Physicochemical and functional properties of full‐fat and defatted Moringa oleifera kernel flour

Full‐fat and defatted Moringa oleifera kernel flours were analysed for their functional properties. The effect of pH and NaCl concentrations on the functional properties of the flours was investigated following standard procedures. The protein content of full‐fat and defatted flour was 36.18 and 62.76 g/100 g, respectively. The concentrations of other proximate constituents of the defatted flour were higher than those of the full‐fat flour. Nitrogen solubility was lowest at pH of 4.0 and 9.0, respectively, with maximum solubility occurring at pH of 6.0. Defatting increased the water absorption and fat absorption capacities of Moringa oleifera kernel flour. The foaming capacity and foam stability of the defatted flour were 86.0% and 82.0 mL, whereas that of full‐fat flour were 20.6% and 18.5 mL respectively. The defatted flour showed better emulsification (97.2 mL g^?1) than full‐fat flour (66.0 mL g^?1). The least gelation concentration of the defatted and full‐fat flours was 14% and 16% (w/v) respectively. Moringa oleifera kernel flour can be a valuable source of vegetable protein in fortified food products formulation.     

The Role of Wheat and Egg Constituents in the Formation of a Covalent and Non‐covalent Protein Network in Fresh and Cooked Egg Noodles

Noodles of constant protein content and flour‐to‐egg protein ratio were made with whole egg, egg white, or egg yolk. The optimal cooking time, water absorption, and cooking loss of salted whole egg noodles was respectively lower and higher than of egg white and egg yolk noodles. However, cooked whole egg noodles showed the best Kieffer‐rig extensibility. Differences in noodle properties were linked to protein network formation. Disulfide bonds in whole egg noodles developed faster and to a larger extent during cooking than in egg yolk noodles but slower and to a lower extent than in egg white noodles. The balance between the rate of protein cross‐linking and starch swelling determines cooked noodle properties. Ionic and hydrophobic protein interactions increase the optimum cooking time and total work in Kieffer‐rig extensibility testing of fresh noodles. Hydrogen bonds and covalent cross‐links are probably the main determinants of the extensibility of cooked noodles.     

蛋清粉对小麦粉及挂面品质的影响

通过在小麦粉中添加不同比例的蛋清粉,测定其糊化、粉质特性及挂面的蒸煮、质构特性和进行感官评价来探讨蛋清粉对小麦粉及挂面品质的影响。结果表明：随着蛋清粉添加量的增加,小麦粉的峰值黏度、低谷黏度、最终黏度和崩解值逐渐增大,峰值时间呈现下降趋势而糊化温度无明显变化。面团吸水率随蛋清粉添加量的增加而明显减少,面团形成时间不随添加量的增加而显著变化,但明显低于对照组,当蛋清粉添加量为3%时,面团稳定时间最长,弱化度最低。挂面的吸水指数、最佳蒸煮时间随蛋清粉添加量的增加而显著增大,但蒸煮损失在添加量为3%时最少。挂面的折断力、拉断力和硬度随蛋清粉添加量的增加而增大。综合挂面蒸煮、质构特性与感官评价结果得出,当蛋清粉添加量接近3%时挂面综合品质最好。     

PROCESSING AND FUNCTIONAL PROPERTIES OF YAM BEANS (SPHENOSTYLIS STENOCARPA)

The proximate and selected functional properties of five flours from yam bean (YB) made after the grains were not processed (raw) and processed as boiled, fermented, roasted and malted, were determined. The functional properties were water and fat absorption, gelation, emulsification and whippability. An improvement was observed for protein content of flours processed beans compared to raw flour. Fermentation improved the oil content of the flour. The emulsifying and foaming capacities (50.7 and 40.20%, respectively) observed for raw flour were significantly higher than those for the flours from processed bean. Gelation was significantly (P < 0.05) increased and decreased by fermentation and malting of the bean, respectively. The water absorption capacities ranged from 131.9% in raw flour to 218.8% in flour boiled beans. There were no significant (P > 0.05) differences in the fat absorption capacities of all flours except for the one of fermented beans (0.40 mL/g), which was significantly lower than the value (0.73 mL/g) obtained for the flour from boiled beans. Although a high foaming capacity was observed for raw flour, it was less stable when compared with that of the processed bean flours. Overall, YB flour was found to exhibit good functional properties, and has a great potential for use as an ingredient in selected food systems.     

