In vitro approach (solubility and Caco-2 uptake) to compare Cu availability from model cookies

Six model cookies were prepared in order to investigate the possibility of using whole grain raw materials other than wheat (inulin in combination with soy, amaranth, carob, apple dietary fibre or oat dietary fibre) for creating novel cookies with improved copper content and bioavailability. For assessment of copper solubility and intestinal uptake, in vitro enzymolysis approach was combined with Caco-2 cell culture technique and copper concentrations were determined using ICP-AES technique. Results indicate significant increase of the content of total and soluble Cu fractions in all modified cookies (with exception of cookies enriched with oat fibre). Average Cu solubility from investigated samples ranged from 51.6 to 68.9%. The highest Caco-2 cell uptake was determined in soy- and amaranth-enriched cookies. Total Cu content and proteins were determined as promoters of Cu absorption and transport, while addition of pure dietary fibre negatively influenced Cu uptake on the Caco-2 cell monolayer.     

Feasibility of use of buckwheat flour as an ingredient in ginger nut biscuit formulation

Ginger nut biscuits are popular traditional biscuits which contain honey. In order to improve their nutritive profile and functionality, standard formulation based on wheat flour was substituted with buckwheat flour at three levels (30%, 40%, 50%). The quality attributes (chemical composition, microelements, bioactive compounds (total polyphenols, rutin, quercetin), antioxidative potential, textural and sensory properties) were compared to control biscuit (based on wheat flour) and biscuits substituted with rye at the same levels, since rye is used as an ingredient which improves the quality of ginger nut biscuits. Substitution with buckwheat flour resulted in a significant increase (p < 0.05) in protein, Zn, total polyphenols, antioxidative and chelating activity. Total dietary fibre, Cu, Mn and Fe contents also increased but did not exceed those in rye substituted biscuits. Consumption of 100 g of enriched biscuits could contribute to reaching ≈18–22% (buckwheat) and 16–17% (rye) of the estimated daily average total polyphenols intake, respectively. With the contents of rutin and quercetin at 3.96–6.57 mg/100 g d.b. and 0.087–0.214 mg/100 g d.b., respectively, buckwheat substituted biscuits may significantly contribute to total dietary flavonoid intake and meet the demands of preventive nutrition. Buckwheat enriched biscuits were rated higher regarding sensory attributes, softness and fracturability as compared to control but lower compared to rye supplemented biscuits.     

无麸质饼干原料及功能性添加成分的研究进展

乳糜泻是患者对面筋不耐受而引起的慢性小肠吸收不良综合征,患者需终身严格遵守无麸质饮食。无麸质食品不含面筋,口感与品质相对较差,研究者通过改进配方、技术等以达到改善的目的。本文介绍了乳糜泻、无麸质饼干的概况及其缺陷,主要对无麸质饼干所用的原料(大米粉、小米粉、藜麦粉、燕麦粉、苋菜粉及其他面粉)、功能性添加成分(亲水胶体、菊粉、酶制剂)进行综述,阐述了国内外关于无麸质饼干的一些研究进展,以期为无麸质饼干的进一步研究与应用提供参考。     

Apple pomace as a source of dietary fiber and polyphenols and its effect on the rheological characteristics and cake making

Apple pomace, a by-product of apple juice industry, is a rich source of fibre and polyphenols. Also in view of the antioxidant property of pomace, it would play an important role in prevention of diseases. Apple pomace procured from fruit juice industry, contained 10.8% moisture, 0.5% ash and 51.1% of dietary fibre. Finely ground apple pomace was incorporated in wheat flour at 5%, 10% and 15% levels and studied for rheological characteristics. Water absorption increased significantly from 60.1% to 70.6% with increase in pomace from 0% to 15%. Dough stability decreased and mixing tolerance index increased, indicating weakening of the dough. Resistance to extension values significantly increased from 336 to 742 BU whereas extensibility values decreased from 127 to 51 mm. Amylograph studies showed decrease in peak viscosity and cold paste viscosity from 950 to 730 BU and 1760 to 970 BU respectively. Cakes were prepared from blends of wheat flour containing 0–30% apple pomace. The volume of cakes decreased from 850 to 620 cc with increase in pomace content from 0% to 30%. Cakes prepared from 25% of apple pomace had a dietary fibre content of 14.2% The total phenol content in wheat flour and apple pomace was 1.19 and 7.16 mg/g respectively where as cakes prepared from 0% and 25% apple pomace blends had 2.07 and 3.15 mg/g indicating that apple pomace can serve as a good source of both polyphenols and dietary fibre.     

