Quality and antioxidant properties of functional rice muffins enriched with shiitake mushroom and carrot pomace

This study developed functional muffin by incorporating bioactive-rich food materials into rice muffin formulation. Rice flour was progressively replaced with shiitake mushroom powder (MP) and carrot pomace powder (CP) and effects on pasting, physical and textural properties, as well as the antioxidant activity and consumer acceptability, were evaluated. The pasting properties of rice flour were significantly influenced (P < 0.05) by MP and CP incorporation. The additional increase in the levels of MP and CP decreased the volume of enriched muffins with a subsequent increase in weight and hardness. Higher polyphenol and carotenoid contents were observed in enriched muffins, exhibiting higher 2,2-Diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity compared to rice muffins. Sensory result revealed enriched muffins to have comparable and better consumer acceptability than rice muffin. Improvement in antioxidant properties of the developed functional rice muffins by MP and CP incorporation makes it a potential snack, suitable for consumption for its health benefits.     

Physicochemical properties of rice flour as affected by alkaline soaking and washing treatments

Effects of alkaline [NaOH, saturated Ca(OH)₂ and/or limewater] soaking and subsequent washing (with water vs. without washing) treatments on physicochemical properties of rice flour were investigated. Alkaline soaking treatment generally caused a loss of granule angularity but some birefringence was observed for unwashed alkali-soaked flour granules. After soaking, protein content of the flours significantly (P < 0.05) decreased but swelling power significantly (P < 0.05) increased compared to the control (soaked in water). The washed flours had lower protein content than unwashed flours (3.77–6.87% vs. 5.26–7.87%). The NaOH-soaking treatment yielded higher swelling power and solubility, respectively, for unwashed and washed flours. Alkaline soaking increased breakdown but decreased pasting temperature, trough viscosity, final viscosity and setback of the paste compared to the control. Compared to the control, hardness of soaked flour paste was lower due to lower final viscosity and setback. Overall, physicochemical properties of rice flour could be modified by alkali-soaking and washing treatments.     

QUALITY CHARACTERISTICS OF GLUTEN‐FREE CHICKEN NUGGETS EXTENDED WITH SORGHUM FLOUR

ABSTRACT

Application of coarse cereal flours is recommended to replace wheat gluten in meat products and to avoid gluten allergy in susceptible populations. Sorghum flour is a good source of dietary fiber and provides nonglutinous flours and scope for making gluten‐free meat products. Keeping this in view, the present research was envisaged to evaluate the different quality characteristic of gluten‐free chicken nuggets prepared with sorghum flour. Three types of chicken nuggets viz., Control chicken nuggets (CCNs), gluten‐free nuggets (GFN1 with 5% sorghum flour and GFN2 with 10% sorghum flour) were compared for different physicochemical, instrumental texture, color and sensory characteristics. Use of sorghum flour significantly (P < 0.05) increased the product yield and dietary fiber content in GFN1 and GFN2 as compared with CCN. Instrumental color results showed that lightness (L* value) and redness (a*) values were significantly (P < 0.05) lower in GFN1 and GFN2 as compared with CCN. Texture profile analysis indicated that incorporation of sorghum flour significantly (P < 0.05) improved hardness, gumminess and chewiness. Sensory scores of GFN1 and CCN were significantly (P < 0.05) higher than GFN2. It was concluded that that 5% sorghum flour is optimum to prepare gluten‐free chicken nuggets.

PRACTICAL APPLICATIONS

Sorghum is coarse millet and a popular staple diet in many developing countries. The results of this study support that sorghum flour can serve as a functional ingredient in developing healthy meat products. Use of sorghum flour in the formulation of wheat free meat products is an alternative to avoid gluten allergy. These gluten‐free meat products have potential to reach the niche markets and will be highly acceptable to gluten allergic consumers who demand gluten‐free products. Therefore, sorghum based food products can be marketed as health/functional products.     

