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Whole Grains and Health


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Others have also suggested that once more than 10% of the dietary fibre has been removed or disintegrated then the resulting ingredient or product can no longer be considered to be whole grain.(1) However, this is complicated, as total dietary fibre may not reflect the effect of processing that can have a major impact on biological function(7) even if total fibre does not change. For example, some water soluble compounds may be leached out during boiling of cereal products.

      Currently, two “user friendly” and accurate ways to report whole grain content are available in different parts of the world, helping researchers, consumers and policy‐makers alike. The first is the QUID labeling used in Europe (see earlier), which clearly documents any whole grains as a percentage of the product as consumed.(1) The second is the Whole Grain Stamp, a labeling certification programme offered through the non‐profit Oldways Whole Grains Council, which displays the grams of whole grain ingredients per serving of more than 13,000 products in 63 countries.

      An important additional aspect of quantifying whole grain content is to report the proportion of different grains. As interest in understanding the differential effects of different grains increases, breaking down daily whole grain intake into different types of grain is necessary(8,9): whole grain oats or rye, for instance, may be associated with different health benefits than whole grain wheat or barley. This is usually done with QUID labeling, and is recommended as part of guidelines for whole grain food labeling.(1)

       5.2.3 Whole grain contents in different cereal foods

      a. Bread

      Bread is one of the most common cereal foods, and intake is nearly ubiquitous among all people. Bread as a product is highly diverse, both in terms of ingredients (e.g., wheat, rye, corn/maize, barley, gluten‐free dough mixes) and processing (yeast leavened, sourdough, crispbread and unleavened flatbreads; short or long fermentation; use of enzymes and additives to improve shelf‐life and loaf properties). The whole grain content of bread varies between 0% and 100% of the flour component, with the increasing amount of whole grain in bread usually leading to denser loaf volume. However, the addition of baking improvers such as vital gluten or enzymes can give acceptable volume to breads with 100% or close to 100% whole grain. Some baking enzymes are known to have side activities that break down dietary fibre, which may be a concern as dietary fibre is sometimes used as a reference for whole grains in a product.

      Sources: Ross AB, Svelander C, Karlsson G et al. (2017) Identification and quantification of even and odd chained 5‐n alkylresorcinols, branched chain‐alkylresorcinols and methylalkylresorcinols in Quinoa (Chenopodium quinoa). Food Chem 220, 344–351; Chen Y, Ross AB, Åman P et al. (2004) Alkylresorcinols as markers of whole grain wheat and rye in cereal products. JAgricFood Chem 52, 8242–8246; Ross AB (2012) Analysis of alkylresorcinols in cereal grains and products using ultrahigh‐pressure liquid chromatography with fluorescence, ultraviolet, and coulArray electrochemical detection. J Agric Food Chem 60, 8954–8962; Ross AB, Kochhar S (2009) Rapid and sensitive analysis of alkylresorcinols from cereal grains and products using HPLC‐Coularray‐based electrochemical detection. J Agric Food Chem 57, 5187–5193; Andersson AAM, Åman P, Wandel M et al. (2010) Alkylresorcinols in wheat and rye flour and bread. J Food Compost Anal 23, 794–80.

      

Product Flour/grain % Type of grains Serving size (fresh weight) Maximum contribution to whole grain intake per serving (g) Total alkylresorcinol content (μg/g dry weight)
Bread
White‐wheat bread 51 Wheat 28 0 20a
Whole‐wheat bread 51 Wheat 28 14 438a
Rye bread 42 Rye and wheat 30 12 412a
Breakfast cereal
Corn flakes Corn 30 0 0
Whole wheat/rice flakes 80 Wheat and rice 30 24 251
Whole‐wheat biscuits 100 Wheat 40 40 478a
Bran‐based cereal 85 Wheat bran 40 0 1700
Rolled oats/oatmeal (not cooked) 100 Oats 30 30 0
Main meals
Pizza