Temporal Texture Profile and Identification of Glass Transition Temperature as an Instrumental Predictor of Stickiness in a Caramel System

Stickiness is an important texture attribute in many food systems, but its meaning can vary by person, product, and throughout mastication. This variability and complexity makes it difficult to devise analytical tests that accurately and consistently predict sensory stickiness. Glass transition temperature (T_g) is a promising candidate for texture prediction. Our objective is to elucidate the temporal profile of stickiness in order to probe the relationship between T_g and dynamic stickiness perception. Nine caramel samples with diverse texture and thermal profiles were produced for sensory testing and differential scanning calorimetry. Sixteen trained panelists generated stickiness‐relevant terms to be used in a subsequent temporal dominance of sensation (TDS) test with the same panelists. Following the TDS study, these panelists also rated samples for overall tactile and oral stickiness. Stickiness ratings were then correlated to TDS dominance parameters across the full evaluation period and within the first, middle, and final thirds of the evaluation period. Samples with temporal texture profiles dominated by tacky, stringy, and enveloping attributes consistently received the highest stickiness scores, although the correlation strength varied by time period. T_g was found to correlate well with trained panelist and consumer ratings of oral (R²_trained = 0.85; R²_consumer = 0.96) and tactile (R²_trained = 0.78; R²_consumer = 0.79) stickiness intensity, and stickiness intensity ratings decreased with T_g of completely amorphous samples. Further, glassy samples followed a different texture trajectory (brittle‐cohesive‐toothpacking) than rubbery samples (deformable‐tacky‐enveloping). These results illuminate the dynamic perception of stickiness and support the potential of T_g to predict both stickiness intensity and texture trajectory in caramel systems.     

蔗糖晶体吸附焦糖色素的规律与呈香呈色糖的制备工艺研究

以Ⅰ类焦糖色素和成品白砂糖为原料,初步探究降温养晶过程中蔗糖晶体吸附焦糖色素的规律。采用日本Asahi结晶器研究以Ⅰ类焦糖色素为辅料的呈色呈香糖的制备工艺,采用正交试验法,研究色素添加量、降温时间和初始过饱和度3个因素对糖品色值的影响。结果表明：BET 理论可以解释本体系吸附,改变起始过饱和度会出现临界点使吸附量最少,实验范围内,较高的色素量或较低的降温速率有助于提高吸附量。本文所研究的呈色呈香糖工艺具有操作简单、周期短的特点,所制备的产品质量符合相关标准规定。     

糖醇替代对芸豆蜜豆品质特性的影响

为开发无糖芸豆蜜豆,选用赤藓糖醇、麦芽糖醇、木糖醇、山梨糖醇完全替代糖渍液中的蔗糖,通过分析不同糖醇对芸豆蜜豆色度、质构、含水量、水分活度、γ-氨基丁酸(GABA)含量、消化特性及感官品质的影响以确定最佳蔗糖替代物。结果表明,4种糖醇在保持GABA含量的基础上(P>0.05),提高了芸豆蜜豆的亮度,显著降低芸豆蜜豆的硬度、咀嚼度、水分活度及估计血糖生成指数(eGI)(P<0.05)。麦芽糖醇芸豆蜜豆的eGI最低,显著降低了30.25%(P<0.05)。4种糖醇及蔗糖芸豆蜜豆综合感官评分分别为72.60、79.50、80.60、72.70、80.70,其中麦芽糖醇、木糖醇芸豆蜜豆与蔗糖组最为接近(P>0.05)。综合考虑,麦芽糖醇是替代蔗糖开发无糖芸豆蜜豆的最佳选择。     

