Properties and nutritional value of wheat bread enriched by hemp products

Abstract

Hemp (Cannabis sativa) is annual plant that is native to China and remained as important material for food, industrial and medical purposes. As source of cannabinoids belongs to controversial, but due to its excellent nutritional profile, non-gluten protein, fat and fibre it has potential in bakery products. Addition of 5% - 20% of hemp press cake fine flour and fine wholemeal significantly increased dietary fibre content, but their influence on volume of laboratory baked bread was different. Reflecting actual dosage, both types of hemp press cake flour diminished bun sizes about 6% - 33%; volumes of bread containing hulled wholemeal were comparable to standard (mean 310 mL/100 g vs. 333 ml/100 g, respectively. Only dehulled wholemeal hemp form increased the bread specific volume (6% - 30%), especially as 10% fortification (434 mL/100 g). Six Canadian hemp products were added as 10% and 20% on wheat flour base, comprising fine hemp flour and coarse hemp powder, dehulled whole seeds, hulled hemp seeds with sea salt as well as 50% and 43% hemp protein concentrates (KP1-KP6, respectively). The higher level of KP1, KP2, KP5 and KP6, the lower bread specific volumes were determined (decrease about 9% - 48%). Soft increase in buns size caused by 10% and 20% KP3 (323 and 319 ml/100 g vs. 296 mL/100 g) was insignificant. The effect of KP4 was reversely verifiable, magnifying the parameter about 25% and 17%, respectively. In terms of protein content in bread, a level 11.75% in wheat bread has risen to approx. 14.5% and 18.0% when 10% and 20% of KP3 and KP5, respectively, was included into bread recipe. All six Canadian hemp products increased dietary fibre content in bread, mainly owing to KP4 and both protein concentrates (up to 4 and 3 times, respectively). Incorporation of hemp flour up to the level of 10% positively affected bread sensorial properties.

The Seed of Industrial Hemp (Cannabis sativa L.): Nutritional Quality and Potential Functionality for Human Health and Nutrition

“…The obtained results showed that the presence of whole hempseeds in the bread dough did not impair the specific bread volume in comparison with the control. A similar finding was noted also by Švec and co-workers [ 169 ] who found that the volume of the bread enriched with whole hempseeds powder (i.e., ground whole hempseeds) was higher than those obtained for the breads enriched with other defatted hempseed products (i.e., hempseed flour or hempseed protein concentrates). This fact has been attributed to the interactions between lipids and proteins and to the influence of the fat in terms of enhancing dough expansion during proofing [ 166 ].…”

“…In this regard, Pojic and colleagues [ 166 ] showed that the bread volume was significantly impaired as the level of hemp flour increased. This result was found also by Hrušková and co-workers [ 171 ] and by Švec and colleagues [ 169 ] for bread enriched with 10%, 15%, or 20% of hempseed flour, and was confirmed also by Mikulec and others [ 172 ] for bread containing 15%, 30%, or 50% of hempseed flour, as well as by Wang and colleagues [ 173 ] for bread enriched with 5%, 10%, or 15% extruded hemp-rice flour (EHR), made by the extrusion of the whole hempseeds (30%) together with the rice flour (70%). According to the authors, the decrease in the bread’s volume could be due to the partial replacement of wheat flour with a non-glutinous one, that may dilute the gluten protein of wheat flour and prevent its extension, or to the increased content of fibre, which reduces the ability to retain fermentation gases.…”

“…Studies about the enrichment of the bread dough with hempseed flour agree that the addition of hempseed flour in the wheat flour significantly reduced the dough’s water absorption, stability, strength, and starch gelatinization, in a proportional manner to the level of hemp flour added as a consequence of the dilution of gluten amount in the dough [ 166 , 169 , 170 ]. Pojić and colleagues [ 166 ], and Švec and others [ 169 ] found that the decrease in the water absorption of the bread dough had a negative impact also on the time required for dough development, but nevertheless, the dough’s stability and strength were not significantly affected by the addition of up to 10% of hempseed flour. Pojic and others [ 166 ] also noted that the increase in the hempseed flour content up to 20%, negatively affected both the dough’s stability and strength.…”

“…The color of both of them became darker after the hempseed flour addition [ 166 , 169 , 172 , 173 ]. Švec and colleagues [ 169 ] asserted that the 5% enrichment has conferred a pleasant coffee brown colour, which intensified to dark brown by increasing the amount of hempseed flour, whereas, Wang and co-workers [ 173 ] observed a significantly decreased in the lightness of both crust and crumb only for the breads enriched with an EHR amount of at least 10%, since the 5%-EHR bread did not show any significant colour’s differences compared to the control bread. Similar changes in the crust and crumb bread’s colour were observed by Wang and colleagues [ 174 ] also after the addition of whole hempseeds powder.…”

“…Concerning the nutritional quality of the hempseed flour or whole hempseed powder-enriched bread, it has been demonstrated that the addition of hempseed product significantly ameliorated the bread nutritional quality, since it proportionally increased the total protein [ 166 , 169 , 170 , 171 , 172 ] and fat [ 166 ] contents, as well as the total, soluble, and insoluble dietary fibre [ 169 ]. About this, it is interesting to note that Švec and colleagues [ 169 ] showed that the increase in the dietary fibre was higher if the enrichment was made with whole hempseed powder rather than hempseed flour. Furthermore, Pojic and co-workers [ 166 ] found that the hempseed flour enrichment also led to an increase in the content of the macro-elements, especially of Mg and Ca and of the micro-elements such as Mn, Cu, and above all, Fe and Zn.…”