Influence of milling methods and particle size on hydration properties of sorghum flour and quality of sorghum biscuits

Application of supercritical carbon dioxide to enhance the aroma of whole sorghum flour for use in 3D printing of sorghum cookies

Sorghum is a promising ingredient for new food products due to its high fiber content, slow digestibility, drought resistance, and gluten-free nature. One of the main challenges in sorghum-based products is the unpleasant aroma compounds found in grain sorghum. Therefore, in this study, sorghum flour was treated via supercritical carbon dioxide (SC-CO2) to remove undesired aroma compounds. The resulting SC-CO2-treated flours were used to generate dough for 3D food printing. At the optimized conditions, sorghum cookies were 3D-printed using 60 % water and a nozzle diameter of 1.5 mm. All dough samples produced with untreated and SC-CO2-treated sorghum flours exhibited shear-thinning behavior. Changing the treatment pressure (8-15 MPa) or temperature (40-60 °C) did not significantly affect the viscosity of the dough samples. Moreover, the sorghum cookie doughs had higher G' and G″ values after the SC-CO2 treatments (G' > G″). Doughs generated from flours treated at 15 MPa - 40 °C and 8 MPa - 60 °C showed lower adhesiveness compared to the ones produced from untreated flour, whereas 15 MPa - 60 °C treatment did not affect the adhesiveness. After baking, the 3D-printed cookies from SC-CO2-treated flour exhibited significantly lower redness (a*), but the hardness of the cookies was not affected by SC-CO2 treatment. Overall, the SC-CO2 treatment of sorghum flour did not negatively affect the quality parameters of the 3D-printed cookies while enhancing the aroma of the flour.

Comparison of milling methods on the properties of common buckwheat flour and the quality of wantuan, a traditional Chinese buckwheat food

The microstructural and techno-functional properties of buckwheat flour and its processability for making wantuan, as affected by different milling methods, were investigated. Results showed that the particle sizes (d(0.5)) of the flours made by stone-milling (SM), hammer-milling (HM), laboratory grinding with steaming pretreatment for 5 min (LG-5) and 10 min (LG-10) were 95.5, 111.5, 35.4 and 41.1 μm, respectively. Moreover, SM and HM flours had less liberated starch granules and 20.84%-24.32% higher relative crystallinity than LG-10 flour. Slurries of laboratory-grinded flours showed excellent suspension stability. LG-10 flour had lowest pasting viscosities but greatest storage modulus and loss modulus. Color differences among the wantuan made from different flours were not visibly perceived (ΔE < 5). Wantuan made from LG-5 flour exhibited highest textual quality due to its greatest resilience (0.376), good springiness (0.933) and accepted chewiness (1093.31). Concluding, steaming prior to grinding could improve the qualities of buckwheat flour for wantuan making.

Characteristics of Highland Barley-Wheat Composite Flour and Its Effect on the Properties of Coating Batter and Deep-Fried Meat

Highland barley flour-based coating batter has rarely been reported, although highland barley flour is promising due to its high β-glucan and amylose content. In this study, highland barley flour was used to substitute 40% to 80% of wheat flour to form a highland barely-wheat composite flour used in the coating batter. The characteristics of the highland barley-wheat composite flour and its effect on the properties of coating batter and deep-fried meat were analyzed. Results showed that the composite flour significantly improved water holding capacity, oil absorbing capacity, and water solubility index. In contrast, no significant change was observed in the water absorption index or swelling power. The incorporation of highland barley flour significantly changed the pasting properties of the composite flour. Compared with the wheat flour, the viscosity and the pickup of the coating batter made with composite flour increased from 4905 Pa·s and 0.53% to more than 12,252 Pa·s and 0.63%, respectively, and its water mobility decreased. These changes were closely related to the substitution rate of highland barley flour. The composite flour significantly increased the moisture content from 27.73% to more than 33.03% and decreased the oil content of the crust from 19.15% to lower than 16.44%, respectively. It decreased L* and increased a* of the crust and decreased the hardness, adhesiveness, and springiness of the deep-fried meat. A spongy inner structure with a flatter surface was formed in all composite flour-based crusts, and the substitution rate influenced the flatness of the crust. Thus, highland barley flour could be used for batter preparation with partial substitution, enhancing the quality of deep-fried meat and acting as an oil barrier-forming ingredient for fried batter foods.

