Impact of salted duck egg albumen powder on proteolysis and gelling properties of sardine surimi

The influences of salted duck egg albumen powder (SDEAP) as salt replacer at various levels (0.5–2.5%) on autolysis and gelling properties of sardine surimi were investigated. SDEAP had high salt (33.67%) and protein contents (64.52%) with trypsin inhibitory activity of 5,975 kunits/g solid. SDEAP was white in color with L*‐value of 96.72. It had low moisture content (3.98%) and water activity (0.38). Autolysis of sardine surimi was drastically inhibited when SDEAP was incorporated with increasing levels as indicated by the more retained myosin heavy chain and the reduced trichloroacetic acid‐soluble peptide content. Breaking force and deformation of surimi gel increased, while expressible moisture content decreased as the levels of SDEAP added were increased (p < .05). Gumminess, hardness, chewiness, springiness, and cohesiveness of surimi gels also increased as SDEAP levels increased (p < .05). Lightness and whiteness were higher in all surimi gels incorporated with SDEAP than the control (p < .05). For microstructure, surimi gels incorporated with SDEAP at all levels used had finer gel network with smaller voids and more connectivity than the control gel. Thus, SDEAP could be used as a salt replacer for sardine surimi gel preparation and it could improve the properties of resulting gel.     

Color,Mechanical, and Microstructural Properties of Vacuum Assisted Microwave Dried Saskatoon Berries

Saskatoon berries were dried using a vacuum assisted microwave technique. Central composite rotate design and response surface methodology were used to develop the regression models and to study the influence of drying processing variables (microwave power, drying time, and fruit load) on color, mechanical properties, and microstructure of dried berries. All the three variables had significant effects on the above mentioned properties (p< 0.05). Drying affected the color at variable levels and increased the lightness of dried berries compared to frozen berries. Hardness, gumminess, and chewiness of dried berries increased and springiness and cohesiveness of dried berries decreased with microwave power and drying time. The porosity and the destruction level in the microstructure of dried berries increased with the microwave power. The findings of this study will be useful to identify desirable microwave-vacuum drying operating conditions for targeted dried Saskatoon berry products.     

The significance of critical processing steps in the production of dried egg albumen powder on gel textural and foaming properties

The purpose of the present work was to study the variation in egg albumen functional properties as a function of seven selected processing steps from the initially raw liquid albumen to the final dried egg albumen powder. Albumen samples in six replicates were analysed for dry matter, pH, glucose, triglycerides, albumen gel properties (ie textural stress and Hencky strain, water‐ and protein‐binding capacity and gel colour L*, a*, b*), foaming properties (ie overrun, stability against drainage and bubble breakdown) and surface tension. The gel texture and water‐holding capacity significantly decreased during the processing steps from raw albumen through storage, centrifugation and ion exchange, whereas the final dry‐pasteurisation resulted in increased gel properties. Covalently linked protein polymers formed during the dry‐pasteurisation, as revealed by SDS‐PAGE, may explain this improvement. The foam overrun increased twofold during the three final steps of ultrafiltration, spray‐drying and dry‐pasteurisation compared with the raw albumen; however, the foam stability decreased, ie drainage and foam volume breakdown rates increased. The surface pressure increase was positively correlated with the foam overrun. This paper reveals at which processing steps the control of functional properties of egg albumen powder can take place. Copyright © 2004 Society of Chemical Industry     

Effect of furcellaran incorporation on gel properties of sardine surimi

Effects of furcellaran, powder (FURP) and solution (FURS), incorporation (2-8% based on surimi solid content) on gel properties of sardine (Sardinella albella) surimi were investigated. Breaking force, hardness, gumminess, chewiness, and whiteness of gels increased with increasing FURP or FURS contents (P < 0.05), where the highest values were observed in gel containing 8% FURS (P < 0.05). Expressible moisture content of gel decreased as levels of furcellaran increased (P < 0.05). The gel deformation, springiness, and cohesiveness were not affected by furcellaran (P > 0.05) as well as the polymerization of myosin heavy chain as visualised by SDS-PAGE. FURP and FURS could enhance the interconnection between chains during heating as indicated by the higher G′. Addition of furcellaran, especially FURS, up to 6% increased sensory property of resulting gel (P < 0.05). Anywise, an abatement in overall likeness score was found in gel with 8% FURS. Finer and denser microstructural network was observed in gel containing 6% FURS when compared to control. Therefore, furcellaran, prepared as solution, at an appropriate level can improve the overall quality of sardine surimi.     

