Oat Flour Research Articles

Impact of a Starch Hydrolysate on the Production of Exopolysaccharides in a Fermented Plant-Based Dessert Formulation.

Plant-based desserts are becoming increasingly popular with and appreciated by consumers. However, they are limited by the choice of ingredients, which are often expensive and unstable with a random texture. Therefore, the aim of the research is to propose a new product that offers an advantageous texture and flavour in a fermented dessert based on a flour mix supplemented with an enzymatic hydrolysate. This study involved the development of two processes: (i) an enzymatic hydrolysis of oat flour and (ii) a fermentation of a flour mixture (oat, chickpea, and coconut) by lactic acid bacteria (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus). The result of the oat flour hydrolysate shows a significant decrease in starch after 60 min of reaction, followed by an increase in sugar content. During 23 days of storage at 4 °C, the formulations used showed post-acidification, water retention capacity decrease, and hardness increase related to the hydrolysate rate (p < 0.05). All formulations allowed the viability of lactic bacteria (over 5 log10 CFU/mL) and verified their ability to produce exopolysaccharides (0.23-0.73 g/100 g). The prototyping of such a product represents a key step in meeting the growing demand for plant-based alternatives, with qualitative sensory characteristics without additives.

Structure changes of ethanol–water modified oat flour and the influence on the processing qualities of oat noodles

The oat dough lacks viscoelasticity and hinders its utilization in noodles. In this study, oat flour was modified by ethanol–water treatment, the changes in starch structure and properties during modification, and the influence of modified oat flour on the processing qualities of noodles containing 50% oat flour was investigated. The granular cold–water swelling starch (GCWS) was prepared during the modification, and the A–type starch crystal transformed to the V–type. No endothermic peaks were observed in the DSC thermograms. Modified oat flour has an advantage over oat flour in that it has higher cold water viscosity. As the modified oat flour content rose from 0% to 10%, the tensile strength of dough sheet increased from 345.57 g to 367.19 g, the transverse relaxation time (T2) of water molecules increased. Water absorption of cooked oat noodles rose from 125.18% to 129.32%, with a reduction in cooking loss from 10.12% to 8.97%. The shear force, which indicates the hardness of cooked oat noodles, showed a decline of from 210.83 g to 190.02 g. The mentioned results indicated the ethanol–water treatment prepared GCWS, and that improves the processing quality of dough sheets via the increase of its tensile strength.

Synthesis in situ of heteropolysaccharide by Levilactobacillus brevis AM7 during fermentation of oat and hemp and its effect on the techno-functional properties of oat yogurt type model

Plant raw materials, such as oat bran concentrate (OBC), oat flour (OF), and hemp protein concentrate (HP), are significant sources of dietary fibers and proteins with high nutritional quality. Exopolysaccharides (EPS) synthesized by lactic acid bacteria (LAB) during fermentation are natural texturing agents that can replace hydrocolloid additives (e.g., carrageenan, guar gum, and pectin). This study aimed to evaluate EPS synthesis in OBC, OF, and HP during fermentation with Levilactobacillus brevis AM7 supplemented with glucose. Monosaccharide analysis identified that EPS from L. brevis AM7 was a heteropolysaccharide (HePS) consisting of rhamnose, mannose, glucose, and glucose-amine. Rheological analysis revealed that HePS production led to increased viscosity and viscoelastic moduli (G′ and G″) of the fermented materials compared to control. Fermented OBC exhibited the most stable structure among the three materials. Fermented OBC also showed the lowest acidity level, whereas fermented HP exhibited intensive acidification. This was likely due to the more abundant flour endogenous sugars (sucrose, raffinose, and stachyose) in HP and their fast utilization during fermentation. A yogurt alternative product was prepared from fermented OBC milk, showing a high LAB cell density, a pH of 4.2, and a significantly higher viscosity than the chemically acidified control. The in situ synthesized HePS counteracted the viscosity loss and inhibited syneresis of the yogurt alternative product during four days of storage at 4 °C. Overall, the use of L. brevis AM7 producing HePS enabled improved techno-functional properties of plant raw materials and showed potential for application in yogurt alternatives.

