Whole wheat bread is high in nutritional benefits, can be a lower quality product.

Whole wheat bread is high in nutritional benefits, but can  have a lower quality than other breads.

Whole Wheat Bread


What is Whole Wheat Bread?

Whole wheat bread is made of whole wheat flour. Whole wheat flour is commonly prepared ether by directly grinding the whole wheat kernel or from blending bran and the corresponding white flour in a proportion to which they were initially milled.

Origin

Whole wheat bread has been popular in health food circles from the early 19th century onward. Commercially manufactured whole wheat loaves became available in American grocery stores in the early 20th century.1

Nutrition

Wheat grain is composed of 83% endosperm (12% protein and 63-72% starch, non-starch polysaccharides, mainly arabinoxylans, 1.5-2.5% in flour, water extractable arabinoxylans 0.5% in flour, water unextractable arabinoxylans, 1.5% in flour), 14.5% bran and 2.5% germ. It is an excellent source of dietary fiber, minerals, vitamins, and bioactive phytochemicals, such as antioxidant compounds. Wheat grain has many benefits.

  • Reduces the risk of obesity, type 2 diabetes, cardiovascular disease and cancer.2
  • Lowers cholesterol in rats in its native form and after use in bread-making.3
  • Ensures higher mineral absorption and bioavailability than white wheat flour in rats. Mineral intake, except for Ca, was significantly greater in rats fed on the WWF diet (4-fold for Mg, 2 fold for Fe and Zn).4
  • Whole grain consumers have a lower risk of coronary heart disease (CHD) by 7-30% compared with low or no whole grain consumers. Whole grain intake is positively associated with vitamin use and negatively associated with body mass index (BMI), waist circumference, and smoking status.5
  • Whole wheat bread exhibits significantly higher antioxidant activities by 1.9-fold than white bread (physiochemical).6

Dietary Guidelines for Americans, 2005, developed jointly by the U.S. Department of Health and Human Service and the U.S. Department of Agriculture (USDA), recommends that Americans consume, among other things, three or more ounce-equivalents of whole grain products per day, with the rest of the recommended grains coming from enriched or whole-grain products and that “in general at least half of the grains should come from whole grains.”7

Problems

The difference between whole wheat bread and white wheat bread is the incorporation of bran in whole wheat flour (WWF). This causes whole wheat bread to have a lower volume, coarser texture and faster staling compared to refined wheat bread, which limits the public’s acceptance of this product.

The presence of bran in WWF physically disrupts the starch-gluten matrix and decreases the gas-holding capacity, resulting in a reduced bread loaf volume. Bran also competes for water with starch and gluten during dough mixing, resulting in bread with a reduced loaf volume. During the fermentation and proof stages, WWF dough is observed to be dry and less extensible. Wheat bran has been reported to expedite starch retrogradation and bread staling.8

WWF exhibits reduced values for all the pasting parameters, like viscosity and dough extensibility. Wheat bran decrease starch gelatinization and increases the firmness in the finished bread.

Application

When baking whole wheat bread, use bran with lower insoluble dietary fiber (IDF). U.S. soft and club wheat brans were lower in IDF and phytate content compared with U.S. hard wheat bran. WWFs with hard wheat bran generally exhibited higher dough water absorption and longer dough mixing time, and they produced smaller loaf volume of bread than that from soft and club wheat bran.2

The prehydration or soaking of bran will improve bran hydration and avoid the dry dough problem of WWF during fermentation. It mitigates the deleterious effects of wheat bran on load volume of WWF bread.8

Add specific xylanase. When Xylanase from Aspergillus foetidus MTCC 4898 is added to whole wheat bread making, volume can increase by 53%. Water absorption also decreases by 11%. Sensory evaluation indicated better flavor, taste, softness and overall acceptability with this additive.9