Effect of different milling methods on physicochemical and functional properties of mung bean flour

There needs to be more information concerning the effect of different milling methods on the physicochemical properties of whole-grain mung bean flour. Therefore, the physicochemical properties of whole grain mung bean flour were analyzed using universal grinders (UGMB), ball mills (BMMB), and vibration mills (VMMB). The results showed that the particle size of the sample after ultrafine grinding treatment was significantly reduced to 21.34 μm (BMMB) and 26.55 μm (VMMB), and the specific surface area was increased. The particle distribution was uniform to a greater extent, and the color was white after treatment. Moreover, the water holding capacity (WHC), oil holding capacity (OHC), and swelling power (SP) increased, and the bulk density and solubility (S) decreased. The Rapid Viscosity Analyzer (RVA) indicated that the final viscosity of the sample after ultrafine grinding was high. Furthermore, rheological tests demonstrated that the consistency coefficient K, shear resistance, and viscosity were decreased. The results of functional experiments showed that the treated samples (BMMB and VMMB) increased their capacity for cation exchange by 0.59 and 8.28%, respectively, bile acid salt adsorption capacity increased from 25.56 to 27.27 mg/g and 26.38 mg/g, and nitrite adsorption capacity increased from 0.58 to 1.17 mg/g and 1.12 mg/g.

Milling and differential sieving to diversify flour functionality: A comparison between pulses and cereals

In this study, pulse (pea, lentil) and cereal (barley, oats) seeds were firstly milled into whole flours, which were then sieved into coarse and fine flours. The particle sizes of the three generated flour streams followed a descending order of coarse > whole > fine, consistent with the observation under scanning electron microscopy (SEM). Among the four crops, the three flour streams showed the same rank order of fine > whole > coarse in starch and damaged-starch contents but the opposite order in ash and total dietary fiber contents. Thus, those functional properties closely related to starch occurring in flour, such as L* (brightness), starch gelatinization enthalpy change (ΔH), and gel hardness, followed the same order of fine > whole > coarse. By contrast, protein contents of the three flour streams did not vary in pea and lentil but showed a trend of coarse > whole > fine in barley and oats, which could partially explain generally comparable foaming and emulsifying properties of the three streams of pulse flours as well as an order of coarse > whole > fine in oil-binding capacity (OBC) of cereal flours, respectively. The different particle sizes and chemical compositions of the three flour streams only resulted in a descending order of fine > whole > coarse in the pasting viscosities of the pulse flours but did not lead to such a clear trend in the cereal flours, which could be partly attributable to the different microscopic structures of the pulse and cereal seeds and their corresponding flours. This research clearly demonstrated that particle size, chemical composition, and microscopic structure were important variables determining the specific techno-functional properties of pulse and cereal flours.

Functional, rheological, and microstructural properties of hydrothermal puffed and raw amaranth flour suspensions

The pseudocereal amaranth is commonly used in food as whole puffed grain. To improve the utilization of amaranth, hydrothermally treated suspensions of puffed and raw Amaranthus caudatus flour and their blends were investigated in this study. The suspensions were hydrothermally treated at 20, 50, and 80°C for 1, 5, and 24 h. The blends were treated at 80°C for 1 h. The effect of hydrothermal treatments of the suspensions on their morphological (color, SEM), water-binding, and rheological-functional properties was studied. The puffed amaranth suspensions exhibited cold swelling properties by rapid viscosity increase and significant water absorption properties. It was found that hydrothermal treatment at 80°C for 1 h significantly increased water absorption and viscosity in puffed and raw flour suspensions. However, the puffed suspensions showed significantly higher values in water binding and viscosity. Suspensions of raw amaranth flour showed increasing color differences with increasing temperature. Blends of raw and puffed amaranth flour resulted in a decreasing color change with increasing puffed flour content. Water absorption of the samples increased with an increasing puffed flour content. Raw amaranth flour and the 50/50 (puffed/raw) blend had the lowest, 10/90 and 20/80 (puffed/raw), and showed similar viscosity profiles to suspensions of pure puffed flour.

Trends in Sieving and Its Applications in Cereals. A Literature Review

In the agroindustry, sieving is a unit operation of great value, this work aims to make a literature review on sieving in cereals, a search equation was carried out in the Scopus database with the keywords sieve, screen, food process, and cereal that resulted in 132 articles and 174 patents. Of the articles, 44 were directly related to sieving and 14 more had something to do with sieving; of the patents, in the last 10 years only 7 were directly related to sieving. To find new trends, raw materials, patent analysis, and information analysis, tables were built with name, year, author, keywords, countries, quartile, journal, relationship with the agroindustry, and purpose. Among the most important conclusions was the application of sieving in raw materials such as Rice, Corn, Wheat, Cotton, Millet, Quinoa, Almonds, Barley, Potato, Yucca, Microorganisms, Oats, Cotton, Protein, Peppers, and Chia Seed. Furthermore, the use of rotating and vibrating sieves was identified, and also their positive effects on the physicochemical, standardization, and classification of raw materials were identified. The different types of equipment or methods focused on sieving, that has been granted use or design patent, were also recognized.

