September 23, 2019

Experts approve new Official Method for accurately measuring lactose even at very low levels

Rockville, Maryland, September 24, 2019—Food safety experts gathered at the 133rd AOAC INTERNATIONAL Annual Meeting and Exposition in Denver, Colorado have adopted a new Official Method of Analysis℠ for measuring low levels of lactose in milk.

Lactose intolerance affects approximately 65 percent of the global human population, although it varies greatly between populations. Approximately 5 percent of northern European and over 90 percent of Southeast Asian populations are affected.

Lactose, the most abundant sugar in dairy products, is normally hydrolyzed during digestion by the enzyme lactase-phlorizin hydrolase. People deficient in this enzyme can experience gastrointestinal symptoms including nausea, cramps, bloating and diarrhea. In commercially manufactured low-lactose and lactose-free dairy products, most of the lactose has already been hydrolyzed into glucose and galactose which are well tolerated. The new method promotes public health by allowing greater precision in measuring remaining lactose.

The new analytical method, “K-LOLAC Enzymatic Low Lactose Assay,” was developed by a team of scientists at Megazyme, headquartered in Bray, Ireland, and was presented to an AOAC Expert Review Panel in a report by R. Ivory, E. Delaney, D. Mangan and B.V. McCleary. The method involves two key steps, namely sample clarification and enzymatic removal of free glucose, followed by spectrophotometric measurement of remaining glucose in the sample before and after incubation with a specific beta-galactosidase. Lactose in the sample is then calculated.

“We wanted to design a lower cost, faster method, where it was possible to run multiple samples at the same time, and that’s what we have developed,” said Barry McCleary, CEO and founder of Megazyme. “A key element of the method being accepted globally is AOAC validation, so we are very gratified that it has now earned First Action status. This is our 11th validated method and we are very committed to the AOAC process.”

The method was adopted as a First Action Official Method of Analysis during a meeting of the AOAC INTERNATIONAL Expert Review Panel for Low-Lactose Methods on September 11, 2019. Official Methods of Analysis of AOAC INTERNATIONAL are microbiological and chemical analysis procedures that have undergone rigorous formal validation by AOAC INTERNATIONAL. After a two-year tracking period, First Action methods are reviewed for approval as Final Action methods, which are published in the “Official Methods of Analysis of AOAC INTERNATIONAL,” a globally recognized standards resource for analytical scientists.

The method was evaluated against Standard Method Performance Requirement (SMPR®) 2018.009: which details the requirements for testing mono- and di-saccharides. Foods currently on the market can contain compounds that interfere with testing or can have much lower levels of sugar than was common when previous testing methods were developed prior to 2000.