Isolation of Egg Yolk Granules as Low‐Cholesterol Emulsifying Agent in Mayonnaise

Egg yolk is an essential ingredient for many food products due to its excellent functional properties such as emulsification. However, the consumers’ concern of its cholesterol level has led food industry to seek solutions for its replacement. Utilization of low‐fat egg yolk granules as emulsifier can be an alternative strategy. In this study, granules with low cholesterol content were separated from egg yolk by a simple method under easily scalable centrifugal conditions. The egg yolk granules isolated within 0.17 M NaCl solution achieved a 22.5% yield that was similar to that using higher centrifugation speeds and longer time. The yield of egg yolk granules increased from 25% to 32% when the yolk:water ratio was changed from 1:1 to 1:2. Mayonnaise was prepared to evaluate the emulsifying capacity of the egg yolk granules. It was found that egg yolk granules exhibited similar emulsifying activity as that of whole egg yolk, but a better emulsion stabilizing property that is evidenced by the higher viscosity of mayonnaise prepared with the granules. In addition, the viscosities of mayonnaise prepared by spray dried yolk and granules were slightly higher than the liquid counterpart, showing a further improvement by spray drying on the emulsion stabilizing properties. The mechanical spectra of mayonnaise samples by frequency sweep also suggested that granules favored the formation of stronger 3‐dimensional arrangements of oil droplets and therefore a more stable emulsion. Results suggest that granules isolated within 0.17 M NaCl solution present best emulsifying properties and can be applied as whole yolk replacer in food emulsions.     

不同品种鲜蛋品质差异分析

目的探究褐壳蛋、粉壳蛋和白壳蛋3种类型鸡蛋的品质差异以及对于蛋粉加工的潜在影响。方法选用京红1号、京粉1号和京白1号所产的褐壳蛋、粉壳蛋和白壳蛋作为试验对象,对37周龄和51周龄蛋鸡所产3种类型鸡蛋的蛋品质进行分析比较。结果 37周龄和51周龄的白壳蛋蛋壳厚度、蛋壳比例和蛋壳强度均显著低于其他2个类型鸡蛋(P0.05);37周龄时3种类型鸡蛋的蛋黄水分含量没有显著性差异(P0.05);白壳蛋蛋清水分含量以及总水分含量均较其他2个类型鸡蛋要低。37周龄时褐壳蛋的蛋黄蛋白质和脂肪含量均显著高于其他2个品种,白壳蛋次之,粉壳蛋最低。37周龄时白壳蛋的蛋清蛋白质含量显著低于其他2个品种。由于蛋清中脂肪含量极少,本试验不予考虑。结论褐壳蛋加工成蛋粉后具有更好的营养价值,而白壳蛋可以提高蛋粉加工的产量。     

基于响应面法优化北虫草蛋卷工艺及其品质分析

目的：以低筋小麦粉为主要原料,添加北虫草粉、鸡蛋液、黄奶油、白砂糖等制作北虫草蛋卷。方法：通过单因素实验和响应面试验构建Box-Behnken多元回归模型,对北虫草蛋卷的配方进行优化,通过TMS-PRO质构仪进行质构特性测定,根据食品安全国家标准测定产品性能指标。结果：以低筋小麦粉总量为基准,当北虫草粉添加量为6%、鸡蛋液添加量为25%、白砂糖添加量为30%、黄奶油添加量为37%,在此条件下,北虫草蛋卷感官评分为91.0。各项性能指标均符合国家安全标准,且具有良好的持水性与持油性,北虫草蛋卷硬度为34.03±0.49 N;黏着性为-1.34±0.01 N·s;凝聚性为0.13±0.01 mJ;咀嚼性为3.36±0.23 N;弹性为0.76±0.01 mm。结论：相较于全粉蛋卷,北虫草蛋卷具有高蛋白、高虫草素、高持水性、低脂肪和低持油性的特点,营养价值更优。     