Physical properties and hypoglycaemic activity of biscuits as affected by the addition of stigma maydis extract

The study aimed to evaluate the potential ingredient of stigma maydis (S.M.) as a hypoglycaemic functional food. In the present study, waxy corn flour and corn-resistant starch were used to make biscuits; the influence of S.M. extracts (aqueous extract, SMA; ethanol extract, SME; mixed solvent extract, SMM) on the physical features and in vitro digestibility of biscuit were surveyed. In the meantime, the α-amylase and α-glucosidase inhibition of different S.M. extracts were analysed. Compared with the control dough, 5% ethanol S.M. extract (SME2) dough was observed to have the lowest storage modulus (G'), loss modulus (G"), hardness, water absorption capacity (P < 0.05), while creep strain was the highest (P < 0.05). Adding S.M. extracts could significantly reduce the L*, b* value and increase the a* value of biscuits. Besides, the S.M. extracts could decrease the glycaemic index (G.I.) of biscuits and reduce postprandial blood glucose levels. The GI of SMA1, SMA2, SME1, SME2, SMM1 and SMM2 was decreased to 62.47, 55.17, 51.46, 44.89, 53.05 and 50.11 respectively. Further, the addition of S.M. extract could show a certain inhibitory rate of α-amylase and α-glucosidase when added to biscuits. The inhibition ratio of 5% extract (SMA2, SME2 and SMM2) biscuit was higher than that of 1% extract (SMA1, SME1 and SMM1) biscuit (P < 0.05). As a natural functional component, S.M. extract could be a potential food supplement for type II diabetic mellitus.     

Evaluation of Starch Degradation and Textural Characteristics of Dietary Fiber Enriched Biscuits

Abstract

The effects of dietary fiber inclusion on biscuit texture, cooking properties, and sugar release after in vitro degradation were investigated. Inulin, β-glucan enriched fraction (BGEF), potato fiber, and a resistant starch were used. Effects of the dietary fibers on the pasting properties of flour based mixtures were investigated using a rapid visco analyzer. Results showed a reduction in visco-pasting properties (peak viscosity and final viscosity) of the flour–dietary fiber systems with increasing fiber content. Addition of dietary fiber into the biscuits affected biscuit shrinkage and height development during cooking, as well as generally reducing the resistance of biscuits to snapping during texture analysis tests. Sugar release during in vitro degradation studies showed a highly significant decline when comparing dietary fiber enriched biscuits to the control samples. This would have a beneficial effect in potentially reducing the glycaemic index and subsequent glycaemic loading of such foods.     

Replacement of buckwheat by black sorghum flour on soba-type noodles

Incorporation of black sorghum flour containing high levels of polyphenols and slowly digestible starch could provide opportunity to enhance nutritional functionality of noodles. Soba-type noodles were prepared based on a typical wheat-buckwheat (65:35) formulation by replacement of buckwheat flour with black sorghum flour at 0%, 25%, 50%, 75% and 100%. Noodle colour, texture, total phenolics, antioxidant capacity, in vitro starch digestibility and sensory acceptability were evaluated. Increasing the addition of black sorghum flour significantly (P < 0.05) decreased the firmness (g) in noodles and imparted a darker colour but increased total polyphenolics and antioxidant capacity. Significantly (P < 0.05) lower rapidly digestible starch and higher resistant starch was found in noodles with >50% replacement with black sorghum flour. Overall acceptability of noodles showed preference for noodles containing 25%–75% black sorghum flour. This study demonstrates the potential of using black sorghum as a novel functional food ingredient in noodle manufacturing.     

