The Supply That Came in From the Cold

Guest contributor: Anders Bonde

The global transportation of commodities has become a necessity in the modern world, with shipping and logistics following rapid economic and political change. This includes the movement of temperature-sensitive goods, perishable commodities that are liable to expire, decay, or spoil quickly. Such goods require the most efficient supply chain, not only in terms of technology and know-how, but also in terms of timely delivery, in order to respond rapidly to market needs.

Yet the practice of perishable logistics is not new. It existed, in its basic form, even back in 1790s when British fishermen used natural ice to preserve piles of fish stock. The process of perishable goods transport continued to improve during the late 1800s with the transportation of dairy products from rural areas to consumption markets. At that time, the first shipments of meat arrived from South America to France and from Australia to Great Britain. At the beginning of the 20th century, the first shipments of bananas were heading towards remote areas where bananas could not grow. Today, the term “seasonal” for fruit and vegetables almost doesn’t exist anymore. Food is shipped from one part of the world to another, on a daily basis, to meet the demand of consumers, regardless of the time of year.

Nowadays, perishable logistics relies on cold chain technology to maintain proper temperatures during handling and transport. This is essential in preserving the quality of perishable goods such as fresh meat, seafood, ripe fruits, and temperature-sensitive medical products. When perishable commodities are transported from producers to consumers, they are expected to stay fresh across considerable distances. Perhaps one of the most important keys to success in the cold chain is controlling the temperature in various shipping circumstances.

This is particularly challenging when considering that different products require different temperature maintenance. Common temperature standards include: banana (13 °C), chill (2 °C), frozen (-18 °C), and deep frozen (-29 °C). Depending of the type of product and standard set, different types of containers and refrigeration methods are required. It is of due importance that proper packaging is used, depending of temperature standard, type of product, duration of transit, size of shipment, and outside temperature.

To ensure the quality of goods and services, a number of cold chain technologies are used. The most common include:

• Dry ice – Solid carbon dioxide which does not melt. It keeps a shipment frozen during extended periods of time at approximately -80°C. It is suitable for shipping of pharmaceuticals, dangerous goods, and food.

• Gel packs – Mostly used for pharmaceutical and medical shipments which must be stored at a temperature between 2° and 8°C. Gel packs may melt during the transit process, while still maintaining an internal temperature. An alternative to gel packs is eutectic plates filled with liquid, which can be reused many times.

• Liquid nitrogen – Used to keep items frozen over extensive periods of time, mostly for the transport of biological cargo. Its temperature is approximately -196°C, and it is considered a hazardous substance.

• Quilts – Serve as a buffer in circumstances of temperature variations. They keep the temperature constant and are therefore often used to keep sensitive goods at room temperature, protecting them from outside temperature changes.

• Reefers – A container with controlled temperature. It can be an ISO container, a van, or a small truck, with the temperature maintained by an attached, independent refrigeration plant.

A professional and organized perishable supply chain and transportation network is the most important component of shipping quality and fresh foods, and, consequently, the food industry worldwide. It requires professional staff, modern equipment, and knowledge of many different regulations in various countries. Long transit times or poor handling may lead to spoilage of perishable goods, which may result in potential food-borne illness.

Distance, transit, and time of transport of perishable goods are not the only challenges of the cold chain. Other factors influence the quality of cold chain services, such as weather conditions, political affairs, various regulations, and technical problems.

Weather conditions are one of the major concerns when it comes to perishable logistics. Extreme warm or cold outside temperatures may be a great disadvantage when loading or offloading trucks and airplanes. Simple solutions, such as loading during night in warm areas, or during midday in cold environments, may help in preserving the quality of goods.

Political affairs, such as the transport of perishable goods to or through conflict areas, may represent another obstacle. In such cases routes should be carefully chosen prior to shipping. Otherwise, there is a danger of long delay, which often results in inability to preserve the freshness of goods. Furthermore, local and regional regulations, such as bans on storing cargo with dry ice in small closed areas in Europe, or special provisions for transport of medical equipment and supplies, should be carefully followed by all cold chain participants and contributors.

Other common problems of cold chain logistics are technical in nature. Equipment is disposable and prone to damage. It is therefore of high importance for any cold chain to ensure backup equipment and technical support, regardless of location, or type of equipment.

Consumption level of perishable foods in the world increases each year. The industry is demand-driven and, therefore, increases the necessity of even more efficient cold chains in terms of reducing the time-to-market. It requires high problem-solving skills supported by technological means. If logistics providers want to stay on top of the cold chain game, they must continuously search for new technologies that will advance their operations and competitiveness.