NDSU Theses & Dissertations

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Research performed to achieve a formal degree from NDSU. Includes theses, dissertations, master's papers, and videos. The Libraries are currently undertaking a scanning project to include all bound student theses, dissertations, and masters papers.

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Application of Response Surface Methodology in the Development of Gluten-Free Bread with Yellow Pea Flour Addition
(North Dakota State University, 2012) Jeradechachai, Thunyaporn
Yellow pea (Pisum sativum L.) flour fortified gluten-free (GF) bread formulation was optimized by response surface methodology (RSM) and the final product was evaluated for shelf life and sensory acceptability. A second-order model was fitted to the precooking temperature of pea flour (PTPF), water level, and proof time as the factors. Higher PTPF and lower proof time significantly (P<0.05) reduced the brightness of bread crumb. Crumb firmness was influenced by the PTPF, water level and proof time. The optimized parameters for PTPF, water level, and proof time were 156.9 °C, 523.8 g, and 18.0 min, respectively. The optimized bread had a brightness (L* value), specific volume, crumb firmness, and cell diameter of 68.2, 2.6 ml/g, 174.2 gf, and 3.81 mm, respectively. The optimized GF bread had longer shelf-life, but had significantly (P<0.05) lower acceptance scores, than the commercial premix bread product.
Assessing Microbial Stability and Quality of Green Beans Using Various Home Canning Methods
(North Dakota State University, 2013) Kuchynski, Jenny
Today many consumers follow processing methods recommended either from family members or the internet, which they interpret as being safe. Processing temperature profiles, survival of B. stearothermophilus spores, texture, and color of green beans processed under four home canning methods were assessed. The products were processed using pressure, boiling water bath, steam, or oven canning methods. Pressure canning produced the greatest microbial reductions but this method resulted in the lowest bean quality. The boiling water bath, steam, and oven canning were found to be less safe because the product temperature never achieved 100°C and the resulting microbial counts, >1.7 log CFU/ml, were observed after processing. However, green bean quality was better than pressure canning, with beans from steam canning having the firmest texture and best green color. Although better green bean quality results were observed from internet or family based methods, their safety is questionable considering the high microbial survival.
Black Bean Milling
(North Dakota State University, 2014) Carter, Claudia Elizabeth
Black bean milling to produce whole-bean flour and cotyledon flour by using a centrifugal mill and a burr mill/roller milling system, respectively, were investigated. The effect of black bean seed pretreatment (cooked-dried, soaked-dried, and tempered) on flour physical, chemical, and pasting characteristics were investigated. Whole flour milling was done with a centrifugal mill using mesh size of 500 μm, rotor speed of 12,000 rpm, and mill feed of 267+18 g/min. Cooked-dried, soaked-dried, and tempered black bean milling yields for whole flour reached 58, 59, and 66%, respectively. Roller mill was used with durum wheat settings. Cooked-dried, soaked-dried, and tempered black bean milling yields for cotyledon flour reached 75, 73, and 75%, respectively. Black bean seed changed physically and internally by cooking or soaking. Differences in moisture content were reflected to change milling-ability and physical quality of flour. Cooked-dried affected the most starch damage and pasting properties and for flour color.
