Rat bioassay of the protein nutritional quality of soy-fortified sorghum biscuits for supplementary feeding of school-age children

BACKGROUND: Protein–energy malnutrition (PEM) remains a major deficiency disease among children in developing countries. The protein nutritional quality of soy‐fortified sorghum biscuits was evaluated with respect to their potential as a protein‐rich supplementary food. Three isonitrogenous diets based on 50:50 ratio decorticated sorghum:defatted soy flour biscuits, 100% sorghum biscuits, casein, and a protein‐free diet were fed to male Sprague Dawley weanling rats. RESULTS: Protein efficiency ratio (PER) for the sorghum–soy biscuit diet was equivalent to the reference casein diet, and zero for the 100% sorghum diet. Faecal bulk for 100% sorghum diet was 1.5 times higher than sorghum–soy and casein diets. True protein digestibility of the three diets was high—88–95%—agreeing with previous rat studies with sorghum. Biological value and net protein utilization of the sorghum‐soy biscuit diet were similar to the casein diet, but lower than the 100% sorghum biscuit diet CONCLUSION: Notwithstanding limitations of rat bioassay for assessing sorghum food protein quality, the high PER of defatted soy flour‐fortified sorghum biscuits (sorghum:soy 50:50 ratio) indicates they have considerable potential as a supplementary food to young children to alleviate PEM. Copyright © 2011 Society of Chemical Industry     

Use of a Bovine Heme Iron Concentrate in the Fortification of Biscuits

Biscuits were fortified with 4, 6, 8, and 10% heme iron concentrate (HIC). The 10% fortification level presented problems of poor dough quality. The 4, 6, and 8% levels were evaluated for appearance, flavor, texture, taste and aroma and 6% was chosen as the appropriate fortification level. Protein of the fortified biscuit was 1.6 times higher and iron 8 times higher than that of the unfortified control. A shelf life study showed that at 40°C, lipid peroxidation of the biscuits was considerably higher than at room temperature and a catalytic effect of the HIC on the lipid autooxidation was observed. Under controlled conditions, the biscuits could be satisfactorily stored up to 7 months. The fortification of biscuits with HIC represents an interesting alternative for the prevention of iron deficiency.     

Flavour of sourdough wheat bread crumb

This study investigates the effect of adding sourdough to wheat bread dough on the production of flavour compounds in wheat bread crumb. The sourdoughs were fermented with starter cultures of lactic acid bacteria alone and in combination with sourdough yeasts. The volatile compounds in the bread crumb were isolated by a dynamic headspace technique and extraction analysis, analysed by gas chromatography (GC), and identified on the basis of GC retention times for reference compounds and mass spectrometry (MS). The chemical analyses were combined with sensory evaluation. The volume of the loaves increased significantly when the doughs had 5–20% sourdough added compared with the control bread (bread without sourdough). In the sourdough bread, the content of acetic acid, 2-methylpropanoic acid, and 3-methylbutanoic acid was generally higher, and loaves made with the addition of sourdoughs fermented withLactobacillus plantarum, L. delbrueckii, orL. sanfrancisco had a higher content of 2- or 3-methyl-1-butanol than control bread. Interactions were seen between the starter cultures and the sourdough yeasts, and the production of the following compounds was increased depending on the starter culture used and on the sourdough yeast: ethanol, 2-methylpropanol, 2/3-methyl-1-butanol, 2-phenylethanol, benzyl alcohol, acetic acid, 2-methylpropanoic acid, and 3-methylpropanoic acid. Bread made with an addition of 5% to 15% sourdough fermented withL. sanfrancisco had a pleasant, mild and sour odour and taste.L. plantarum bread had a strong, sour and unpleasant odour and a metallic sour taste with a sour aftertaste, but when the sourdough was also supplemented with the sourdough yeastSaccharomyces cerevisiae, the bread attained a more aromatic wheat bread flavour, which may be caused, in part, by a higher content of 2/3-methyl-1-butanol, 2-methylpropanoic acid, 3-methylbutanoic acid and 2-phenylethanol.     

