Temperature excursions during refrigerated food transportation reduce product shelf life. Maintaining the integrity and quality of refrigerated cargo is paramount to preventing these issues. Stakeholders, from fleets that transport food to distribution centers and manufacturing facilities, follow industry standards to ensure food safety.
As an ecosystem, it’s vital that all involved in the food transportation and storage cold chain understand these procedures. Temperature-controlled vessels transport perishable cargo. Consistent temperatures preserve the integrity of the product to prevent spoilage, and fleets maintain a tight temperature band with minimum variations to ensure the product has the longest possible shelf life. In addition to standard food safety procedures, fleets can follow food transport best practices to ensure the product quality and longest shelf life while realizing fuel savings.
The Pre-Trip Inspection
The first step to ensure optimal food quality is to perform a pre-trip inspection of the transport refrigeration unit (TRU) and the trailer. Manufacturers should set pre-trip inspection requirements that include clearing previous alarm codes or addressing and mitigating existing alarms. Drivers should perform a visual inspection of the trailer to ensure the unit isn’t physically compromised in any way. Lastly, drivers should ensure there’s enough fuel onboard to operate the unit for the expected duration of the trip.
Pre-cooling the trailer ensures that cargo doesn’t reach inappropriate temperatures during or immediately after loading. The same standards apply regardless of the starting and final trailer temperature to ensure temperatures are within food safety guidelines.
Fleets begin the pre-cooling process by setting the TRU setpoint at the manufacturer’s desired temperature. Some air will escape the unit during loading, so some manufacturers prefer the temperature to be set below the set point. Distributors of the product in transport generally set the pre-cooling guidelines.
Protocol dictates that those pre-cooling conditions are met before operators load pallets onto the truck or trailer. For example, a manufacturer of ice cream might want to pull down the temperature to -20 degrees Fahrenheit before loading, while others may prefer to load at -10 degrees Fahrenheit. The key is keeping within the product’s tolerance range to maintain the its integrity.
Single-temperature refrigeration units pull down the temperature of the truck or trailer to the desired temperature. Typically, refrigeration units utilize a high speed to pull down to the setpoint quickly. Pulling the trailer temperature down at a low speed may take longer, but it’s a worthwhile consideration, as it can equate to significant savings in fuel costs.
Maintain Precise Temperature Control During Refrigerated Transport
Fleets can optimize the refrigeration unit and trailer to maintain desired temperature control, ensuring product integrity and negating potential losses from temperature variations. Airflow is one of many important factors in reducing temperature excursion risk. Here are four ways to improve airflow within the trailer:
1. Install Door Switches. It’s a best practice to turn off the trailer before opening doors to load cargo. Hot air will be pulled into the trailer if the unit is running when trailer doors are open. In food distribution with multiple stops throughout the day, drivers may forget to turn off the unit before unloading cargo, which repeatedly increases the overall trailer temperature. Trailers with door switches will automatically turn the unit off when the driver opens the doors. This process protects the integrity of the cargo throughout the loading and unloading process.
2. Stimulate Airflow and Circulation. Consistent airflow and circulation from the front of the trailer to the back helps maintain appropriate temperatures throughout the trailer. This is key to minimize the risk of hot spots, especially around temperature-sensitive cargo. An air chute distributes cold air to the back of the trailer before it cycles back toward the front, which reduces risk of short cycling.