Browsing by Subject "Baking quality"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Chemical Characterization, Functionality, and Baking Quality of Intermediate Wheatgrass (Thinopyrum intermedium)
    (2017-05) Rahardjo, Citra
    Environmental problems have exacerbated the challenges of food production. Soil erosion, run-off from irrigation, and greenhouse gas emissions have significantly impacted the ecosystem through their cumulative effects over decades. As the population increases, these aforementioned problems will grow in scale and scope. Thus, it is important to address these concerns by investigating sustainable solutions and conducting research on new approaches to food supply. Specifically, the development of perennial crops for food use would have environmental benefits such as reduced soil and water erosion. Further, the usage of perennial crops for food applications would provide alternatives to the current and ever diminishing food supply, provide incentives to farmers for planting these crops, and address consumers’ growing interest in sustainable food systems. One of several perennial crops available for potential food use is intermediate wheatgrass (IWG) (Thinopyrum intermedium). Little is known about the chemical and functional characteristics of IWG. Therefore, the overall objective of this work was to characterize the chemical and functional properties of IWG grains from multiple breeding lines for food applications, namely bread baking. Sixteen IWG experimental lines along with one bulk IWG sample and two wheat controls (Arapahoe and commercial hard red wheat) were analyzed for proximate composition following standard methodologies. Dietary fiber, total starch content, and percent damaged starch were determined using Megazyme kits. Amylose/amylopectin ratio and their molecular weight distribution were determined using size exclusion chromatography. Gluten forming proteins profile and molecular distribution were determined using gel electrophoresis and size exclusion chromatography. Dough rheology was assessed using a farinograph and a texture analyzer equipped with a Kieffer rig, while starch pasting properties were monitored using a rapid visco analyzer. Bread baking tests were performed following the AACCI 10-10.03 method. Compared to wheat controls, IWG samples had higher protein, dietary fiber, and ash contents, yet were lower in starch content and deficient in high molecular weight glutenins (HMWG), important protein components responsible for dough strength and elasticity. Specifically, wheat controls had more high molecular weight polymeric proteins (HMWPP), while IWG samples had more albumins and globulins. The ratios of amylose to amylopectin among the IWG samples and the wheat controls were similar. However, percent damaged starch was higher in the wheat controls than in IWG samples. On the other hand, the soluble to insoluble dietary fiber ratio was higher in wheat controls than in IWG samples. Dough rheology data showed that IWG dough was weaker than that of the controls. Farinograph and Kieffer data demonstrated that doughs made from wheat controls were more stable, more resistant to extension, and more extensible than doughs made from IWG samples. In terms of starch pasting properties, wheat controls had higher peak, hold, and final viscosities than the IWG samples, indicating the superiority of wheat controls over IWG samples as viscosity builders. The starch pasting properties data illustrated the samples’ behavior upon heating and cooling treatments, which are important characteristics to consider when evaluating IWG for commercial applications. Even though IWG had similar specific volumes to one of the wheat controls (hard red wheat), both wheat controls had a higher rising capability due to the wheat’s gluten network forming ability. Deficiency in HMWG and high fiber content of IWG samples, contributed to the poor gluten network and consequently inferior baking quality. Overall, results of this work suggest that IWG has a superior nutritional profile as compared to wheat, but poses challenges for baked products that require dough rising properties. Further studies on IWG, such as investigating the effect of conditioners on enhancing protein functionality, determining the effect of fiber on dough development, effect of blending with wheat, and exploring other food applications would enhance its potential utilization as a food crop. This research and future efforts will support breeders in their current screening and future breeding efforts for the development of IWG lines suitable for food applications.