Black Bean Milling and Flour Functionality
(North Dakota State University, 2020) Fernando, Hettige Supun Sandaru
Dry bean utilization by the food industry can be increased by developing value-added processing applications. The goals of this research were to evaluate (1) the effect of milling method on the physical, chemical and functional properties of whole black bean flour and its fractions and (2) the effect of removing soluble phenolic compounds on the functional and rheological properties of black bean protein isolates. Black bean was milled with five laboratory mills [cyclone mill, hammer mill, stone mill (fine, medium, coarse), disc mill (fine, coarse), and centrifugal mill (10,000 or 12,000 rpm and 250, 500, 1000 μm aperture screen)] and the resulting flours were evaluated for their physical, chemical and flow properties of bulk samples and particle size fractions. Whole black bean flour and cotyledon flour were subjected to phenolic extraction and protein isolation, resulting in protein isolates with and without soluble phenolics. Solubility, wettability, dispersibility, water binding capacity, foam capacity and stability, emulsification capacity, and gelation properties of protein isolates were evaluated. Variation in milling method produced flours with significantly different flour characteristics. Geometric mean size of whole bean flour was negatively correlated with starch damage (r = -0.92), L* (r = -0.94), angle of repose (r = -0.94), and angle of slide (r = -0.80 to -0.90) and positively correlated with moisture (r = 0.72), and loose bulk density (r = 0.72). Milling method and particle size interaction was significant on characteristics of black bean flour fractions. Particle circularity of flour fractions had a negative correlation of r = -0.93, r = -0.81, r ≈ -0.95, and r = -0.94 with L*, angle of repose, angle of slide and compact density, respectively. Particle circularity had a positive correlation of r = 0.93 and r = 0.89 with average minimum particle size and loose bulk density, respectively. The removal of soluble phenolic compounds improved the brightness, solubility, wettability, dispersibility, foaming capacity, foaming stability, emulsion capacity, emulsion stability and gelling properties of protein isolates. These findings will help food manufacturers to process black bean ingredients using different mill settings to achieve different functionalities depending on the consumer requirements.
Carbohydrate-Based Micro and Nano Scale Materials from Soybean Meal, Distillers Dried Grains, and Sugar Beet Pulp for Food and other Applications
(North Dakota State University, 2013) Sivapragasam, Nilushni
Study 1 was carried out to isolate and produce enzyme resistant micro and nano scale carbohydrates from soybean meal (SBM), distillers dried grains (DDG), and sugar beet pulp (SBP). All materials produced were in micro and nano scales, and the yields were different depending on the starting material. Study 2 determined the physiological stability of study 1 materials for potential encapsulation applications. Both SBM and SBP were stable under simulated physiological conditions; the stability of the SBM was higher than SBP. In study 3 the SBM nanomaterial from buffer extraction was used for in vitro fermentation by Bifidobacterium brevis. The B. brevis showed a good growth in the presence of SBM nanomaterial. Study 4 characterized the SBM- resistant starch thin films produced with pectin and carboxymethylcelllulose. The films formed with SBM-resistant starch and pectin at 3:1 and 1:3 provided good barrier and viscoelastic properties.
Causes of Dull Brown Color in Durum and Traditional Semolina Pasta
(North Dakota State University, 2019) Cabas Lühmann, Patricia Alejandra
Bleaching of durum wheat (Triticum turgidum L. ssp. durum [Desf.] Husn.) was evaluated by determining the effect of grain moisture content, temperature, and wet/dry cycles with bulk water and with high relative humidity on the hydration of durum wheat grain and their effect on some physical grain quality parameters. Low initial grain moisture, high temperature, and wet/dry cycles increased water gain. Scanning electron microscopy and light microscopy showed that the germ and ventral surface of grain were important for water absorption. A single exposure to moisture (bulk water or high relative humidity) seems to be enough to cause a decline in grain quality. The effect of the environment on pasta color was evaluated by quantifying the relative importance of environment and genotype effects on pasta color and related traits. The relationship between environmental growing conditions, pasta color and semolina quality traits was determined. The environment had the highest relative proportion of variance for pasta color and related traits. Stepwise multiple linear regression indicated that the number of days with RH ≥ 80% diminished pasta color which could be related to increased speck count in semolina, soluble brown pigment content and an increased in semolina redness. The number of days ≤ 13°C enhanced pasta yellowness and pasta color score. However, why the positive effect occurred was not clear. Milling and processing effects on pasta color were evaluated by determining the effect of milling and pasta processing on polyphenol oxidase (PPO) activity, peroxidase (POD) activity, soluble brown pigment content, and yellow pigment content. Milling caused a reduction in yellow pigment content, soluble brown pigment content, PPO activity and POD activity while pasta processing reduced yellow pigment content, and for some genotypes, increased soluble brown pigment content. Stepwise multiple linear regression indicated that yellow pigment content had a positive effect and protein content, semolina ash content, and speck count had a negative effect on pasta color.
