Implicit evaluation of the emotional response to premium organic herbal infusions through a temporal dominance approach: Development of the temporal dominance of facial emotions (TDFE)

One of the greatest challenges when designing research on emotions is the conception of an efficient tool for their measurement. The FaceReader™ emerged as an implicit tool capable of analysing facial expression patterns whether in recorded or real-time videos. This software produces large datasets on temporal variation of the intensity of basic emotions.The main goals of this research were: (i) to develop a new data analysis procedure, based on temporal dominance approaches to evaluate temporal data from Face Reader, called the Temporal Dominance of Facial Emotions (TDFE), (ii) to relate the results from TDFE with the EsSense Profile® evaluation, (iii) to evaluate different market samples and to establish its emotional profile.An untrained panel of 50 naïve panellists tasted five samples. For each infusion, the overall liking was evaluated using a 9-point scale (1-dislike extremely to 9-like extremely) followed by the evaluation of the emotional profile, using an adapted version of the EsSense Profile®. The entire test was video- recorded using web cameras placed in front of the panellists and adjusted, to obtain a correct measurement of their facial expressions.Significant differences (p ≤ 0.05) between samples were found for overall liking. The correlation between TDFE and EsSense Profile® was 0.704, above the reference value of 0.680. However, from both methods one can identify a clear emotional profile of the samples under evaluation.Both methodologies appear to be promising regarding the emotional profile characterization. However, the lower direct correlation can be explained by the difference in positive and negative emotions. FaceReader™ identifies more negative than positive emotions, while the EsSense Profile® identified the opposite. Therefore, both approaches should be regarded as complementary.     

Formaldehyde as an interference of the 2-thiobarbituric acid test

The 2-thiobarbituric acid (TBA) test is widely used for measuring rancidity in foods. It is based on the colorimetric determination of a pink chromogen which is formed by reaction between TBA and TBA reactive substances (TBARS). Besides malonaldehyde (MA) many other substances have been reported to react with TBA. The formation of formaldehyde (FA) from the trimethylamine oxide (TMAO) decomposition in sea fish has been extensively studied. Considering that FA reacts with the TBA forming a white precipitate or cloudiness the interference of FA with TBA test is studied concluding that FA contents over 25 μg ml^?1 extract interfere with the colorimetric determination during the storage of frozen blocks of Patagonian hake (Merluccius hubbsi) filleted and minced.     

Development of a total quality scoring system based on consumer preference weightings and sensory profiles: application to fruit dates (Tamr)

A scoring system for evaluating the total quality of a food product (Tamr) based on consumer preferences was developed and tested for validity. The development process started with a survey among adult date consumers in the United Arab Emirates to identify their perception of characterizing total quality of date fruit among specified attributes. The consumer subjective ranking of eleven specified attributes was used to derive a quantitative weighted factor for each attribute. Based on the weighted factor a quantitative scoring guide was developed. A panel evaluation of five date varieties (Khlas, Barhee, Boumaan, Fard and Ruzeiz) was conducted as an application of the developed scoring system. Panel evaluation results and consumer ranking and preference data of the same varieties compared well. In both panel evaluation and consumer ranking, Khlas variety was perceived to have the best quality by far among the tested varieties. Barhee and Boumaan varieties showed no significant variation between them in both panel evaluation and consumer ranking, and both were in the second order of preference. Variety Ruzeiz was in the lowest order of preference in both panel evaluation and consumer ranking. Testing of the method indicated its appropriateness in predicting total quality of a food product as would be perceived by consumers.     

