香气增甜的作用机制及评价方法研究进展

食品减糖比较常见的方法是使用非营养性甜味剂,但非营养性甜味剂会带来不受欢迎的苦味或金属味及安全风险。研究表明,在某些食物中加入香气物质可以增强人体对食品的甜味感知,即利用香气增甜作用达到食品减糖效果。从气味物质种类、甜味剂浓度2个方面总结了对香气增甜作用有重要影响的因素;从正鼻途径和后鼻途径的嗅觉感受机制、脑神经及味觉感受机制、心理感受机制3个方面阐述了香气增甜的作用机制,总结了分子模拟在分析甜味剂与味觉受体结合、释放过程的应用;归纳了评价香气增甜作用大小的感官分析方法,并比较描述性感官分析法、时间强度法和感觉时间支配分析法3种感官分析方法的差异性;对香气增甜作用在食品工业中的应用现状进行了汇总;对香气增甜研究方向以及分析气味增强味觉作用机制的方法提出展望,以期为香气减糖的研究提供新思路。     

A RESEARCH NOTE: STUDY ON THE QUALITY OF PACHARÁN BY SENSORY EVALUATION

Pachardn is a traditional drink of Navarra, Spain. This spirit is an alcoholic drink which ranges from intense pink to red in color and whose base is sloe (Primus spinosa, L.) flavored with, the essential oils of aniseed and sugar. Sensory analysis was performed using samples from twenty-one different brands of commercial pachardn. Statistical techniques employed were formations of a linear correlation matrix, followed by factor analysis and multiple linear regression. Factor analysis permitted reduction of the sensory variables examined (color, aroma quality, flavor quality, sweetness, acidity and overall impression) to two factor variables (“flavor and aroma” and “color”). The position of the brands with respect to these two factors indicate the necessary changes to improve pachardn quality. The factors “flavor and aroma” had the chief direct effect on Overall Impression.     

Quality of Retail Florida-Packed Frozen Concentrated Orange Juice as Determined by Consumers and Physical and Chemical Analyses

Six commercial Florida-packed frozen concentrated orange juice samples drawn from the U.S. retail market on a monthly basis for 1 yr were evaluated for sensory attributes, color (by colorimeter), Brix, acid, and bottom pulp. Consumers rated flavor “like moderately” on a 9-point hedonic scale for every sample. The degree of sweetness and tartness of samples was “just right;” bitterness was somewhat excessive and color was somewhat too light (P < 0.05). Generally, as the °Brix to % acid ratio increased, the flavor improved, and the closer to “just right” was the degree of sweetness, tartness, and bitterness. A significant amount of bitterness was perceived as tartness or lack of sweetness (P < 0.01). Plant-to-plant variation was found in ratings of flavor and colorimeter color and °Brix to % acid ratios.     

RELATIONSHIP OF NITROGEN-SULFUR FERTILIZATION AND HYBRID TO SENSORY CHARACTERISTICS OF shrunken2 SWEET CORN KERNELS

Sweet corn hybrids significantly affected the primary components of eating quality, i. e. sweetness (P < 0.001), sweet corn aroma (P = 0.004), crisp pericarp (P = 0.002) and tender endosperm (P = 0.020). To some degree, N-S fertilization had an influence on the sweetness of the kernerl (P = 0.067). Hybrids with high levels of kernel DMS and sucrose had more intense sweet corn aroma and sweetness, respectively, with a corresponding increase in sweet corn flavor. A positive relationship was also observed between sweet corn aroma and kernel DMS concentration. Although overall liking did not display significant differences between hybrids and was not correlated with any of the chemical components of flavor, it was positively related to aroma, sweetness and texture, and negatively related to grassiness and starchiness in the kernels. The results in this study demonstrated the importance of conducting sensory evaluation to understand the complex nature of the sensory quality in food crops.     

Memory of sweetness and fatty flavours: Effects of gender and liking

Memory plays a major role in determining people’s expectations and choices of foods. In an experiment we investigated how well young people remember sweetness and fattiness under natural conditions, where they had not been instructed to remember anything about the stimuli when they were first encountered (incidental learning). In order to be able to compare memory of fattiness and sweetness, we also determined perceptual discriminability between the targets and distracters used in the experiment. A full account of the experiment is provided in Hausner and Møller (2006).