Impact of differing population levels of Rhyzopertha dominica (F.) on milling and physicochemical properties of sorghum kernel and flour

The effects of different population levels of Rhyzopertha dominica (F.), the lesser grain borer, on physiochemical properties of sorghum kernels and flour, were investigated through a laboratory study at 27 and 32 °C, and 57% relative humidity. Initial population level and temperature, and their interaction, were significant for the number of F₁ progeny and feeding damage (P<0.01). A strong positive correlation was also found between initial population size, number of F₁ progeny, percentage of insect-damaged kernels (IDKs) and feeding damage. The impact of R. dominica on the milling quality of sorghum was seen through a reduction in abrasive hardness, milling yield, and kafirin content. Initial population and temperature affected most pasting properties, and overall pasting viscosity increased with initial population, number of F₁ progeny, and percentage of IDK at 32 °C. Results show that R. dominica can potentially impact the milling quality of sorghum and also alter the physicochemical properties of sorghum flour.     

Effects of protein and transglutaminase on the preparation of gluten-free rice bread

Effects of transglutaminase (TGase) and proteins such as whey protein, caseinate, and soy protein on the preparation of gluten-free rice breads using non-waxy rice flour were investigated. Rice flour (about 12% moisture content) was prepared from dry milling of dried grain after rice got soaked. Unlike general dry milled flour, newly developed rice flour increased water binding capacity (WBC), swelling power, and peak viscosity. Soy protein increased WBC but other proteins slightly decreased with the increase of levels. Lightness decreased and yellowness increased with the addition of whey and soy protein. All pasting viscosities decreased with the addition of protein. The TGase improved the network structure of rice batter. The 2^nd proof time of rice batter with protein was shortened by 4–9 min with the addition of TGase. The specific volumes of rice breads with whey and soy protein also increased. TGase and protein additions decreased the hardness of rice bread. Sensory test showed that roasted flavor, volume, air cell homogeneity, and overall quality were significantly different (p<0.05) with protein and TGase additions.     

Effect of Fat Replacement by Inulin on Textural and Structural Properties of Short Dough Biscuits

The aim of this study was to evaluate the effects of inulin as fat replacer on short dough biscuits and their corresponding doughs. A control formulation, with no replacement, and four formulations in which 10, 20, 30, and 40 % of shortening was replaced by inulin were studied. In the dough, shortening was observed surrounding flour components. At higher fat replacement levels, flour was more available for hydration leading to significant (P?<?0.05) harder doughs: from 2.76 (0.12)?N in 10 % fat-replaced biscuits to 5.81 (1.56)?N in 30 % fat-replaced ones. Biscuit structure was more continuous than dough structure. A continuous fat layer coated the matrix surface, where starch granules were embedded. In general, weight loss during baking and water activity decreased significantly (P?<?0.05) as fat replacement increased. Biscuit dimensions and aeration decreased when fat replacement increased, e.g., width gain was +1.20 mm in 10 % fat-replaced biscuits and only +0.32 mm in 40 % fat-replaced ones. Panelist found biscuits with 20 % of fat replacement slightly harder than control biscuits. It can be concluded that shortening may be partially replaced, up to 20 %, with inulin. These low fat biscuits are similar than the control biscuits, and they can have additional health benefits derived from inulin presence.     

Relationships Between Selected Properties of Seeds,Flours, and Starches from Different Chickpea Cultivars

ABSTRACT

Five desi (PBG-1, PDG-4, PDG-3, GL-769, and GPF-2) and one kabuli type (L-550) chickpea cultivars were evaluated for their seed mass, volume, hydration capacity, swelling capacity, cooking time, and instrumental textural properties (hardness, cohesiveness, gumminess, and chewiness). Flour was prepared from these chickpea cultivars and various physicochemical and functional properties were determined. The pasting (pasting temperature, peak viscosity, breakdown, and final viscosity) and gelatinization (T _o, T _p, T _c, and ΔH _gel) properties of these flours were measured using Rapid Visco Analyzer (RVA) and Differential Scanning Calorimeter (DSC), respectively. Starch was also isolated from chickpea cultivars and evaluated for amylose content, swelling power, solubility, and syneresis values. Physicochemical, cooking, and instrumental textural properties of seeds of different chickpea cultivars were related to physicochemical, gelatinization, and pasting properties of their flours and physicochemical properties of their starches. Selected properties of chickpea seeds were significantly correlated with the properties of their starches and flours. Hardness value of soaked chickpea seeds was positively correlated to cooking time, seed mass, seed volume, hydration, and swelling capacity (p < 0.01). Water solubility index (WSI) of chickpea flours was positively correlated to seed mass, volume, hydration capacity, and hardness value (p < 0.05). Selected instrumental textural parameters of seeds had positive correlation with ΔH _gel of flours (p < 0.01). Peak viscosity of flours showed positive correlation to breakdown, final viscosity, bulk density, and negative correlation to cohesiveness of soaked seeds (p < 0.01). Final viscosity showed negative correlation to bulk density and water absorption index (WAI) (p < 0.01) of flours.     