New alternatives from sustainable sources to wheat in bakery foods: Science, technology, and challenges

Ongoing research in the food industry is striving to replace wheat flour with new alternatives from sustainable sources to overcome the disease burden in the existing population. Celiac disease, wheat allergy, gluten sensitivity, or non-celiac gluten sensitivity are some common disorders associated with gluten present in wheat. These scientific findings are crucial to finding appropriate alternatives in introducing new ingredients supporting the consumer's requirements. Among the alternatives, amaranth, barley, coconut, chestnut, maize, millet, teff, oat, rye, sorghum, soy, rice flour, and legumes could be considered appropriate due to their chemical composition, bioactive profile, and alternatives utilization in the baking industry. Furthermore, the enrichment of these alternatives with proper ingredients is considered effective. Literature demonstrated that the flours from these alternative sources significantly enhanced the physicochemical, pasting, and rheological properties of the doughs. These flours boost a significant reduction in gluten proteins associated with food intolerance, in comparison with wheat highlighting a visible market opportunity with nutritional and organoleptic benefits for food producers. PRACTICAL APPLICATIONS: New alternatives from sustainable sources to wheat in bakery foods as an approach that affects human health. Alternatives from sustainable sources are important source of nutrients and bioactive compounds. Alternatives from sustainable sources are rising due to nutritional and consumer demand in bakery industry. New alternatives from sustainable sources improve physicochemical, pasting, and rheological properties of dough. Non-wheat-based foods from non-traditional grains have a potential to increase consumer market acceptance.

Effect of sorghum flour properties on gluten-free sponge cake

As the demand for gluten-free products increases, the use of sorghum flour becomes a good alternative. Sponge cakes are consumed worldwide and suitable for formulations that could replace wheat flour. One of the most influential parameters on sponge cake quality is the flour particle size. In this study, we obtained and characterized different flours by milling white and brown sorghum grains and evaluated the influence of flour characteristics on batter properties and gluten-free sponge cake quality. Flours were produced by pearling, milling and sifting; and were characterized for flour composition, particle size distribution, damaged starch and water absorption. The structure, density, and viscosity of the batters; and specific volume and crumb properties of the sponge cake were evaluated. The results showed that flour composition, and properties were modified by the milling processes. Pasting viscosity increased as the particle size of the flours was reduced. Brown or white sorghum flour with smaller particle size produced high density and viscosity batters with small and homogeneous air bubbles distribution. Independently of the sorghum variety used, smaller particle size flour leads to sponge cakes of high volume and low firmness.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05150-0.

Effects of Dry Heat Treatment and Milling on Sorghum Chemical Composition, Functional and Molecular Characteristics

This study aimed to highlight the effects of grains dry heat treatment, flour particle size and variety on sorghum flour nutritional, functional, and molecular characteristics. The results obtained showed that dry heat treatment led to fat, fiber and water absorption capacity increase, while the moisture, protein, ash, water retention capacity, solubility index, foaming capacity, and FT-IR absorption bands characteristic to phytic acids decreased with temperature applied raised. Particle size reduction determined lower protein, solubility index, and emulsifying activity and higher fat content, oil absorption capacity, swelling power, and foaming capacity. White sorghum flour fractions presented lower protein content, except when they were treated at 140 °C, lower carbohydrates and fibers and higher fat content compared to those made of red sorghum. Moderate significant correlations (p < 0.05) were observed between some of the functional properties and proximate composition of flours. Thus, both dry heat treatment conditions and particle size exerted significant influences of sorghum flour chemical and functional properties. These results showed the importance of particle size and dry heat treatment on sorghum flours functionality, being helpful for further optimizations and choices for bakery products use.