Effect of NaCl on physical characteristics and qualities of chicken breast surimi prepared by acid and alkaline processing

We investigated the effect of NaCl on the physical characteristics and qualities of chicken breast surimi prepared by acid (pH 2.5 and pH 3.0) and alkaline (pH 10.5 and pH 11.0) adjustments. Salt addition resulted in increased (p < 0.05) yellowness, but decreased (p < 0.05) lightness and whiteness of surimi, regardless of pH adjustment. Surimi prepared by alkali had the highest (p < 0.001) values of lightness and whiteness. Textural properties except cohesiveness were higher (p < 0.05) in acid-prepared surimi without salt, however, addition of salt caused higher (p < 0.05) springiness, gumminess or gel strength of chicken surimi. Salt addition also caused an increase in the sensory properties. Furthermore, alkali-treated (pH 10.5 or pH 11.0) surimi had higher (p < 0.001) values of all the sensory properties. Therefore, the alkali treatment diminished gumminess and chewiness of texture property, while better color (high lightness or whiteness), gel characteristics and sensory properties were obtained from salt-added surimi. Especially the surimi at pH 10.5 and with salt was better one which had high values of whiteness, springiness and sensory properties among the surimi.     

TEXTURAL PROPERTIES OF RESTRUCTURED BEEF PRODUCTS WITH FIVE BINDERS AT FOUR ISOTHERMAL TEMPERATURES1

Texture profile analysis (TPA) and shear force of restructured beef products with one of five binders (isolated soy protein, sodium caseinate, waxy modified corn starch, carrageenan, and oat flour) were analyzed at 35, 45, 55 and 65 C. Hardness, cohesiveness, springiness, gumminess, and chewiness were significantly affected (p<0.05) by binders, temperatures and their interactions. Hardness and gumminess showed no significant (p<0.05) differences among binders and temperatures below 45C, but each increased between 45 – 65C. Isolated soy protein gave the highest hardness and gumminess values; oat flour, the lowest at 55 and 65C. Except for oat flour, cohesiveness, springiness and chewiness decreased from the raw state until 45C, and then increased. Oat flour gave the highest values for cohesiveness, springiness and chewiness < 45C; the lowest at 55 and 65C. Oat flour gave the lowest shear force (N) values at 55 and 65C. Conclusions were reached that the influence of these binders on the textural parameters of restructured beef products was temperature-dependent.     

Physicochemical,cooking and textural characteristics of some Indian black gram (Phaseolus mungo L) varieties

Physicochemical, cooking and textural properties of black gram varieties were studied and related to each other using Pearson correlation. Different varieties showed significant variation in their physicochemical, cooking and textural properties. Varieties having higher seed weight and seed volume had higher values of cooking time, swelling capacity, hydration capacity and hardness. The relationships between textural parameters of cooked grains from different black gram varieties showed a significant positive correlation of hardness with cohesiveness (r = 0.472), gumminess (r = 0.938) and chewiness (r = 0.859). Swelling index, cohesiveness and gumminess of black gram varieties were observed to be related to their fibre content. Swelling capacity and swelling index correlated well with cooking time, hardness and gumminess. Cooking time had a positive correlation with hardness (p < 0.05) and gumminess (p < 0.05) and a negative correlation with springiness. Copyright © 2004 Society of Chemical Industry     

Physical and chemical characteristics of Asian sea bass bio-calcium powders as affected by ultrasonication treatment and drying method

The effects of ultrasonication and drying method on particle size and other product characteristics of bio-calcium powder from Asian sea bass (Lates calcarifer) backbone were investigated. Ultrasonication was performed at different amplitudes (60%, 70%, and 80%) for varying periods (15 and 30 min). Ultrasonication at higher amplitudes for a longer time reduced the powder particle size more effectively (p < .05), but had no impact on zeta potential (p > .05). The bio-calcium powder ultrasonicated at 70% amplitude for 15 min had the smallest particle size (3.38 µm) when compared to the control (28.85 µm). When the ultrasonicated bio-calcium was subjected to drying, freeze-drying produced powders with higher calcium solubility but lower whiteness than hot air (tray) drying. The results suggest that the ultrasonication is a potential suitable method to reduce the size of bio-calcium powders, while the drying method slightly affected the product characteristics. The bio-calcium powder could serve as a suitable functional ingredient for food fortification aimed at improving the calcium bioavailability. Particle size of bio-calcium powder from fishbone could affect the mouth feel and calcium solubility when used for food product fortification. This work showed that ultrasonication could be used to obtain up to 10-fold reduction in the particle size of fishbone bio-calcium powders, which promotes increased calcium solubility when subjected to simulated gastrointestinal tract digestion. Few differences in characteristics of the bio-calcium powder were observed for freeze-dried and hot air-dried samples. Thus, an economical, safe, and fast process can be implemented for the production of small particle size bio-calcium powder from fishbone.     