Experiment

Food choice and food behaviour in general depend on appropriateness, expectations and preferences. What is appropriate and which expectations and preferences we entertain rely on previous encounters with foods and memory for foods thus play an important role in determining food choice. In light of the serious problems of overweight in many parts of the world, it is important to better understand the relationships between sensory and nutritional properties of foods (Sørensen, Møller, Flint, Martens, & Raben, 2003).In the experiment we investigated how well young people remember sweetness and fattiness under natural conditions, i.e. conditions where they had not been instructed to remember anything about the stimuli (a milk based rice product, MiniMeal, ARLA Foods Ltd.) when it was first presented to the subjects (incidental learning). In previous work (Møller et al., 2004 and Møller et al., submitted for publication) we have demonstrated that memories of incidentally learned smells, tastes and flavours are stored differently than stimuli stored intentionally. In this experiment it was crucial to make sure that subjects build up their memories in an incidental way, which is exactly how memories for food behaviour develop as a result of our every-day dealings with foods.Subjects in the experiment arrived in the laboratory at 8 a.m. after having fasted for 12 h. They were exposed to the stimulus to be remembered (the ‘target’) via participation in another experiment in which male/female subjects ate 10 portions of 50/40 g of the target. Subjects scored liking, wanting (to eat more of the target) as well as feelings of hunger and satiety during this phase of the experiment. They returned to the laboratory 3 h later and it was only at this time it was revealed to them that we would measure how well they remembered the target they had eaten previously. To evaluate memory of the target we had prepared 3 sweeter versions (S1, S2 and S3) and three more fat versions (F1, F2 and F3) of the product we used as target. These distracters were then presented to the subjects in a random sequence of an equal number of sweet distracters, fatty distracters and targets. On the basis of the number of hits and false alarms we calculated d-prime values for recognition. In order to be able to compare memory of fattiness and sweetness, we also determined perceptual discriminability between the targets and distracters used in the experiment.In this experiment we were particularly interested in the following questions:How well do we remember sweet and fat foods after incidental (ecologically interesting) learning?Both men and women remember fattiness better than sweetness. The womens’ d-prime values for both sweetness and fattiness are larger than they are for men. This result does not occur because women discriminate the target better from the distracters than men do. We found no difference in discriminability between men and women.Does memory for sweetness and fattiness depend on liking?Dividing subjects into likers and non-likers of the stimuli (fat and sweet distracters) at the median (same number of subjects in the two groups) we find that non-likers have much better memories for sweetness and fattiness than likers.Is memory for sweetness and fattiness veridical?Interestingly, we find negative memory d-prime values for sweetness for men in the liking group. This means that subjects score more false alarms than hits. Since all our distracters were sweeter than the target, this means that men who like the (sweet) food we used in the experiment remember the food as more sweet than it was.Is memory based on remembering previous encounters of a stimulus or does it rather serve to detect deviant stimuli (“novelty detection”)?Operationally, remembering requires that memory d-prime values are significantly different from zero. Scoring a large number of hits (‘Reply yes when you are presented with the target in the test phase of the experiment.’) or a low number of false alarms (‘Reply no when you are presented with a distracter in the test phase of the experiment.’) will produce d-prime values different from zero. In this experiment we find that both men and women have difficulty ‘recognizing’ the target. The number of hits and misses are about the same. On the other hand, the correct rejection rate is large corresponding to a low false alarm rate. Memory for sweetness and fattiness is thus based on correctly rejecting new stimuli (the distracters) subjects have not encountered previously.

