江苏富士苹果的理化及感官特性分析

江苏省苹果以丰县为集中产地,富士为主栽品种,隶属于黄河故道产区,为明确其鲜食特性的地域特点,对丰县富士糖酸含量、色泽和质构等理化指标和硬性、易碎性、多汁性、酸甜度等感官属性进行了测定,并与陕西富士进行了比较。结果显示丰县苹果蔗糖和苹果酸含量偏低,分别为陕西苹果的75.88%和58.90%。江苏苹果果皮L*为64.37,a*值为11.19,b*值为32.12,a*值低而L*、b*值高于陕西苹果,说明果皮红色弱而偏黄色;果肉L*值为81.19,b*值为29.00,L*值低而b*值高于陕西苹果,说明果肉色泽偏黄。质构仪测得江苏苹果的脆度显著高于陕西苹果。感官评价结果显示江苏苹果具有硬性低、易碎、易嚼、酸度低的特点,而多汁性和甜度差异不显著。在偏爱性比较中,73.7%的评价人员偏爱陕西苹果的色泽,而对滋味和质地的偏爱程度差异不显著。研究结果将为江苏富士品质评价提供借鉴。     

Surimi-Derived Elver Substitutes: Microscopic Appearance and Physicochemical and Sensory Properties

ABSTRACT: Elver substitutes made from kamaboko-type fish gels have recently been introduced onto the market in Spain. Kamaboko is made by addition of 2.5 to 3.0% salt, and optionally other additives, to surimi (minced fish). The present study investigated the usefulness of microscopy techniques for characterizing the structure and composition of two elver substitutes of this type. Sensory and physicochemical analyses were also performed, with the aim of defining the organoleptic characteristics of these products. The results obtained indicate that microscopy techniques are useful for rapid identification of certain additives in products of this type. Furthermore, many of the between-brand differences in microscopic appearance showed clear correspondence with differences in physicochemical and sensory properties.     

Bulgur Quality as Affected by Drying Methods

ABSTRACT: Solar-drying and microwave-drying methods significantly affected the bulk density of bulgur samples in our study. The pilaf bulgur yield was highest for solar-dried bulgur, followed by microwave-, tray-, and sun-dried bulgur samples, respectively. The drying method affected protein extractability, bulgur yield, and water and oil absorption values of bulgur. The lightness (L) value was found significantly higher for solar-, sun-, and microwave-dried pilav bulgur samples compared with tray-dried bulgur. The redness (a) and yellowness (b) values of bulgur were also affected by drying methods. The drying method had no significant effect on flavor, mouthfeel, and appearance of bulgur samples.     

基于模糊感官评价的大豆品种对豆浆加工品质影响分析

以黑龙江产区6?个大豆品种为原料,测定了大豆籽粒的百粒质量和粗蛋白质、粗脂肪、钙、磷水平等理化指标以及加工制成豆浆的得率、理化品质,并基于模糊感官评价方法分析了不同品种大豆的豆浆感官品质,进一步分析了大豆籽粒与豆浆理化指标和感官品质之间的相关性。结果表明：6?个大豆品种中‘中龙606’制得的豆浆综合感官品质最佳,且具有甜度高、豆香味浓郁、色泽良好、豆腥味和涩感相对较弱的特点;在现有的品种中蛋白质量分数低于40%,且脂肪质量分数较高的品种更有利于加工高品质豆浆。     

普通法焦糖色存储特性的研究

焦糖色在食用色素领域占有重要地位,因为普通法焦糖色具有高安全性,正日渐成为当下研究的热点。本文以普通法焦糖色为对象,探究了保温时间、样品浓度、热处理等因素对其理化性质的影响,试验结果显示:保温时间越长,p H越低且下降幅度越小,并最终趋于平衡;色率随保温时间的延长呈先增后减的趋势,120 min后基本稳定;红色指数、黄色指数随保温时间的延长呈先减后增的趋势,120 min后保持稳定;色率、红色指数、黄色指数的热处理前后变化基本遵循随保温时间延长变化值增加的趋势,保温超过90 min,变化值接近;样品制备终止后,保温促进物质的后续反应,促使物质稳定,利于各指标的稳定;样品浓度影响焦糖色的稳定性,高浓度焦糖色抑制物质的传递,因此稳定性更高。     