Commercial test kits and the determination of histamine in traditional (ethnic) fish products-evaluation against an EU accepted HPLC method

Although commercial test kits are generally used and/or evaluated for determining histamine in fresh and canned fish, and fish meal, there is little information on their performance and the application for traditional fish products (TFPs), which generally differ in product properties. In this study, three quantitative (Food EIA, Veratox, Histaquant) and four qualitative (Histasure, Histameter, Transia qualitative and semi-quantitative) commercial histamine test kits were evaluated against HPLC method for detecting histamine in several traditional fish products. Among the quantitative kits, Histamine Food EIA showed the best correlation with HPLC method for TFPs (R² = 0.9132) as well as good recoveries ranging between 89 (±4.11)% and 117 (±1.50)%. Although good recoveries were also observed with Veratox kit, poor correlation was found with HPLC. Poor correlation and low recoveries were also observed with Histaquant. Histasure and Transia tube histamine kits showed good agreement with HPLC results. However, the detection limit for Transia qualitative kit is 100 ppm, and for Histasure and Transia semi-quantitative kits can be set to 50 ppm. Therefore, Histasure and Transia semi-quantitative kits are found more suitable for either HACCP monitoring histamine in seafood processing plants or regulatory purposes according to Food Drug and Administration (FDA) legislation for TFPs. However, Transia semi-quantitative kit should be used in caution for histamine cut off values <50 ppm. This study shows that each test kit can represent different performance for determining histamine in TFPs according to product type, and therefore new commercial test kits should be evaluated against an approved analytical method before applications in future for these types of products.     

纺织品染色的电荷效应和阳离子试剂开发应用(待续)

纺织品染色是一个较为复杂的过程,影响因素很多,其中染色过程中的电荷效应就是重要因素之一,它不仅影响染料的上染速度、匀染程度和色牢度,还和染色的节能减排直接相关.简要介绍了染色的电荷效应,重点介绍了阳离子试剂对纤维染色电荷效应的影响,指出合理应用阳离子试剂,包括纤维阳离子化改性和阳离子固色剂的应用,可以大大提高节能减排效能,但是阳离子试剂的应用也会产生一些负面作用,因此,不仅需开发新型的阳离子试剂,还应根据纤维结构和性质,合理选用应用工艺,才可以获得良好的效果.介绍了阳离子试剂的类型、应用工艺和改性纤维的染色特点,并对电荷效应作了分析,以期获得最佳节能减排的效果.     

Effect of chargrilled flavoring on the sensory perception and consumer acceptability of bulgogi (Korean barbecued beef)

Food Science and Biotechnology - As the home-meal replacement food industry grows, there is an increasing need for smoky flavorings that can satisfy the diverse tastes of consumers. In particular,...     

超临界CO2萃取滩枣精油工艺条件优化研究

采用正交试验,考察萃取压力、温度、携带剂和料液比四个因素对滩枣精油萃取率的影响,并对精油成分进行GC-MS分析。得到的最佳萃取条件为:萃取压力35MPa,萃取温度40℃,乙醇作携带剂,料液比1:0.9,在此条件下经过0.5h萃取,滩枣精油的萃取率可达1.51%。     

蓝圆鲹抗氧化肽与其他抗氧化剂的协同效应的研究

以DPPH·和O₂^-·清除率为指标,探讨了蓝圆鲹多肽（RSH-III）分别与其他肽类抗氧化剂GSH和非肽类抗氧化剂vitamin C的协同抗氧化效应。研究结果表明,当清除DPPH自由基时,低浓度条件下的RSH-III(0.2、0.4 g·L^-1)分别与GSH(1.0×10-3、2.0×10-3g·L^-1)和vitamin C(0.7×10-3g·L^-1)复合时未表现出协同效应;较高浓度(0.8 g·L^-1)时表现出负协同作用。当清除O₂^-·自由基时,RSH-III与低浓度GSH(1.3×10-3g·L^-1)复合时未表现出协同效应,较高浓度(2.5×10-3⁴.2×10-3g·L^-1)时表现出负协同作用;而与vitamin C复合清除O₂^-·自由基的清除率与抗氧化剂的添加浓度无关,均表现出负协同效应。该研究为蓝圆鲹抗氧化活性肽的应用奠定了较好的基础,可用于指导抗氧化活性肽的高效应用。      