Characteristics of Yam Composite Flour: Properties and Function of Bread and Tortilla Making
(North Dakota State University, 2017) Asiyanbi-Hammed, Tawakalit Tope
Consumer interest in dietary fiber is on the rise as more information about its potential impact on health has become available. Flour from yam (Dioscorea rotundata) could have useful applications in the baking industry, in composite flour blends, because of its high level of dietary fiber and other essential nutrients. Study of the chemical composition, physicochemical characteristics, and pasting properties of unfermented-white yam flour (UYF) and fermented-brown yam flour (FYF) were investigated. Studies show that composite flour from yam has high ash, total starch, and fiber content than refined wheat flour. Thermal studies showed the energy required for composite flour gelatinization is greater than that of refined wheat flour. The firmness of FYF gel significantly increased with increasing number of days unlike UYF where slight hardness in texture was observed. This study revealed that each flour type exhibited different characteristics when compared to refined wheat flour. This necessitates further studies to substitute the yam flour samples with refined wheat flour to create composite flours that could be employed in bakery products. Inclusion of UYF and FYF flour at 5, 10, 15 and 20% levels of substitution with wheat flour affect the dough physicochemical, rheological pasting properties, and the nutritional quality. Proximate analysis of the flours carried out shows composite flours were of lower protein value but had higher fiber content than refined wheat flour. Impact on the gluten quality, gassing power, farinograph parameters was observed. The farinograph water absorption increased significantly (p<0.05) for blends prepared with UYF. Investigation revealed that the end-product quality (oven spring, loaf volume, bread crumb, tortilla weight, flexibility, thickness and color) of bread loaves and tortilla was significantly affected. This study demonstrated that incorporation of up to 10% FYF flour appears to give acceptable dough with good viscoelastic properties and bread with quality traits similar to refined wheat bread. This might be because bread itself is a fermented bakery product. For the tortilla; an unfermented product, 20% UYF inclusion seems to be more suitable to produce tortillas with good extensibility, acceptable thickness and whiteness with no dark spots that will appeal to the consumers.
Characterization of Edible Bean Flours: Properties and Functionality
(North Dakota State University, 2013) Simons, Courtney W.
Consumption of pulses is considered part of a healthy diet. Therefore, the opportunity exists for development of new pulse-based ingredients. However, a better understanding of their properties is necessary. The compositional and functional properties will vary depending on the bean type, their physical form (pre-cooked, raw flour, starch or protein fractionates) and growing location. In this study, edible bean flours (pinto, navy, black and small red) were subjected to extrusion cooking to produce snacks and texturized high-protein flour. The extrudates were studied to determine the effect of extrusion on the physical, physicochemical, chemical, sensory, and digestibility properties. Texturized high-protein flour was used in a bread formulation study. Finally, a preliminary study of location effect on production of grassy compounds, e.g. hexanal and hexanol, in pinto beans was conducted to determine importance of growing environment on flavor development during storage. The results of these studies showed that bean flours generally had excellent extrusion properties (good expansion and texture). However, pre-cooked flours had much lower expansion and textural integrity compared to raw bean flours and starch fractionates. Nutritional content (protein, total starch, fiber and ash) of flours were generally retained after extrusion. Lipids and resistant starch (RS) however were significantly reduced. Significant reduction in RS resulted in snacks having high glycemic index. Extrudates had 20% lower raffinose content suggesting reduced potential for flatulence after extrusion processing. Sensory evaluation of pinto, navy and black bean snacks indicated good overall acceptability. Pinto bean high-starch fraction differed in composition and functionality (viscosity and thermal properties) compared to its raw whole flour and extruded form. Adding 5% texturized pinto bean protein to bread increased its lysine content by 50%; without significantly affecting bread quality. A significant statistical interaction between growing location and storage time on hexanol and hexanal concentrations was observed for pinto beans grown in Forest River, Johnstown and Hatton North Dakota. This Dissertation will help processors understand the potential for beans as a food ingredient. Applications may include use in breads and other baked products, extruded puffed snacks, pasta, and soups. Bean flours can improve nutritional quality and provide unique functionality to food systems.