Physicochemical and Sensory Evaluation of 'Rocha' Pear Following Controlled Atmosphere Storage

ABSTRACT: The effects of several processing factors (storage time, time in the open air at room temperature, and overhead concentrations of O₂ and CO₂) on color, firmness, polyphenol oxidase (PPO) activity, and sensory attributes of pears (cv. Rocha) grown in 2 locations were studied using a multiple linear regression model. Backward elimination (F ≥ 0.005) was used to assess the significant factors. Extended storage time, long‐time exposure at room temperature, and high O₂ concentration played major roles on color changes assessed instrumentally and further confirmed by a sensory panel. Firmness was strongly affected by storage time and by time in the open air at room temperature. Finally, PPO activity was dependent on the growing location.     

不同贮藏条件下牛肉的理化性质及感官品质的对比分析

为分析牛肉在不同包装方式与贮藏温度下理化性质及感官品质的变化,该试验将牛肉背最长肌分别采用空气包装(air-packaging,AP)、真空包装(vacuum packaging,VP)和气调包装(modified atmosphere packaging,MAP),其中MAP包括两种气体比例:MAP1为78.8％O2...     

大足黑山羊宰后成熟过程中感官与理化性质的变化

本实验以大足黑山羊后腿肉股四头肌为实验材料,测定其在成熟过程中的感官及理化指标（滴水损失、色泽、剪切值、蒸煮损失、pH值、糖原含量、肌原纤维小片化指数（myofibrillar fragmentation index,MFI）、挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量和硫代巴比妥酸（thiobarbituric acid reactive substances,TBARS）值）的变化。结果表明：滴水损失、pH值、糖原含量、TBARS值等发生明显变化,并且主要变化在宰后前72 h内基本完成,而滴水损失、pH值在24 h后变化不显著（P＞0.05）;MFI值在成熟24 h后变化差异显著（P＜0.05）;TVB-N含量在0～72 h时,符合一级鲜肉的标准。羊肉的成熟时间依感官、色泽、pH值、TBARS值等指标的变化判断,以72 h为宜;从TVB-N含量的变化看,成熟时间应小于72 h。综合考虑,确定大足黑山羊的最佳成熟时间为72 h。     

改性水解明胶的理化性质分析——热力学和流变学性质

本实验对改性水解明胶的流变学性质、热力学性质进行了研究。结果表明,相对于水解明胶而言,改性水解明胶的变性温度范围较窄,焓变升高。改性水解明胶溶液的黏度随浓度的升高而升高,但是改性水解明胶在质量浓度为30%时还具有较好的流动性。温度对改性水解明胶溶液黏度的影响很大,黏度与温度的关系符合Arrhenius模型lgη=lgA＋Ea/2.303RT。在剪切速率较低的范围内,溶液呈现一种剪切变稀的假塑性流体状态。在剪切速率高于30Pa·s时,呈现牛顿流体的状态。     

Nutritional, Sensory, and Physicochemical Properties of Vitamin E- and Mineral-fortified Fresh-cut Apples by Use of Vacuum Impregnation

