Search

Definitions for whole grain (WG) have been published by governments, the food industry, and grain organizations and generally fall into 2 categories: WG and WG food. WG definitions focus on the principal components of the WGs and their proportions, whereas WG-food definitions describe the quantity of WGs present in food. In the United States, widespread agreement exists on the main parts of a definition for a WG, with a definition for a WG food still in its early stages; a standard definition that has been universally accepted does not exist. Furthermore, nutrition policy advises consumers to eat WGs for at least one-half of their total grain intake (2010 and 2015 Dietary Guidelines for Americans), but confusion exists over which foods are considered WGs and how much is needed to achieve health benefits. In December 2014, a workshop sponsored by the subcommittee on collaborative process of the US Government's Interagency Committee on Human Nutrition Research convened in Washington, DC, and recognized WG definitions as a key nutrition and public health-related issue that could benefit from further collaboration. As a follow-up to that meeting, an interdisciplinary roundtable meeting was organized at the Whole Grains Summit on 25 June 2015 in Portland, Oregon, to help resolve the issue. This article summarizes the main opportunities and challenges that were identified during the meeting for defining WGs and WG foods internationally. Definitions of WGs and WG foods that are uniformly adopted by research, food industry, consumer, and public health communities are needed to enable comparison of research results across populations.

The majority of whole grain flour is produced using modern milling techniques, usually with steel rollers, in which a batch of grain is separated into multiple millstreams, sifted, and recombined. In some cases constituent millstreams are purchased and combined by a supplier or end user to achieve a reconstituted whole grain flour or meal with desired functional, safety, and nutritional properties. In a very small number of cases whole grain flours are stone-ground, with the grain kernels crushed between rotating stones. Data comparing single-stream milling and multiple-stream milling with recombination do not show any strong advantage for either milling method. The separation of millstreams, in fact, allows highly labile brans and germs to undergo a stabilization treatment to make them less susceptible to rancidity—the net result of which is greater safety, stability, and nutrient retention. Data comparing use of stones and steel rollers in milling, in most cases, show improved nutrient and dietary fiber retention and greater protein availability in grains such as barley when steel-roller mills are used. The AACCI Whole Grains Working Group supports increasing whole grain intake through the use of intact whole grains and grains milled with stones and steel rollers in single-stream milling, multiple-stream milling where streams are recombined at the mill, and multiple-stream milling in which whole grains are responsibly reconstituted.

This paper is the first in a series that will be published in Cereal Foods World with the purpose of providing a unified grain health message. This installment focuses on whole grains. Whole grains are defined as “consisting of the intact, ground, cracked, or flaked caryopsis (fruit or kernel) of the grain whose principal components, the starchy endosperm, germ, and bran, are present in the same relative proportions as they exist in the intact grain.” Dietary recommendations on whole grain consumption vary widely among countries and organizations and can come in three stages: first, a recommendation for the consumption of grain foods in general; second, the inclusion of a nonspecific reference to whole grains to encourage consumption; and third, a recommendation for a specific amount of whole grains in the diet. Upon recommendation, defining “whole grain” becomes important. Most academic and government sources abide by the definition put forward by AACCI and the FDA, but the definition can lose clarity wi...