Composition and Stability of Phytochemicals during Food Processing
(North Dakota State University, 2015) Gebreselassie, Etsehiwot Yohannes
Dietary phytochemicals are thought to reduce the incidence of chronic degenerative diseases. The concentration of these phytochemicals has been extensively studied, but less is known about their stability during food processing. The objective of this study was to determine the stability of lignans and other phytochemicals during the vinification and brewing processes. The amount of secoisolariciresinol diglucoside (SDG), gallic acid, caffeic acid, coumaric acid, chlorogenic acid, and ferulic acid increased up to 45 % during the vinification process; however, the amount of folic acid remained unchanged. SDG content was determined in barley for the first time. The SDG content also varied among barley varieties and showed a year-to-year variation. In addition, no SDG was detected during the mashing, lautering, boiling, and fermentation steps of the brewing process. Overall, processing techniques used in this study caused various effects on the stability of phytochemicals.
Debranning Affects Durum Wheat Milling Properties and Semolina Quality
(North Dakota State University, 2020) Shinezorigt, Delgersaikhan
Wheat can undergo debranning before milling. Debranning involves the removal of the outer bran layer from wheat kernels by friction and abrasion forces. This research was conducted to determine the effect of durum cultivar and debranning time on milling extraction and semolina and pasta quality. Four cultivars of durum wheat were debranned for 0, 1, 3 and 5 minutes and milled on a Bühler 202 MLU laboratory mill. Cultivars differed in the amount of bran removed at a given debranning time. Debranning for 3 min removed 8% of outer layer which resulted in 69% increase in mill throughput and 35% reduction in semolina speck count. Total and semolina extractions were increased with debranning when calculated based on milled products. However, debranning decreased both extractions when they were calculated using total bran removed during both debranning and milling. Cooking properties of spaghetti were not affected by debranning.
Decoding tofu quality: an integrative investigation of soybean seed characteristics and innovative evaluation approaches
(North Dakota State University, 2024) Malik, Amanda
This research unravels the intricate relationship between soybean seed characteristics, geographical origin, and the resultant quality parameters of tofu. The study analyzed 178 soybean varieties from diverse regions, categorizing them into distinct clusters based on protein, moisture, and other attributes. Significant variations emerged, with soybeans from the United States exhibiting higher protein, while Chinese sources displayed higher moisture content. Subsequently, the research delved into diverse tofu quality parameters using multivariate analysis. Distinct clusters were identified based on attributes including yield, texture, moisture content, and brix levels. These parameters exhibited complex interrelationships, providing insights into factors defining tofu sensory qualities. Furthermore, an innovative integration of Hyperspectral Imaging and machine learning accurately predicted tofu quality categories from soybean seeds with 96-99% precision, revolutionizing conventional assessment methods. The research underscores the multifaceted nature of factors influencing tofu quality, considering seed origin and composition. It highlights the need to tailor soybean sourcing and processing practices to achieve desired textural and sensory attributes aligned with consumer preferences. The pioneering use of advanced technologies sets the foundation for enhanced quality evaluation, improved production practices, and product innovations in the tofu industry.