青稞全谷及麸皮对饼干品质的影响

饼干是颇受消费者喜欢的休闲食品,提高其品质对人们的生活有着重要的影响。本文通过在饼干的制作过程中添加0%、5%、10%、15%不同比例的青稞全谷物和青稞麸皮,测定了其蛋白质含量、质构、颜色变化并对饼干进行感官评价,结合对CML含量的抑制效果来确认最优添加量。结果表明:青稞全谷物及青稞麸皮添加量均为15%时,此时蛋白质含量最高,分别为6.83%±0.03%和6.78%±0.14%;且质构指标硬度、内聚性、弹性、咀嚼性均在消费者可以接受的范围;饼干呈现棕褐色,深受消费者喜爱;感官得分分别为15.8分和15.1分;对晚期糖基化终产物CML的抑制率分别为27.46%和22.54%,抑制效果最佳。因此在杂粮饼干的加工中,选择青稞全谷物和麸皮添加量均为15%,既能保证饼干具有较好的感官,又能最大限度的抑制CML的生成。     

Analysis of flavour compounds in beer with extruded sorghum as an adjunct using headspace solid‐phase micro‐extraction and gas chromatography–mass spectrometry

Sorghum is a widely used adjunct that is used in the production of beer and increasingly affects beer flavour as the amount added increases. The aim of this work was to establish a simple, solvent‐free technique, without derivatization, to analyse flavours and typical volatile compounds present in extruded and unextruded sorghum beer, and to compare the flavour differences of the two types of beer. Headspace solid‐phase micro‐extraction gas chromatography–mass spectrometry was used to determine the flavours in the two beers and eight typical volatile compounds were quantified using GC. Forty‐five flavour compounds were identified and quantified in extruded white sorghum beer, while 31 flavour compounds were identified in unextruded white sorghum beer. Extruded or unextruded white sorghum can be used to produce ale beer, but the primary flavour content in the extruded white sorghum beer was higher than in the unextruded white sorghum beer. Copyright © 2016 The Institute of Brewing & Distilling     

Performance and fatty acid profiling of interesterified trans free bakery shortening in short dough biscuits

Short dough biscuits were prepared using interesterified trans free bakery shortening (IETFS). Hydrogenated shortening (HS) based biscuits were prepared as a control. The diameter, height and spread ratio were determined. Biscuits were analysed up to 8 months for hardness, moisture and acidity of the extracted fat. IETFS biscuits were significantly (P < 0.05) less hard, had a higher spread ratio and were rated higher on all sensory attributes. Their overall acceptability score on a nine point hedonic scale was 8.2 ± 0.8 as compared to 7.3 ± 0.7 for control biscuits. The fatty acid fraction of control biscuits was: saturated fat, 51.6%; trans fat, 14.5%; monounsaturated fat, 28.0%; and polyunsaturated fat, 5.9% and that of IE trans free biscuits was: saturated fat, 54.8%; trans fat, 0.6%; monounsaturated fat, 38.1%; and polyunsaturated fat, 6.5%. The IETFS was found to be appropriate as an alternate to hydrogenated shortening, providing both functionality and nutritive advantage in biscuits.     

Sourdough products for convenient use in baking

Sourdough fermentations require a specific knowledge on the effects of process parameters, raw materials and micro-organisms in order to obtain a specific, reproducible sourdough and bread quality. This knowledge is not necessarily available in bakeries. Sourdough starter cultures, either active sourdoughs (Reinzuchtsauerteig) or freeze-dried micro-organisms are used to start sourdough fermentation with the required micro-flora. As sourdough fermentation is a labour-intensive and a time-consuming process, a growing demand for convenient products arised early. First organic acids (lactic acid, acetic acid, citric acid) and mixtures thereof came in use. These agents were used directly without or in combination with a sourdough; however, flavour and taste of the resulting breads were unsatisfactory. Based on modified and optimized traditional sourdough processes, dried, pasty and liquid sourdoughs were developed. Companies which produce such ready-to-use products, claim for a convenient, direct production of baked goods in constant quality, in combination with all advantages of a biological sourdough fermentation, e.g. flavour and taste, fresh keeping and prolonged microbial shelf-life. Currently, a broad variety of sourdough products with different fermented cereals is available on the market. In order to obtain a stable product, it is a necessity to inactivate the sourdough micro-biota by e.g. pasteurization, drying or autosterilization.     

