Biological response to different diets of fermented and unfermented mixtures of flour and cereal brans

The objective of this study was to biologically evaluate eight mixtures of flour and brans prepared with non‐conventional foods popularly denominated ‘multimixtures’, which differed from each other in terms of type of bran (wheat or rice), presence or absence of cassava leaf powder and submission or non‐submission to a solid‐state fermentation with Saccharomyces cerevisiae for 6 h/30 °C, utilising female Wistar/UFPEL rats. Biological indices determined were food efficiency ratio (FER), protein efficiency ratio (PER), net protein efficiency ratio (NPR) and in vivo digestibility. Liver, spleen and kidney specimens were collected at the end of the experiment. In vivo digestibility of diets containing multimixtures formulated with wheat bran was superior to diets containing rice bran, presenting values from 76.5% to 82.8%, which corresponds to up to 85% of casein digestibility. The results allowed the conclusion that fermentation tended to improve food efficiency, but did not influence in vivo digestibility.     

Mathematical models for maximum improvement of in vitro protein digestibility of high dietary fibre cookies

Via substituting with wheat flour some high dietary fibre cookies were prepared (with 6, 12, 18 and 24%) from cereal industry by-products: corn bran (CB), rice bran (RB) and barley husk (BH). In vitro protein digestibility assay was used to examine the effect of substituting on protein digestibility. The applied nonlinear mathematical models indicated a higher determination coefficient between experimental and predicted data (R2 ≥ 0.999). A maximum in vitro protein digestibility (IVPD) of 88.4, 84.1, 85.2% was obtained when using optimum level substituting with wheat flour (7.9, 9.3 or 5.2%) in the CB, RB or BH respectively for producing cookies. The maximum improvement or minimum reducing IVPD by using fibre sources in producing cookies ranged from ?0.25% in RB to 4.9% in CB.     

Relative Protein Efficiency Ratios for Wheat-Based Breakfast Cereals

Male weanling rats were subjected to standard 28-day PER trials following the outline by the AOAC (1984) except that the diets contained 8.5% protein (N × 6.25) as one of six wheat-based breakfast cereals, white flour, whole wheat flour or casein. One of the cereals was an extrusion puffed product, three were flaked and toasted cereals and two were extruded cereals. Of the two extruded cereals, one was lightly toasted and the other was more heavily toasted. Relative PER (R-PER) was lowest for the puffed cereal (- 15.3) and highest for the extruded-lightly toasted cereal (69.9). R-PER for the flaked cereals ranged from 1.7 to 16.3; the other extruded cereal had a R-PER of 2.8 and each of the two flours had a R-PER of 42.9.     

Nutritional Evaluation of Breadfruit-containing Composite Flour Products

Composite flours containing wheat, breadfruit flour and soy protein, whey or peanut meal were formulated and incorporated into western style bread and biscuits. Bread containing 10% breadfruit flour and 5% whey, and biscuits containing 10% breadfruit flour and 5% soy protein were judged most acceptable in flavor, color, and texture. Breadfruit flour contained 4.4% protein and was lower in sulfur containing amino acids and higher in lysine than wheat flour. Breadfruit containing bread and biscuits had low amino acid scores. The protein efficiency ratio (PER) of the biscuit product, however, was similar to that of the casein control while the PER of bread was significantly lower. Results suggest that acceptable products can be made with composite flours containing 10% breadfruit flour.     