ABSTRACT: This study evaluated fresh-cut apples (Fuji) fortified with vitamin E and minerals by use of the vacuum impregnation (VI) technique. A 20% diluted high fructose corn syrup (HFCS) or 1% calcium caseinate (CC) aqueous solution were used as VI solutions, and 0.4% a-tocopherol acetate, 7.5% Gluconal Cal° (GC), and 0.04% zinc lactate (ZL) were incorporated into the VI solutions for the purpose of nutritional fortification. For VI treatment, fresh-cut apples were immersed in VI solutions subjected to vacuum at 100 mm Hg for 15 min following atmospheric restoration for 30 min. Apples were packed in the polyvinyl chloride (PVC) hinged clear containers and stored at 2 °C and 88% RH up to 3 wk. Nutritional contents, consumer sensory acceptability, microbial population, color, and firmness of the apples were evaluated during cold storage. In 100 g of fresh-cut apples, vitamin E content increased more than 100 times, and calcium and zinc contents increased about 20 times compared with unfortified apples. Consumer sensory study demonstrated that HFCS-treated apples were highly accepted by consumers in respect to overall liking, color, and texture quality. Bacterial growth was concurrently detected in all apples, but the total plate accounts were under 2.6 log colony-forming units (CFU)/ g apple at the end of 7 d of storage, significantly lower than the industrial standard. Instrumental analysis indicated that VI treatment in both HFCS and CC solutions significantly decreased color change and retained the firmness of fresh-cut apples during 3 wk of cold storage.     

黄秋葵果胶理化特性的研究

以商品柑橘果胶为对照,研究黄秋葵果胶的理化特性及果胶质量浓度、加热温度、pH值、蔗糖质量浓度和CaCl2质量浓度等因素对黄秋葵果胶黏度的影响。结果表明：黄秋葵果胶总半乳糖醛酸含量为86.68%,酯化度为75.45%,溶解度为82%,pH值为4.63,属于弱酸性高酯果胶;黄秋葵果胶的黏度随着加热时间的延长而下降,但其热稳定性优于商品柑橘果胶;黄秋葵果胶的黏度与其质量浓度、蔗糖质量浓度均成正相关,与加热温度成负相关,而随pH值、CaCl2质量浓度的增大呈先上升后下降的趋势,表现出一般果胶的黏度特性。黄秋葵果胶的黏度及热稳定性能优于商品柑橘果胶,是一种优质果胶。     

不同种类活性短肽的理化与功能特性比较

比较了大米肽、大豆肽、小麦肽、白蛋白肽、花生肽、山药肽、玉米肽、海洋胶原蛋白肽和乳清肽在不同p H值和钠离子强度条件下的乳化活性、乳化稳定性、溶解性、起泡性及泡沫稳定性。结果表明:碱性条件下各活性短肽的乳化活性、乳化稳定性、溶解性、起泡性均优于酸性条件下的,但其泡沫稳定性差异不明显;随着钠离子强度的增强,各活性短肽的起泡性增强,乳化活性、乳化稳定性及溶解性降低,但其泡沫稳定性变化不明显;在相同p H值条件下,乳清肽、玉米肽、大豆肽和花生肽的乳化活性、乳化稳定性、起泡性及泡沫稳定性优于大米肽、小麦肽、白蛋白肽、山药肽和海洋胶原蛋白肽;在相同的钠离子强度条件下,乳清肽、玉米肽、大豆肽、海洋胶原蛋白肽和花生肽的乳化稳定性优于大米肽、小麦肽、白蛋白肽和山药肽,乳清肽和大豆肽的乳化活性、起泡性和泡沫稳定性优于其他7种短肽。不同种类活性短肽上述理化特性差异与其氨基酸组成和分子质量大小密切相关,应根据其特性差异进行选择性应用。     

The Physicochemical Quality Characteristics of Charcoal Grilled Mackerels

ABSTRACT: :
The effects of different fuel sources used in grilling on the physicochemical and sensory characteristics of mackerel were investigated. Oak and sawdust charcoals were used as fuel sources. The content of saturated fatty acids was increased during grilling. Histidine was the most predominant amino acid; grilling significantly increased glutamic acid. Mackerel shows a high inosine 5'-monophosphate content that is increased during grilling. Oak charcoal and sawdust charcoal contained high levels of potassium and sodium, respectively. Potassium content was increased at the surface muscle of oak charcoal grilled mackerel (OM). The flavor preference for OM was significantly (p < 0.05%) higher than for sawdust charcoal grilled mackerel. These results indicate that physicochemical and sensory properties of grilled foods can be affected by the fuel source.     