Quality characteristics of biscuits prepared from finger millet seed coat based composite flour

Finger millet seed coat is an edible material and contains good proportion of dietary fibre, minerals and phytochemicals. The seed coat matter (SCM) forms a by-product of millet milling, malting and decortication industries and can be utilised as composite flour in biscuit preparation. The SCM from native, malted and hydrothermally treated millet contained 9.5–12% protein, 2.6–3.7% fat and 40–48% dietary fibre, besides 3–5% polyphenols and 700–860 mg/100 g of calcium. The biscuits prepared using the composite flour were of crisp texture and exhibited breaking strength of 1480–1690 g compared to control biscuits (1560 g). The biscuits were of mild grey colour (ΔE = 40–50) and exhibited higher protein, dietary fibre and calcium contents. The sensory evaluation of the biscuits indicated that 10% of SCM from native and hydrothermally processed millet and 20% from malted millet could be used in composite biscuit flour.     

Influence of depigmentation of pearl millet (Pennisetum gluacum L.) on sensory attributes, nutrient composition and in vitro digestibility of biscuits

Presence of high concentration of pigments in the pericarp and endosperm regions of pearl millet imparts undesirable gray color to its products. This study attempts to improve the acceptability of pearl millet products through processing technique and to study its effect on nutritional composition of pearl millet product. Pearl millet grains were depigmented by soaking in 0.2 N HCl for 18 h followed by washing, blanching at 98°C for 30 s and sun drying. Three different types of biscuits were prepared from refined flour (Reference), native or unprocessed pearl millet (T-I) and depigmented pearl millet (T-II). Results indicated that depigmentation improved the sensory attributes especially the color of pearl millet biscuits (T-II). The protein, fat, ash and total dietary fiber of pearl millet based biscuits (T-I as well as T-II) were significantly (P?0.05) higher than the reference biscuits. Depigmentation significantly improved the in vitro starch digestibility, in vitro protein digestibility and the soluble dietary fiber content of pearl millet biscuits (T-II) by 14.50, 6.56 and 6.18%, respectively. On the other hand, a significant decrease of 6.73, 2.43 and 17.03 g/100 g in protein, starch and insoluble dietary fiber was detected in pearl millet biscuits (T-II) due to depigmentation.     

Physicochemical characterisation of dietary fibre components and their ability to bind some process-induced mutagenic heterocyclic amines,Trp-P-1, Trp-P-2, AαC and MeAαC

The physicochemical properties of potato fibre, wheat bran and oat samples were investigated, along with their binding capability to heterocyclic amines (HCAs). Potato fibre displayed highest total dietary fibre content (71.8/100 g dry weight basis, dwb), followed by wheat bran (57.2/100 g dwb) and oat sample 2 (53.0/100 g dwb). Oat samples 1, 3 and 4 displayed considerably lower dietary fibre content (20.5–28.8/100 g, dwb). Oat samples 3 and 4 displayed highest soluble fibre content (70–83%), and oat sample 3 also displayed highest swelling and water retention capacity (WRC). Dietary fibre samples, except samples 3 and 4, displayed improved binding to HCAs as sample weight increased. The behaviour of wheat bran and potato fibre was similar to oat samples 1 and 2. Binding of MeAαC was comparatively greater than that of other HCAs. Dietary fibre fractions with high insoluble fibre and functional groups of HCAs may significantly contribute to the binding capacity.     

Influence of fibre from different cereals on the rheological characteristics of wheat flour dough and on biscuit quality

Demand for health oriented products such as sugar-free, low calorie and high fibre products is increasing. One such recent trend is to increase the fibre content in food products to overcome health problems such as hypertension, diabetes, and colon cancer, among others. Consumption of high fibre products consisting of indigestible cellulose, hemicellulose, lignin and gums have several health benefits. Apart from these benefits, β-glucan-rich fibres have the benefit of reducing the absorption of glucose. Fibre sources from wheat, rice, oat and barley were used to study their influence on rheological characteristics of wheat flour dough and biscuit making quality. Ash, total protein and dietary fibre content of bran samples ranged between 4% and 10%, 12% and 14% and 20.4% and 49.5%, respectively. Farinograph characteristics of the wheat flour-bran blends showed increase in water absorption from 60.3% to 76.3% with increase in the level of bran from 0% to 40%. The resistance to extension values as well as extensibility of the dough decreased with increase in the bran level. The spread ratio of the biscuits prepared from wheat, rice and oat bran blends decreased from 8.38 to 7.52, whereas the same increased to 9.3 for biscuits prepared from barley bran blends. The breaking strength values of biscuits ranged between 1.34 and 3.83 kg. Highly acceptable biscuits could be obtained by incorporating 30% of oat bran or 20% of barley bran in the formulation.     