Effects of wheat flour particle size on flour physicochemical properties and steamed bread quality

In this study, differently sized particles of wheat flour (from 52.36 μm to 108.89 μm) were obtained by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1 mm) of a heart mill. Results showed that reducing the particle size significantly increased the damaged starch (DS) content. Uniaxial tensile measurement of dough showed that reducing the particle size of wheat flour can effectively increase the maximum tensile resistance, but the extensibility reaches the maximum in samples at medium particle diameter (78 and 66 μm). Additionally, the ratio of dynamic moduli (G″/G') decreased with a reducing particle size. The results of disulfide bond content, gluten microstructure, showed that finer flour granulation can strengthen the gluten network. The steamed bread (SB) making test showed that SB made from wheat flour of a smaller particle size had a significantly smaller specific volume than that made from a larger particle size. The texture profile analysis showed that with a decrease of wheat flour particle size, the hardness, chewiness of SB increased, the resilience decreased, and there was no significant difference in adhesiveness. Overall, the quality of SB made flour of medium particles (78 μm) is better.

Effect of Sorghum on Rheology and Final Quality of Western Style Breads: A Literature Review

Due to the extreme weather conditions, caused by the climate change, the usual wheat harvest yield and quality in the Western countries were difficult to maintain in the past few years. The altered wheat quality was primarily characterized by a rising protein content. The application of high protein wheat flours in baking products leads to baking difficulties due to its elastic dough behavior. As these issues will further face the Western cereal cultivation, heat resistant cereals, like sorghum, are attracting increasing interest. A partial substitution of wheat with sorghum might offer one possible solution to address the current challenging situation. To introduce sorghum in the Western cereal and baking industry, the grain and its unique chemical and rheological properties need to be more widely promoted. Until now, several authors have conducted studies in order to emphasize the high potential of sorghum. The aim of the present review is to broaden the current knowledge of the chemical, rheological and baking properties of sorghum in comparison to wheat. The review further demonstrates promising approaches, which might be from interest in order to achieve higher wheat-sorghum bakery end product qualities.

Effects of milling methods on the properties of glutinous rice flour and sweet dumplings

Glutinous rice flour (GRF) was prepared using three milling process (wet milling, low temperature impact milling (dry milling), and roller milling (dry milling)) to investigate their effects on the physicochemical properties of glutinous rice flour and sweet dumplings prepared with that flour. Results revealed that a method of grinding used in the milling process had a significant (P < 0.05) effect on the properties of GRF and the resulting sweet dumplings. Dry milling (low temperature impact milling and roller milling) resulted in higher damaged starch content and coarser particle size than wet milling. Dry-milled flour exhibited a significantly lower hunter whiter value, apparent viscosity, pasting temperature, enthalpy value, and degree of crystalline compared to the wet-milling method. Dry milling significantly decreased the smoothness of the surface, whiteness value, transmittance of soup, resilience of dumplings, as well as increased the cracking rate and water loss during the fast-freeze. The obtained results could be used as reference for improving sweet dumpling made from dry-milled GRF.

Chemical and Physical Characterization of Sorghum Milling Fractions and Sorghum Whole Meal Flours Obtained via Stone or Roller Milling

Due to climate change sorghum might gain widespread in the Western countries, as the grain is adapted to hot climate. Additionally sorghum contains a notable amount of health-promoting nutrients. However, Western countries do not have a long history of sorghum consumption, and thus little experience in processing it. Milling systems in these areas were mostly developed for wheat or rye milling. In the present work, the effectiveness of sorghum milling when using a stone and a roller milling system (pilot scale) was investigated as well as its impact on the chemical and physical properties of the obtained flour fractions and whole-grain flours. Results showed that both milling systems could be successfully adapted to producing chemically and physically distinct flour and bran fractions from the small sorghum kernels. Fractions with increased bran material that contained higher amounts of ash, protein, fat, total dietary fiber, and total phenolic content but less starch, showed enhanced water absorption indices and water solubility indices. Interestingly, no significant difference was found in the ash and fat content of the different fractions obtained from stone milling. Overall, the study provided information on the production and composition of distinct flour fractions, which offer a wider range of future food applications.

The Effect of Inulin on the Physical and Textural Properties of Biscuits Containing Jet Milled Barley Flour

The quality properties of biscuits with partial replacement of sugar by inulin (at 0, 10, 20 and 30%) and wheat flour by barley flour (at 0, 10, 20, 30 and 40%) were studied. A commercial and a jet milled finer barley flour were used. For all flour substitutions, elevated amounts of inulin led to increased weight and decreased spread ratio of the biscuits. Inulin biscuits, within the same flour composition, were softer than those with no inulin but inulin’s concentration was not statistically important. The incorporation of barley flour resulted in reduced lightness, more evident in the case of the finer barley flour. Inulin also affected the lightness of the biscuits. Phenolic content was affected by the presence of barley flour but no clear trend of inulin’s effect was detected. The interactions between barley substitution, inulin substitution and particle size of the barley flour were important for all studied properties, i.e., weight, spread ratio, hardness, total phenolic content and color.