蛋清蛋白添加对籼米-绿豆粉粉质特性及挤压米粉丝品质特性的影响

将籼米粉、绿豆粉和蛋清蛋白粉按照一定的比例复配,开发高纤维含量的杂粮米粉丝。研究了绿豆和蛋清蛋白的添加对米粉糊化特性、流变特性以及挤压米粉丝微观结构、蒸煮特性和质构等品质特性的影响。结果显示:添加一定量的绿豆粉和蛋清蛋白粉后,混合粉的峰值黏度、最低黏度、最终黏度、回生值、弹性模量、黏性模量均逐渐下降。随着绿豆粉的添加(25%,50%),米粉的蒸煮时间、断条率、蒸煮损失和吸水率均上升,硬度降低,表明米粉的品质显著降低,由扫描电镜图可以发现,加了绿豆粉之后米粉截面变得越来越粗糙,裂纹和孔洞明显增多。但当加入7.5%的蛋清蛋白后,米粉的蒸煮时间、蒸煮损失和断条率均下降,质构特性有一定程度的改善,表明蛋清蛋白良好的凝胶特性有助于提升高纤维含量挤压米粉丝的品质。     

β-环状糊精包合法脱除胆固醇对蛋黄卵磷脂及其功能性质的影响研究

研究了β-环状糊精包合法脱除鸡蛋黄胆固醇工艺对卵磷脂物质及蛋黄功能性质的影响。高效液相色谱（HPLC）检测结果表明，利用该法脱除蛋黄中90％以上的胆固醇时，蛋黄卵磷脂物质损失不超过8．0％。与普通蛋黄粉相比，起泡性能增强但色泽略浅，乳化稳定性略有下降。     

CERTAIN FUNCTIONAL PROPERTIES OF SUNFLOWER MEAL PRODUCTS

Certain functional properties including water absorption, fat absorption, emulsification, whippability and foam stability were determined on the sunflower flour, protein concentrates and isolate. The results were also compared to those obtained on soy products. Data on water and fat absorption studies suggest that soy products are more hydrophilic in nature while sunflower material exhibited greater lipophilic properties than the soy products. Emulsification tests showed that sunflower flour was superior to all other soy and sunflower products. In general, whipping properties of soy and sunflower isolates were similar, while less whippability was observed for the soy flour and protein concentrates. Whipped foams produced by soy and sunflower protein isolates and sunflower flour were more stable than soy flour, soy and sunflower protein concentrates.     

Effect of Defatted Maize Germ Addition on the Functional and Textural Properties Of Wheat Flour

The objective of this study was to assess functional properties of wheat flour blends with defatted maize germ flour (DMGF), a byproduct of the corn oil industry, at 5–25% levels. The bulk density, oil, and water absorption capacities, emulsion/foaming capacity and stability, objective color, least gelation concentration, and rheological properties (apparent viscosity and dough compression) were determined in control and flour blends. With DMGF addition, bulk density and foaming capacity decreased from 0.62 g/mL to 0.55 g/mL and 33.7% to 25.7%, respectively, both at 25% level. In general, when compared to control, oil and water absorption and emulsion capacities increased significantly in flour blends with >10% DMGF. Overall, regardless of the DMGF level, complete or partial gelling was observed at ≥ 8% gelation concentration. The apparent viscosity increased with increasing DMGF levels (0–25%) in all flour blends and also at all 4 concentrations from 5% to 20%. The control flour dough had a hardness value of 7.56 N, which increased significantly to 84.6N, when the DMGF level increased to 25% in the flour blend. These results indicate that most of the functional properties of wheat flour blends improved with DMGF addition, thus DMGF has a great potential to be used in a variety of food products.     

Emulsifying Properties of Low-fat, Low-cholesterol Egg Yolk Prepared by Supercritical CO2 Extraction

Comparisons were made with native egg yolk, dried egg yolk and a commercial yolk substitute (soy lecithin). Aqueous emulsions were prepared by sonicating water containing 0–5% NaCl, 20% peanut oil, HC1 or NaOH as needed for pH adjustment, and 1–3% emulsifier expressed as the total of phospholipids, glycolipids and proteins contributed by yolk ingredients or soy lecithin. The median diameters of fat particles in the emulsions with and without dispersing fat droplet floes using Triton X-100, were evaluated by laser light diffraction. The emulsifying properties of low-fat, low-cholesterol egg yolk were similar to or better than those of native yolk and dried egg yolk. Soy lecithin had less effective emulsifying properties than yolk ingredients with respect to coalescence of fat droplets during storage and separation during 70°C treatment.     