基于亚甲基蓝还原法指导酵母的培养

亚甲基蓝还原实验法(MBRT)是一种新的评价酵母活力的方法,该文首次使用该方法考察了几种主要离子及无机氮源对酒精酵母生长的影响,并指导了劣质原料木薯渣糖化清液中高活力酵母的培养.从几种主要离子及无机氮源对酵母活力的影响结果初步分析得出如下结论,酵母生长过程中K+的作用最为明显,最适浓度为0.015mol/L;Mg2+是必须的,但当浓度超过0.004mol/L时,就会抑制酵母生长;低浓度的Na+与Ca2+对酵母生长有促进作用,最适浓度分别为0.0025mol/L、0.001mol/L.与硫酸铵相比,尿素是较好的无机氮源,最适浓度为2g/L.利用木薯渣糖化清液培养酵母时,添加2g/L的尿素及0.015moi/L钾离子后,可使培养出的酵母数增加6倍,酵母活力值为105s(空白为256s).     

Development of Titanium Dioxide (TiO2) Nanocoatings on Food Contact Surfaces and Method to Evaluate Their Durability and Photocatalytic Bactericidal Property

Titanium dioxide (TiO₂) is a well‐known photocatalyst for its excellent bactericidal property under UVA light. The purpose of this study was to develop physically stable TiO₂ coatings on food contact surfaces using different binding agents and develop methods to evaluate their durability and microbicidal property. Several types of organic and inorganic binders such as polyvinyl alcohol, polyethylene glycol, polyurethane, polycrylic, sodium and potassium silicates, shellac resin, and other commercial binders were used at 1:1 to 1:16 nanoparticle to binder weight ratios to develop a formulation for TiO₂ coating on stainless steel surfaces. Among the tested binders, polyurethane, polycrylic, and shellac resin were found to be physically more stable when used in TiO₂ coating at 1:4 to 1:16 weight ratio. The physical stability of TiO₂ coatings was determined using adhesion strength and scratch hardness tests by following standard ASTM procedures. Further, wear resistance of the coatings was evaluated based on a simulated cleaning procedure used in food processing environments. TiO₂ coating with polyurethane at a 1:8 nanoparticle to binder weight ratio showed the highest scratch hardness (1.08 GPa) followed by coating with polycrylic (0.68 GPa) and shellac (0.14 GPa) binders. Three different techniques, namely direct spreading, glass cover‐slip, and indented coupon were compared to determine the photocatalytic bactericidal property of TiO₂ coatings against Escherichia coli 0157:H7 at 2 mW/cm² UVA light intensity. Under the tested conditions, the indented coupon technique was found to be the most appropriate method to determine the bactericidal property of TiO₂ coatings and showed a reduction of 3.5 log CFU/cm² in 2 h.     

再谈臭氧用于重碳酸钙镁型矿泉水生产中所出现的问题及解决方法

重碳酸钙镁型矿泉水在我国分布区域较广。沉淀是影响该种矿泉水质量和销路的主要因素。从产生沉淀的原因着手分析 ,提出了采用冷却后过滤、再通入微量的CO2 的方法来解决这个问题 ,较好地提高了产品质量     

天然食用香料草莓酸对黄曲霉的抑菌作用研究（网络首发、推荐阅读）

产毒真菌及其毒素污染严重影响粮油食品安全,天然防腐剂的研发与应用是食品微生物控制领域的重要技术和研究热点。以食品常用防腐剂山梨酸为阳性对照,采用生长速率法研究了天然食用香料草莓酸对黄曲霉的抑菌作用,并进一步评价草莓酸控制黄曲霉侵染储藏花生的实际效果。结果表明,草莓酸的抑菌活性优于山梨酸,二者在离体条件下对黄曲霉的最小抑菌浓度（MIC）分别为0.6和1.0 g/L;草莓酸在10.0 g/L浓度下能够完全抑制黄曲霉在储藏花生中的侵染和生长,而山梨酸需要20.0 g/L才能达到相同的控制效果。研究表明天然食用香料草莓酸显示出良好的抑菌作用,具有开发成为天然食品防腐剂的潜力。     

Popping of amaranth grain (Amaranthus caudatus) and its effect on the functional,nutritional and sensory properties

