Physico-chemical properties of low-fat cookies containing wheat and oat bran gels as fat replacers

Wheat and oat bran-based fat replacers in the form of gels were used for partial replacement of fat (30–50%) in a cookie formulation. Dough rheological properties, physical (cookie dimension, weight loss, moisture content and water activity), textural (hardness and fracturability), colour and sensory parameters were evaluated to characterize full-fat and fat-reduced cookies. Based on the obtained results it was concluded that the fat reduction in cookie formulation at the level of 30% maintained sensory properties of the full-fat cookies. Therefore, this level of fat replacement was chosen for further analysis: 30% WBG (wheat bran gel-containing cookies) and 30% OBG (oat bran gel-containing cookies) were examined in terms of nutritional and functional properties. It was revealed that fat replacement using bran gels at the level of 30% resulted in the fat-reduced added-value cookies in terms of dietary fibre, minerals and phenolics. 30% WBG cookies possessed higher dietary fibre, mineral and phenolic content in comparison to 30% OBG and the full-fat cookies.     

Effect of Extrusion Conditions and the Optimization of Phenolic Compound Content and Antioxidant Activity of Wheat Bran Using Response Surface Methodology

The extrusion process (EP) consists of heat and mechanical treatments under different conditions of moisture, shear, and pressure and rapidly causes structural alterations and changes in the functional properties of the extruded material. The aim of this study was to evaluate the effect of extrusion conditions and optimize the wheat bran extrusion conditions to achieve the greatest content of phenolic compounds and antioxidant activity using response surface methodology. The EP factors evaluated were feed moisture (FM) (25–33.54%) and final extrusion temperature (T) (140–180 °C). The properties evaluated in the extruded material were bound total phenol content (BTPC), total phenolic compounds and antioxidant activity (AOX). Analysis of variance (ANOVA) and response surface methodology were used in the evaluation. The determination coefficients, (FM)² and (T)², very significantly affected the BTPC and bound 2,2-diphenyl-1-picrylhydrazyl content (BDPPHC). The optimization was performed by overlaying two contour plots to predict the best combination regions. The optimized extrusion conditions were the following: FM?=?30% and T?=?140 °C, which provided BTPC?=?3547.01 μgGAE/g (predicted: 3589.3 μgGAE/g) and BDPPHC?=?9.5 μmolTE/g (predicted: 10.4 μmolTE/g); and FM?=?30% and T?=?180 °C, which provided BTPC?=?3342.3 μgGAE/g (predicted: 3727.7 μgGAE/g) and BDPPHC?=?9.5 μmolTE/g (predicted: 9.3 μmolTE/g). The EP increased the phenolic compounds and AOX, and enhancement of these properties in wheat bran products could make them functional foods.     

Some Nutritional Characteristics of Enzymatically Resistant Maltodextrin from Cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz) Starch

Cassava (Manihot esculenta Crantz) native starch was treated with pyroconversion and enzymatic hydrolysis to produce a pyrodextrin and an enzyme-resistant maltodextrin. Some nutritional characteristics were quantified for both compounds. Pyroconversion was done using a 160:1 (p/v) starch:HCl ratio, 90 °C temperature and 3 h reaction time. The resulting pyrodextrin contained 46.21% indigestible starch and 78.86% dietary fiber. Thermostable α-amylase (0.01%) was used to hydrolyze the pyrodextrin at 95 °C for 5 min. The resulting resistant maltodextrin contained 24.45% dextrose equivalents, 56.06% indigestible starch and 86.62% dietary fiber. Compared to the cassava native starch, the pyrodextrin exhibited 56% solubility at room temperature and the resistant maltodextrin 100%. The glycemic index value for the resistant maltodextrin was 59% in healthy persons. Its high indigestible starch and dietary fiber contents, as well as its complete solubility, make the resistant maltodextrin a promising ingredient for raising dietary fiber content in a wide range of foods, especially in drinks, dairy products, creams and soups.     

Incorporation of Buriti Endocarp Flour in Gluten-free Whole Cookies as Potential Source of Dietary Fiber

Cookies were prepared by replacing a mixture of brown rice flour (70 %) and corn starch (30 %) (BRFCS) by buriti endocarp flour (BEF) (0, 5, 10, 15 or 20 %). BEF figured as a potential source of dietary fiber (70.53 g 100 g^?1), especially of insoluble fiber (67.50 g 100 g^?1), and gluten-free whole cookies showed increased dietary fiber content by adding 5, 10, 15 and 20 % BEF (8.58 to 20.02 g 100 g^?1) when compared to control cookie (6.91 g 100 g^?1). The addition of BEF affected diameter, spread ratio, color and texture of cookies. All cookies added with BEF were darker, harder and presented smaller diameter and smaller spread ratio than the control cookie. These difference increased proportionally to level of substitution of BRFSC by BEF. Gluten-free whole cookies with up to 15 % BEF were well accepted by consumers. Therefore, the use of BEF in cookies may increase the availability of functional ingredients source of dietary fiber for celiac consumers, add economic value to buriti processing by-products and decrease environmental impacts due to the high amounts of waste generated by buriti processing industries.     