Influence of oat flour characteristics on the physicochemical properties of oat-based milk substitutes

This study aimed at investigating the effect of oat composition on the quality characteristics of oat-based milk substitute (OBMS). Raw materials for OBMS consisted of thirty pure cultivar oat flours produced by industrial milling process. The main steps in OBMS preparation included mixing of 10% oat flour with water, starch hydrolysis, solid-liquid separation and formulation of the final product. OBMS was characterised in terms of mass and protein yields, protein content, reducing sugars, particle size, viscosity, dispersion stability and colour. The different composition of oat flours affected the characteristics of the OBMS in terms of mass yield (81.3–88.1%), dry matter yield (56.7–73.8%), protein content (0.63–1.10%), protein yield (31.4–61.6%), content of free reducing sugars (13.1–19.1%), and physical properties including particle size, dispersion stability and viscosity. OBMS mass and dry matter yields correlated positively with both total and damaged starch contents of the oat flour as well as the share of damaged starch of the total starch of the sample, while flour starch content correlated negatively with protein content of OBMS. Protein content of the flour correlated negatively with the mass, dry matter and protein yields and positively with protein content of OBMS. All colour values (L*, a*, b*) of the flour correlated with colour value b* of the OBMS. Protein content and viscosity of OBMS correlated positively with dispersion stability of OBSM. In conclusion, the clear relation between oat composition and the final properties of OBMS suggest relevance of selecting specific oat raw materials to produce good quality OBMS.

Understanding the impact of water-extractable cereal flour constituents on network formation in gluten-starch dough

Water-extractable cereal flour constituents influence bread loaf specific volume, suggesting a contribution to gas cell (de)stabilization in dough. However, the underlying mechanism remains largely unexplored. We studied the impact of incorporating five cereal flour aqueous extracts in model gluten-starch bread (doughs) on specific volume, dough extensional rheology, and protein extractability changes during bread making. Incorporating wheat, rye, or triticale flour aqueous extracts in gluten-starch doughs increased bread specific volume by 12–17%. There were no changes in dough rheology that could explain this specific volume increase, suggesting that other mechanisms relating to gas cell stabilization might be at play. Incorporating oat flour aqueous extracts decreased bread specific volume by 50%. This negative impact was related to poor dough strain hardening behavior, in turn probably explained by disruption of intermolecular glutenin disulfide bonds, as revealed by chromatography. While this study has provided a novel perspective on the mechanisms by which water-extractable cereal flour constituents influence bread volume, it also demonstrates that the compositional heterogeneity of the flour aqueous extracts needs to be addressed to allow an even better understanding of the role of water-extractable cereal flour constituents in stabilizing gas cells in bread dough.

Protein fortification in oat flour gel using various dairy protein ingredients: An evaluation of textural and pasting properties

The effects of dairy ingredient substitution including whey protein concentrate (WPC), whey lactalbumin concentrate (WLAC) and skim milk powder (SMP) on functional properties of oat flour were investigated. Pasting analysis revealed that adding dairy ingredients at low substitution concentrations (5% and 10%) weaken the gel strength. WPC and WLAC resulted in increased hot paste stability compared to SMP as indicated by results obtained from a rapid visco analyser (RVA). Textural analysis suggested that WPC and SMP resulted in more elastic gels in comparison with WLAC, whereas WLAC reduced the elasticity of gel owing to the high denaturation resistance of α‐lactalbumin.

The modification of buckwheat polyphenols by different pretreatments and complexation, and its application in oat flour model