Chemical and microbial evaluation of Egyptian dried egg white prepared by different techniques

Egg white was dehydrated (pan drying, spray drying) without and with glucose removal (using bacteria, yeast and enzyme). Although, moisture, protein and ether extract percentage in spray dried samples were, in general, in the same range as the imported Swiss made spray dried sample (as standard), yet the least moisture percentage was found in samples in which sugar was removed by yeast. The standard sample had the best solubility (99.79%). followed by the spray dried sample desugarized by yeast (99.67%). Samples in which Streptococcus lactis was used gave the highest percentage of insoluble matter (4.24%). Pan dried and spray dried samples were similar in solubility. The total microbial counts were found to decrease in egg white after drying (max. 4.9 × 10 org. in prepared samples, zero in the standard). Salmonella was absent in all dried samples. There are variations in the type of protein fractions of liquid egg white when the enzyme treatment or controlled bacterial fermentation were used. When yeast fermentation was used a decrease in some protein fractions was noticed in comparison with the nondesugarized sample. The dehydrated egg white proteins indicate that there was no difference between the different techniques applied for glucose removal, between drying methods and between prepared samples and imported one; 5 fractions were obtained in each sample.     

日粮中添加不同油脂对鸡蛋工艺特性及质构指标的影响

摘 要：目的 本试验旨在探究蛋鸡饲粮添加不同油脂后对鸡蛋起泡性、乳化性、凝胶特性及蛋黄TPA、剪切力及蛋黄膜强度的影响。方法 在玉米-豆粕型基础日粮的基础上,分别添加1.5％豆油、1.5％猪油、1.5％混合油脂。结果 试验结果表明：与对照组相比,添加1.5％的猪油和混合油脂会不同程度的降低鸡蛋的工艺特性,显著增加蛋黄的硬度、咀嚼性;而1.5％豆油对鸡蛋的工艺特性及质构指标不会造成不良影响。结论 因此,为了满足蛋鸡生长能量需求及蛋品功能特性,建议在日粮中添加1.5％豆油。     

基于模糊数学感官评价法研究黄花菜粉添加量对牛肉丸品质的影响

为了改善传统牛肉丸的食用品质,将黄花菜粉添加到牛肉糜中,采用模糊数学感官评价法分析不同黄花菜粉添加量(5%、10%、15%、20%、25%,质量分数)对牛肉丸流变性质、质构特性、凝胶强度、蒸煮损失率、持水性和色泽的影响。结果表明:随着黄花菜粉添加量的增加,牛肉丸蒸煮损失率先降低后上升,在添加的质量分数为20%时最低;牛肉丸的持水性、凝胶强度、硬度、胶黏性、咀嚼性均升高,且硬度上升效果更为明显,弹性和回复性无显著变化;添加黄花菜粉能显著改善牛肉丸的色泽,随黄花菜粉添加量的增加,牛肉丸的L*值和a*值呈下降趋势,b*值升高;当添加的质量分数为20%时,牛肉丸的感官评分最高。添加黄花菜粉可以改善牛肉丸的品质。     

Effect of l-lysine on the physicochemical properties of pork sausage

Effects of l-lysine on physicochemical properties of pork sausage were investigated. WHC values significantly increased using 0.8% l-lysine, but significantly decreased at 0.4% l-lysine (p<0.05), compared with controls. l-Lysine increased pH values and a* values, but significantly decreased CL, cohesiveness, L* values, and b* values (p<0.05), compared with controls. Addition of 0.4% l-lysine significantly (p<0.05) increased hardness, springiness, and chewiness values, compared with controls. SEM analysis showed that addition of 0.8% l-lysine induced formation of a smoother, more compact, and more uniform gel matrix, compared with controls. DSC analysis indicated that addition of 0.8% l-lysine significantly (p<0.05) increased thermal transition temperatures and enthalphy values, compared with controls, showing that interactions between l-lysine and myofibrillar proteins affected the properties of pork sausages.     