Effect of Amylase Content and Gluten on Gelatinization and Retrogradation of Starch Blends and Starch/Gluten Blends and on Bread Staling
(North Dakota State University, 2010) Matkovic, Kornelija;
Effect of amylase content and gluten on starch gelatinization and retrogradation properties, and consequently bread staling, still is not clear. In the case of starch and starch/gluten blends, information on the relationship between functional properties of starch blends and amylase and gluten contents is scarce. Effects of amylase content on baking and staling properties of bread were investigated by using 20, 30, and 40% blends of waxy spring (WS) or waxy durum (WD) wheat flour with non-waxy wheat flour. Crumbs with 30% and 40% waxy flour exhibited very open, porous structure. Retrogradation enthalpies and bread firmness were higher for waxy than for non-waxy crumbs and higher for WD than for WS crumbs at the end of storage (5 days), although waxy crumbs had a higher amount of soluble starch (especially WD crumbs) than non-waxy crumb. Results indicated that retrogradation and staling are complex processes that depend not only on amylase content, but also possibly on interactions of starch with other crumb components or interactions between two starches in a blend. To elucidate the effect of amylase content and gluten on properties of starch, blends of WD starch (0, 12.5, 25, 50, 75, and 100% w/w) and non-waxy starch, as well as starch blends combined with 30% gluten were studied. Gelatinization and retrogradation properties, as well as properties of soluble starch isolated from gels after 5, 10, 15, 20 days of storage and fractionated by gel permeation chromatography (GPC}, were studied. Gelatinization enthalpy (11H) was higher for blends with low than for blends with high amylase content. However, l).H was not significantly different between each consecutive blend although their amylase contents were different. Retrogradation enthalpy of starch blends (l).HaR) increased during 20 days of storage. On each storage day, M-laR was lower for low amylose blends than for high amylose blends, showing that low amylose content in starch blends slowed the process of retrogradation. Similar to t:.H, M-laR was not significantly different between each consecutive blend. Apparently, gelatinization and retrogradation properties of starch blends with different amylose contents were more complex than in single starches and could not be interpreted as a simple sum of contributions of individual components. Gluten did not affect gelatinization enthalpy of starch blends due to excess amount of water in the system. However, it significantly lowered the M-laR of low amylose blends (50, 75, 100% WO) compared to that of high amylose blends, especially on day 15 and day 20, which was interpreted as the result of gluten interacting with branched starch molecules. Analysis of GPC fractions of soluble starch showed that retrogradation patterns of O wx, 12.5 wx, and 25 wx blends were different, although their M-laR were similar. Low proportion of branched fraction in O wx soluble starch after day 5 and low ratio of blue value/total peak carbohydrate on days 15 and 20 indicated retrogradation due to reassociation of branched molecules with long chains. In 12.5 wx and 25 wx soluble starch, low values for the wavelength of maximum iodine absorption (Amax) of linear fraction indicated that some amylopectin fragments eluted with the linear fraction. Recrystallization of these molecules could have been facilitated by the presence of amylase in the fraction. Gluten affected retrogradation pattern of starch by promoting reassociation of branched molecules (reduction in A.max) at the beginning of storage. All starch/gluten blends had similar retrogradation patterns. Overall, amylose content affected gelatinization and retrogradation properties of starch significantly; however, in starch blends these properties were not simple averages of properties of two starches. In addition to the amylose content, properties of blends also could be governed by specific interactions between two starches or between starch and gluten.
Effect of Flaxseed Fiber on Bread Quality Obtained from Frozen Dough
(North Dakota State University, 2012) Schlepp, Emily Beth
Fiber in frozen bread dough is thought to reduce the loss of yeast vitality and improve nutrition and quality of bread. The objective of this study was to determine the applicability of flaxseed fiber in frozen bread dough. Fiber was extracted from two sources of brown flaxseed and added to bread formulas at 0%, 1% and 3%. Dough was blast chilled and kept frozen until thawed at scheduled intervals. Thawed dough was proofed, baked into bread. Bread was tested analytically and by a sensory panel. Loss of overall quality was observed overtime. Breads containing flaxseed fiber had significantly larger loaf volumes (cc) and reduced firmness (g). A trained sensory panel detected significantly lower crumb firmness and stale flavors in breads containing flaxseed fiber. These results suggest flaxseed fiber has the potential to improve the perceived quality of frozen bread dough.
Effect of Operational Parameters on Laboratory Determination of Malt Fermentability
(North Dakota State University, 2013) Sehrawat, Jaidev
Prediction and variability in malt fermentability is a concern for breeders and brewers. The primary purpose of this study was to determine the variation in fermentability using two different laboratory mash methods. Another experiment was conducted to develop a relationship between malt/wort parameters and malt fermentability with addition of adjunct. The prediction of malt fermentability was achieved by using stepwise multiple linear regression analysis to evaluate which quality factors were able to best explain the observed variation in fermentability. The hot water extract (HWE) mash protocol showed a wider range of fermentability values than did the Congress mash. However, hot water extract mash method clearly showed better discriminative power. Diastatic Power (DP) explained about 50% of the variation in fermentability when using the Congress mash with all malt (i.e. 100%) and also with adjunct. While in case of HWE extract protocol, limit dextrinase activity was able to explain 32% of variation in fermentability with all malt and also with adjunct.