Potentials of Lactobacillus plantarum and Pichia kudriavzevii in co-fermentation of sourdough from millet

The use of millet in the production of gluten-free sourdough has significant benefits such as its suitability for individuals with gluten sensitivity. Lactic acid bacteria and yeasts were screened for functional properties from unmalted and malted millet for sourdough preparation. Lactobacillus plantarum MLd27 and Pichia kudriavzevii MYd23 were selected, used individually and mixed starter cultures to produce sourdough. The specific volume (3.07 ± 0.06 cm³ g⁻¹) of the bread made with unmalted flour and Pichia kudriavzevii MYd23 was significantly higher (P < 0.05) compared to all the other samples. The protein, ash and fibre contents of the bread samples ranged from 10.1 to 11.4, 2.2 to 4.5 and 1.45 to 1.74 g/100 g, respectively. The sourdough bread samples were generally acceptable, while spontaneously fermented bread from malted flour showed the significantly highest (P < 0.05) overall acceptability of (7.90). The production of gluten-free millet sourdough bread can aid in food security.     

Impact of dairy protein powders on biscuit quality

The effects of whey protein concentrate and sodium caseinate (NaCas) on a short dough biscuit formulation were investigated with respect to dough characteristics and final product quality. Dairy powders were added at levels of 5, 10 and 15% of flour weight. Addition of 5 and 10% dairy protein powders reduced dough hardness. Doughs containing 10 and 15% NaCas had significantly higher springiness and cohesiveness values compared with the values of the control (p<0.05). Addition of both protein powders increased surface brownness, indicated by an increase in L* value. Whey protein concentrate resulted in biscuit shrinkage during baking, whereas biscuits containing NaCas powders were significantly larger than the control (p<0.05). In general, biscuits containing protein powders were harder than the control and hardness increased as the level of protein powder was increased. Confocal laser microscopy showed that doughs with NaCas had an extensive protein network and NaCas appears to interact with the flour proteins.     

Precooked sorghum flour as proper vehicle of ACE-I and DPP-IV inhibitory sorghum peptides

Sorghum flour was heat treated for producing an instant dispersion ingredient. The precooked sorghum flour was added with ACE-I and DPP-IV inhibitory sorghum peptides (3.0 g peptide 100 g⁻¹). The product was reconstituted in water, and peptide bioaccessibility was evaluated by equilibrium dialysis method after simulated gastrointestinal digestion. Total peptide dialysability of precooked sorghum flour added with sorghum peptides was higher than those obtained for precooked sorghum flour (315.9 ± 14.8 vs. 45.2 ± 5.6 µmol, respectively) (P < 0.05). The ACE-I and DPP-IV-IC₅₀ values of the bioaccessible peptides from the bioactive product were lower than those obtained for precooked sorghum flour ingredient (1.04 ± 0.12 vs. 1.82 ± 0.09 and 0.86 ± 0.02 vs. 2.12 ± 0.08 mg protein mL⁻¹, for ACE-I and DPP-IV, respectively) indicating a higher activity. Precooked sorghum flour was a good vehicle since it did not affect the bioaccessibility of ACE-I and DPP-IV inhibitory peptides provided by sorghum protein hydrolysate.     