Development of protein-Rich Sorghum-Based Expanded Snacks Using Extrusion Technology

Sorghum is an important staple crop in semi-arid regions of Africa and India because of its drought tolerance. But low protein content and quality limit its widespread use. This project focused on developing sorghum-based extruded snacks. Results from preliminary lab-scale extrusion experiments were used to design a 2×5 factorial pilot-scale study. Two blends of sorghum flour and corn flour were prepared (6:1 and 5:2 w/w ratios) as the controls. Three different sources of protein—whey protein isolate, defatted soy flour, and mixed legume flour—were added to the sorghum/corn flour blends at 30%. A 50:50 blend of defatted soy flour and whey protein isolate was also added at 30% to the sorghum/corn flour blends. The resultant ten formulations were extruded on a pilot-scale twin-screw extruder to investigate the effects of sorghum/corn flour ratio and protein addition on product expansion, microstructure, mechanical properties, and sensory attributes. Expansion ratio of extruded product increased at the higher level of corn flour, and decreased with the incorporation of protein sources. Extrudates with defatted soy flour had a lower expansion ratio (5.3–5.4) than those with whey protein isolate (7.7–7.9), legume flour (7.1–9.9), or whey protein isolate-defatted soy flour (6.1–6.9). Extrudate microstructure, obtained by X-ray microtomography, corresponded well with expansion characteristics. Extrudates with defatted soy flour had the lowest cell diameter. Average crushing force (ranging from 40.9 to 154.87 N) was lower for extrudates with a higher level of corn flour. However, contrary to expectations, crushing force and crispness work both decreased with incorporation of protein sources. Consumer acceptability results showed that the addition of protein sources enhanced taste and overall acceptability of the extruded snacks, with the treatment sorghum/corn flour 5:2 and whey protein isolate-defatted soy flour as the protein source having significantly higher ratings than the other treatments.     

麦麸对酥性饼干物理性质和淀粉消化性的影响

目的 研究麦麸对酥性饼干颜色、物理性质以及淀粉消化性的影响。方法 将麦麸按0～50%比例添加到面粉中制作饼干,测定混合粉的溶剂保持力,测定饼干颜色、延展度、硬度以及淀粉消化性。结果 添加麦麸导致混合粉的水和碳酸钠溶剂保持力值增加,乳酸溶剂保持力值和面筋性能指数降低(4.71%～33.20%和25.73%～34.11%),饼干颜色变暗。当麦麸添加量大于20%时,饼干的延展度和硬度增大(53.54%～64.31%和135.98%～408.53%)。此外,麦麸的添加在一定程度上降低了饼干淀粉消化性。麦麸添加量与饼干物理性质呈强正相关性,与消化终点葡萄糖含量呈负相关。通过主成分分析,提取了2个主成分,累计方差贡献率为85.3%。结论 适量添加麦麸有效改善了饼干酥脆性,并在一定程度上抑制了饼干淀粉的消化,增加了饼干的功能性质,可以为麦麸产品的进一步开发提供参考。     

Effect of Different Binders on the Physico-Chemical, Textural, Histological, and Sensory Qualities of Retort Pouched Buffalo Meat Nuggets

ABSTRACT: The functional properties of 4 binders, namely corn starch, wheat semolina, wheat flour, and tapioca starches, were evaluated to improve the quality of buffalo meat nuggets processed in retort pouches at F₀ 12.13. Incorporation of corn starch in buffalo meat nuggets produced more stable emulsion than other binders used. Product yield, drip loss, and pH did not vary significantly between the products with different binders. Shear force value was significantly higher for product with corn starch (0.42 ± 0.0 Kg/cm³) followed by refined wheat flour (0.36 ± 0.010 Kg/cm³), tapioca starch (0.32 ± 0.010 Kg/cm³), and wheat semolina (0.32 ± 0.010 Kg/cm³). Type of binder used had no significant effect on frying loss, moisture, and protein content of the product. However, fat content was higher in products with corn starch when compared to products with other binders. Texture profile indicated that products made with corn starch (22.17 ± 2.55 N) and refined wheat flour (21.50 ± 0.75 N) contributed firmer texture to the product. Corn starch contributed greater chewiness (83.8 ± 12.51) to the products resulting in higher sensory scores for texture and overall acceptability. Products containing corn starch showed higher sensory scores for all attributes in comparison to products with other binders. Panelists preferred products containing different binders in the order of corn starch (7.23 ± 0.09) > refined wheat flour (6.48 ± 0.13) > tapioca starch (6.45 ± 0.14) > wheat semolina (6.35 ± 0.13) based on sensory scores. Histological studies indicated that products with corn starch showed dense protein matrix, uniform fat globules, and less number of vacuoles when compared to products made with other binders. The results indicated that corn flour is the better cereal binder for developing buffalo meat nuggets when compared to all other binders based on physico-chemical and sensory attributes.     