Effects of Pasteurization (Heating) on Milled Flaxseed Quality
(North Dakota State University, 2013) Turner, Cody Troy
Current food industry practices include the use of pasteurization (heat treatment) as a means to reduce the microbial counts of flaxseed (Linum usitatissimum). Flaxseed was pasteurized using a dry air heat treatment of 148 °C for 16.25 minutes and the oxidative stability was observed over a 20 week storage period. Flaxseed quality was measured using peroxide value, percent free fatty acid (as oleic), and propanal content. Peroxide values of the pasteurized milled flaxseed were found to significantly increase (P ≤ 0.05) by week 2. Propanal formation coincided with peroxide value development over 20 weeks of storage. Pasteurized flaxseed milled under refrigerated temperatures (10 – 18 °C) did not exhibit any significant (P > 0.05) improvement in oxidative stability. Flaxseed pasteurization at 148 °C for 16.25 minutes using dry heat was found to be detrimental to the oxidative stability flaxseed once milled.
Effects of Pretreatments on Separating the Seed Coat from the Cotyledon of Black Bean
(North Dakota State University, 2017) Fernando, Hettige Supun
Separation of seed coat from the cotyledon could result in an additional black bean food ingredient. The objective of this study was to develop a standard milling procedure that can achieve optimum seed coat removal from black bean seed. Black beans were cooked in boiling water for 0, 5, 10, and 20 min or were tempered to 10, 20, 30, 40 and 50% moisture. Then all samples were dried to the original moisture content in ambient air or at 90°C. Pretreated black beans were milled using a burr mill and a roller mill. Seed coat was removed by aspiration. Seed coat yield was greater with tempered than with boiled seed dried at 90°C. The chemical and physical changes in the bean flours were less in tempered-dried pretreatment than with cooked-dried pretreatments. Higher seed coat separation with less changes in flour is important in food applications with health benefits.
Enhancing mechanical properties and water interactions of arabinoxylan films from corn bran through enzymatic-chemical modification
(North Dakota State University, 2024) Alahmed, Abdulrahman
Due to the need to replace non-biodegradable plastics, arabinoxylan (AX) films were evaluated for potential use in food packaging. The mechanical properties, hydrophobicity, and biodegradability of AX films were evaluated after extracting AX from corn bran byproducts of dry-milling (DCB), wet-milling (WCB), and dried distiller’s grains with solubles (DDGS) using acid-alkali procedure. Packaging materials were created using the three AX extracts combined with laccase and sorbitol as the basis for each film. The three AX films were then modified by immersing their surfaces in a lipase-acetate solution. Thickness of modified DCB AX and modified DDGS AX films was significantly increased (P<0.05) compared to their unmodified AX films. Tensile properties of the modified DCB AX films were significantly improved (P<0.05), as opposed to the unmodified DCB AX films. Tensile properties of the modified WCB AX and modified DDGS AX films were enhanced, but insignificantly (P>0.05), compared to their unmodified AX films counterparts. Significant increase (P<0.05) in tear resistance and insignificant increase (P>0.05) in puncture resistance were observed for all modified AX films. Moisture content of modified AX films created from DCB, WCB, and DDGS was significantly decreased (P<0.05) compared to unmodified AX films. Significant decrease (P<0.05) in water solubility and insignificant decrease (P>0.05) in water vapor permeability were found in modified DCB AX films compared to unmodified DCB AX films. Insignificant decrease (P>0.05) in water solubility resulted in modified WCB AX films compared to unmodified WCB AX films. Water vapor permeabilities of the modified AX films made from WCB and DDGS were significantly reduced (P<0.05) compared to their unmodified AX films. AX films were positively affected by suspension in the lipase-acetate mixture, making the modified films ductile, flexible, and more resistant to deformation when stretched compared to unmodified AX films. WCB AX and DDGS AX films were more hydrophobic and biodegradable than DCB AX film with the modification of film surface suspension in the lipase-acetate solution. The modified DCB AX films showed better physical and mechanical properties, while the hydrophobicity and biodegradability of modified WCB AX films make it a safer packaging material which can also elongated shelf-life for food.