Phytase is another option. Phosphorous in wheat is present in the form of phytic acid or phytates, which can’t be utilized by monogastric animals. Phytates chelate multivalent cations. Adding phytase can improve the bread nutrition by decreasing phytate content. Also, adding phytase releases the calcium ions from phytate-calcium complexes. The released calcium ions activate the endogenous alpha-amylase. All the benefits produced by alpha-amylase addition can be obtained by adding phytase.10

If baking organic, malt flour, vital gluten, Cephalaria syriaca and rosehip have been confirmed to enhance whole wheat bread quality. Malt flour is rich in amylolytic enzymes. Rosehip is used to replace synthetic ascorbic acid. Cephalaria syriaca has positive effect in the extensograph characteristics of wheat flour.11

FDA Regulation

FDA regulated the definition of whole wheat bread in article 21CFR136.180 in Code of Federal Regulations.12 The dough is made from the optional ingredient whole wheat flour, bromated whole wheat flour, or a combination of these.12

References

  1. Olver, Lynne. “Whole Wheat Bread.” The Food Timeline: History Notes–bread. www.foodtimeline.org/foodbreads.html#wholewheat. Accessed 03 Jan. 2017.
  2. Cai, Liming, Induck Choi, Choon-Ki Lee, Kwang-Keun Park, and Byung-Kee Baik. “Bran Characteristics and Bread-Baking Quality of Whole Grain Wheat Flour.” Cereal Chemistry Journal 91.4 (2014): 398-405.
  3. Adam, Aline, Hubert W. Lopez, Michel Leuillet, Christian Demigné, and Christian Rémésy. “Whole Wheat Flour Exerts Cholesterol-lowering in Rats in Its Native Form and after Use in Bread-making.” Food Chemistry 80.3 (2003): 337-44.
  4. Levrat-Verny, M. A., C. Coudray, J. Bellanger, H. M. Lopez, C. Demigné, Y. Rayssiguier, and C. Rémésy. “Wholewheat Flour Ensures Higher Mineral Absorption and Bioavailability than White Wheat Flour in Rats.” British Journal of Nutrition 82.1 (1999): 17-21.
  5. Harris, Kristina A., and Penny M. Kris-Etherton. “Effects of Whole Grains on Coronary Heart Disease Risk.” Current Atherosclerosis Reports 12.6 (2010): 368-76.
  6. Bae, Woosung, Bon Lee, Gary G. Hou, and Suyong Lee. “Physicochemical Characterization of Whole-grain Wheat Flour in a Frozen Dough System for Bake off Technology.” Journal of Cereal Science 60.3 (2014): 520-25.6.
  7. “Draft Guidance for Industry and FDA Staff: Whole Grain Label Statements.” U.S. Department of Health and Human Services, Food and Drug Administration, 17 Feb. 2006. www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation/ucm059088.htm. Accessed 31 Dec. 2016.
  8. Cai, Liming, Induck Choi, Chul Soo Park, and Byung-Kee Baik. “Bran Hydration and Physical Treatments Improve the Bread-Baking Quality of Whole Grain Wheat Flour.” Cereal Chemistry Journal (2015): 557-564.
  9. Shah, Amita R., R.k. Shah, and Datta Madamwar. “Improvement of the Quality of Whole Wheat Bread by Supplementation of Xylanase from Aspergillus Foetidus.” Bioresource Technology97.16 (2006): 2047-053.
  10. Haros, Mónica, Cristina M. Rosell, and Carmen Benedito. “Use of Fungal Phytase to Improve Breadmaking Performance of Whole Wheat Bread.” Journal of Agricultural and Food Chemistry49.11 (2001): 5450-454.
  11. Boz, Hüseyin, Mehmet Murat Karaoğlu, Halis Gürbüz Kotancilar, and Kamil Emre Gerçekaslan. “The Effects of Different Materials as Dough Improvers for Organic Whole Wheat Bread.” International Journal of Food Science & Technology 45.7 (2010): 1472-477.
  12. “CFR – Code of Federal Regulations Title 21CFR136.180.” U.S. Food & Drug Administration. www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=136.180 1 Apr. 2016. Accessed 05 Jan. 2017.