Effect of soy milk powder addition on staling of soy bread

Effect of soy milk components (soluble fibre (SF), insoluble fibre (ISF), soy protein) on physicochemical properties (crust and crumb colour, water activity, total moisture content, “freezable” water (FW), “unfreezable” water (UFW), amylopectin recrystallisation (ARC), stiffness and firmness) of soy breads stored for 7 days was studied. By the end of storage ISF additions significantly increased ARC (from 0.01 to 0.57 W/g), whereas SF additions (0.30 W/g) retarded staling with respect to soy flour bread (0.39 W/g). Principal Component Analysis (PCA) of all the different treatments and formulations indicated that SMP addition resulted in the lowest firmness and least amylopectin retrogradation at the end of storage, likely due to the synergistic effect of soluble fibre, partly denatured soy proteins and lipid content of this ingredient.     

菊粉改善酥性饼干的品质及降低消化速率

可溶性膳食纤维可以抑制淀粉的水解消化,为研究菊粉对饼干品质的影响,通过均匀设计法优化菊粉饼干的配方工艺,并通过模拟人体胃肠道消化过程研究菊粉对饼干消化的影响。结果表明;最佳配方为低筋粉100 g,水20 g,木糖醇15.05 g,菊粉12.60g,油脂(黄油:玉米油=1:1)31 g,小苏打0.5 g,食盐0.5 g。另外,测得菊粉饼干脂肪含量为16.54%,蛋白质3.33%,膳食纤维6.87%,碳水化合物56.63%。通过体外消化模拟结果表明加入菊粉之后,饼干的快消化淀粉含量从14.51%下降到3.06%,慢消化淀粉和抗性淀粉的含量分别增加了3.67%和0.20%,且菊粉饼干的体外消化率低于空白饼干,预测菊粉饼干血糖指数为68.36,属于中等血糖指数食品。故对于高油脂饼干而言,菊粉可以抑制其淀粉的水解消化,降低其血糖指数,菊粉的应用对于开发中低血糖指数产品具有重要意义。     

籽粒苋保健面包的研制(II)——籽粒苋对赖氨酸和膳食纤维的营养强化作用

以 5%、10 %、15%、2 0 %、2 5%籽粒苋粉代替小麦粉 ,制成籽粒苋保健面包。对这类面包中赖氨酸、膳食纤维含量进行分析 ,结果表明籽粒苋粉能明显提高赖氨酸和膳食纤维的含量 ,特别是能改善可溶性膳食纤维与不溶性膳食纤维的配比。与全麦粉面包相比 ,籽粒苋面包中蛋白质的提高率为 0 .58%～ 6 .91% ,赖氨酸含量提高率为 13.50 %～ 56 .57% ,总膳食纤维提高 8.2 6 %～ 39.4 5% ,不溶性膳食纤维提高 7.91%～33.33% ,可溶性膳食纤维提高 9.76 %～ 6 5.85% ;而脂肪的含量则随籽粒苋粉的增加而减少。由于籽粒苋对赖氨酸和膳食纤维具有强化作用 ,使籽粒苋保健面包可以作为高脂血症、糖尿病和肥胖人群的理想食品     

Organoleptic and nutritional evaluation of wheat breads supplemented with soybean and barley flour

Supplementations of soy (full fat and defatted) and barley flours to wheat flours at 5, 10, 15 and 20% levels were carried out to test the effects on organoleptic and nutritional evaluation of the supplemented bread. Additions of 15% barley flour, 10% soy flour (full fat and defatted), 15% barley plus full fat soy flour and 15% barley plus defatted soy flour to wheat flour produced acceptable breads. However, substitution of soy (full fat and defatted) and barley flours to wheat flour separately and in combinations at 20% levels did not produce organoleptically acceptable bread. Various nutritional parameters, such as protein, fat, total lysine, protein digestibility (in vitro), sugars, starch digestibility (in vitro), total and available minerals, antinutrients, dietary fibre and β-glucan were determined in supplemented and control bread. Increasing the level of substitution from 5 to 10% of full fat and defatted soy flour to wheat flour significantly (P<0.05) increased protein (from 12.1 to 13.7 and 12.4 to 13.8%), lysine (from 2.74 to 3.02 and 2.76–3.05 mg/100 g protein) and total calcium (from 70.2 to 81.4 and 71.9–81.8 mg/100 g) contents. However, there was also an increase in phytic acid (238–260 and 233–253 mg/100 g), polyphenol (324–331 and 321–329 mg/100 g) and trypsin inhibitor activity (193–204 and 193–198 TIU/g). When barley flour was substituted separately, and in combinations, with full fat and defatted soy flour up to 15%, this significantly increased the contents of protein, total lysine, dietary fibre and β-glucan. It may be concluded that breads supplemented with barley and defatted soy flour, up to a 15% level, are organoleptically and nutritionally acceptable.     