Summary

We have found evidence that there are gender differences with respect to memory for sweetness and fattiness. Women have better memories for both sweetness and fattiness than men. Hedonicity also influences how well we remember these stimuli. Non-likers have much better memories than likers, with the notable exception of women in the case of fattiness. Female likers of fat stimuli remember the stimuli as well as female non-likers.It is interesting to note that likers of sweetness tend to remember the stimuli as more sweet than they were. This might be a contributing factor in the generation of craving for sweet foods.The results of this experiment are in line with other recent experiments by Köster et al., 2004, Mojet and Köster, 2002, Mojet and Köster, 2005, Møller et al., 2004 and Møller et al., submitted for publication. Investigating memory for smell, taste, flavour and texture, these authors consistently find that memory in the “lower senses” is tuned to “novelty detection”, rather than remembering the precise attributes of the target they are asked to pick out among a set of different stimuli (distracters).     

摇青工艺对“崇庆枇杷茶”加工红茶的香气品质的影响

该研究以一芽一叶的野生乔木型“崇庆枇杷茶”茶树鲜叶为原料,以四川传统工夫红茶的加工工艺为对照(CK),引入乌龙茶的摇青工艺摇青20 min(CP1)、40 min(CP2)、60 min(CP3)为处理,对比分析了摇青工艺对“崇庆枇杷茶”红茶香气的物质组成、含量、感官品质、相对气味活度值(relative odor activity value,ROAV)呈香特征及相对贡献度。结果表明,与CK相比,摇青工艺可使“崇庆枇杷茶”红茶增加10~11个香气成分;新增摇青工艺较CK可显著改善“崇庆枇杷茶”红茶香气感官品质,CP1果香、烘烤香、甜香突出;CP2呈现出甜香、花香、木香浓郁的特征,CP3呈现出果香丰富的特点;而异戊醛、异丁醛、2-甲基丁醛这3个香气成分可能是构成“崇庆枇杷茶”红茶香气中果香、甜香-焦糖香和烘烤香的主体香气物质。综合分析认为新增摇青工艺加工的“崇庆枇杷茶”红茶香气品质优异,能为实际生产提供理论支撑。     

INTEGRATING SENSORY ANALYSIS AND HEDONIC EVALUATION FOR APPLE QUALITY ASSESSMENT

ABSTRACT

Apple cultivars were subjected to a consumer test in order to appreciate individual preferences and set up a protocol for a practical hedonic‐sensory evaluation. Cultivars subjected to the test were “Golden Delicious,”“Modì,”“Pink Lady” and “Fuji” of two different origins. Apples had the sensory profile defined by a trained panel and were evaluated by 154 consumers. According to their preferences, consumer population could be divided in six clusters. Consumer preference responses clearly associated the two “Fuji” and showed “Modì” and “Pink Lady” to have appeal on the same consumers groups. Besides expressing hedonic judgment, consumers were requested to indicate the positive sensory attributes determining their choice. Consumers appreciated “Golden Delicious” and “Fuji” on the basis of sweetness and aroma, while preferences for “Pink Lady” and “Modì” were expressed by consumers appreciating crispness, juiciness and a certain degree of acidity. The involvement of consumers in defining attributes driving preferences provides details useful for weighing up the consistency between consumers' response and sensory panel profile.

PRACTICAL APPLICATIONS

This work contributes to the knowledge on consumer preferences and concerning apple sensory quality. In particular, the tested varieties could be divided in three groups on the basis of perceived attributes. Knowledge of consumer preferences related to apple qualities can be a key point in planning production and marketing strategies. A protocol integrating sensory characteristics defined by a trained panel, hedonic consumer judgments and sensory preference drivers is proposed.     

Sheep milk kefir sweetened with different sugars: Sensory acceptance and consumer emotion profiling

The objective of this study was to determine the sensory acceptance and emotional profile of sheep milk kefir sweetened with different sugars (demerara sugar, brown sugar, fructose, coconut sugar, and honey, 100 g/L). Consumers (n = 100) assessed sensory acceptance (appearance, aroma, taste, texture, and overall impression), and expressed their emotions (satisfied, active, loving, calm, comfortable, energetic, happy, healthy, refreshing, disgusted, worried, and upset). The emotions “satisfied,” “active,” “comfortable,” “energetic,” “healthy,” and “refreshing” were found between moderate and very high levels, indicating that they are important emotions for the characterization and sensory acceptance of kefir samples. The use of different sugars had no influence on the intensity of the emotions “calm,” “comfortable,” “happy,” or “disgusted,” and resulted in a greater sense of satisfaction. The use of demerara sugar or fructose did not alter the acceptance of the products or the intensity of emotions. The use of brown sugar decreased acceptance (taste, texture, and overall impression) and the intensity of the emotions “active,” “loving,” “energetic,” “healthy,” and “refreshing.” The use of coconut sugar decreased acceptance (appearance, aroma, and taste) and the intensity of the emotions “refreshing” and “upset.” The use of honey improved acceptance in appearance and aroma but reduced the intensity of the emotions “active,” “loving,” “energetic,” and “healthy.” Based on sensory data, it is recommended to use demerara sugar or fructose as a substitute for sucrose. In conclusion, the study of emotions can be used as an additional tool for obtaining data related to the sensory acceptance of products.     