Effects of gamma-ray,electron-beam,and X-ray irradiation on physicochemical properties of heat-induced gel prepared with salt-soluble pork protein

The objective of this study was to investigate the physicochemical and textural properties of heat-induced gels prepared with pork muscles irradiated with gamma rays, electron beams, and X-rays. Pork muscles were irradiated at 5 kGy using the different irradiation sources, and heat-induced gels were prepared from the irradiated pork muscles at a protein concentration of 5 mg/mL. Each irradiation treatment produced lower water-holding capacity, protein solubility, apparent viscosity, hardness, springiness, cohesiveness, gumminess, and chewiness than the control gel prepared with non-irradiated pork muscle (P < 0.05). In addition, gamma irradiation was more influential than electron or X-ray irradiation on the negative impacts on water-holding capacity and texture of heat-induced gels. Therefore, this study suggests that the irradiation source could be one of the significant factors affecting gelling properties of irradiated meat.     

Microencapsulation of Corn Wastewater (Nejayote) Phytochemicals by Spray Drying and Their Release Under Simulated Gastrointestinal Digestion

Corn lime cooking generates a large amount of wastewater known as nejayote that is composed of suspended solids and solubilized phytochemicals. Spray drying can be an alternative to recover bioactive molecules, such as ferulic acid, from nejayote. Besides the yield, the physicochemical properties (solubility, water activity, pH, moisture, hygroscopicity, total phenolic content, and distribution of free and bound hydroxycinnamic acids) of spray‐dried nejayote powders were analyzed. The powders were obtained at 200 °C/100 °C or 150 °C/75 °C (inlet/outlet) air temperatures with the addition of maltodextrin (MD) or 2‐hydroxypropyl‐beta‐cyclodextrin (HBCD) as encapsulating agents. Even when no carrier agent was used, a spray‐dried nejayote powder was produced. The use of MD or HBCD as carrier increased the yield from 60.26% to 68.09% or 71.83%, respectively. As expected, a high inlet temperature (200 °C) allowed a satisfactory yield (>70%) and a low powder moisture (2.5%) desired by the industry. Water activity was reduced from 0.586 to 0.307 when HBCD was used in combination with a drying inlet temperature of 150 °C; and from 0.488 to 0.280 when the inlet temperature was set at 200 °C. Around 100% bioaccessibility of the compounds was observed after in vitro digestion. The addition of HBCD increased the release time (P < 0.05). Under simulated physiological conditions, there was no reduction of total phenolics, suggesting a good stability. This paper showed the feasibility to engage the spray drying technology to the corn industry to minimize their residues and reuse their by‐products.     

Texture and color characteristics of swell-dried ready-to-eat Zaghloul date snacks: Effect of operative parameters of instant controlled pressure drop process

In this work, development of ready-to-eat snacks from Zaghloul date using swell-drying process was studied. Pre-dried Zaghloul date samples having 12% water content on dry basis were textured by instant controlled pressure drop technique (DIC) at different operative parameters, saturated steam pressure (p) and processing time (t), ranged from 0.2 to 0.6 MPa and from 9 to 35 s, respectively. The effect of these operative parameters on texture, color, and sensory characteristics of swell-dried (SD) Zaghloul date snacks were determined and optimized through the response surface methodology. Textural (expansion ratio, hardness, springiness, cohesiveness, and chewiness) and color (L*, a*, b*, C*, and ΔE*) characteristics were significantly affected by the operative parameters of DIC. The optimized textural characteristics was identified for SD Zaghloul date at p = 0.6 MPa and t = 22 s with slight yellowness, while the best color properties were observed for texturing conditions of p = 0.2 MPa and t = 22 s. The expansion ratio ε_r was then 46% higher and the hardness was 262% lower for SD than airflow-dried date. Instrumental analysis such as texture profile analysis and Hunter's Lab color analyzer could be used to describe the texture and color changes occurred during food drying. Beside these analyses, the expansion ratio could be used to describe the texture as well. Swell-drying process, an alternative drying process, is defined as DIC-assisted hot air drying. The thermo-mechanical effects of DIC are mainly induced by the abrupt pressure drop toward a vacuum after short-time treatment (9–35 s) by saturated steam pressure (0.2 up to 0.6 MPa). The abrupt pressure drop rate induces an autovaporization of product's water immediately decreasing the product's temperature allowing it to cross the glass transition Tg border. The impact of DIC operative parameters on Zaghloul date could be observed through the expansion ratio, and the textural characteristics (hardness HA, springiness SP, cohesiveness CO, and chewiness CH).     