不同发酵剂生产的酸奶感官评定和TPA质构分析

质构剖面分析法(Texture Profile Analysis,TPA)是食品质构分析的重要方法。该文通过质构剖面分析法研究了不同发酵剂对酸奶质构的影响,并和感观评价方法进行了比较。结果表明,不同发酵剂对酸奶的硬度和胶粘性影响很大,单一保加利亚乳杆菌和嗜热链球菌生产的酸奶硬度和胶粘性最高。两菌混合硬度和胶粘性明显降低,但内聚性最高。嗜热链球菌可明显增加产品粘度。TPA分析和感观评价中硬度参数值非常吻合,TPA分析中的胶粘性和感观评价中的喉咙口滞留度有较好的关联性。两菌混合后提高杆菌比例生产的酸奶综合感观评价值最高。     

Texture of Pecans Measured by Sensory and Instrumental Means

The texture of pecans (Carya illinoensis) from four cuhivars (Barton, Mahan, Western and Wichita) was analyzed using sensory and instrumental methods. Sensory hardness, flexibility and crispness were rated by trained panelists. Ranking of hardness and crispness was also carried out. A Texture Analyser TAXT2 was used for 50% compression, texture profile analysis (TPA), puncture and bending. Puncture and 50% compression gave best reproducibility, least variability and agreement with sensory data. The most relevant TPA parameters were cohesiveness, elasticity and fracturabihty. Parameters from the bending test did not indicate texture of the pecans suitably.     

不同糖质对焦糖理化性质的影响

采用相同生产工艺对不同糖质进行生产焦糖试验。选用的工艺为非氨法、氨法两种,糖质为优质白砂糖、一级葡萄糖、转化糖三种。并分别对其生产的焦糖的一般特性、等电点、胶体特性等进行了观察测定,通过对试验结果的分析和讨论,得出了一些有益的结论,对焦糖生产和应用具有一定的指导作用。     

Sensory Profiles and Seasonal Variation of Black Walnut Cultivars

Black walnut (Juglans nigra L.) is a North American hardwood tree valued for producing nuts and wood. Black walnut cultivars were evaluated by a trained panel over 2 growing seasons to determine the seasonal variation in the sensory profile. Results showed that cultivars were significantly different on 3 appearance (skin color, nutmeat color, and kernel roughness), 1 aroma (black walnut ID), 5 flavor (black walnut ID, banana‐like, piny, rancid, and overall nutty), and 2 texture attributes (surface roughness and hardness). These profiles were compared to results collected in 2011 to determine differences between growing seasons. Results showed 4 flavor attributes (black walnut ID, overall nutty, fruity‐dark and rancid) had an interaction effect of year and cultivar, while 6 attributes (brown, caramelized, floral/fruity, piny, musty/dusty, and oily) showed a main effect of year. In general, flavor attributes had higher intensities in 2011 than in 2013. These results suggest that seasonal variation may influence flavor profile more than cultivar. Thus, using samples from only 1 growing season when testing agricultural products may not provide adequate information for the long term.     

FP/QDA法在无糖酸奶感官性质分析中的比较

分别利用Flash Profile(FP)法和定量描述分析(QDA)法对4种市售无糖酸奶进行了描述性分析.FP法中10名未经训练的和QDA法中6名经过培训的感官评价员分别建立感官描述词,对所有样品进行感官特征评价,并对得到的数据进行了方差分析、主成分分析和系统聚类分析.结果 表明,两种方法都能将样品合理分类,但所分类别...     

蒸发光散射液相色谱测定无糖酸奶中糖醇

建立无糖酸奶中糖醇测定的蒸发光散射检测器方法。采用氨基柱Waters柱CarbohydrateHighPerformance(4.6×250mm,4μm),以乙腈-水(75∶25,体积分数)为流动相,流速1.0mL/min;蒸发光散射检测器载气压力172kPa,漂移管温度45℃,进样量10μL。木糖醇、山梨醇、麦芽糖醇的线性范围均为0.025 mg/g～1.000 mg/g,定量限均为0.10%,样品的平均加标回收率范围分别为85.5%～92.7%、92.2%～147.7%、101%～139.8%,相对标准偏差分别为1.65%、2.67%、2.53%。该方法操作简便、快速、准确,应用于无糖酸奶中糖醇的分析,取得了较好的结果。