Review of fiber methods and applicability to fortified foods and supplements: choosing the correct method and interpreting results

Abstract

Fiber is known to be an important part of our nutrition and has many positive health benefits, including weight management and maintaining heart health. In recent years, a number of new ingredients have been manufactured or isolated that are being used to increase the health benefits of a product. Some are used as prebiotics that stimulate the growth of the beneficial bacteria in the gut, or are used as replacements for sugars, starch, or fat in manufactured foods. Fiber supplements have also been produced that can be taken to provide additional fiber to the diet. The term “fiber” does not relate to a single analyte or entity, but instead relates to a multitude of components. This adds to the complexity of analytical testing as there are a number of AOAC International and AACC International official methods which have been validated and can be used. Although methods have been developed for specific fiber ingredients, a number of methods have also been developed to capture just “fiber”. These “fiber” methods will capture differing degrees of the different fiber ingredients, so knowledge of the fiber sources is critical. The net result is that a variety of testing approaches may be used, but caution must be exercised in order to ensure that the total fiber result is accurately determined. A critical review of available fiber methodology and possible testing approaches is presented, along with how to accurately interpret and understand results.