Characterization of Quinoa Seeds Milling Fractions and Their Effect on the Rheological Properties of Wheat Flour Dough

Replacement of refined wheat flour with milling fractions of quinoa seeds represents a useful way for the formulation of value-added baked products with beneficial characteristics to consumers. The aim of this study was to assess the chemical composition and physical properties of different particle sizes of quinoa flour on Falling number index (FN) and dough rheological properties determined by Mixolab in a planned research based on design of experiment by using full factorial design. The ash and protein contents were higher in medium particle size, whereas the carbohydrates presented a lower value, this fraction having also the highest water absorption and water retention capacity. The reduction of particles led to an increased swelling capacity and a decreased bulk density. The particle size significantly influenced the FN values in linear and quadratic terms (p < 0.05), showing a decrease with the particle size increasing. Particle size decrease significantly increased water absorption and the rate of protein weakening due to heat (C1–2), whereas starch gelatinization rate (C3–2), starch breakdown rate related to amylase activity (C3–4) and starch retrogradation speed (C5–4) decreased. By increasing the amount of quinoa flour (QF) in wheat flour, the dough stability and the torques C2, C3, C4 and C5 followed a decreased trend, whereas water absorption and dough development time rose. Optimization, determined by particle size and level of QF added in wheat flour based on which of the combination gives the best rheological properties, showed that the composite flour containing 8.98% quinoa flour of medium particle size was the most suitable.

From the Laboratory to the Kitchen: New Alternatives to Healthier Bakery Products

Due to the growing interest in improving the nutritional profile of bakery products, we have dealt with the most recent and relevant contributions regarding potential replacements for carbohydrates, proteins, and fats. Focusing on the influence of carbohydrates on metabolism, their excess implies obesity, diabetes and tooth decay. However, they are technologically important, since they are responsible for the structure of many bakery products. Regarding of the lipid profile, saturated fats have a great impact on the appearance of cardiovascular disease. Fortunately, nature and the food industry offer alternatives to traditional oils/butters with large amounts of omega 3 and other components that can mitigate these problems. Other relevant aspects are related to allergies concerning egg proteins, gluten or even requirements for vegan consumers. Several studies have been performed in this line, replacing eggs with milk serum, different mucilages obtained from legumes or some gums, etc. In conclusion, many papers have been published showing the possibility of successfully replacing (both at technological and sensory levels) less healthy ingredients with others that are nutritionally better. The challenge now is to combine these better components in a given product, as well as to evaluate possible interactions among them.

Biscuits Enriched with Dietary Fibre Powder Obtained from the Water-Extraction Residue of Maize Milling by-Product

A maize milling by-product was defatted by aqueous extraction and the residue was dehydrated, comminuted and sieved to obtain two powders differing in particle size and having a very high fibre content. The powders were then incorporated into the structure of short-dough biscuit, at two wheat flour substitution levels (10 and 20%), aiming at the development of a nutritionally improved product. Their impact on biscuit dough properties and the quality and sensory characteristics of the final products was evaluated. As it was revealed, powders' addition altered dough consistency and alveograph indices mainly due to interactions between wheat flour proteins and polysaccharides and enhanced the nutritional profile of the biscuits by inducing a 4- to 6-fold increase of their fibre content. Additionally, it influenced only to a limited extent the degree of some of the final product characteristics, e.g., protein and fat content, spread ratio, breaking strength, depending both on the level of incorporation and the particle size of the residue. On the whole, products' sensory quality was not negatively influenced, suggesting that it is possible to use both powders for the fortification with fibre of biscuits and possibly other bakery products.

Influence of Flour Particle Size Distribution on the Quality of Maize Gluten-Free Cookies

The objective of the present study was to analyse the influence of particle size distribution of maize flour in the formulation of gluten-free cookies. Different cookie formulations were made with three distinct maize flour fractions obtained by sieving (less than 80 µm; between 80 and 180 µm; greater than 180 µm). Cookies dimension, texture and colour were evaluated. Flour hydration properties and cookie dough rheology were also measured. Overall, an increase in maize flour particle size decreases the values of water holding capacity (WHC), swelling volume and G’ (elastic modulus) for the doughs. An increase in average particle size also increases diameter and spread factor of the cookies but decreases their hardness. A higher percentage of thick particles is more effective to reduce cookie hardness, but a certain percentage of thinner particles is necessary to give cohesion to the dough and to allow formation of the cookies without breaking. Cookies with a larger diameter also presented a darker colour after baking.