The popping of amarunth grain (Amaranthus caudatus var INIAP‐Alegría) by hot air processing was studied. A household corn popper adapted to control heating and airflow was used. The effects of temperature, load, airflow and moisture on the popping capacity and on the functional properties, nutritional quality, crude protein content, lysine content and sensory texture of the poppei grain were investigate. The yield, expansion volume and density of popped grain showed that the optimal conditions for the popping process were 240 °C, 22 g load, 0.013 m³ s^?1 airflow and 12% grain moisture. The proportion of popped grain with butterfly shape was highest (p < 0.05) at 220 °C, 22 g load, 0.014 m³ s^?1 airflow and 14% grain moisture. The functional and physic‐chemical properties of popped grain obtained by various treatments showed completely gelatinised starch. The total, available and resistant starch contents were similar among the different treatments. The enzymatic degradation of starch was 65% within 5–15 min of incubation with α‐amylase. The crude protein content was almost 15% for all the treatments, while the total lysine content was 45.2–48.0 mg g^?1 protein. The in vitro availability of protein of popped grain obtained at 0.013 m³ s^?1 airflow and 14% grain moisture was above 84%. The highest available lysine value was found for popped grain obtained at 0.014 m³ s^?1 airflow, 18–22 g load and 12–14% grain moisture. However, six of the eight treatments had available lysine contents that varied between 41.2 and 47.4 mg g^?1 protein. Sensory analyses showed that the treatments with the highest popping capacity produced grains with high crunch and expansion capacities. © 2002 Society of Chemical Industry     

基于栅栏因子协同作用的中国对虾保鲜效果研究

以漳州东山港产中国明对虾(15.0±1.0)g为原材料,在-4℃下采用1.5%壳聚糖保鲜及阻氧剂、0.1%植酸钠为护色剂及流化冰低温处理为栅栏因子,协同作用贮藏对虾,并设定对照组(-4℃贮藏)。通过考察贮藏期挥发性盐基氮含量(TVB-N值)、菌落总数、明度值、pH值、PPO、持水率、弹性等理化及生物指标,以及感官品质,探究栅栏因子应用于对虾的保鲜效果。结果表明:与对照组相比,处理组A(流化冰处理+-4℃贮藏)及处理组B(壳聚糖+植酸钠+流化冰处理+-4℃贮藏)可以有效延缓挥发性盐基氮、菌落总数、pH值及PPO上升,同时可显著提高对虾明度值、持水率、弹性及感官评分(P0.05);贮藏中后期(4,6,8d),处理组B保鲜效果显著优于处理组A。栅栏因子协同作用可以明显改善对虾贮藏品质,延长货架期约4d。     

硫酸铵电解液添加剂对铅酸电池电化学性能的影响

采用循环伏安、线性极化和恒流充放电等电化学方法研究硫酸铵添加剂对铅酸电池正极、负极、板栅合金及电池电化学性能的影响.结果表明,适量(15～20 g/L)硫酸铵用作电解液添加剂的加入可以改善电极性能,增强板栅合金的耐腐蚀性,提高电池放电容量。     

Optimization of an active package for wild strawberries based on the release of 2-nonanone

Active packaging is becoming in an emerging food technology to improve quality and safety of food products, commonly based on the retention or release of compounds which are beneficial for the product. In this work, an active packaging system based on the release of 2-nonanone has been optimized to increase the postharvest shelf life of fresh wild strawberries during the marketing stage. To avoid that excessive levels of this volatile could affect the berries' taste and cause consumer rejection of the product, a preliminary sensory analysis was carried out to determine the threshold value of 2-nonanone, 7.16 mg/kg fresh wild strawberries. Taking this threshold value into account, diverse quantities of 2-nonanone were tested to optimize the packaging parameters. Wild strawberry fruits were packaged in the active packages developed and their quality monitored during storage at 10 °C with exposure to light to simulate real-life conditions on supermarket shelves. The analyses of weight loss, SSC, gas composition and aroma volatiles provide evidences that exposure to the highest-tested 2-nonanone concentrations are an effective way of maintaining the quality of wild strawberries during distribution and sale without modifying their typical taste.