Effect of extrusion process variables on physical and chemical properties of extruded oat products

The purpose of this research was tostudy the effects of initial moisture levels andextrusion temperatures on bulk density, waterabsorption and water solubility indexes, viscosity,and color of extruded oat products. The dehulledgrains were ground in a Brabender Quadrumat Seniormill and the coarse fraction, with higher amounts ofcrude protein, lipids, and dietary fiber content, wereconditioned to moisture levels of 15.5–25.5% andextruded in a Brabender single-screw laboratoryextruder. The water absorption index of extrudateswere relatively low (4.16–6.35 g gel/g sample) butincreased as the initial moisture of the raw materialas well as the extrusion temperature was elevated.The water solubility index was inversely proportionalto the extrusion temperature. Initial viscosity of thepaste increased with the increase of raw materialmoisture and extrusion temperature, while the maximumviscosity (at a constant temperature) diminished withthe increase of temperature. Products with lowervalues of L* (luminosity) and greater values ofa* (red) and b* (yellow) were obtained athigh moisture rates and at a 120 ^°C extrusiontemperature.     

Effect of steam explosion on enzymatic hydrolysis and baking quality of wheat bran

In this study, the effect of steam explosion (SE) treatment on microstructure, enzymatic hydrolysis and baking quality of wheat bran was investigated. Coarse and fine bran were treated at different steam temperatures (120–160 °C) and residence times (5 or 10 min) and then hydrolysed with carbohydrase enzymes. The SE treatment increased water extractable arabinoxylan (WEAX) content from 0.75 to 2.06% and reducing sugars from 0.92 to 2.41% for fine bran. The effect was more pronounced with increased SE temperature and residence time. The highest carbohydrate solubilisation was observed in fine bran at SE treatment of 160 °C, 5 min. WEAX content increased to 3.13% when this bran was incubated without enzyme, while WEAX content increased to 9.14% with enzyme addition. Microscopic analysis indicated that cell wall structure of wheat bran was disrupted by severe SE conditions. Supplementation of SE treated (150 °C, 10 min) bran at 20% replacement level decreased the baking quality of bread. However SE followed by enzymatic hydrolysis increased specific volume and decreased crumb hardness (on the day of baking and after three days of storage). Phytic acid content of bread supplemented with SE treated bran was lower than the one supplemented with untreated bran.     

咖啡果皮粉对饼干品质和淀粉消化性的影响

咖啡果皮是咖啡加工过程中产生的副产物,约占咖啡果实的50%,测定结果显示咖啡果皮中含有丰富的膳食纤维,总膳食纤维的含量可达64.80%,且脂肪含量低,仅为1.62%。但咖啡果皮仅有一小部分被用作堆肥和动物饲料,大部分被丢弃,造成了不可忽视的环境问题和资源浪费。为了探寻咖啡果皮在焙烤食品中的加工利用,本研究利用超微粉碎的咖啡果皮0%、5%、10%、15%、20%替代小麦粉来制作饼干,通过测定饼干的含水率、膳食纤维的含量、DPPH清除率、淀粉消化性能、血糖生成指数、色泽、质构及感官性状,发现与对照组（0%）相比,随着咖啡果皮粉替代量的增加,饼干的含水率从6.57%下降至5.32%,膳食纤维含量和DPPH清除率显著增加,分别从1.84%增加至10.65%,从2.89%增加至36.69%,淀粉的消化率、C_∞和k值与咖啡果皮粉的替代量呈负相关,最终预测的饼干血糖生成指数从91.16降至66.35,但5%、10%、15%替代量的饼干仍为高血糖生成指数的食物,色泽中L^*和b^*值逐渐下降,而a^*值在5%和10%替代量时超过了对照组,饼干呈现咖啡果皮的棕红色,另外,饼干的硬度和咀嚼性逐渐增加,但在5%替代量时硬度增加并不显著（P<0.05）,脆性、恢复力、粘结力和弹性均逐渐下降,当咖啡果皮粉添加量为5%时,可获得理想的感官评分,尤其是在色泽和气味上的得分达到最高,分别为4.8和4.7分。结果表明,咖啡果皮粉可以考虑作为一种饼干的配料来增加消费者对膳食纤维、抗氧化性物质和低糖化淀粉的摄入,该研究结果为咖啡果皮的综合利用提供理论依据。     

