over wide temperature change and ensure consumer appeal.
The essential requirements to comply with environmental standards are:-
- Packaging must be minimal subject to safety, hygiene and acceptance for the packed product and for the consumer.
- Noxious or hazardous substances in packaging must be minimised in emissions, ash or leachate from incineration or land-fill.
- Packaging must be recoverable through at least one of the following: material recycling; incineration with energy recovery; composting or biodegradation
- Packaging may be reusable
3. A brief guide to legislation and GMP for the cold chain management
General legislative directives relevant to cold chain operations include:
- The Food Safety Act (1990, COP No. 13, MAFF, UK)
-covering descriptions of safety, quality, description offences, defence and enforcement and penalties
- Compositional Standards
– covering specific product categories, e.g. quick-frozen foods, meat products, milk and dairy products, bread and bakery products
- Labelling, presentation and advertising (SI 1996, No. 1449)
– covering nutritional declarations, ingredient declarations, minimum durability, e.g. ‘best-before’, ‘use-by’ dates.
- Additives and contaminants
– E.g. colours and sweeteners, pesticides and residues, metals
- Packaging directives (SI 1994, No. 979)
– E.g. materials in contact with foods, packaging waste
- General Food Hygiene (IFST Guidelines for the handling of chilled foods (ISBN 0905367073; RFIC Guidelines for the storage and handling of frozen foods (British Frozen Foods Federation, London))
– covering basic food hygiene and standards, guidance on temperature control and specific product needs within the cold chain.
The various GMP to be followed for Cold Chain Management are:
Step 1: Raw materials and packaging
- Set product specifications, e.g. microbiological, temperature, quality, hygiene
- Adopt ‘approved suppliers’ and incoming product inspection regimes
- Comply with packaging directives, e.g. contact materials, environmental
- Ensure packaging meets technical requirements, e.g. barrier, insulation
Step 2: Control the manufacturing operation
- Use appropriate freezing equipment to maximise quality
- Pass through ‘zone of crystallisation’ as quickly as possible
- Regard freezing as complete only when product reaches –18oC throughout
- If manufacture requires heating, cool as soon and quickly as possible
- Ensure storage and transportation of chilled foods is below 4oC
- High risk categories require special (segregated) manufacturing conditions
Step 3: Maintain the appropriate storage conditions
- Maintain primary and secondary freezer stores at between –20oC to –28oC
- Maintain frozen product temperatures at less than –18oC
- Maintain chill stores at between 0oC and 8oC
- Maintain chilled products that spoil rapidly at between –1oC and +2oC
- Maintain microbiologically susceptible products at between 0oC and +5oC
- Minimise air temperature variations in cold stores
- Ensure optimum stacking patterns in storage regimes
- Monitor and record air temperatures in warmest part of the storage facility
- Provide alarms to indicate temperature abuse
Step 4: Distribution of chilled and frozen foods
- For primary frozen distribution, temperatures between –12oC and –18oC
- For local frozen distribution, -12oC to –15oC
- For chilled foods temperatures control, ensure
- Category 1 (-1oC to +2oC): fresh meat, poultry, offals, comminuted meats, fish and shellfish, smoked fish
- Category 2 (0oC to 5oC): pre-cooked foods, cured meats, sandwiches, pasteurised milk/cream
- Category 3 (0oC to 8oC): fruit and vegetables, fermented meats, hard cheese, bakery products, butter/margarine, spreads
Step 5: Ensure appropriate conditions for retailing/foodservice
- Inspect and measure incoming food for temperature control
- Monitor in-house cold store facilities
- Operate retail display cabinets according to manufacturer’s guidance
- For cook-chill and cook-freeze products, ensure a minimum reheating operation of 70oC for 2 minutes is achieved
- Maintain food temperatures above 63oC for foodservice
A vital component to ensuring this the presence of Hazard Analysis and Critical Control Point. It prevents the food from physical, biological and chemical hazards during processing.It ensures that the final product is safe and risks are reduced to a safe level. It is present at every level of the food chain and is adopted by USDA and FDA. HACCP certification is an important step for every food business owner, however as per ‘The Food Safety and Standards Act, 2006’. Read More..