In this study, we selected yeast fermentation, hydrothermal treatment, enzymolysis, ultrasonic treatment, and steam explosion to treat buckwheat bran, based on their known potential to enhance the extraction rate of polyphenol content. Enzymolysis was identified as the most efficient method, leading to a 1.9-fold rise in the extraction rate of polyphenol content from buckwheat and a 1.05-fold increase in ABTS values. To further improve the properties of buckwheat polyphenols, they were complexed with chitooligosaccharide (PP–COS) via hydrogen bonding between the polyphenols' aromatic protons and the hydroxyl group of COS. The antioxidant and antibacterial properties were further augmented in PP-COS, demonstrating excellent storage stability. The ABTS, DPPH, and FRAP values were 1.08-fold, 1.12-fold, and 1.04-fold higher than those of control polyphenols, respectively. Additionally, PP-COS was successfully applied to oat flour, further expanding its potential benefits. When compared to pure oat flour, oat flour supplemented with PP-COS exhibited lower pasting parameters, higher solubility and swelling power, lower peak temperature, lower crystallinity, and reduced in vitro digestibility. This study illustrates that various pretreatments exhibit differences in the way and degree of cell wall disruption. The careful selection of optimal pretreatments along with molecular complexation can significantly amplify the extraction efficiency and bioactive potential of grain polyphenols, as exemplified by those present in buckwheat.

Development and application of a laboratory baking test for the characterisation of wholemeal oat flours

The aim of this study was to develop a standardised, small-scale laboratory baking method for testing the baking quality of 100% oat flours. During the method development using wholemeal flours of 5 Hungarian oat varieties, the mixing measurements and baking tests were performed at 300, 200 and 150 FU maximum dough consistencies applying different mixing times (6 and 10 min). Our results showed that an optimal, instrumentally registered, and numerically expressed dough consistency and corresponding water addition level for oat flours could be defined on the model of wheat flour testing methodology. Based on this, the lowest dough consistency and the shortest mixing time were found the most appropriate regarding the specific volume and crumb structure of oat breads. Then, the newly developed baking method was applied for testing 9 oat varieties, which were tested also for chemical composition and rheological (mixing, pasting) properties. Protein, fat, and β-glucan content significantly influenced both rheological and baking properties, and relationships between techno-functional parameters were also found. Our results suggested that high quality 100% oat bread can be produced by a standardised and optimised baking test as well as oat varieties being more preferable for bread making can be identified.

Sorption comparative study of nectarine powder and flour mixtures with its participation

The current paper presented the sorption comparative study of nectarine powder and four mixtures with its participation. Four mixtures were made replacing 30% of the basic flour (white wheat, whole wheat, einkorn, and oat) with nectarine fruit powder of Bulgarian origin. Sorption characteristics were done at temperatures 10°C, 25°C, and 40°C, and the water activities (aw) in the interval 0.112 to 0.868 by the gravimetric-static method. For all compared products, augmentation in the temperature leads to a diminution in the sorption capacity. Using the statistical software “Statistica”, it was evaluated four models of Oswin, Chung-Pfost, Henderson, and Halsey. According to the obtained coefficients of each model and the criteria – P and SEM, the most appropriate model is the Halsey (for nectarine powder, white wheat, whole wheat, and einkorn mixtures). The Oswin model was suggested for the satisfactory description of the oat flour mixture with nectarine powder. The results showed that the monolayer moisture content varied in the large limits from 5.78% d.b. to 11.38% d.b. for water activities below 0.5.

Effect of extrusion on the structural and flavor properties of oat flours

As widely consumed functional grain worldwide, oats have received increasing attention due to numerous health benefits. Compared to the traditional multistep baking methods (saturated steam and kiln drying), extrusion offered economic and practical advantages in time and energy savings, as well as consumer product quality. With the purpose of discovering potentially new products, this study investigated the impact of extrusion on starch structural and flavor profiles (volatile and non-volatile) in oat flour. The high temperature, high pressure, and high shear in the extrusion process changed the intimate texture of the oat flour into irregular, spongy texture, which forms V-type crystal structure. Extruded oat flour's gelatinization temperature was significantly lower than unextruded. Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry demonstrated significant increases in aldehydes and heterocycles after extrusion of oat flours. The odorants in raw oat flours, identified by gas chromatography-olfactometry and odor activity value changed from green to pleasant nutty, grass and bean fragrance in extruded flours. Furthermore, umami amino acid contents increased, while bitter amino acid contents decreased significantly. This study identified the structural and flavor differences in extruded oat flours and provided clues that could improve potential in the development of ready-to-eat cereals and snack foods.

