壳聚糖双胍盐酸盐抑菌活性及其涂膜保鲜圣女果的研究

测定了壳聚糖双胍盐酸盐(CGH)对金黄色葡萄球菌、大肠杆菌和番茄丝核菌的抑菌能力;并通过涂膜的方法处理圣女果,测定贮藏过程中果实失重率、硬度、可溶性固形物含量(TSS)、维生素C(VC)含量、细胞膜透性和总酸含量的变化。结果表明,相对于壳聚糖(CTS),CGH对金黄色葡萄球菌、大肠杆菌具有较强的抑菌能力,其最小抑菌浓度(MIC)分别为0.31mg/mL和0.62mg/mL;当CGH浓度达到2.00mg/mL时对番茄丝核菌菌丝生长抑制率可达到100%。以质量浓度为3%的CGH涂膜处理的圣女果在(28±2)℃存放12d后,失重率仅为7.5%,硬度仍有21.121N/cm2,TSS为7.2%,VC含量为21.70mg/100g FW(鲜重),膜渗透率为27.4%,可滴定酸含量为0.35%。与对照(CK)相比,显著保持了果实的品质。      

樱桃酒感官评价与电子舌感官分析的相关性研究

对五种不同樱桃酒的感官属性(酸、甜、苦、涩)进行了感官评价和电子舌指纹分析,利用主成分(PCA)与判别因子(DFA)分析对电子舌区分樱桃酒的能力进行了评价,并通过PCA、偏最小二乘法(PLSR)将感官评价结果与电子舌7根传感器(ZZ、BA、BB、CA、GA、HA、JB)响应相关联。结果表明,电子舌指纹分析系统对樱桃酒具有较好的区分辨别能力,传感器JB与酸味,传感器HA、CA与甜味,传感器ZZ与涩、苦味具有较高的相关性。      

Bioactive compounds and sensory attributes of sour cherry puree sweetened with natural sweeteners

The aim of this study was to describe a phytochemical profile, including phenolic compounds, antioxidant capacity, colour and sensory quality attributes (colour, aroma, consistency, sweetness intensity and desirability) of a sour cherry puree (SCP) supplemented with different natural sweeteners. Supplementation of SCP with the sweeteners only slightly affected polyphenol content, which was by 9% (SCP with steviol glycosides) to 26% (SCP with erythritol) lower than in pure SCP. Furthermore, the products with natural sweeteners were characterised for the lowest antioxidant activity than the SCP sample, especially in SCP with erythritol and xylitol. In addition to having high content of polyphenols and high antioxidant activity, these products were also attractive to consumers, especially when supplemented with xylitol, palm sugar or sucrose, but not with Luo Han Kuo fruit, which was found unacceptable. The results showed that most of the obtained SCPs had very promising and interesting phytochemical properties and sensory profiles.     

Comparison of optical and physical measurements with sensory assessment of the ripeness of tomato fruit Lycopersicon esculentum

Knowledge of the inter-relationships among objective physical and optical measurements and their relation with sensory perception of foods can be applied to improve quality control and consumer acceptance. Changes in the optical and mechanical properties of tomatoes were found to be related to the perceived ripeness of the fruit over a storage period. The sensory attributes and instrumental parameters significant in the assessment of ripening tomatoes were translucency, green, orange, lightness, hue and chroma. The chromatic co-ordinate a^* was significantly correlated with the mechanical modulus of the fruit, which in turn was inversely related to ripening associated with colour changes from green to red. It is feasible that mechanical and optical data may be combined to provide an on-line system for the evaluation of ripeness of tomato fruit.     