Temperatures and ethanol effects on the properties of extruded modified starch

Temperature and blowing agent are major factors influencing the properties of extruded foam materials. This study was conducted to determine the influence of temperature and alcohol content on selected properties and molecular weight of acetylated starch foam. Starch acetate, with degree of substitution of three, was prepared from 70% amylose corn starch and extruded with either 16 or 18% (db) ethanol in a single screw extruder at either 120 or 160°C. Unit and solid densities, specific mechanical energy, compressibility, spring index, water absorption and water solubility indices, glass transition temperature, molecular degradation and degree of substitution (DS) of the starch were measured. The samples extruded at 120°C had lower spring indices and water absorption indices (WAI), but higher compressibility and unit density than acetylated starch extruded at 160°C. The samples extruded with 16% ethanol content on a dry basis had lower spring indices and higher WSI than samples extruded with 18% alcohol. The extruded samples had lower solid density, WSI and WAI as compared to non-extruded acetylated starch. A slight decrease in the average molecular weight was recorded as a result of the extrusion processing. The samples extruded at 160°C had high spring indices and low unit densities and thus were more suitable for use as a loose-fill packaging material.     

Characterisation of Glass Transition of Durum Wheat Semolina using Modulated Differential Scanning Calorimetry

The glass transition of wheat durum semolina was characterised at different moisture contents using modulated differential scanning calorimetry. The total, reversing and non-reversing heat flows were quantified during heating, cooling and re-heating. An endothermic peak was observed on the non-reversing heat flow during first heating and was not greatly affected by changes in moisture content (below 20 g water/100 g dry matter). This peak was associated with endothermic relaxation of the protein fraction in wheat semolina. An endothermic baseline shift was observed on the reversing heat flow during first heating, cooling and re-heating. The temperature at baseline shift decreased (from 110 °C to 27 °C) when moisture content increased (from 6% to 27% db). The measured heat capacity change (0·10–0·25 J/g/°C) was not significantly affected by moisture content. This endothermic baseline shift was presumed to be the glass transition of amorphous polymers in wheat durum semolina. The plasticising effect of water on the glass transition temperature (Tg) was described using Gordon Taylor and Kwei models and compared with Tg of the main wheat components.     

Evaluation of roller milling potential of amaranth grains

In the present study roller milling potential of amaranth grains was evaluated. The conditioning moisture influenced the millability of the amaranth grain. The results showed that the coarse seed coat (CSC) fraction increased from 12.91 to 38.33% with increase in conditioning moisture of the grains from 11 to 18.5%. The nutrients were more concentrated in the CSC fraction, while flour (FL) fraction showed low protein, ash, fat and dietary fiber contents. As the grain moisture content was increased from 11.0 to 15.5%, the yield of flour decreased with improvement in the brightness values. CSC showed higher values for redness and yellowness and lower values for brightness compared to other milled fractions. CSC had the highest water and oil holding capacities with the values of 410 g/100 g and 215 g/100 g respectively. The swelling power was also higher for CSC and fine seed coat (FSC) fractions. Among milled fractions, highest pasting temperature of 75.9 °C and peak viscosity of 212 BU was recorded for CSC and FL fractions respectively. These results showed that the roller mill can be used for milling amaranth grains to produce fractions rich in nutrients with unique functional properties.     

The effect of infrared stabilized rice bran substitution on physicochemical and sensory properties of pan breads: Part I

Infrared stabilized rice bran (SRB) substitution to white wheat, wheat bran and whole grain wheat breads at the levels of 2.5, 5.0 and 10.0% was evaluated in terms of proximate composition, crumb color, dietary fiber, texture and sensory attributes. An increasing tendency was observed in crude fat and ash content of the breads. Redness (+a*), yellowness (+b*) chroma and redness (a*/b*) values were increased gradually with the addition of SRB. Crumb color was found to be darker when 10% of SRB was added to the breads. SRB inclusion did not affect the content of soluble dietary fiber while it significantly increased the insoluble and total dietary fiber contents of the breads (p < 0.05). In general, whole grain wheat bread differed from the other bread types in terms of textural behavior. Based on the overall acceptability scores, white wheat and wheat bran breads were sensory accepted up to 10% of flour replacement with rice bran, while substitution levels higher than 2.5% negatively affected the sensory scores of whole grain wheat bread.     