三相卧螺法生产小麦淀粉工艺中轻相液蛋白质的营养学评价

将小麦面粉和谷朊粉中蛋白质的营养进行比较,评价了三相卧螺法生产小麦淀粉过程中的副产物轻相液中蛋白质的营养价值。结果表明：轻相液中蛋白质的氨基酸评分和化学评分均高于小麦面粉和谷朊粉,其中必需氨基酸指数（EAAI）、生物价（BV）、氨基酸比值系数分（SRCAA）、体外蛋白质消化率（IVPD）、蛋白质的效率比（PER）以及蛋白质消化率校正的氨基酸评分（PDCASS）分别为0.95、92.06、73.73、85.4%、1.89和0.43。同时,利用模糊识别法计算得到轻相液中蛋白质的贴近度为0.85,高于小麦面粉和谷朊粉。因此,轻相液中的蛋白质优于小麦面粉和谷朊粉中的蛋白质。     

A farinograph study on the viscoelastic properties of sago/wheat flour dough systems

Doughs containing mixtures of sago and wheat flours of differing protein content at different levels of sago substitution (10, 15, 20, 25, 30, 40 and 50%) were prepared as follows: sago + high protein wheat (HPW) flour, sago + medium protein wheat (MPW) flour and sago + low ? protein wheat (LPW) flour. The viscoelasticity of doughs from control sago and wheat flours and sago/wheat flour mixtures was determined using a Braberder farinograph. It was found that arrival time increased with increasing protein content in the mixture. Peak time for control wheat flours and sago/wheat flour mixtures increased with increasing protein content. Dough stability, 20 min drop and water absorption were found to decrease as the sago proportion in the mixture decreased. The 50% sago/LPW mixture was unable to form a dough. Breakdown times for control HPW flour and HPW flour mixtures were the highest, followed by MPW flour and then LPW flour. However, breakdown time for control MPW flour was higher than that for HPW flour mixtures. The same trend was observed at all ratios of mixture over the whole experiment. Copyright © 2004 Society of Chemical Industry     

USE OF ANIMAL BLOOD AND CHEESE WHEY IN BREAD: NUTRITIVE VALUE AND ACCEPTANCE

Breads in which water and milk powder were replaced with unrefined pork blood and/or cottage cheese whey were compared with commercial white bread and an "organic" whole wheat bread. Loaves were evaluated for appearance, composition and acceptance. Rat feeding studies in which the breads contributed about 10% protein to otherwise complete diets indicated no significant differences in growth performance (adjusted PER's) between commercial and "organic" bread. Significantly better performance was obtained for loaves containing blood, whey and blood: whey mixtures. The experimental loaves were comparable in acceptability to commercial breads, although loaf volumes were much lower and crumb texture coarser.     

Studies on nutritive value of left protein from lucerne (Medicago sativa). 3. Supplementation of rat diets based on wheat

Growth responses of weanling female rats for 4 to 8 weeks, and the Protein Efficiency Ratio (PER) for 4 weeks were measured for diets of wheat flour (W) and three mixtures of wheat and lucerne leaf protein (W:LP). Increasing the proportion of leaf protein in, and the protein content of the mixtures led to progressive improvements up to 4 weeks, but there was no significant difference in weight gain after 8 weeks between the supplemented diets. 4-week growth and PER studies using diets of wheat, lucerne leaf protein and mixtures of these two substances in various proportions, but all containing around 10% protein, showed that the diets containing 40–60% of the mixture-protein derived from lucerne preparations promoted significant responses the best results being given by the W50:LP50 mixture. The content of some of the essential amino acids in these diets, on calculation, showed that in the W50:LP50 mixture the deficiency (in comparison with the F.A.O. Reference Protein) of threonine, valine, isoleucine and lysine in wheat is eliminated. Both wheat and lucerne leaf protein are deficient in methionine; cystine, of which there is an adequate amount in wheat but not in lucerne leaf protein, becomes marginal at a protein ratio of W80:LP20 and is deficient by only 10% in the W50:LP50 mixture. The optimum response obtained from the latter indicates that it contains the best balance of essential amino acids possible with these two substances. The decrease in the efficiency of mixed diets containing more than 50% of the protein from lucerne preparation is possibly due to the progressively increasing deficiency in total S-containing amino acid content.     