Utilization of Lentinus edodes mushroom β-glucan to enhance the functional properties of gluten-free rice noodles

β-Glucan-rich fractions (BGRFs) were prepared from Lentinus edodes mushrooms and utilized to improve the functional properties of gluten-free extruded rice noodles. The mixture of rice flour and BGRFs in a slurry exhibited increased water absorption index and swelling power at room temperature. However, the water hydration properties were significantly reduced with increasing levels of BGRFs upon starch gelatinization, consequently reducing the pasting parameters of rice flour. On the other hand, the incorporation of BGRFs into a rice dough system caused a distinct increase in the thermo-mechanical Mixolab properties of rice flour, probably contributing to the formation of a rigid dough structure. It could be closely correlated with the enhanced extensibility and firmness of BGRF-incorporated rice noodles. Moreover, BGRFs played a positive role in improving the cooking qualities of rice noodles by significantly reducing their swelling index and cooking loss.     

Effect of varying the microencapsulation process on the functionality of hydrogenated vegetable fat in shortdough biscuits

The effects of the microencapsulation process of fat on the quality of biscuits was determined and compared to biscuits produced with a control fat. Protein level in the microencapsulated high fat powders affected dough hardness. All the biscuits produced with the powders had a darker colour than the control biscuits (P⩽0.05). The L-values were negatively correlated to the protein% of the powders. The control biscuits were thicker than biscuits produced with microencapsulated fat indicating that microencapsulation of fat had a significant effect (P⩽0.05) on biscuit heights. Control biscuits showed lower snap values than biscuits containing microencapsulated powders (P⩽0.01). Break test values were positively correlated to homogenisation pressure used in powder production.     

Instrumental Assessments of Japanese White Salted Noodle Quality

Strong correlations were found between some sensory evaluation results and instrumentally (Instron, Model 4301) assessed quality parameters for Japanese white salted noodles made from 32 Australian wheats. The sensory texture parameter, softness, had a strong negative correlation (r=-0·74, P<0·001) with the instrumental texture parameter, cutting force peak area divided by time. Other sensory texture parameters, smoothness and elasticity, showed significant correlations with another instrumental parameter, compression force peak area divided by time (r=-0·58, P<0·001 and r=0·52, P<0·01 respectively). Brightness, yellowness and discolouration of both raw and cooked noodles were measured using a colorimeter (Minolta, Model CR310). Strong correlations were observed between yellowness and discolouration of raw noodles and CIELAB b* (r=-0·79, P<0·001) and L*a* (r=-0·63, P<0·001) values, respectively. Similar relationships were found for cooked noodles (r=-0·74, P<0·001 for yellowness and r=-0·53, P<0·01 for discolouration). Both flour pasting properties including the flour swelling test and mixograph dough properties showed strong correlations with instrumental measures of noodle texture. Protein and ash content significantly affected noodle colour. In an attempt to simplify objective noodle quality measurements instrumental texture tests were carried out on flour gels. Textural measurements of flour gels showed that sensory softness of cooked noodles was correlated with an instrumental parameter, cutting peak force divided by time (r=-0·46, P<0·01). However, in this study no strong correlations were found between the smoothness and elasticity of noodles and any parameters of compression force-time profiles derived from gels. Yellowness of flour gels measured by a colorimeter showed a significant correlation with that of cooked noodles (r=-0·68, P<0·001). © 1997 SCI.     