Application of near (NIR) infrared and mid (MIR) infrared spectroscopy as a rapid tool to classify extra virgin olive oil on the basis of fruity attribute intensity

A sensory analysis of 112 virgin olive oils was performed by a fully trained taste panel. The samples were divided in “defective” and “not defective” on the basis of their olfactory attributes. Then, the “not defective” samples were classified into “low”, “medium” and “high” according to the fruity aroma intensity perceived by assessors. All samples were also analysed by FT-NIR and FT-IR spectroscopy and processed by classification methods (LDA and SIMCA). The results showed that NIR and MIR spectroscopy coupled with statistical methods are an interesting technique compared with traditional sensory assessment in classifying olive oil samples on the basis of the fruity attribute. The prediction rate varied between 71.6% and 100%, as average value. The spectroscopic methods, combined with chemometric strategies, could represent a reliable, cheap and fast classification tool, able to draw a complete fingerprint of a food product, describing its intrinsic quality attributes, that include its sensory attributes.     

Asians’ Facial Responsiveness to Basic Tastes by Automated Facial Expression Analysis System

Growing evidence shows that consumer choices in real life are mostly driven by unconscious mechanisms rather than conscious. The unconscious process could be measured by behavioral measurements. This study aims to apply automatic facial expression analysis technique for consumers’ emotion representation, and explore the relationships between sensory perception and facial responses. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with 6 levels plus water were used, which could cover most of the tastes found in food and drink. The other contribution of this study is to analyze the characteristics of facial expressions and correlation between facial expressions and perceptive hedonic liking for Asian consumers. Up until now, the facial expression application researches only reported for western consumers, while few related researches investigated the facial responses during food consuming for Asian consumers. Experimental results indicated that facial expressions could identify different stimuli with various concentrations and different hedonic levels. The perceived liking increased at lower concentrations and decreased at higher concentrations, while samples with medium concentrations were perceived as the most pleasant except sweetness and bitterness. High correlations were founded between perceived intensities of bitterness, umami, saltiness, and facial reactions of disgust and fear. Facial expression disgust and anger could characterize emotion “dislike,” and happiness could characterize emotion “like,” while neutral could represent “neither like nor dislike.” The identified facial expressions agree with the perceived sensory emotions elicited by basic taste solutions. The correlation analysis between hedonic levels and facial expression intensities obtained in this study are in accordance with that discussed for western consumers.     

An itinerant sensory approach to investigate consumers' perception and acceptability at a food exhibition