Detection of adulteration in Eragrostis tef (Zucc.) Trotter flour using EDXRF and ComDim-MLR data fusion

The teff cereal gained worldwide attention because it is gluten-free and rich in iron; thus, its flour is subject to fraud. This study evaluated the ability of Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) to identify teff flours adulterated with rice, whole wheat, oat, and rye flours. The adulteration followed a {5,4} simplex-lattice design. After smoothing and pretreatments, 15 kV and 50 kV spectra were fused by Common Dimension Analysis (ComDim). Multiple Linear Regression (MLR) models using EDXRF-ComDim scores and percentage of teff were adjusted. The best model presented four common dimensions (CD), r2prediction = 0.8534, low RMSEP (0.0564), and absence of overfitting. The obtained model was robust to quantify adulteration in teff flour even with the differences in the intensity of EDXRF spectra of different crops. Therefore, EDXRF, in tandem with ComDim data fusion, was an efficient tool for the adulteration control of teff flours.

Oat arabinoxylans and their potential glycemic index-lowering role: an in vitro study

ABSTRACT Oat (Avena sativa) is a cereal crop rich in dietary fibers, which are generally considered beneficial for human health. The objective of this work was to investigate the in vitro starch digestibility-reducing effect of the flour of a high arabinoxylan (AX) content (6.1%) oat line obtained from a random mutagenized oat population, compared to the original variety as a reference. The effect of the oat flours was tested on gelatinized potato starch as a dietary starch model, using a digestion dialysis method to calculate the predicted Glycaemic Index (pGI). The high AX flour reduced the potato starch pGI to larger extent than the flour from the original line. The pGI-lowering effect of the AX in the mutant line was confirmed by its attenuation following pre-treatment of the flour with xylanase. The larger pGI-lowering effect of the high AX oat line suggested this type of mutant as a potential functional food/ingredient for better management of postprandial glycemic responses.

Effects of enzymatic extrusion on the structure and physicochemical properties of oat flour and its application in oat milk production

SummaryOat milk has received increasing attention because of its health benefits, however, the problems of easy sedimentation and deterioration of taste during storage are common problems faced by the industry. Enzymatic extrusion is a technology that combines high‐temperature, high‐pressure and high‐shear extrusion with enzymatic hydrolysis for rapid biological transformation of materials. To evaluate the feasibility of enzymatic extrusion to overcome these disadvantages, the effects of this technology on the physicochemical properties of oat flour and on the stability and sensory score of oat milk have been studied. The results showed that the water solubility index of the enzymatic extrusion sample (2‰ α‐amylase) increased by 37.64% (from 5.99% to 43.63%) and the reducing sugar content increased about 11 times (from 11.61 to 128.31 mg g−1) compared with original oat flour. The enzymatic extrusion samples were almost completely gelatinised and their viscosity and degree of order were significantly reduced. The rheological results indicated that the enzymatic extrusion samples exhibited greater viscous fluid characteristics. After enzymatic extrusion treatment, the stability of oat milk was significantly enhanced, sensory evaluation indicated a highest score of 7.29 on the 9‐point hedonic scale (2‰ α‐amylase). This study provides a new way to produce high‐quality oat milk.

Use of Vegetable Fibers as a Substitute for Animal Fats in the Manufacture of Burgers and the Study of its Qualitative Characteristics

There is a relationship between the quantity and quality of fat consumed and common diseases such as heart disease, atherosclerosis and obesity. Therefore, the consumer’s interest in foods that contain a low percentage of fat, especially meat products, has increased. Therefore, the study aimed to know the effect of molecular substitution of some vegetable sources, namely oat flour and chia flour, instead of beef fat. To manufacture a low-fat, low-calorie burger and to compare the factory burger with the commercial burger available in the market. The beef burger had been manufactured from 80 % veal annotation and 20 % beef fat, which is the control burger. The fat was replaced with oat flour by 50 % and chia flour by 50 % for the beef burger. The study also included identifying the characteristics of the beef burger in terms of chemical composition, physical characteristics, and sensory characteristics. They were stored by freezing at a temperature of (-18 ± 2 C) during the storage period for 60 days, and their characteristics were monitored during the storage period by (1, 30, and 60) days. The results also showed a clear and remarkable improvement for all the technological characteristics under study. Therefore, the study recommends the use of oatmeal and chia flour as a substitute for beef fat in the manufacture of burgers.