Reducing phytate content in wheat bran by directly removing the aleurone cell content with teeth roller mill and ultrasonic cleaner

Wheat bran is good for human health due to the abundance of dietary fiber. However, it also contains much phytate which has been well documented as an anti-nutritional factor. This study is the first to explore the effectiveness of reducing phytate content in wheat bran by directly removing the aleurone cell content utilizing different roller mills (smooth roller, coarse smooth roller and teeth roller) and different clean-up methods (brushing and ultrasonic washing). Through analysis of phytate content in wheat bran obtained from different mill systems, the best raw material was found to be obtained from the 5B system. By investigating various roller types and clean-up methods, the optimal technique was found to use a teeth roller mill combined with ultrasonic washing, which could reduce the phytate content by the greatest amount: the reduction of phytate content achieved 62.98% (from 26.80 mg/g to 9.92 mg/g) in wheat bran. The optical microscope observation indicated that ultrasonic washing could wash the aleurone cell content out from broken aleurone cells which were destroyed by the teeth roller mill.     

Effect of wheat bran addition on in vitro starch digestibility,physico-mechanical and sensory properties of biscuits

Biscuits contain high amount of fat and sugar thus having high calorie but low nutrient density. Wheat bran is a good source of dietary fibre (DF) and protein and is thus a good candidate for nutritional enrichment of cereal foods. The aim of this study was to understand the effect of bran incorporation and particle size reduction on biscuit microstructure, texture and in vitro starch digestibility. Five different biscuits containing 5–15% DF were produced. Two different particle sized wheat brans were used: coarse (450 μm) and fine (68 μm). Bran particle size reduction increased the elastic modulus and hardness of biscuits. Biscuits containing fine bran had visually more compact structure without any surface or internal defects than those with coarse bran. Fine bran containing sample had the highest hardness value. Sensory evaluation showed that roughness and breakdown of biscuits in the mouth was significant for the coarse bran with highest level of bran addition. The instrumental elastic modulus, stress and hardness were closely related to sensory hardness and strength to break. Increasing DF content from 5 to 15% increased hydrolysis index by 16%, from 32 to 37.     

Assessment on Proximate Composition,Dietary Fiber,Phytic Acid and Protein Hydrolysis of Germinated Ecuatorian Brown Rice

Germinated brown rice (GBR) is considered healthier than brown rice (BR) but its nutritive value has been hardly studied. Since nutritive quality of GBR depends on genetic diversity and germination conditions, six Ecuadorian BR varieties were germinated at 28 and 34?ºC for 48 and 96 h in darkness and proximate composition, dietary fiber fractions, phytic acid content as well as degree of protein hydrolysis and peptide content were studied. Protein, lipids, ash and available carbohydrate ranged 7.3–10.4 %, 2.0–4.0 %, 0.8–1.5 % and 71.6 to 84.0 %, respectively, in GBR seedlings. Total dietary fiber increased during germination (6.1–13.6 %), with a large proportion of insoluble fraction, while phytic acid was reduced noticeably. In general, protein hydrolysis occurred during germination was more accused at 28?ºC for 48 h. These results suggest that GBR can be consumed directly as nutritive staple food for a large population worldwide contributing to their nutritional requirements.     

Effect of thermal processing and storage on digestibility of starch in whole wheat grains

Gelatinisation and retrogradation of starch in wheat flour systems and whole wheat grains were studied using DSC and the impact of these events on starch digestibility was investigated. Gelatinisation of starch was possible in wheat flours with more than 60% moisture content (dwb) and gelatinised samples had higher digestibility values. Retrogradation of starch was studied with partially and fully cooked (boiled at 100 °C for 12 min and 32 min, respectively) wheat grains that were subjected to storage at 22 °C for 48 h. Stored samples had lower digestibility values when compared to the freshly cooked counterparts. The effect of moisture on retrogradation was studied with fully cooked wheat grains that were dried to a range of moisture contents (14.6–35.9%, wwb) and stored at 20 °C for 24 h. Retrogradation enthalpy increased with increasing moisture content; however, digestibility values did not reflect the changes in retrogradation enthalpy. The possibility of estimating the degree of retrogradation in fully cooked grains (32 min cooking) was investigated using a wheat flour-water system. The retrogradation enthalpy of fully cooked grains was slightly higher than the wheat flour-water system (at a moisture content of 49%, wwb) during the course of storage at 22 °C.     

