Passing the Test
March 1, 2005
Passing the Test
Advances in lab/testing equipment help ensure product quality
There isn’t a single beverage that hits U.S. store shelves without first undergoing extensive testing on the product itself and the container. Testing for microorganisms is standard, but beverage-makers also perform myriad tests to determine such things as the amount of carbon dioxide or sugar in a product, whether a sodium-free product is actually free of sodium, the strength of a product’s container, and whether its closure is correctly applied.
Testing methods are basically the same throughout the industry, but some product categories require different tests, or different applications of a particular test, than others.
“Oxygen is a good example of something that would be tested in one environment and not another,” says Marc Epstein, vice president of Terriss Consolidated Industries Inc., an Asbury Park, N.J.-based manufacturer and distributor of scientific instruments and laboratory supplies. “Although a soft drink is not very sensitive to oxygen, metal cans can still corrode in the presence of oxygen. This means that soft drinks are tested for oxygen in cans, but not in glass and plastic bottles. Beer and juice are more sensitive to oxygen because the product can oxidize and turn color. Just like bananas eventually turn brown, orange juice can turn brown if there’s too much oxygen present in the container.”
While some products are more regulated than others, manufacturers perform the majority of tests to ensure product quality rather than to meet mandated standards.
“Any food or beverage plant is going to be concerned with the possibility of microbial activity,” says Epstein. “Companies are always trying to evaluate and ensure product quality and make sure that plants are running according to company-developed protocols. That could be as simple as ensuring a changeover is handled properly so you don’t create a drink that’s a combination of two products.”
For beverage-makers, microbiological testing is conducted, in part, to ensure that products are free of pathogens, such as E. coli or Listeria, which can cause illness or even death. But the presence of microorganisms in a beverage, even if they’re not pathogens, can also affect flavor, quality and shelf life. Accordingly, microbiological testing is performed by virtually all beverage companies as part of the quality-testing process.
Bacteria and fungi are the two major types of microorganisms for which beverage-makers test. The traditional testing method involves taking a product sample, placing it in a petri dish, or a glass plate or slide, incubating the sample, and waiting to see if bacteria or fungi grow. Lab technicians typically take a 100-ml. product sample, put it through a monitor and use a vacuum pump to pull the sample through a membrane at the bottom of the monitor before combining it with the appropriate media and placing it into an incubator.
Bacteria tests take two to three days, while fungi tests require five to seven days. Media used in these tests include MF-Endo; M-Green Yeast and Mold; MI, which is used to test the presence of total coliform and E. coli; M-FC; and HPC. These media are combined with the samples to detect the growth of specific types of microorganisms. While this type of testing and the media are standard, membrane sizes vary by product; for example, more viscous products, such as those containing syrup, or carbonated products would use a different size/thickness membrane than bottled water.
“It’s usually a 100-ml. size sample, and lab technicians will use a 47- or 56-ml. monitor,” says John Perini, director of sales and marketing for Keene, N.H.-based Schleicher & Schuell BioScience Inc., a provider of quality control materials for bottled water and beverage QC labs, including testing media and monitors, and filtration equipment and supplies. “They want to make sure they capture everything in that sample to ensure they’re getting a very accurate portrayal if there’s any type of contaminant or organism present in the product,” he says.
One of the challenges beverage-makers face is that the testing process can slow the production process. While manufacturers want to ensure the quality of their products, they also want to complete testing in a timely fashion so production can continue and the finished beverages can be shipped to stores. This is particularly true in the case of high-volume products such as bottled water or soft drinks, and for perishable products such as milk and orange juice.
At the same time, beverage-makers are under pressure to hold down both production costs and consumer prices. As a result, many manufacturers are employing rapid analysis methods and equipment so testing can be completed faster. “Price in this field is critical,” says Pascal Yvon, chief executive officer at AES Chemunex Inc., a Princeton, N.J.-based provider of lab equipment for microbiology analysis. “Consumers always ask for better products and lower prices. A beverage company has to be creative and innovative in the way they develop their products, and at the same time, make sure that they produce better products at a lower cost.”
To that end, AES Chemunex introduced a rapid analysis product last year, the BactiFlow compact microbial analyzer, which detects the presence of microorganisms within a day, and allows for testing of larger sample sizes. Rapid methods allow beverage-makers to streamline their operations and gain a competitive edge in the marketplace.
“If a company decides to be very safe and stock a juice product in tanks for seven days for testing, it’s a lot of money that’s not moving,” says Yvon. “It’s very important to beverage companies to be extremely reactive to the market. For example, if a maker of juices or concentrates has hundreds of liters of product, but says to a customer, ‘you’ll have to wait two weeks to get it,’ somebody else is probably going to come along and say, ‘our product is available now.’ So it can be a competitive advantage to be ready now, which is why rapid methods are so attractive to beverage-makers.”
Other beverage testing
Beverages aren’t the only thing manufacturers test. Ensuring that packages are filled properly and meet standards for safety and strength also requires testing. Zahm & Nagel Co. Inc., of Holland, N.Y., is among the companies providing CO2 (carbon dioxide) and air testers for bottles and cans to brewers and bottlers; this equipment tests a product’s volume of CO2 and head space air, respectively, as well as the purity of CO2 gas sources.
“Beverage-makers perform the CO2 test because carbon dioxide has such an effect on the flavor of the product. They want to be sure they have the proper amount of carbon dioxide,” says Zahm & Nagel President David Koch. “It would be used in a soft drink or in alcoholic beverages like beer or champagne, anything that is carbonated.”
Tests for carbon dioxide and head space air have been standard since the 1930s and ‘40s, when products such as beer and soft drinks began to be mass produced and distributed throughout the country.
“Head space air is the air that is picked up during the process of producing soft drinks or alcoholic beverages. They might pick it up during the filling process through leaky seals or bad gaskets or something like that,” says Koch. “It’s really detrimental to the product, so manufacturers want to make sure it doesn’t get in there.”
Like other testing technology and equipment, the technology used to measure CO2 and head space air has remained virtually the same since its widespread use began. However, many industry suppliers have introduced advances that tweak the basic technology or make it easier or more convenient to use. Terriss, for example, offers an electronic device to measure head space air, a process traditionally performed manually. But testing technology has generally been designed to keep pace with processing technology to ensure compatibility between systems.
“Production equipment is a fixed investment. It has a life cycle and inherent control capabilities,” says Epstein. “Analytical equipment has to be able to measure as well as, if not better than, production equipment. But it doesn’t make sense to radically change your analytical equipment if you can’t change your process. If the process can only be controlled to a specified extent, having analytical ability that goes beyond that doesn’t buy you a better product.”
While some of the technology hasn’t changed much, there has been a move toward employing analytical tools across the beverage industry, such as software packages that track various plant metrics that give an overall picture of the production process, including testing.
“The primary thrust for the last five to 10 years has been the use of more sophisticated statistical tools and software packages to be able to do a better job of slicing and dicing data to see how a plant’s doing,” says Epstein. BI