Comparative life history and demographic parameters of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) on maize and oat flours

Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), Mediterranean flour moth, is a major pest of stored food products, causing significant economic losses. Understanding the life history and population dynamics of E. kuehniella is crucial for developing effective pest management strategies and improving the sustainability of the food industry. In this study, we conducted an age-stage, two-sex life table analysis of E. kuehniella reared on maize and oat flours. The aim of the study was to compare the demographic parameters of the E. kuehniella populations reared on the two different types of flour including maize in laboratory conditions at 26 ± 1 °C, 60 ± 5% R.H., and a 16:8 (light: dark) photoperiod. Our findings suggest that while the flour type had a minor effect, there was no significant impact on the developmental time, survival rate, fecundity, and population growth rate of E. kuehniella. However, adult female longevity was significantly longer in the maize flour group compared to the oat flour group. The pre-adult survival rate was higher in the maize flour group (83%) than the oat flour group (72%). Additionally, our results indicate that fecundity of the E. kuehniella was slightly higher on oat flour than on maize flour, while the population growth rate was similar on both flours. Our results demonstrated that the larvae fed with maize flour consumed a significantly higher amount of flour (394 mg) than those fed with oat flour (278 mg). Furthermore, after 120 days of simulation the population growth projection of E. kuehniella was twice as high in oat flour compared to maize flour. These findings suggest that both maize and oat flours are susceptible to E. kuehniella infestation, which has important implications for the development of effective pest management strategies and the sustainability of the food industry.

EFFICIENCY OF SOURDOUGHS OF SPONTANEOUS FERMENTATION FROM CEREAL FLOUR IN BAKERY TECHNOLOGIES

Subject. Sourdoughs of spontaneous fermentation from buckwheat, oat and rice flour, as well as dough and bread with the addition of the above-mentioned sourdoughs. The goal is to investigate the effectiveness of the use of oat, buckwheat and rice sourdoughs of spontaneous fermentation in the technology of bread products of various assortments. Methods. When conducting research, generally accepted methods were used, as well as cause-and-effect analysis, experimental, calculation and logical generalization. Results. In the conditions of the development of discrete production and the popularity of sourdough products, it is effective to use spontaneous fermentation. At the same time, it is worth paying special attention to the search for non–traditional ingredients to improve the nutritional value of wheat flour products and dietary types of bread. The scientific novelty of the results consists in the development and description of the cycles of conducting spontaneous fermentation starters with non-traditional fermentation substrate – green buckwheat, oat and rice flour with further modeling of recipes of bread products of various assortments: wheat, wheat-rye and gluten-free. As a result of the developed management schemes, buckwheat, oat and rice sourdough of spontaneous fermentation was created and the effectiveness of their use in the technology of a wide range of bread products was proven. The feasibility of using buckwheat and oat sourdough in the recipes of wheat and wheat-rye bread, and rice and buckwheat sourdough in the recipe of gluten-free bread is justified. Using the method of trial laboratory baking, the optimal dosages of each leaven were selected and the specifics of using each of them were described, depending on the recipe of the bread. It has been established that the addition of leavens contributes to the improvement of the taste–aromatic properties of the products and more intensive acid accumulation in the dough. Scope of results. The obtained results can be used by manufacturers in the modeling of new and correction of already existing recipes of health and dietary bread.