水牛奶奶油冰淇淋的研制

以水牛奶奶油为主要基料,加入奶粉、白砂糖、复配增稠剂等,以感官评分为参考,研究开发一款特色水牛奶冰淇淋。通过单因素试验研究奶粉、水牛奶奶油、蛋黄粉、白砂糖、复配增稠剂、浓缩蛋白粉添加量对产品感官质量的影响,在单因素的基础上,结合二次通用旋转组合设计优化确定水牛奶冰淇淋的最佳配方,并研究其产品质量。结果表明,水牛奶冰淇淋最佳工艺配方为奶粉19.1%、水牛奶奶油47.7%、蛋黄粉1.2%、白砂糖1.7%、复配增稠剂28.6%、浓缩蛋白粉1.7%。在此配方下加工的产品口感细腻、奶香味浓郁,感官评分可达83.7分,理化指标符合相关标准要求。     

Functional Properties of Protein Products of Mass Cultivated Blue-Green Alga Spirulina Platensia

Water and fat absorption capacity, Emulsification Capacity (EC), Foaming Capacity (FC) and Foaming Stability (FS) of flour and protein concentrate of Spirulina cells were compared with those of soybean meal both as a function of pH and NaCl concentration. Water and fat absorption capacities of Spirulina flour were 220g and 190g/100g of sample respectively; those of soybean meal were 230g and 120g/100g of sample. Protein concentrate had a lower water absorption capacity, higher fat absorption capacity than its flour. It had higher EC and similar FC. Spirulina flour had similar EC and FC to that of soybean meal. The FS of flour (18%) and protein concentrate (27%) was poor when compared to soybean meal (55%).     

马铃薯粉添加量对新疆馕品质特性影响研究

摘 要：探讨马铃薯粉添加量对新疆馕品质特性的影响。面粉中添加不同比例（0%-50%）的马铃薯粉成混合粉,测定混合粉粉质特性、面团拉伸特性、产气能力、及制备马铃薯馕制品挂壁率、质构特性及感官评价值。随着马铃薯粉添加量的增加,混合粉吸水率增高,弱化度增高;马铃薯粉添加量10%以上,会使面团加工性能下降。但随着和面时间增加,面团阻力增大。马铃薯粉添加量35%以上,会导致面团醒发体积迅速减小。马铃薯粉添加量45%以上,马铃薯馕会出现无法挂壁或脱壁滑落现象。马铃薯粉添加量5%以上,馕边硬度显著下降。马铃薯粉添加量15%以上,会降低酥脆口感。但20%以上,馕风味值下降。马铃薯粉的添加对混合粉的粉质、面团拉伸特性、产气能力及馕制品的挂壁率、质构、感官评价值均有不同程度的影响。     

Use of Mucor miehei lipase to improve functional properties of yolk-contaminated egg whites

Egg yolk contamination of egg whites continues to be a serious problem in the egg industry. The ability of egg whites to form stable and voluminous foams is greatly inhibited by yolk contamination, even at very low levels, between 0.01% and 0.2% w/w yolk in white. Experiments were conducted to determine if Mucor miehei lipase could regenerate the functional properties of yolk-contaminated egg whites. Lipase from M. miehei and colipase from porcine pancreas were added to yolk-contaminated (0.2%, w/w) egg white samples to hydrolyze triglycerides originating from egg yolk. Enzymatic hydrolysis of triacylglycerols was confirmed using thin-layer chromatography. Treatment of yolk-contaminated samples with lipase and colipase yielded significant (P < 0.05) improvements in a number of the functional properties, including the final foam volume, foam capacity, and foaming power. These functional properties showed complete restoration to control levels. However, foam stability and foam drainage levels were not statistically different from yolk-contaminated samples that had not been enzymatically treated. Enzyme-treated yolk-contaminated egg whites were also tested in angel food cakes. Enzyme-treated, yolk-contaminated egg whites performed similarly to non-yolk-contaminated control, and much better than yolk-contaminated sample in angel food cakes. The results show that most negative effects of yolk contamination can be reversed by treatment with Mucor miehei lipase and colipase.     