  • Thumbnail Image
    Item
    Effects of Dough Conditioners on Rheology and Bread Quality of Intermediate Wheatgrass
    (2018-07) Banjade, Jaya
    Studies have shown the detrimental effect of agricultural practices on the environment. One solution to combat those problems would be to focus on alternatives that would lead to sustainable environmental benefits, like cultivating perennial crops. While annual crops are dominating current agricultural production, cultivating perennial crops would contribute to several environmental benefits like reduced nitrogen losses, and soil erosion. With expanding global food insecurity, using perennial crops for food would offer an alternate to diminishing food supply. Among the several perennial crops screened for domestication, intermediate wheatgrass (Thinopyrum intermedium, IWG) has been considered a promising crop to be used as food. The aim of this study was to evaluate IWG of same genetic material, cultivated at two location in Minnesota- Rosemount (RM) and Roseau (RS) for chemical and functional characteristics of dough and breads as affected by refinement (bran removal) and the use of dough conditioners. Five dough conditioners were used- wheat protein isolate, (WPI), vital wheat gluten (VWG), ascorbic acid (AA), Powerbake (a commercial enzyme mix) (PB) and transglutaminase (TG). While IWG kernels were studied for kernel physical properties, IWG flour at three refinement levels - 0 %bran (0B), 50 %bran (50B) and 100 %bran was investigated for proximate composition and dietary fiber following respective standard methods. Dough extensibility and resistance to extension were measured with the texture analyzer equipped with Kieffer extensibility rig, and dough stickiness was measured with a texture analyzer equipped with Chen-Hoseney stickiness cell. Baked breads were evaluated for dimensions, specific volume, crumb firmness, and crumb grain characteristics. Controls consisted of annual hard red winter wheat (W) and IWG dough without conditioners (N). IWG kernels were thinner, with lower weight, volume and bulk density in comparison to wheat. Results from proximate composition indicated an increased fat, protein and ash content with increasing bran concentration, and a decrease in moisture and carbohydratecontents. While there was no difference between IWG and wheat at 0B for moisture and carbohydrate, for the remaining two bran concentrations, wheat had higher moisture and carbohydrate, and lower protein, fat and ash content than IWG. IWG had higher dietary fiber content than wheat at 50 and 100B refinement levels, the difference attributed to insoluble dietary fiber, as no differences was observed in soluble fiber between wheat and IWG at all bran concentrations. At all bran concentrations, extensibility of wheat dough was higher than for the dough made with IWG from both locations. Adding dough conditioners did not improve extensibility for any samples. Some differences were noted between the two locations- 50B-N, 50B and 100B with WPI, 100B with VWG, 50B and 100B with AA, 50B and 100B with PB and 0B and 100B with TG. At 0B and 50B, resistance to extension of wheat dough was higher than for dough made with IWG from both locations, however, for 100B, IWG from RM N, with AA, and PB and IWG from RS N, with WPI, VWG, AA and PB were different. TG increased resistance to extension for IWG from RM at 0B and 50B; for IWG from RS at all refinement levels. At all bran concentrations, stickiness of wheat dough was lower than for dough made with IWG from both locations. Adding PB and TG to 100B IWG from RM reduced stickiness to match values of wheat, however, no such effect was seen in IWG from RS. Adding WPI and VWG reduced stickiness of 0B IWG samples from both locations, in addition, TG also reduced stickiness of 0B RM IWG dough. While no conditioners reduced stickiness of 50B IWG from RS; WPI, VWG, PB and TG reduced stickiness of 50B IWG from RM. While dough conditioners did not reduce stickiness of 100B samples from RM; WPI, VWG and TG reduced stickiness of 100B samples from RS. Bread results indicated a negative effect of bran on dimensions, specific volume and crumb grain characteristics. While WPI, VWG, AA and PB improved or did not change the bread dimensions, TG always reduced them. The effect of dough conditioners was more pronounced for length and width than for height; indicating IWG expanded more than rose. While none of the conditioners increased the specific volume of RS IWG samples at any refinement level, PB increased the volume of 0B IWG from RM. TG decreased the specific volume of all samples. At 0B concentration, controls and breads with WPI and VWG demonstrated collapse when in oven. A noticeable surface smoothing effect was observed for 0B samples with AA and PB. AA and PB improved the crumb grain properties with uniform air cells distribution for 0B samples. Bran negatively affected the air cells count, and adding dough conditioners did not improve the crumb grain characteristics. While there was no effect of TG on 0B samples; cell count, cell area and cell size decreased with TG addition for higher bran contents. The breads were unacceptably dense and the effect was pronounced at higher bran concentrations. This work provides insight on ways to improve functionality and product quality of IWG breads. AA and PB produced loaf of consistent appearance with smoother surface and uniformly distributed gas cells in the crumb. WPI and VWG exhibited expansion before the dough collapsed and thus, the loafs were unable to hold gas. Adding starch or other functional ingredients to increase viscosity would help in retaining the gas, and is thus recommended. This research would facilitate future efforts towards using IWG as a standalone flour for breads, as well as help breeders for markers selections towards developing IWG bread flour.