Incorporation of canola proteins extracted by electroactivated solutions in gluten‐free biscuit formulation of rice–buckwheat flour blend: assessment of quality characteristics and textural properties of the product

Canola proteins extracted by electroactivated solutions were incorporated to gluten‐free biscuits made from blend of rice and buckwheat flours. Physical and textural properties were significantly influenced by these proteins. Isolates and concentrates did not behave in a similar way. A significant increase in diameter was noted for all of the supplemented samples. An increase in thickness was observed for the samples added with protein concentrate, whereas the spread ratio decreased for all the samples compared to control. The hardness of biscuits decreased with the addition of the proteins as compared to the control. The changes in biscuit hardness or fracture strength were in line with the changes in dough hardness. Biscuits containing protein concentrate had lighter, more aerated texture as shown by scanning electron microscopy with lesser amounts of gelatinised starch, indicating improved gas‐holding capacity and more stabilised structure. Protein‐supplemented biscuits have lower moisture and water activity.     

Quality attributes and firming kinetics of partially baked frozen wholewheat bread with sourdough

Partially baked frozen (PBF) process prolongs bread shelf life, but diminishes its volume and crumb texture. Therefore, we investigated the possibility of using sourdough for the quality improvement in PBF wholewheat bread. Sourdough was fermented with either Lactobacillus plantarum, Lb. brevis or Leuconostoc mesenteroides mixed with yeast Candida humilis and added at 7.5, 15, 22.5 or 30% on bread dough basis. The choice of sourdough starter significantly affected bread acidity characteristics, flavour, specific volume, shape and crumb firmness. The sourdough amount and acetic acid content of bread inversely correlated to flavour score, specific volume, shape and crumb softness. The overall quality of PBF wholewheat bread was most efficiently improved after adding Lb. plantarum sourdough at 15–22.5%, resulting in retarded firming rate (74–94%) and improved specific volume (25–28%) in comparison with PBF bread without sourdough. Such sourdough has lactic to acetic acid higher than previously recommended for traditional sourbreads.     

Utilisation of pigeon pea (Cajanus cajan L) byproducts in biscuit manufacture

Biscuits were prepared by substituting wheat flour with dehulled pigeon pea (Cajanus cajan L) flour (PPDF) or pigeon pea byproduct flour (PPBF). PPBF was obtained by recovering edible cotyledon material from milling byproducts. PPBF had a higher level of protein (29.42 g/100g) compared to PPDF (24.67 g/100g). Composite flour blends were prepared by substituting wheat flour (WF) with either PPDF or PPBF at 95:5, 90:10, 85:15, 80:20 and 75:25 incorporation levels. Biscuits were analysed for composition, physical and sensory parameters. Protein content of PPDF and PPBF fortified biscuits increased by 1.3 and 1.4 times respectively compared to control along with a significant increased in fibre content. Results indicate that good quality biscuits with increased levels of protein and fibre can be prepared by substituting wheat flour using 85:15 of PPDF or 90:10 of PPBF without significantly affecting the sensory quality of biscuits. This study demonstrates the potential feasibility of incorporating pigeon pea milling byproducts in the manufacture of biscuits.     

Wheat flour confectionery products as a source of inorganic nutrients: zinc and copper contents in hard biscuits

Cereal-based confectionery products being consumed through whole human life are considered mainly to be a source of carbohydrates, that is energy, although cereals are a rich source of minerals as well. To evaluate some hard biscuits produced in Croatia as a source of different trace elements in nutrition, in this study Zn and Cu contents were determined in classic wheat flour biscuits and in dietetic biscuits enriched with whole wheat grain flour or whole wheat grain grits, soya flour and skimmed milk. Zn was determined by flame atomic absorption spectrometry (AAS); Cu was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results show that the Zn content in different kinds of biscuits ranges from 5.89 up to 17.64 mg/kg and the Cu content ranges from 1.15 up to 2.79 mg/kg depending on the type of wheat milling products and mineral content of other ingredients used. Enriched dietetic biscuits produced from wheat flour type 850 and whole wheat grain flour and/or soya flour and skimmed milk were almost 200% and 150% higher in Zn and Cu, respectively, in comparison to classic white wheat flour biscuits and can be considered as good sources of Zn and Cu in nutrition.     