Composition and functional properties of raw and heat processed velvet bean (Mucuna pruriens (L.) DC. var utilis) flours

Summary The proximate composition and functional properties of raw and heat-processed velvet bean (M ucuna pruriens (L.) DC. var utilis ) flours were studied. The flours were prepared by soaking raw beans for 14 h, boiling for 30 min (heat-processed), manual dehulling, oven-drying (65 °C) and milling. The heat-processed flour contained 6.8% moisture, 24.3% protein, 4.9% fat, 1.3% crude fibre, 3.5% ash and 61.2% carbohydrate. The flour was rich in potassium (125 mg/100 g), zinc (9.8 mg/100 g) and phosphorus (361 mg/100 g). Differences in proximate and mineral composition of raw and heat-processed flours were not significant. The flours showed minimum protein solubility at pH 4.5 and formed reasonably stable emulsions and foams. Compared to raw flour, heat-processed flour had better water and fat absorption capacities, but lower protein solubility, emulsion and foam capacities. The flours have potential for food product development.     

Functional Properties of Chitin and Chitosan

Chitin (poly-β (1?4)-N-acetyl-D-glucosamine), chitosan (deacetylated chitin) and microcrystalline chitin (redispersible chitin powder) were compared with microcrystalline cellulose to examine the use of those cellulose-like biopolymers as functional additives for potential application in food formulations. Water binding, fat binding and emulsifying properties were studied. Baking tests were performed with 0.5–2.0% (flour basis) of microcrystalline chitin added to wheat flour bread or to potato protein fortified (8% potato protein concentrate) white bread. Water-binding capacity and fat binding capacity of chitin, chitosan and microcrystalline chitin ranged from 230–440s (w/w) and from 170–315% (w/w). Chitosan and chitin did not produce emulsions but microcrystalline chitin showed good emulsifying properties and was superior to microcrystalline cellulose. Increasing concentration of microcrystalline chitin (0.12–0.8 g/100 ml water) had a positive effect on emulsion stability. Addition of microcrystalline chitin increased specific loaf volume of white bread and protein fortified breads. Water addition of 65% (flour basis) was found to be optimum for “chitin breads.”     

Influence of selected factors on functional properties of textured milk proteins

Studies were made on the influence of two variable factors—fat content and added salt—on the following functional properties of textured milk proteins: water absorption capacity, thermal shrinkage, consistency, viscosity, fat absorption, emulsifying capacity and emulsion stability.
Variation in fat content of the product (11% and 15%) was obtained by introducing various amounts of fat to skim milk in the course of the production of textured milk proteins. The salt concentration of the preparation was modified by adding sodium chloride, Hamine polyphosphate mixture or both those salts jointly.
The results indicate that the functional properties of the preparation were influenced by the two above mentioned factors in a statistically significant manner. The higher fat content of the product (15%) was accompanied by better fat emulsifying capacity and emulsion stability and lower thermal shrinkage. The salts used for these studies were found to influence favourably the functional characteristics of the preparation. The addition of sodium chloride appears to be most expedient, as it improves important technological properties such as fat absorption and emulsifying capacities.     

Chemical composition and functional properties of raw and roasted Nigerian benniseed (Sesamum indicum) and bambara groundnut (Vigna subterranean)

Benniseed and bambara groundnut seeds were roasted at 80 and 120 °C for 10–60 min. For both flours, the effects of roasting temperature and time on selected functional properties and chemical composition were determined, as were the effects of pH on the emulsification capacity and nitrogen solubility. The chemical constituents of the raw flours were present at higher concentrations than those of the roasted flours except for fat and ash. Protein concentrates of both flours contained 80.5–81.5% crude protein as the major constituent. Nitrogen solubility was lowest at pH 4.0 for raw and roasted benniseed flour and pH 5.0 for raw and roasted bambara groundnut flour. Roasting generally lowered the nitrogen solubility and increased the water and oil absorption capacities while decreasing the foaming capacity and emulsification capacity of both flours.