Product safety and superior taste are the bottom line, while spoilage and poor quality can hurt, and even destroy sales. Processors must therefore set quality standards and stick to them.
But where do you set the standard, and how much of a safety margin do you need? When it comes to moisture content, too many manufacturers use a ‘by guess and by golly’ measuring standard.
An example can be found in a typical pet food manufacturer who’s production is at an 8% moisture content. At that level, the manufacturer has no spoilage problems or shelf life concerns, and therefore – a safe product.
Instead, however, profits dry up. After using a water activity measurer to get a more accurate food quality picture; the product’s water activity is found to be at 0.50aw. A little additional information revealed that the manufacturer needed only to stay below 0.65aw to produce a quality, shelf stable product, which was below the mould growth limit.
Without knowing exact costs, it is possible to estimate the profit margin represented by a difference in 0.50aw and 0.65aw. If 20,000 pounds of product is produced per hour, operating 16 hours a day, five days a week, and selling the product for 40 cents a pound, raising the target aw level would allow an additional 1,877,314 pounds of product to be produced, generating an additional $750,925 in revenue.
Since this change would reduce utility costs while keeping man hours, raw material costs, and wear and tear on equipment at the same levels, much of this would amount to pure profit.
Many manufacturers have, in this way, decreased costs and increased profits. However, moisture content measurements alone can not give the safety and quality information manufacturers need.
Knowing water content reveals nothing about the total food quality picture, and good operating decisions can only be made by using thorough and trustworthy information. Usually, water activity is one of the best pieces of information available in setting and maintaining food quality standards.
The food industry, together with the FDA and USDA is adopting a system to improve safety and reduce the incidence of food-borne illness. The Hazard Analysis Critical Control Point program (HACCP) involves setting critical control points that measure food quality throughout production.
Rather than relying on a ‘check-and-chuck’ method at the end, these critical control points detect problems all along the production line. Water activity is a critical control point in many processes as it defines limits for microbial and chemical parameters which must be controlled to prevent food safety hazards.
Even when safety isn’t an issue, water activity is an important measure of quality. Setting critical control points to avoid loss of crispness in dry products, caking and clumping of powders, tough and chewy textures in moist products and shortened shelf life is imperative.
Water activity is a powerful force, and measuring and managing it allows for greater control over the quality of product. Producing a consistently high quality product and meeting consumer expectations without having to throw away mistakes, could mean doing away with a huge safety margin that wastes potential profit.