Effect of Defatted Soybean and Soybean Isolate Fortification on the Nutritional, Physical, Chemical and Sensory Properties of Wheat Flour Tortillas

Wheat flour fortified with 11.1% defatted soybean meal (SBM) or 5.6% soybean isolate (SBI) was processed into flour tortillas. Fortified tortillas contained 35% more protein and twice as much lysine as the 100% wheat flour tortilla. Addition of SBM or SBI decreased dough elasticity but increased dough water absorption and the force required to stretch the dough. The SBM fortified tortilla had better texture (P < 0.05) than the 100% wheat flour tortilla and similar flavor and color (P > 0.05). Rats fed fortified tortillas gained three times as much weight and doubled the protein efficiency ratio (PER) when compared to rats fed wheat flour tortillas. The apparent biological and net protein utilization values of the fortified tortillas were similar (P > 0.05) and higher (P < 0.05) than the wheat flour tortilla. The SBI fortified tortilla had a higher apparent protein digestibility (P < 0.05) than the 100% wheat flour and SBM fortified tortillas.     

Biological study on the effect of supplementing wheat flour with fish protein concentrate.

The protein quality of 4 Egyptian pastries made from different combinations of flour and fish protein concentrate (0%, 4% and 6%) was measured by rat growth study. Weight gain, feed consumption and PER were determined. Weight gain of rats fed cottage cheese crescents was higher than that fed date bars followed by that fed brouche, then rats fed salty sticks. Feed consumed by rats fed with the corresponding commercial pastries was low except in date bars group. Commercial pastries led to low weight gain and low PER values. Supplementing wheat flour with 6% fish protein concentrate gave the highest weight gain and the highest PER values.     

Biological study on the effect of supplementing wheat flour with fish protein concentrate

The protein quality of 4 Egyptian pastries made from different combinations of flour and fish protein concentrate (0%, 4% and 6%) was measured by rat growth study. Weight gain, feed consumption and PER were determined. Weight gain of rats fed cottage cheese crescents was higher than that fed date bars followed by that fed brouche, then rats fed salty sticks. Feed consumed by rats fed with the corresponding commercial pastries was low except in date bars group. Commercial pastries led to low weight gain and low PER values. Supplementing wheat flour with 6% fish protein concentrate gave the highest weight gain and the highest PER values.     

Blockage of available lysine at different stages of infant cereal production

Determination of available lysine was used to assess the heat damage produced during the processing of cereals for infant foods. The infant cereals analysed were: wheat, 7 and 8 cereals, rice, rice–corn, rice–corn–soy and oat. Lysine losses during the toasting of flours ranged between 14 and 29%. Roller‐drying treatment caused considerable heat damage, with a 53% decrease of available lysine in roller‐dried rice–corn–soy. However, oat flour was less susceptible, with a 5% reduction in available lysine during roller‐drying. © 1999 Society of Chemical Industry     

Dispersibility of cereal proteins in urea solutions

Protein estimations by the biuret method were highly correlated with Kjeldahl determinations for 87 samples of the seven major cereal grains. The extent of binding of acid orange 12 in a phosphate buffer at pH 1·7 was correlated with the protein content but was affected by non-specific binding which varied with the tested cereals. Extraction with 3M-urea at 4° yielded an average of 67·9% protein from wheat, 67·3% from wheat flour, 66·2% from rye, 71·2% from oats, 46·7% from barley, 32·1% from rice, 22·3% from corn, and 24·6% from sorghum. Differences in dispersible proteins seem to be affected by the disaggregating and hydrogen-bond-disrupting effect of urea, and seem to be related to amino-acid composition and functional properties of cereal proteins. The urea-dispersible protein fraction in wheat flour was higher than in whole wheat.     