Studies on multigrain milling and its effects on physical,chemical and rheology characteristics of milled streams

The multigrain blends of wheat-green gram-barley in the ratio of C (100:0:0); B1 (90:5:5); B2 (80:10:10); B3 (70:15:15) were co milled using a Buhler roller mill to produce nutritious flour. The studies showed that the yield of straight run flour (SRF) increased gradually with an increase in blending of green gram and barley with wheat. The highest SRF of 79.71% was obtained from the B3 blend. The coarse bran decreased from 15.95% for the control sample to 9.52% for B3 blending. The milling yield of pollard and fine bran showed a decreasing trend from control to B3 blending. In general, flour yield decreased for reduction passages from C1 to C3 and reduction passages produced higher flour compared to break rolls for all blends. The multigrain milling resulted in an increase in protein(113.1–13.35%) and dietary fiber (2.91–4.65%) content of flour, but sedimentation values (52–38 ml), which is the index of flour strength, decreased significantly. The distributions of mineral matters and fat show wide variation among the mill streams and concentrated in coarse and fine brans. The rheological properties of flour obtained showed increased water absorption (55.8–57.5%) and decreased dough stability(5.5–2.8 min), amylograph peak viscosity (388-335BU) and setback (265-224BU) with an increase of multigrain in blends.     

Dephytinization of wheat bran by fermentation with bakers' yeast,incubation with barley malt flour and autoclaving at different pH levels

Wheat bran is an important source of dietary fiber but also contains considerable amounts of phytic acid, which is known to impair mineral absorption. The present study was conducted to investigate the phytic acid reduction in coarse and fine wheat bran by fermentation with the different levels of bakers' yeast (3, 6 and 9%) for 8 h at 30 °C, incubation with the different levels of barley malt flour (2.5, 5.0, 7.5 and 10.0%) for 8 h at pH 5.2 and 55 °C, and autoclaving at the different pH levels (pH 5.0, 4.5, 4.0 and 3.5) adjusted with acetic acid for 2 h. The phytic acid content of the wheat bran was effectively reduced by all treatments, and the phytic acid lost was in the range of 88.4–96.9%. Without addition of yeast or malt flour, or autoclaving without pH adjustment, the phytic acid content of the bran samples was reduced at most to 44.9% of the initial amounts under the investigated conditions. Increasing the concentration of yeast or malt flour or decreasing the pH towards 3.5 did not enhance the phytic acid reduction. The most reduction occurred after 2 h of yeast fermentation and malt flour incubation, and after 30 min of autoclaving, which made up 92–98% of the total phytic acid loss. Extending the treatment periods contributed nominally to further increase in the phytic acid reduction, and the rate of the phytic acid loss decreased progressively.     

Effect of extrusion processing on the soluble and insoluble fiber,and phytic acid contents of cereal brans

The health benefits associated with dietary fiber have resulted in it now being used in virtually all food product categories, including many products which are manufactured using extrusion processing. The objective of the present study was to determine if extrusion processing affected phytic acid, and soluble and insoluble fiber contents. The effect of screw speeds of 50, 70, and 100% of maximum rotations per minute (% MRPM) on these components was investigated. A BI-EX Model DNDG-62/20D co-rotating intermeshing self-cleaning twin-screw extruder, manufactured by Bühlerag, CH-9240, Uzwil, Switzerland, was used to process wheat, oat and rice brans. It was found that extrusion did not affect the insoluble fiber content of wheat bran; however, a decrease in this component was observed in rice and oat brans. The effect on rice bran insoluble fiber was greatest at screw speeds of 50 and 70% MRPM. This occurred in oat bran at 50% MRPM. Soluble fiber content increased in all brans after extrusion, except ER₁₀₀. For oat and rice bran soluble fibers, the greatest increase occurred at 50 and 70% MRPM, while for wheat bran this occurred at 70 and 100% MRPM. Extrusion did not affect the phytate content of the cereal brans.     

Extrusion process improves the functionality of soluble dietary fiber in oat bran

Extrusion processing is a thermal process applied to food preparation. However, its effects on food ingredients are ambiguous. The aim of this study was to elucidate the effects of extrusion processing on soluble dietary fiber (SDF) in oat bran. The yield, composition, thermal properties, rheological behavior and functionality of SDF in extruded oat bran were compared with those of SDF in untreated oat bran. The results showed that SDF in extrude oat bran had higher yields (14.2%), mean particle diameter (1718.1 nm), peak temperature (T_p = 69.0 °C), solubility, swelling capacity, solvent retention capacity, foam ability, apparent viscosity and consistency coefficient, and lower flow behavior index than those of SDF in untreated oat bran. The extrusion process improves some properties of SDF from oat bran.