Effect of extrusion processing parameters on structure, texture and dietary fibre composition of directly expanded wholegrain oat-based matrices

Oat flour mixed with 30 g/100 g rice flour was extruded with a twin-screw extruder using a central composite orthogonal design. Temperatures (120 °C,140 °C, 160 °C) and moisture (14.5 g/100 g, 17.7 g/100 g, 20.6 g/100 g) were adjusted during extrusion, while screw speed was kept constant (400 rpm). Extrudates were analysed for structure (expansion, density, microstructure), texture (hardness), β-glucan (molecular weight and extractability), as well as fibre content. Expansion varied between 250 and 329%, density between 165 and 457 kg/m3 and hardness between 27 and 64 N. The response surface model showed that more expanded, less dense and less hard extrudates were achieved at low moisture, while high temperature resulted in lower density and hardness. Significant differences in β-glucan extractability were observed depending on extrusion conditions, with values ranging between 0.64 and 1.31 g/100 g. β-glucan extractability correlated with positively with porosity, and negatively with moisture content during extrusion, cell wall thickness and density. The results indicate that conditions that produce a more porous, crispier structure, also increases β-glucan extractability.

Vegetable-based frankfurter sausage production by different emulsion gels and assessment of physical-chemical, microbiological and nutritional properties

The present work aimed to evaluate emulsion gels from plant sources and their application in frankfurter-type sausages by determining the nutritional, physical-chemical, and microbiological properties of the formulations. Emulsifying capacity and emulsion stability were evaluated with canola oil, water, and three different vegetable-sourced flours (oat, flaxseed, and coconut) to select the emulsion gels. From these results, vegan sausages were formulated to resemble frankfurters and meat Frankfurter-type sausages were employed in the control. Emulsion gels from flaxseed and oat flours displayed high emulsifying capacities and more resistance once the gelling agent was added. Both vegetable-sourced sausages displayed significant differences in protein, fat and sodium. Stability, pH, and water activity did not present significant alterations in 120 days of storage. It was possible to conclude that vegetable-sourced emulsion gels allow the formulation of plant-based sausages with enhanced nutritional properties when compared to traditional meat sausages.

Quality assessment of value-added Indian recipe pedakiya prepared from composite flour and sesame seeds.

The present study was designed to enhance the nutritional value of the Indian recipe pedakiya/gujiya, a traditional sweet deep-fried dumpling, by utilizing the beneficial properties of composite flour (oat and peas flour) and sesame seeds. Furthermore, the study aimed to investigate the effects of partial substitution of refined wheat flour with oat and peas flour on nutritional, sensory, and microbiological parameters as affected by different cooking (deep-fat frying, baking, and air-frying) methods. The dough was developed by partially substituting a high percentage of refined wheat flour with oat flour, peas flour, and sesame seeds and based on the different treatments, these were coded as P0 (control), P1 (value-added pedakiya processed by deep-fat frying at 120 °C /5 minutes), P2 (air-fried at 120 °C /30 minutes), and P3 (baked at 200 °C /25 minutes). Based on sensory evaluation, sample P1 was the most acceptable by the sensory panel. Chemical analyses revealed that the addition of composite flour and sesame seeds substantially increased the nutritional parameters of the product. The product's microbiological analyses revealed that, up to a 15-day storage period, the product was well within safe levels. Aluminum bags were determined to be a suitable packaging material for storing the value-added pedakiya based on the water activity (at 37 °C/91% RH) and overall acceptability scores. This study has provided an alternative approach for preparing traditional pedakiya by utilizing healthier options. The topic of the present study is very timely since consumers are constantly looking for better alternatives to traditional fried dishes.

Characterisation of the Enzymatically Extracted Oat Protein Concentrate after Defatting and Its Applicability for Wet Extrusion.

An oat protein concentrate (OC1) was isolated from oat flour through starch enzymatic hydrolysis, by subsequent defatting by ethanol and supercritical fluid extraction (SFE) reaching protein concentrations of 78% and 77% by weight in dry matter, respectively. The protein characterisation and functional properties of the defatted oat protein concentrates were evaluated, compared and discussed. The solubility of defatted oat protein was minor in all ranges of measured pH (3-9), and foamability reached up to 27%. Further, an oat protein concentrate defatted by ethanol (ODE1) was extruded by a single screw extruder. The obtained extrudate was evaluated by scanning electron microscope (SEM), texture and colour analysers. The extrudate's surface was well formed, smooth, and lacking a tendency to form a fibrillar structure. Textural analysis revealed a non-unform structure (fracturability 8.8-20.9 kg, hardness 26.3-44.1 kg) of the oat protein extrudate.