Physical and textural properties of biscuits containing jet milled rye and barley flour

The biscuit-making performance of flour depends on both its botanical source and particle size. Several quality parameters of biscuits produced by partial replacement of wheat flour by barley and rye flours at 0, 10, 20, 30 and 40% were measured. Moreover, in order to investigate the effect of particle size, a commercial and two jet milled finer samples of both rye and barley flours were used. For most of the composite flours, the level of substitution was not statistically significant for the weight and the spread ratio of the biscuits. Biscuits with composite flours were softer and darker than the control biscuit (100% wheat flour). In addition, their total phenolics content and antioxidant activity were greater. Among composite flour biscuits, the finer barley flour biscuits were harder than those with the commercial flour. Moreover, as rye flour is darker than wheat and barley flours, rye biscuits were the darker of all. Porosity, bulk and true densities were affected by the particle size of the substitute flours.

Optimization of hot-air drying conditions for cassava flour for its application in gluten-free pasta formulation

The design and development of gluten-free foods requires a comprehensive understanding of the behavior of the raw materials to attain the same cooking and nutritional quality as gluten-based food. The objective of this study was to determine the optimal hot-air drying conditions for elaboration of cassava flour to be used in a gluten-free pasta formulation. The results showed that the operational conditions to minimize the hot-air drying time (57 min) to produce cassava flour with higher water holding capacity was 57 ℃ at 3 m/s. Then, the optimal formulation for the pasta was found to be cassava (26 g/100 g), amaranth flour (12 g/100 g), and carboxymethyl cellulose (0.23 g/100 g), which maximized the A_w (0.160), moisture content (3.10 g/100 g), hardness (5.02 N), and protein content (9.30 g/100 g), and it is used for the sensorial analysis, which showed that an earthy taste was the main problem with consumer satisfaction.

Contribution of instant amaranth (Amaranthus hypochondriacus L.)-based vegetable soup to nourishment of boarding school adolescents

Uganda has one of the youngest populations in the world with about 78% of its population below 30 years of age, most of which are adolescents. The boarding school diet fed to adolescents is rich in carbohydrates and proteins but lacks adequate amounts of micronutrients to meet the adolescent RDA requirements. This study aimed at contributing to the improvement of the nutritional status of boarding school adolescents in Uganda by developing an acceptable convenient instant vegetable soup rich in protein (12.30 ± 0.25–13.26 ± 0.25%), total carotenoids (154.19 ± 12.62–292.68 ± 3.56 RAE/μg), and iron (2.33 ± 0.06–4.37 ± 0.03 mg). The three soup formulations showed desirable reconstitution and instant characteristics owing to the observed functional properties. The soup had a high dispensability (69%–71%), water absorption capacity of 1.53–1.98 g/g, bulk density of 0.79–0.80 g/ml, and swelling capacity of 5.05–5.38 g/g. The overall sensory acceptability was within a range of 6.2–6.7 and not significantly different from the control commercial soup. The soups contributed over 25% of the adolescent RDA requirements for carbohydrate, protein, dietary fiber, vitamin A, and iron but not for zinc (5.7%) and calcium (9.7%). These results indicate the potential of the soup to improve the nutritional status of adolescents. However, there is a need for additional research to increase the formulated soups’ acceptability, its contribution to zinc and calcium RDA adolescent requirements, as well as to determine its bioavailability and shelf stability.

Influence of jet milling and particle size on the composition, physicochemical and mechanical properties of barley and rye flours

Finer barley and rye flours were produced by jet milling at two feed rates. The effect of reduced particle size on composition and several physicochemical and mechanical properties of all flours were evaluated. Moisture content decreased as the size of the granules decreased. Differences on ash and protein contents were observed. Jet milling increased the amount of damaged starch in both rye and barley flours. True density increased with decreased particle size whereas porosity and bulk density increased. The solvent retention capacity profile was also affected by jet milling. Barley was richer in phenolics and had greater antioxidant activity than rye. Regarding colour, both rye and barley flours when subjected to jet milling became brighter, whereas their yellowness was not altered significantly. The minimum gelation concentration for all flours was 16%w/v. Barley flour gels were stronger, firmer and more elastic than the rye ones.