Pilot Scale Production of a Lager Beer from a Grist Containing 50% Unmalted Sorghum

Pilot scale (1000 L) brews were carried out with a grist comprising of unmalted sorghum (50% of total wet weight of grain) (South African variety) and malted barley (50% of total wet weight of grain) grist using a mashing program with rests at 50°C, 95°C and 60°C. Mashes were supplemented with a high heat stable bacterial α‐amylase, a bacterial neutral protease and a fungal α‐amylase. A control brew containing 100% malted barley was also carried out. Saccharification difficulties were encountered during mashing, and extraction of the grist was lower for the sorghum mashes. The sorghum mashes showed comparable lautering behaviour to that of the control mash. At mashing off the sorghum worts were starch positive. Apparent degree of fermentation of the sorghum gyles were less than the control gyles. Green beer filtration proved unproblematic. The sorghum beers compared quite closely with the control beer with regard to colour, pH and colloidal stability. Foam stability deficiencies were apparent with the sorghum beer. However, the fermentability of the sorghum worts were lower. Hence the sorghum beers were lower in total alcohol. Sensory analysis indicated that no significant differences existed between the sorghum beer and both the control beer and a commercial malted barley beer with regard to aroma, mouth‐feel, after‐taste and clarity. However, the sorghum beer was found to be significantly different to both of the other beers with regard to colour, initial taste and foam stability.     

A study on functional,pasting and micro-structural characteristics of multigrain mixes for biscuits

The four different multigrain mixes were developed by combining whole cereals (barely, sorghum, maize, oats,wheat germ), pulses (chickpea dhal, green gram, peas, soya flour) and millets (finger millet, pearl millet) to get mutual supplementation benefits. The protein content of different mixes ranged from 22.91 to 27.84 % and dietary fiber ranged from 16.82 to 18.72 %. The functional, pasting and micro-structural characteristics of different mixes have been studied to predict its suitability for the preparation of biscuits. The results indicated that the water absorption capacity of these mixes varied from 1.51 to 1.57 g/g, oil absorption capacity varied from 0.84 to 1.03 g/g, water absorption index varied from 3.54 to 3.70 g/g, water solubility index varied from 3.54 to 3.70 g/g, bulk density varied from 0.53 to 0.62 g/ml, peak viscosity varied from 63.83 to 84.79 RVU. Among the different multigrain mixes studied, Mix III had the desired functional characteristics as indicated by its higher water absorption index, water solubility index, bulk density, α-amylase activity and lower alkaline water retention capacity, breakdown viscosity suggesting thereby its suitability for the preparation of biscuits. The biscuit making trials conducted on different multigrain mixes at 20 % level of incorporation have also confirmed that among different multigrain mixes, the multigrain mix III containing barley, sorghum, chickpea, pea and soya flour gave best quality biscuits.     

Impact of sourdough fermented with Lactobacillus plantarum FST 1.7 on baking and sensory properties of gluten-free breads

Sourdoughs were produced from buckwheat, oat, quinoa, sorghum, teff and wheat flour using the heterofermentative lactic acid bacteria Lactobacillus plantarum FST 1.7 and added to a basic bread formulation of flour from the same grain type (20 % addition level). Dough rheology, textural (crumb hardness, specific volume) and structural bread characteristics (crumb porosity, cell volume, brightness) of sourdough-containing breads were compared to non-sourdough-containing breads (control). Changes in protein profiles as analysed with capillary electrophoresis were observed in all sourdoughs. Furthermore, sourdough addition led to decreased dough strength resulting in softer dough. No influences on specific volume and hardness on day of baking were found for gluten-free sourdough breads. The staling rate was reduced in buckwheat (from 8 ± 2 to 6 ± 2 N/day) and teff sourdough bread (13 ± 1 to 10 ± 4 N/day), however, not significantly in comparison with the control breads. On the contrary, in wheat sourdough bread, the staling rate was significantly reduced (2 ± 1 N/day) in comparison with control bread (5 ± 1 N/day). Sourdough addition increased the cell volume significantly in sorghum (+61 %), teff (+92 %) and wheat sourdough breads (+78 %). Therefore, crumb porosity was significantly increased in all gluten-free and wheat sourdough breads. Shelf life for sourdough breads was one (teff and oat), two (buckwheat, quinoa and sorghum) and 3 days (wheat) and was not prolonged by sourdough addition. The inferior aroma of breads prepared from the gluten-free flours was also not improved by sourdough addition.     