Tempeh flour from chickpea (Cicer arietinum L.) nutritional and physicochemical properties

The effects of solid state fermentation (SSF) on physicochemical and nutritional properties of chickpea flour were studied. Fermented (tempeh) flour showed higher particle size index, gelatinization temperature, dispersability and resistant starch content, and lower gelatinization enthalpy and water solubility than unfermented flour. SSF increased the content of the essential amino acids (EAA) Ile, total sulphur (Met + Cys), total aromatic (Phe + Tyr), and Thr in 37, 41, 107, and 39 g kg⁻¹ protein, respectively; Trp content decreased 8 g kg⁻¹ protein. Total sulphur (EAA score = 0.87) was limiting in unfermented flour and Trp (0.93) in tempeh flour. SSP improved the in vitro and true protein digestibility (72.2–83.2% and 83.7–88.8%, respectively), protein efficiency ratio (PER, 1.59–2.31), cPER (1.54–2.21), and corrected protein digestibility (0.73–0.89). Chickpea tempeh flour may be considered for the fortification of widely consumed legume-based food products.     

Extrusion of a hard-to-cook bean (Phaseolus vulgaris L.) and quality protein maize (Zea mays L.) flour blend

Heated extrusion was tested as an alternative process for incorporating “hard-to-cook” beans into food products. A 3² factorial design was used to evaluate extrusion conditions for a 40/60 (w/w) blend of “hard-to-cook” beans and quality protein maize. Tested extrusion variables were temperature (155, 170 and 185 °C) and moisture content (15.5, 17.5 and 19.5 g/100 g). Screw speed was fixed at 130 rpm. The extrudates obtained at 155 and 170 °C with 15.5% moisture had the best physical characteristics and were chosen for comparative analysis of nutritional changes between the unprocessed “hard-to-cook” bean/quality protein maize flour blend and the resulting extrudates. In vitro protein digestibility was higher in the extrudates (80%) than in the flour blend (76%). In vitro starch digestibility was higher at 155 °C (89%) and 170 °C (92%) than in the flour blend (12%). Processing conditions decreased dietary fibre content by 38% at 155 °C and 44% at 170 °C.     

酶解改性对燕麦粉中淀粉含量及消化性的影响

为研究酶解对燕麦粉的淀粉含量和消化性的影响,本文采用双波长法测定天然燕麦粉、焙烤燕麦粉、酶解燕麦粉中直链淀粉、支链淀粉及总淀粉含量,并测定其快速消化淀粉、慢速消化淀粉和抗性淀粉含量以评价其消化性,利用红外光谱仪及电镜对其结构和颗粒形貌进行分析。结果表明,与天然燕麦粉相比,焙烤燕麦粉中直链淀粉、支链淀粉及总淀粉含量没有显著变化(p>0.05),但酶解改性燕麦粉变化极显著(p<0.01),分别下降了77.97%、43.55%、46.19%;焙烤燕麦粉中快速消化淀粉、慢速消化淀粉和抗性淀粉含量没有显著变化(p>0.05),但酶解改性燕麦粉变化极显著(p<0.01),分别下降了82.29%、57.06%、33.48%;经淀粉的红外光谱及1047/1022、1022/995 cm-1特征吸收比值没有显著变化(p>0.05)。经焙烤和酶解改性的燕麦粉中大淀粉颗粒表面出现较多的凹陷,而酶解改性后的淀粉中含有的小颗粒较少,且表面的凹陷程度不同。酶解改性极显著降低了燕麦粉的直链淀粉、支链淀粉、总淀粉、快速消化淀粉、慢速消化淀粉及抗性淀粉含量(p<0.01),会对燕麦粉加工性能及营养价值产生影响。     

Interpretation of mechanical spectra of carob fibre and oat wholemeal-enriched wheat dough using non-linear regression models

Oscillation and creep shear tests were applied to test the effect of fibre-rich additions - carob fibre (0-5%) and black oat wholemeal (0-20%) - on the rheological properties of wheat flour dough. Interpretation of changes in the values of the storage modulus (G′) and loss modulus (G″) and the tangent of the phase angle (tan δ) in the function of oscillation frequency (f) was performed on the basis of proposed 3-parameter non-linear regression models. The results of creep measurements were analysed using the 6-parameter Burgers model. Increase in the share of the fibre-rich additions caused the G′(f) and G″(f) curves to shift towards higher values, and steeper slope and stronger bending of the shapes of the curves, while the tan δ(f) curve tended to shift towards lower values. The application of carob fibre and oat wholemeal at rates of 2% and 10%, respectively, caused that the ratio of viscous to elastic properties of wheat flour dough was the least dependent on the shear rate (f). The result of creep tests showed an increase in the instantaneous and retarded moduli of elasticity and the Newtonian viscosity of wheat flour dough with increase in the share of the additions.     

