Weather and humidity are factors that we deal with daily. Quality issues within food and beverage products can be traced back to inconsistencies in humidity levels, and even the slightest humidity fluctuation can require procedural changes. Hygroscopic substances absorb moisture, and a small change in humidity will impact the consistency of the product, including during the material separation phase.
This article will evaluate the importance of regulating humidity, the impacts of high and low humidity, best practices for controlling storage conditions, and recommended equipment to control humidity. Examples will highlight the confectionery industry, where high sugar content in these sweet treats accelerates the products’ sensitivity to humidity fluctuations.
Importance of Regulating Humidity Levels
Humidity is not present in only one industry; it affects all processing industries. It’s important to recognize where humidity is present and rectify the situation quickly. Maintaining control over humidity is necessary to ensure that a consistent, high-quality product is produced, that performance is optimal for manufacturing processes, and that a product is stored correctly when it is ready to be consumed.
The issue of various humidity levels can play a role at any stage, even as early as particle separation. Hygroscopic powders absorb water from humidity in the air, which increases the cohesion and decreases the ability to flow. If a material were to expand when introduced to humidity, the particles could form together as they expand. Powdered materials that clump together as the humidity rises will end up halting production at some point due to their moisture level and inability to be properly processed. The challenges that are faced when processing materials in different parts of the country or in environments that experience multiple seasonal changes must be considered for proper processing techniques.
When an increased level of moisture is present, there is the risk of microorganism growth even in areas that are usually clean.
Aside from the inconvenience of lost product or decreased revenue due to incorrect humidity levels, there are serious implications to keep in mind. When an increased level of moisture is present, there is the risk of microorganism growth even in areas that are usually clean. Airborne bacteria can grow without the proper airflow, which is then passed along to the food. Suddenly, there is a much larger problem than an inconsistent product. Humidity that is too high or too low can also foster mold or bacteria growth, leading to decreased shelf life.
The Impacts of High and Low Humidity
As humidity levels fluctuate, product will become more difficult to transfer or convey because it is absorbing moisture, weighing more, and becoming stickier. Over time, conveying lines will start to clump and cake up, decreasing the pneumatic rate and slowly clogging the line. Aside from lower efficiency, sanitary concerns begin to rise when lines are clogged. When humidity levels are not balanced, plant maintenance teams will need to service the lines more frequently, causing downtime in the systems.
Knowing this, effective process systems that battle humidity will be equipped with a dryer or desiccant dryer that will help to dry the product properly. Other process systems will be integrated with delumping or declumping devices, which will combat the clumping and prevent clogs. In mechanical or pneumatic transfer systems, humidity is key to ensure a consistent rate of transfer.
In the confectionery industry specifically, inconsistent humidity levels lead to many product issues, most of which are visible to the naked eye. Candy is typically made of sucrose and corn syrup, both of which are highly hygroscopic. Effects of high humidity on confections include a cloudy appearance, grainy and irregular coatings, and sugar blooms. Products may experience sticky, runny, or high-water content in the product, as the product cannot cool properly. These issues may result in lower shelf life and the cost of returned or spoiled products from consumers. Confectionery products experiencing lower humidity will be more fragile; product may crack as it dries too quickly. Dry material is also more abrasive, causing the equipment to wear at an increased rate. Appearance of product is very important for confectionery products, so high or low humidity levels strongly affect the “shelf appeal” of these products.