Effects of washing and packing on sensory and chemical parameters in carrots (Daucus carota L)

Carrots washed and packed by hand or machine and stored at 2, 10 or 20 °C in three different package types were analysed for taste, flavour and content of sugars, terpenes, 6‐methoxymellein and ethanol as well as for ethylene, CO₂ and O₂ concentrations in the packages. Carrots washed by machine had increased micro‐organism decay and higher sensory scores for bitter taste, aftertaste, terpene flavour and odour, green odour and earthy flavour. The ability of packages to ventilate was important to avoid anaerobic conditions that caused decreased sucrose content, increased production of ethanol and a higher intensity of ethanol flavour and sickeningly sweet taste. Increasing temperature enhanced the concentration of ethanol, CO₂ and ethylene and decreased the O₂ concentration as well as the content of sucrose and total sugar. High temperature also increased the intensity of ethanol flavour and odour, aftertaste, earthy flavour, terpene flavour and bitter taste. Bitter taste was positively correlated with 6‐methoxymellein level, although this level was below the sensory threshold. Bitter taste, earthy flavour and aftertaste were correlated with total terpenes and several individual terpenes. Carrots washed and packed early in the long‐term storage period (November) were more bitter and had a higher level of 6‐methoxymellein and a higher intensity of terpene flavour and odour, green flavour and earthy flavour than those handled in January or March. Copyright © 2004 Society of Chemical Industry     

FACTORS AFFECTING FRACTURE PROPERTIES OF SHORT-DOUGH BISCUITS

Fracture properties of short-dough biscuits were determined in three-point bending tests. Biscuits exhibited an essentially elastic behaviour and fractured at small strain. Span length did not influence the parameters measured, in accordance with theory. Biscuits fractured with the bottom side upwards had slightly higher fracture stress and fracture strain than those in the inverted position. Presumably, air cells at the bottom side acted as sites of stress concentration. Fracture strain was strain-rate dependent over the range studied possibly due to local plastic deformation. Reducing the fat content increased the fracture stress of the biscuits, which indicates that the method provides a useful tool for discriminating among short-dough biscuits of various composition.     

Wheat flour confectionery products as a source of inorganic nutrients: iron and manganese contents in hard biscuits

To evaluate some wheat flour based hard biscuits produced in Croatia with regard to their Fe and Mn contents and thereby their functionality, Fe and Mn are determined by cold-vapor atomic absorption spectrometry (CVAAS) in seven biscuits: classic white wheat flour biscuits and in dietetic biscuits enriched with whole wheat grain flour or whole wheat grain grits, soya flour and milk. Presented data show that Fe contents in seven analyzed biscuits range from 9.32 up to 24.80 mg/kg while Mn contents range from 3.76-16.37 mg/kg depending on type and share of cereal milling products and mineral content of other raw materials used. Thus, enriched biscuits produced from wheat flour type 850 and whole wheat grain flour, having the highest concentrations of Fe and Mn, were about 150% and 250%, respectively, richer in those elements in comparison with classic white flour biscuits of Petit Beurre type. Data show that wheat flour based hard biscuits, particularly enriched biscuits, can be considered as a good additional source of Fe and Mn in diets.     

牡蛎酶解产物添加量对苏打饼干品质的影响

为探究牡蛎酶解产物添加量对苏打饼干品质的影响,制作牡蛎酶解产物添加量为0、2%、4%、6%、8%、10%的饼干,探究其在感官、色度、质构指标上的差别,并应用固相微萃取气相色谱质谱联用法对挥发性风味成分进行分析鉴定。结果表明:随着牡蛎酶解产物添加量的增加,饼干的外观形态、色泽、风味、组织、口感和综合评分呈现较大的分数差异。牡蛎酶解产物添加量为6%的饼干,呈现最好的外观形态、色泽、组织、口感和综合评分。添加牡蛎酶解产物的饼干,L*值和b*值均高于未添加的饼干,而a*值均低于未添加的饼干。添加牡蛎酶解产物的饼干,硬度、内聚性和咀嚼性均高于未添加的饼干。未添加牡蛎酶解产物饼干中鉴定出24个风味成分,而6%牡蛎酶解产物饼干中鉴定出30个风味成分。添加6%牡蛎酶解产物饼干比未添加牡蛎酶解产物饼干的风味物质更加丰富。