酿酒酵母对樱桃酒挥发性组分及感官品质的影响

鉴于酿酒酵母（Saccharomyces cerevisiae）对樱桃酒挥发性香气及感官品质的重要贡献,测定了5种商业化酿酒酵母的产香性能,以期从中挑选适用于樱桃酒酿造的优质发酵剂。结果表明,5种酵母发酵的樱桃酒基本理化指标无差异（P＞0.05）,但是挥发性组分含量却存在显著差异（P＜0.05）。Lalvin 2323与Lalvin 71B能够增加丁酸乙酯、己酸乙酯、苯甲醛、β-大马酮等多种挥发性物质的合成量,赋予樱桃酒更浓郁的果香和花香特征,且Lalvin2323的整体香气比Lalvin 71B更浓郁;Laffort B0123可以提高里那醇、异戊醇、乙酸异戊酯的含量,感官品质也较好;Laffort X16酿造的樱桃酒果香味寡淡,生青气味浓郁,评分较低;Laffort Cervisiae（AC）酿造的樱桃酒整体香气略显不足,评分最低。总体来看,酵母Lalvin2323发酵樱桃酒的感官品质优于其他酵母。     

Use of electronic nose and trained sensory panel in the evaluation of tomato quality

In this paper the performances of an electronic nose based on metalloporphyrin‐coated quartz microbalance sensors and of an experienced panel of seven human assessors in the evaluation of gases derived from degradation reactions in tomatoes are presented and discussed. The performances are measured in terms of the capability of both systems to distinguish between samples of different quality coming from conventional and organic production systems. The study deals with the application of pattern recognition techniques based on either multivariate statistical methods (PCA, GPA) or artificial neural networks using a self‐organising map (SOM). The response pattern of the sensor array and the sensory data are analysed and compared using these methods. Similarities in the classification of the data by electronic nose and human sensory profiling are found. © 2000 Society of Chemical Industry     

Consumer preferences for fresh tomato at the European scale: a common segmentation on taste and firmness

Although tomato flavor has not been a major goal for breeders, nowadays it becomes important as it is a subject of consumer complaint. A better knowledge of tomato consumer preferences, at the European level, should provide the basis for improvement of fruit quality and for market segmentation. In the framework of a large European project, 806 consumers from 3 countries, The Netherlands, France, and Italy, were presented with a set of 16 varieties representing the diversity of fresh tomato offer in order to evaluate their preferences. In parallel, sensory profiles were constructed by expert panels in each country. Preference maps were then constructed in each country revealing the structure of consumer preferences and allowing identification of the most important characteristics. Then a global analysis revealed that preferences were quite homogeneous across countries. This study identified the overall flavor and firmness as the most important traits for improving tomato fruit quality. It showed that consumer preferences from different European countries, with different cultures and food practices, are segmented following similar patterns when projected onto a common referential plan. Moreover, the results clearly showed that diversification of taste and texture is required to satisfy all consumers' expectations as some consumers preferred firm tomatoes, while others preferred melting ones and were more or less demanding in terms of sweetness and flavor intensity. Detailed comparisons also showed the importance of the fruit appearance in consumer preference.     

Application of agglomerative hierarchical clustering to identify consumer tomato preferences: influence of physicochemical and sensory characteristics on consumer response

A multiple regression model was developed to predict the acceptability of the four tomato varieties studied (Aranka, Cherry, Beef and Pitenza). Agglomerative hierarchical clustering showed the presence of four consumer clusters. One cluster preferred small tomatoes (Aranka and Cherry) and another cluster the larger tomatoes (Beef and Pitenza). In the sensorial analysis Aranka was the preferred variety, scoring more highly in taste, odour, acidity, sweetness and hardness. In the physicochemical analysis Aranka also obtained the highest values for titratable acidity (TA) and sugars (SSC), confirming that these parameters are important in tomato flavour. Lower values for both sets of parameters were reflected by lower consumer acceptability, with Beef and Pitenza receiving the lowest score for these flavours attributes (except odour). A significant correlation between the sensorial and physicochemical parameters was also observed: odour was positively correlated with calibre, while taste, acidity, hardness and acceptability were negatively correlated with calibre, pH and SSC/TA and positively correlated with SSC and TA. Copyright © 2005 Society of Chemical Industry     