Biscuit making properties of flours from hard and soft milling single variety wheats

Bench scale baking tests for two types of biscuits,¹ a hard sweet (HS) and a short sweet (SS), have been used to examine the biscuit making properties of a large number of flour samples from wheats grown in four consecutive years (1980–1983). Multiple regression models for prediction of biscuit properties using a range of standard cereal laboratory tests as independent variables on results from 1980–1981 harvest wheats confirmed earlier observations that such tests are of limited commercial value for biscuit flour specification. However the results of baking tests, with both types of biscuit, from single wheat varieties grown during 1981–1983 showed that flours from soft milling wheats (SMW) required less water to give biscuit doughs of standard consistency (measured instrumentally) than did flours from hard milling wheats (HMW). In addition biscuit doughs made with SMW flours gave greater oven spring, i.e. biscuits of lower bulk density, than doughs made from HMW flours. In each season the difference in the mean values of both parameters for flours milled from SMW and HMW was highly significant (P<0.001). With one exception the variability of the measured parameters within seasons was not significantly different between SMW and HMW. However within both SMW and HMW varieties highly significant differences (P<0.001) were observed between seasons for the mean values of both measured biscuit parameters. The effect of flour particle size on the biscuits was studied by regrinding a number of flours. With flours from both SMW and HMW reduction in particle size resulted in HS biscuits of higher density but SS biscuits of lower density.     

Impact of moisture and grinding on yield,physical, chemical and thermal properties of wholegrain flour obtained from hydrothermally treated sorghum grains

The present work evaluates the potential of sorghum with high content of tannins for wholegrain flour production. Two types of mills were used: a roller mill (RM) and a blade (BM) mill. The impact of moisture and grinding on yield, physical, chemical and thermal properties were evaluated. Maximum yield was obtained using a BM with 25% moisture in the grain, resulting in 60.9% versus 28% (g flour g⁻¹ of wholegrain sorghum) for the RM. Grain moisture and milling type affected flour colour and ashes. For both mills, the pasting and thermal properties of flour with grain moisture variation were significantly different from the untreated control sample. By studying the procedures for flour production and quality characteristics, it is possible to produce flour with good physical attributes, which can contribute to the development of gluten-free foods based on sorghum for the coeliac population.     

Potato flour as a functional ingredient in bread: evaluation of bread quality and starch characteristics

Potatoes have been added to bread for improvement of texture and moisture retention. The functional quality and starch digestibility in bread containing 5%, 10% or 15% potato flour were evaluated. Farinograph absorption of wheat and potato flour blends ranged from 59.0% to 77.7%. Bread with potato flour had significantly (P < 0.05) lower bread firmness during storage. There was a significant (P < 0.05) decrease in starch molecular weight as the level of potato flour increased. Inclusion of potato flour in these breads significantly (P < 0.05) increased the level of resistant starch (RS), while significantly (P < 0.05) decreasing the estimated glycemic index (eGI). Bread with no potato flour had 5.2% RS and an eGI of 95, while the bread with 15% potato flour had 11.3% RS and an eGI of 87. Overall, the addition of potato flour may reduce dough strength and loaf volume, but it reduced staling and increased resistant starch content of the bread.     

Studies on the Optimization and Stability of Low-Fat Biscuit Using Carbohydrate-Based Fat Replacers

The objective of this study was to optimize and develop low-fat soft dough biscuits using carbohydrate-based fat replacers (combinations of polydextrose and guar gum). Central composite rotatable design was utilized to optimize the levels of sugar, composite fat (fat, polydextrose, and guar gum), ammonium bicarbonate, and water. The parameters measured were spread ratio, hardness, stress-strain ratio, and sensory properties. Composite fat and sugar were found to be important determinants of biscuit hardness. The principal effect of fat substitutes on biscuits’ attributes was crisper texture but with higher brittleness. The level of water had a significant effect on spread ratio (p < 0.1), hardness (p < 0.1), and stress-strain ratio (p < 0.05). It was also observed that by varying the level of ammonium bicarbonate in the formulation from 0.5 to 2.5 g/100 g flour, the dimensions and texture of the biscuits were affected. The optimum ingredient levels on 100 g flour basis were found to be sugar 24 g, fat 10.5 g, polydextrose 24.2 g, guar gum 0.3 g, ammonium bicarbonate 2 g, and water 24 mL. It was found from the storage study that low-fat biscuit with 70% fat replacement was more oxidative stable than the control sample.