REEFER MANAGEMENT

Know Your Product

Sustaining freshness and quality is the most important aspect in perishable cargo handling and the endurance in achieving that is to understand the commodity and its pre- and post-harvest characteristics.

Perishable Commodities are classified under three broad categories:

Chilled Cargo

This segment refers to commodities which need to be shipped and stored above product freezing temperatures.

Frozen Cargo

This segment refers to commodities which needs to be shipped and stored at freezing temperatures -20^oC or -4^oF or lower temperatures.

Special Sensitive Cargo

This segment refers to non-food products which needs humidity protection and /or temperature protection during shipment and storage.

Commodities in each category:

Chilled Cargo

Commodities under this segment have relatively shorter shelf life and requires diligent handling during transportation owing to its sensitive characteristics. Chilled cargoes have several factors influencing their shelf life.

Temperature

Temperature is the most important factor influencing shelf life as well preserving product quality and freshness of commodities because the rate of respiration is directly proportionate to the rate of deterioration, which increases exponentially as temperature increases. Optimum maintenance of temperature during transportation will maximize shelf life because it helps:

• Controls respiration
• Controls moisture and eventual water loss
• Avoids bacterial or fungus growth
• Impede any type of growth or sprouting
• Avoid chilling injury to the product
• Helps protect visual effect of the product

Respiration

All horticultural products such as fruits, vegetables, live plants etc. continue to respire even after harvest, consuming oxygen, generating heat, and letting off gases and moisture. All fruits and vegetables have different respiration rates which is part of their natural ripening or maturing process and determines their post-harvest shelf lifespan which has a direct influence on the colour, odour, flavour, texture, water content and, most importantly, value.

Ethylene Production

Ethylene gas is a natural by-product during post-harvest respiration. This needs to be effectively managed using temperature management in order control the ripening process during transportation. Ethylene production levels and concentration play a significant role in the product freshness and quality. Factors influencing rate of ethylene production are temperature, moisture, physical impact and pollutants.

Water Loss

Water loss in products during the post-harvest period has a direct influence in their lifespan and causes rapid deterioration, especially in leafy products. Product outturn is significantly stable when water content is sustained during transportation. Factors influencing water loss are temperature, humidity settings, product pre-cooling and packaging types.

Frozen Cargo

Commodities under this segment have longer shelf life. However they need steady and very low temperature management during the entire course of transportation to protect against decay and poisoning of products from growth of bacterial and disease forming organisms.

Frozen cargoes have several factors influencing its shelf life and quality:

Pre-shipment commodity freezing

Rapid freezing commodities prior transportation helps preserve the quality and prevents any micro-organism growth and enables slowdown in enzyme activities in all such products. Fast freezing results in superior quality and retention of texture, colour, and flavour.

Thawing

Product thawing is result of weak temperature management and can lead to product degeneration and soft or mushy products.

Packaging

Packing must be impermeable with required glazing which can prevent freeze burn or surface dryness and nutrient loss, bacterial contamination and any type oxidizing impact on the product.

Pre-cooling of Containers

Containers must be pre-cooled appropriately at frozen temperature which is essential to avoid thawing of products, freeze burns, and condensation of any type.

Stowing

Cargo stacking or stowing in a container must be in solid blocks, so that the cold air circulation around the periphery of the load is facilitated and also for maintaining the frozen state of all the cartons throughout the transportation process.

Ventilation

The vents of the container must be closed during the entire transportation to maintain the ultra-low internal temperature and it to remain in the frozen mode during transit and delivery.

Special Sensitive Cargo

Commodities under this segment require special handling in terms of humidity protection and/or temperature management during transportation. It is important to adhere to all special handling requirements – which vary from one product to another – for these diverse products. Some reefer containers are able to achieve down to 60% humidity.

Special sensitive cargoes have several factors influencing its outturn and quality:

Dehumidification

Humidity is lowered within a container to reduce or eliminate fungal growth or influence of vapour on products.

Temperature Management

These products are very sensitive in nature and needs steady temperature management with proper monitoring process in order avoid any reactions or deterioration. The knowledge of the product and its temperature compatibility must be well understood pre-shipment.