Evaluation of Barley and Malt Quality in the Eastern Spring Barley Nursery
(North Dakota State University, 2019) Li, Yingya
In the northeastern United States, craft beer is on the rise. With local brewing increasing, the supply of local raw materials becoming an urgent problem in some northeastern states, like Michigan, New York, Ohio, Pennsylvania, and Vermont. The overall goal of the project is to determine which cultivars are best adapted to specific regions in the northeastern United States, and to detect the impact of different environment factors on the barley genotypes. In general, cultivars from Europe had better resistance to pre-harvest sprouting (PHS) and lower beta-glucan levels than two-rowed cultivars developed in North America. The varieties, Explorer, LCS Genie, LCS Odyssey, KWS Fantex, and KWS Beckie are candidates for production in the eastern United States because of their higher levels of resistance to PHS and malt extract, and their lowers levels of beta-glucan.
Evaluation of Extraction Methods and Groat Type With Effects on Quality Analysis of Oat Beverage
(North Dakota State University, 2021) Olson, Brandon Robert
The recent uptick in consumption of plant-based beverages has forced companies to modify production methods to further optimize the process. The objective of this study was to evaluate how groat type, water to grain ratio, and extraction method affect the quality and composition of oat beverage. Wet milling and the use of an amylase treatment produced significantly (p<0.05) higher values of degree Brix, solids, and total starch within the beverage base. Stabilized groats produced the highest value of total starch of 61.97%. Microbial analysis revealed that amylase treated products had a much lower colony forming units per gram (CFU/g), when compared to dry and wet milling. To produce an oat beverage with ideal rheological and composition values, the beverage must be derived from heat treated groats, a grain to water ratio of 1:4, and must undergo an α-amylase treatment.
Evaluation of Pea Protein and Modified Pea Protein as Egg Replacers
(North Dakota State University, 2012) Hoang, Hieu Duy
Native yellow pea (Pisum sativum) protein isolates (PPIs) showed good foaming and emulsifying properties but a poor gelling characteristic. However, this can be corrected by Transglutaminase (TGase) treatment. PPIs were obtained using alkaline extraction method in which extracting pH, precipitating pH, flour–to–water ratio, and extraction time were optimized to obtain maximum yields and least change in protein functionalities. Extraction pH of 10.0, precipitating pH of 4.3, flour–to–water ratio of 1:6, and 30 minute extraction time were found to be optimum values for pea protein extraction. SDS–PAGE gels showed that the PPI had a very similar protein molecular weight profile as its original flour. TGase treatment was applied on PPIs at different pH levels from 4.3 to 7.0. The SDS–PAGE and RVA tests showed that treatment at pH 6.0 provided the best overall functionality. Large molecular weight (MW) proteins (~ 90,000 Da) and medium MW proteins (~50,000 – 80,000 Da) were the main substrates for TGase catalyzed reaction whereas most low MW the proteins (< 45,000 Da) were not involved. RVA results indicated that treatments at pH 6.0 and 7.0 had the highest viscosities but the treatment at pH 6.0 had better stability and consistency. Functionality tests indicated that modified PPIs possessed a better viscosity profile than the native PPIs but no improvement in gelling capacity and only minor impact on foaming and emulsifying properties. PPIs performance greatly depended on their final pHs. The foaming capacity, foaming stability, and emulsion capacity were significantly improved when the final pH of PPIs was adjusted from 4.3 to 7.0. The overall sensory evaluation results suggested that TGase–treated PPIs and PPIs were not yet able to replace egg in the cake system. Only PPI can replace egg in the cookie system. TGase–treated samples had a lower acceptability due to an “off–taste” and a “strange” flavor. Future work, therefore, should study TGase combined with other treatments to further improve PPIs functionalities. Purification should be integrated into extraction process and other food systems should also be included to extent the scope and role of modified PPIs in food industry.

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