Sensory lexicon and relationships among brown colour,saltiness perception and sensory liking evaluated by regular users and culinary chefs: a case of soy sauces

This study was performed to develop lexicon to describe soy sauces using regular users (consumers) vs. culinary chefs, to perform product grouping using a free-sorting task and to determine relationship among physicochemical properties (colour, %NaCl) and consumer perception of soy sauces. Both panels identified eighteen terms to describe soy sauces, of which eleven terms (light, medium and dark brown colour, weak, medium and strong saltiness, sweetness, saltiness–sweetness, tasty/umami, and soy sauce and fermented aroma) were similar. For culinary chefs, three distinctive soy sauce groups based on brown colour (light, medium and dark brown) were identified, while two groups (light and medium dark brown) for regular users. From free-sorting maps, both panels associated brown colour intensity with saltiness expectation/perception. From PCA biplots, both panels shared some similarities for sensory liking (colour, saltiness, flavour, overall liking) for soy sauces. This study suggested that brown colour intensities affected saltiness expectation/perception and were used for product grouping for soy sauces.     

Old and endangered tomato cultivars under organic greenhouse production: effect of harvest time on flavour profile and consumer acceptance

The influence of two different harvest times (optimal and 4 days earlier) on thirty flavour compounds, titratable acid and sugars as well as consumer acceptance of four old and endangered tomato cultivars (‘Ananas’, ‘Auriga’, ‘Green Zebra’ and ‘Lukullus’) was analysed. In most cases, cultivar type had a greater effect on the volatiles profile than harvest times. Sugar contents were mostly higher at optimal harvest compared with early harvest, whereas acid content was in most cases not affected by harvest time. Consumers perceived differences in several visual and sensory aspects between cultivars as well as harvest times. The optimal harvest was regularly preferred to or at least regarded as equal to the early‐harvest time. Sensory evaluation was poorly related to the aroma volatile profile and only partly to the acid and reducing sugar contents of tomatoes. This was probably owing to the special external characteristics of the tomatoes: differing in size, shape and colour from the ‘normal’ red types.     

Water quality concerns and acceptance of irradiated food: a pilot study on Mexican consumers

BACKGROUND: Poor quality irrigation water is a major cause of disease transmission for urban inhabitants consuming fresh produce in many developing countries. Irradiation of food is an alternative approach to reducing health risks for consumers, but its implementation depends heavily on consumer acceptance. RESULTS: In this pilot study, we show that most respondents consider the water quality of Mexico City to be poor and a health risk, and would be willing to pay for irradiated food as a means of pasteurizing fresh iceberg lettuce. CONCLUSION: Irradiated food could, potentially, be accepted in developing countries that have problems with water quality. Such acceptance would presumably be due to the perception that such a novel technology would (1) alleviate water impairment, and (2) lead to economic improvement. It is then possible that the public considers that water quality is a more pressing concern than any potential side effects of food irradiation. Copyright © 2010 Society of Chemical Industry     

Odour investigation of granular polyolefins for flexible food packaging using a sensory panel and an electronic nose

A study was carried out of the odour properties of polyolefins destined for flexible food packaging. A total of 25 homo- and copolymers of ethylene and five homo- and copolymers of polypropylene in pellet grade were analysed by a sensory panel. Principal component analyses of sensory data showed a perceptible and quantifiable difference between samples. Generally, polypropylene materials were judged less odorous than the majority of polyethylene pellets, especially the ethylene vinyl acetate copolymers. The feasibility of using a commercial electronic nose, equipped with 10 metal oxide semiconductors, to discriminate between the odour of plastic materials was also explored. Instrumental results were satisfactory and correlated well with panel answers, as shown by partial least-squares regression. Furthermore, application of a cluster analysis made it possible to differentiate polymer odours into strong, medium and weak.