Calculation of water sorption isotherms for multicomponent protein-containing mixtures

This paper presents a method of calculating water sorption isotherms for multicomponent mixtures from the mass fractions and sorption isotherms of the particular components. Interactions between the components are also considered. to compare experimental and calculated data, investigations on protein concentrates produced from blood plasma, baker's yeast and whey were carried out. Calcium carbonate, molecular sieves, cellulose, wheat bran and some types of flour were used as additives.     

Use of acid whey protein concentrate as an ingredient in nonfat cup set-style yogurt

Acid whey resulting from the production of soft cheeses is a disposal problem for the dairy industry. Few uses have been found for acid whey because of its high ash content, low pH, and high organic acid content. The objective of this study was to explore the potential of recovery of whey protein from cottage cheese acid whey for use in yogurt. Cottage cheese acid whey and Cheddar cheese whey were produced from standard cottage cheese and Cheddar cheese-making procedures, respectively. The whey was separated and pasteurized by high temperature, short time pasteurization and stored at 4°C. Food-grade ammonium hydroxide was used to neutralize the acid whey to a pH of 6.4. The whey was heated to 50°C and concentrated using ultrafiltration and diafiltration with 11 polyethersulfone cartridge membrane filters (10,000-kDa cutoff) to 25% total solids and 80% protein. Skim milk was concentrated to 6% total protein. Nonfat, unflavored set-style yogurts (6.0 ± 0.1% protein, 15 ± 1.0% solids) were made from skim milk with added acid whey protein concentrate, skim milk with added sweet whey protein concentrate, or skim milk concentrate. Yogurt mixes were standardized to lactose and fat of 6.50% and 0.10%, respectively. Yogurt was fermented at 43°C to pH 4.6 and stored at 4°C. The experiment was replicated in triplicate. Titratable acidity, pH, whey separation, color, and gel strength were measured weekly in yogurts through 8 wk. Trained panel profiling was conducted on 0, 14, 28, and 56 d. Fat-free yogurts produced with added neutralized fresh liquid acid whey protein concentrate had flavor attributes similar those with added fresh liquid sweet whey protein but had lower gel strength attributes, which translated to differences in trained panel texture attributes and lower consumer liking scores for fat-free yogurt made with added acid whey protein ingredient. Difference in pH was the main contributor to texture differences, as higher pH in acid whey protein yogurts changed gel structure formation and water-holding capacity of the yogurt gel. In a second part of the study, the yogurt mix was reformulated to address texture differences. The reformulated yogurt mix at 2% milkfat and using a lower level of sweet and acid whey ingredient performed at parity with control yogurts in consumer sensory trials. Fresh liquid acid whey protein concentrates from cottage cheese manufacture can be used as a liquid protein ingredient source for manufacture of yogurt in the same factory.     

不同杂粮对面粉品质特性的影响研究

本文以谷物杂粮为研究对象,通过将不同质量的红豆粉、绿豆粉、玉米粉和燕麦粉混合于小麦粉中,观测其对面粉的品质特性和面包质量的影响。试验结果表明：除玉米粉外,随着其他杂粮添加量的增加,其蛋白质、面筋和灰分含量呈增加趋势;而混合粉的峰值黏度、最低黏度、衰减值、最终黏度和回生值均有所下降;添加绿豆粉和红豆粉的小麦粉在添加量12%时其峰值黏度最低,而添加12%燕麦粉的小麦粉峰值黏度突然增大;峰值时间和糊化温度明显降低。杂粮的添加改变了面团的品质特性。综合评价后认为最佳添加比为不超过12%。     

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