The effect of par‐baking and frozen storage time on the quality of cup cake

The effects of frozen storage and initial baking time of par‐baked cake on baking loss, volume, moisture, colour and textural properties of cake obtained after thawing and rebaking were investigated. Cakes, par‐baked at 175 °C for 15, 20 and 25 min, were stored at ?18 °C for 3, 6 and 9 months. After storage, par‐baked cakes were thawed and rebaked at 175 °C for 10, 15 and 20 min. Baking loss, moisture content, L and +b colour values, firmness, gumminess and chewiness of the resulting full‐baked cakes were significantly affected by both par‐baking and frozen storage time, while specific volume, cohesiveness, springiness and resilience values were significantly affected by frozen storage time. The increase in the time of frozen storage of the par‐baked cake leads to a decrease in the quality of the rebaked cake, namely an increase of baking loss and cake crumb firmness, and a loss in the moisture content and specific volume. Moisture of cake crumb, L and +b colour values, firmness, gumminess and chewiness significantly increased as the par‐baking time increased. However, regarding baking loss, specific volume, moisture content and textural properties, 3‐month intermediate storage at ?18 °C and 20‐min initial baking time gave the best result among the cakes produced by using the two‐step baking procedure.     

腌制过程中添加木瓜蛋白酶对猪肉糜的影响

猪肉糜腌制过程中添加木瓜蛋白酶,测定其对猪肉糜品质的影响。结果表明,添加木瓜蛋白酶腌制,随酶添加量的增加,肉糜水溶性总氮含量及氨氮含量显著升高(p<0.05);水分活度没有显著性变化(p>0.05);pH呈显著下降趋势(p<0.05);CIEL*,CIEa*,CIEb*均显著升高(p<0.05),当酶添加量增加到一定程度时,呈平缓趋势;肉糜硬度、胶性、咀嚼性随酶添加量的增加均呈现显著降低趋势(p<0.01),凝聚性、黏着性呈显著升高趋势(p<0.05),弹性没有显著性变化(p>0.05)。色差值、TPA(Texture Profile Analysis)质构、氨氮、pH之间的变化均具有良好的相关性(p<0.01)。通过对肉糜加酶腌制工艺的研究,可为肉糜类制品的加工提供一定理论依据和方法指导。      

Evaluation of spray drying conditions on properties of microencapsulated oregano essential oil

Response surface methodology (RSM) was employed to investigate variations in powder characteristics with respect to spray drying operating parameters including both feed rates (L min^?1) and inlet temperatures (°C). Inlet temperatures around 180 °C provided the lowest values for moisture. Powder recovery was significantly affected (P < 0.10) by inlet air temperature and feed rate, where a raise in inlet temperature and feed rate resulted in higher powder recovery. No significant difference (P > 0.05) was observed for water activity, solubility and hygroscopicity between treatments. Regarding oil retention, the results showed a significant (P < 0.05) interaction between the two studied factors. A tendency for higher values of oil retention was observed when using combinations of high inlet temperatures/low feed rates and low inlet temperatures/high feed rates. Particle size distribution averaged 2.0, 8.1 and 18.3 μm for D₁₀, D₅₀ and D₉₀, respectively. The morphology of particles showed no cracks in most capsules. The results indicate that high temperature (185 °C) and moderated feed rate (0.63 L min^?1) are the best spray drying conditions.     

The effect of whitening agents on the gel-forming ability and whiteness of surimi

The effect of different concentrations of the whitening agents, calcium carbonate, titanium dioxide and soybean oil, on the gel‐forming ability and whiteness of a mixture of bigeye snapper and mackerel surimi was investigated. The whiteness of the surimi gels increased as the concentration of all whitening agents increased (P < 0.05). Titanium dioxide was a good whitening agent and it had no detrimental effects on gel‐forming ability, while oil reduced the gel breaking force and deformation. The addition of calcium carbonate did not result in a marked increase in whiteness, but it did increase the breaking force and deformation to some extent. The different whitening agents showed different influences on the whiteness and gelling characteristics of surimi gel.     

不同干燥方法对南美白对虾品质的影响

干燥方法对南美白对虾品质具有重要影响。本文研究了热风干燥、冷风干燥、微波真空干燥3种干燥方法对南美白对虾色泽、虾青素含量、组织结构、质构和感官质量的影响。结果发现:干燥后L*下降,其大小依次为微波真空干燥>冷风干燥>热风干燥;虾青素含量降低,微波真空干燥产品虾青素含量最高,为77.5μg/g;热风干燥后肌纤维断裂严重,而冷风干燥和微波真空干燥产品肌纤维结构较为完整;干燥后南美白对虾硬度、胶着性、咀嚼性提高,其中微波真空干燥产品增加最为显著;感官方面,微波真空干燥产品口感风味更好。综合来看,微波真空干燥方法较为理想。