Whole Grains and Health. Группа авторов
a Average based on products with the same designation but different amounts of cereal ingredients.
b Alkylresorcinols only, not including methyl and branched chain alkylresorcinols.
In some countries, it is common practice to add syrup or caramel coloring to give bread a darker appearance, or to add bran, intact grains or seeds in bread dough made from largely white flour to get a bread with good loaf volume and soft texture, but with the appearance of “wholesomeness” (Figure 5.1). This makes it very difficult to judge the whole grain content of bread based on appearances alone. Information on‐pack, or from manufacturers, is necessary to get an accurate measure of the whole grain content of individual breads. In some countries, such as the Netherlands and Germany, there are clear guidelines for labeling bread as whole grain, requiring 90–100% of flour to be whole grain flour,(1) though in other countries, it may be difficult or impossible to determine whole grain content for “dark bread.”
Due to the highly variable nature of bread, and the fact that the use of whole grain flour may be highly specific for different countries or regions, it is necessary to carry out on‐the‐ground surveys of both pre‐packaged bread and bread bought directly from local bakeries to get an idea of whole grain content.
b. Breakfast cereals
Breakfast cereals represent a diverse range of products and in some countries, notably in North America, the United Kingdom and Ireland,(10,11,12,13,14,15) are one of the main sources of whole grains in people’s diet. Breakfast cereals encompass “ready to eat” (RTE) breakfast cereals that are often based on flour (frequently with added sugar) that is mixed with water, then heated and extruded, as well as cooked porridges and mueslis. As with bread, breakfast cereals range from 0–100% whole grain with no reasonable “average” for whole grain content of a whole grain–containing breakfast cereal.
Recent years have seen efforts to promote the whole grain content of packaged cereals so that, in many countries, this is either prominently displayed on the packaging or clearly indicated in the ingredients list. Importantly, breakfast cereals often include grains that are otherwise not so commonly consumed. Due to the dominance of wheat in bread and pasta‐type products, the frequent use of oats for breakfast cereals, porridges and mueslis provides some diversity in the types of cereals eaten. Specialty cereals often contain less common grains, and while on a population basis median intake may be negligible, intake by those who do consume these cereals may be important for health outcomes. As with all cereal foods, it is important that information on the type of cereal in the diet is recorded, not just the total amount.
Several well‐known RTE breakfast cereals are 90–100% whole grain, and with serving sizes ranging from 30–60 g dry cereal, these can represent an important part of daily whole grain intake. Although breakfast cereals are more likely than other cereal‐food categories to be high in whole grain content, making assumptions about whole grain content based solely on color or texture is fraught. A further complication in some breakfast cereals is the inclusion of cereal bran, an ingredient that is sometimes mistakenly thought to be a whole grain. Although the focus of this chapter is not to discuss the relative merits of whole grains versus bran, it should be noted that in the most widely accepted whole grain definitions,(16,17) bran is not considered to be a whole grain, and nor is there any equivalency assumed. Bran‐based cereals are an important source of dietary fibre, and efforts should be made to separate intake of cereal bran as an ingredient (as opposed to estimating cereal bran coming from both whole grains and as a separate ingredient, which has been done previously,(18,19) but suffers from the high degree of collinearity between whole grain intake and bran intake estimated in this manner).
Porridge is a common food in many countries, consisting of cereal (intact, rolled and heat treated, or flour) and water or milk, boiled until a thick consistency is reached. In many cases, the grains used are whole grains, such as oat porridge, but others may be refined, such as wheat semolina and degerminated cornmeal. Estimating intake of whole grains from porridge is greatly affected by whether the product is reported on a dry‐ or wet‐weight basis, as cooked porridge is generally 80–90% water.