Comparative analysis of fruit-based functional snack bars

The aim was to develop snack bars with high dietary fibre (DF) and polyphenol contents. Snack bar base was formulated without (control bar) or with fibre (inulin or apple DF bar). Snack bar filling was formulated with or without apple polyphenol extract (APE). Nutritional assessment of snack bars was based on the total DF, phenolics, protein, fat, uronic acid (UA) and moisture contents, water activity, Hunter L^∗a^∗b^∗ colour, hardness, and phenolic composition. Results showed that snack bars with added apple DFs gave the highest amount of total DF (∼5.3% w/w). Good quantities of phenolics were also retained in the snack bars with added apple DF and APE after baking. With APE in the bar filling, the snack bars enhanced with apple DF or inulin had higher levels of extracted phenolics (2.87 and 2.22 mg catechin equivalent (CtE)/g bar) than the control bars (1.45 mg CtE/g bar). The phenolic profiles of snack bars obtained by HPLC resembled that of the APE ingredient. The Hunter L^∗a^∗b^∗ colour and water activity values suggested that the addition of APE did not cause extra browning and the resultant snack bars would possess a good shelf life. Therefore, snack bars enhanced with apple DF and APE may be a convenient functional food, offering a good source of DF and apple polyphenols.     

Microstructure and nutrient composition of hairless canary seed and its potential as a blending flour for food use

Canary seed is a true cereal with unique composition. The current study employed light and fluorescence microscopy to visualise starch, protein, phenolics and phytate in hairless canary seed (CDC Maria), a cultivar developed potentially for food use. Macronutrients, minerals and vitamins were evaluated in the developed cultivar and compared with a commercial hairy canary seed, cv. Keet. A control common wheat, cv. Katepwa, was grown adjacent to the canary seed varieties. The compositions of the two canary seed varieties were found to be similar with an average of 55.8 g/100 g of starch, 23.7% g/100 g of protein, 7.9% of crude fat, 7.3 g/100 g of total dietary fibre, 1.8 g/100 g of soluble sugar and 2.3 g/100 g of total ash in the whole grain. Regardless of the milling fraction (whole grain flour, white flour or bran), canary seed had more protein and crude fat and less starch, total dietary fibre and soluble sugar than had wheat. It also had higher concentrations of several minerals and vitamins than did wheat. The structure of the canary seed grain exhibited compound starch granules and protein bodies embedded in a protein matrix similar to that of the oat kernel. Baking tests showed that bread made with 100% hairless canary seed flour was significantly lower in loaf volume and crust and crumb colour than was wheat bread. However, bread with loaf volume, specific volume and crust colour comparable to those of the bread control was achieved by using up to 25% of hairless canary seed or 15% of roasted canary seed flour, thus demonstrating its potential for food applications.     

Use of farinograph measurements for predicting extensograph traits of bread dough enriched with carob fibre and oat wholemeal

Farinograph and extensograph tests were applied to determine the effect of carob fibre and oat wholemeal on the rheological properties of wheat flour dough, and characterisation of relationships between the results of the tests was performed. The applied additions of carob fibre (1-5%) and oat wholemeal (5-25%) increased the water absorption of the dough within nearly identical ranges (56-59%). Enrichment with carob fibre made the dough more rheologically stable during mixing compared to dough with oat wholemeal. In the extension test, dough with an admixture of carob fibre was more resistant, but it was less extensible than dough with oat wholemeal.Analysis of relationships of the extensograph traits to the farinograph ones revealed that longer periods of development of dough enriched with the additions under examination involved the formation of a looser dough structure, as a result of which its resistance to extension, ratio number and energy decreased and the dough extensibility increased. Opposite effects were caused by increasing farinograph elasticity and its loss. The degree of softening, negatively correlating with resistance, ratio number and energy, coupled with water absorption or with loss of elasticity, permitted their more accurate prediction. In turn, combining in a regression model of water absorption with development time or with elasticity was the most suitable for predicting dough extensibility.