分级糌粑粉的理化性质及风味特性研究

以熟青稞为原料,采用分层碾磨的方法制备不同品质特性的分级糌粑粉,研究了分级粉的理化性质、糊化特性及感官特征。结果表明:随着碾磨程度由外层至内层,分级粉的粗纤维、蛋白质、脂肪、灰分含量降低,淀粉和β-葡聚糖含量增加;分级粉初始及最终黏度增大;气相色谱总峰面积下降,"糌粑谷味"和"生青稞谷味"特征峰面积下降;进一步进行感官评价,分级粉的外观及口感分值增加、风味分值降低。本研究表明,经分层碾磨获得的分级糌粑粉的理化性质、糊化特性及风味特征差异较大。本研究为糌粑粉的加工提供了依据。     

韧化处理对大米淀粉性质的影响

为韧化处理在大米淀粉改性中的应用提供理论依据,作者以余赤早籼米为原料,在不同温度（50～70℃）和水分质量分数（45%～65%）条件下对大米进行韧化处理,然后提取韧化处理后大米中的淀粉,以未经韧化处理提取的大米淀粉为对照,研究韧化处理对大米淀粉溶解度、膨润力、糊化特性、消化特性和冻融稳定性的影响。研究结果表明：与对照组相比,经韧化处理的大米淀粉溶解度和膨润力降低;峰值黏度、最终黏度、谷值黏度、回生值和衰减值均有所降低,糊化温度升高,不同韧化处理温度对衰减值的影响差异显著;淀粉中RDS（快消化淀粉）质量分数升高,RS（抗性淀粉）质量分数减少,SDS（慢消化淀粉）质量分数随着韧化处理条件的不同而不同,说明韧化处理提高了大米淀粉的消化性,也使大米淀粉冻融稳定性下降。     

10种淀粉的理化特性研究

通过对10种植物淀粉糊透明度、凝沉性、冻融性、流变性的理化特性研究,结果表明:薯类淀粉相对于其他类的淀粉糊具有更高的透明性、较低的凝沉比和黏度。加糖加盐对不同淀粉糊有不同的凝沉作用。相对于其他淀粉,玉米、糯米、高粱和小麦淀粉的析水率较低,有较好的冻融性。高粱淀粉、绿豆淀粉,马铃薯淀粉、藕粉淀粉、木薯淀粉黏度均随着剪切速率的增加而明显剪切稀化,呈典型的假塑性流体特性和具有触变性。高粱淀粉、绿豆淀粉有较高的黏性。高粱、小麦、糯米淀粉糊不耐酸性,而红薯、马铃薯、绿豆、藕粉、木薯淀粉糊相对来说比较耐酸性。所有类型的淀粉糊随着pH增加黏度有渐增趋势。     

冷却肉低剂量辐照后的理化和感官特性变化

研究真空包装冷却猪肉经保鲜液处理和未经过保鲜液处理,再分别经1kGy、2kGy和3kGy低剂量辐照后的理化和感官特性变化,进而确定最佳的辐照处理方式以延长冷却猪肉的货架期。结果表明:经过2kGy辐照的处理组,在贮藏的过程中,鲜红色泽保持相对的稳定。冷却猪肉经过保鲜液处理 2kGy剂量辐照 冷藏(4±1℃),可以有效的延长冷却猪肉的货架期。     

甘薯抗性淀粉理化特性研究

选择3个不同类型甘薯品种,以提取获得的抗性淀粉为研究对象,通过X-射线衍射分析仪、差示扫描量热分析仪(DSC)、快速黏度测定仪(RVA)、紫外-可见吸收光谱仪、近红外光谱分析仪(NIRS)和扫描电镜等仪器分别对甘薯原淀粉和其对应抗性淀粉晶体结构类型、熔融温度、淀粉糊化特性、平均聚合度和淀粉分子结构等理化特性深入研究与分析。结果表明,不同甘薯品种间抗性淀粉熔融温度具一定差异,抗性淀粉与其原淀粉间糊化特性、晶体结构等特性呈明显差异。