Pre-shipment knowledge and handling

These products need proper handling and sanitation prior shipment to ensure that there is no contamination or mis-management of products which can lead to decay or damage during shipment.

Packaging and Stowage

These products require specialized packaging and will differ per product, basis its characteristics or composition. The packages must be ventilated to enable proper air circulation within, as well as during stowage in the container to manage the sensitivity.

Know Your Handling

Product outturn and resultant quality is the most important aspect when shipping perishable commodities and hence the end-to-end handling of a product is integral which also underwrites the value of the product as well as the reputation and knowledge of the supplier.

Pre-Planning

It is important for every company to know the following information before effecting a shipment:

• Mode of Shipment – Sea, Air or Land
• Type and Size of Container – Sea Shipment
• Product Post-harvest Shelf life information
• Shipping Transit Times with Schedules
• Optimum carriage temperature, humidity and vent setting
• Product Quantity and Post-Harvest Weight
• Market and Regulatory Requirements

Pre-Cooling of the Product

Fundamental

It is very essential and important for the product’s sustained freshness, quality and shelf life if the cargo is pre-cooled prior to shipment. This benefits the cargo value as well.

Temperature

The storage temperature and conditions under pre-cooling must be in-line with the optimal temperature recommended for the commodity. The ideal temperature for the product/s must be verified prior setting at storage.

Benefits

Proper pre-cooling measures adequately followed pre-shipment offers direct benefit to the commodity from having any kind of spoilage or water loss or fungus or sprouting issues.

Packaging

Fundamental

It is very important to ensure that the packaging of the cargo is designed and constructed properly to sustain the value, quality and life of the product during the entire cool chain of the product.

Protection

The chosen packaging must withstand a variety of handling pressures and environmental conditions. It must protect the product end-to-end from every type of rough handling and ambient external conditions, i.e. high humidity, direct sunlight, snow, rain etc.

Strength

The design and quality of materials used in package construction must be strong enough to hold the product intact during stacking and every other stage of handling during the entire chain of carriage from storage to delivery.

Quality

The packaging must complement towards proper temperature management of the product including ideal permeability to hold product freshness.

Stuffing and Stowage inside a Container

Stowage

Fundamental

Proper stowage of cargo in a container or storage is very essential in order to maintain the required air flow at the desired temperature. A clear stowage is one of the critical elements in maximizing the post-harvest shelf life of all perishable products.

Chilled Cargo

Heat generated from chilled cargo due to respiration (refer Chilled cargo section) needs to be controlled with stable and steady flow of temperature-controlled air passing through in sizeable proportions enabling steady contact of air with all parts of the products within the load.

Essentially,

• Packages must have air vents inbuilt in them.
• When stacking vent holes must be aligned from top to bottom tier to facilitate airflow from the bottom air vents of the containers.
• Packages must be stowed or stacked as a solid block leaving nil space between them that may enable smooth flow of air through the products.

Frozen cargo

Frozen cargoes may be easier to handle, as there is no risk of respiration of cargo or sensitivity of cargo undergoing growth or loss of moisture or colour. Care must be taken to ensure steady flow of air at the set low temperature.

Essentially,

• Load should be stacked in solid block with nil space between packages or pallets, so that air can circulate around the load.
• Air must be allowed to circulate all over and around the entire load.
• Air vents must be closed all through the journey.

For an effective cargo stowage/loading plan the following basics must be adhered to:

1. The entire floor is stacked with the cargo so that there is steady air flow from the bottom air vents and air is not short cycled.
2. The cargo stowed must be below the redline with minimum space at the rear of the container to avoid hot spots.
3. Cargo is always block stacked/stowed to avoid air deviation since air always takes the path of least resistance.
4. The vents of the packaging are aligned for smooth flow of air through them.
5. Do not use shrink wrap or other materials that may block package vents and obstruct air flow.
6. Cargo should not be stowed too tightly against the side walls of the containers to prevent heat penetration from the sides coming into contact with the load , and allowing air to circulate around the cartons.