In a food exhibition where several producers of the same product category are present at the same time, consumers usually have the opportunity to taste several free samples of the same product type, thus they can experience and compare the sensory characteristics of each and evaluate their liking for each sample tasted. This study assessed the potential of an itinerant sensory data collection in understanding the consumers' perception and acceptance of cheese during a multiple tasting experience at a food exhibition. Subjects tasted seven samples of Parmigiano Reggiano cheese aged for different times (24 and 36 months) at seven producer stands and recorded their evaluations using tablets, on which an application specifically developed for this study was installed. This evaluation situation was defined as “pseudo-natural,” in opposition to the “natural” and the “naturalistic” settings. The itinerant sensory session comprised a liking test, a rate-all-that-apply (RATA) test using a just about right (JAR) scale, a food pairing test, and a questionnaire. Consumers significantly (p < 0.05) discriminated the cheeses as a function of the aging time, describing with different attributes the 24 months (sweetness, fresh fruit, grass, yogurt, butter flavors, elasticity, and humidity) and the 36 months (saltiness, bitterness, sourness, spicy, aromatic herbs, cheese rind flavors, crumbliness, granularity, hardness, and hotness) aged products. The combined application of regression models, Penalty-Lift analysis, and decision tree models in investigating the relationships between liking and the RATA data, provided results revealing that the attributes elasticity, sweetness, humidity, fresh fruit, and butter were the main drivers of liking. Whereas, the attributes sourness, bitterness, and hardness were the main drivers of dislike. Therefore, even though no significant differences in terms of liking were observed among the tested cheeses, consumers preferred the attributes more frequently perceived in the least aged products. In conclusion, the presented itinerant sensory approach had provided meaningful information to understand the consumers' cheese perception and acceptability. In the future, it could advantageously be applied for studying food perception in other situations in which subjects naturally choose or consume several products while freely moving from one to another (e.g. self-service restaurant).     

Sensory Characterization of Sweet Corn Lines Differing in Physical and Chemical Composition.

Chemical, physical and sensory characteristics were determined in a population of 103 F₃ families derived from the cross between two sweet corn inbreds that differed in kernel properties associated with eating quality. Kernel characteristics correlated well with panel perception of sensory attributes. Chemical, physical and sensory properties were grouped into three factors: taste—including sweetness, starchiness, juiciness, and sucrose and starch concentrations; texture—crispness, tenderness, juiciness and cooked kernel tenderness; and aroma—sweet corn aroma, grassy aroma, grassy flavor and concentrations of an unknown volatile (V179). The relative importance in determining overall liking was taste 45.1, texture 30.5, and aroma 24.4%.     

Spin versus fair speak in food labelling: A matter of taste?

The article sheds new light on sensory elements in legal cases concerning misleading food labelling. It presents the findings of a qualitative review of 821 cases on misleading food labelling registered in 2002–2007 by the Danish food authorities. The cases show that sensory tends to be backgrounded by other arguments more easily verbalized. A taxonomy of the sensory dimensions of the cases is set up and different sensory aspects are analyzed in order to establish to what the extent and how sensory variables can be integrated into experimental setups for testing the misleading potential of food naming and labelling solutions with a view to promoting “fair speak” principles for in-store food-to-consumer communication. The study is part of the cross-disciplinary research project “Spin or fair speak – when foods talk” which aims at providing new knowledge, tools, and experimental evidence for self-regulation, public control, and innovation in food naming and labelling.     

Sensory methods and electronic nose as innovative tools for the evaluation of the aroma transfer properties of food plastic bags

Despite the key role of the sensory quality for food acceptance, the aroma transfer properties of food packaging materials have not yet been studied using sensory approaches. This research investigated the suitability of sensory and electronic nose methods to evaluate the aroma transfer properties of plastic materials that come in contact with food. Four (W, X, Y, and Z) commercial freezer bags (polyethylene) for domestic uses were compared. The degree of the aroma transfer through the materials was estimated as the sensory contamination of an odor absorber food (bread) by an odor releaser food (onion), separated by the bags and stored under frozen conditions. Bread samples were analyzed by means of an electronic nose, and 42 assessors used three different sensory methods (triangle, scoring, and partial sorted Napping tests). From the triangle test, none of the plastic bags acted as a complete aroma barrier, showing a sensory contamination of bread stored in all four materials. Partial sorting Napping results clearly described the sensory contamination of bread as “onion flavor”, due to the aroma transfer from the odor releaser food to the odor absorber food through the plastic bag. Scoring tests showed significant (p < 0.0001) differences of aroma transfer properties among the plastic bags, revealing the highest aroma permeation for W (3.1 ± 0.1), the lowest aroma transfer for X and Y (2.0 ± 0.1), and intermediate aroma transfer properties for Z (2.6 ± 0.1). Electronic nose data were in good agreement with the sensory responses, and a high correlation with the scoring data was observed (R² = 0.988). The presented approaches had suitable results to provide meaningful information on the aroma transfer properties of freezer plastic bags, and could advantageously be applied in the future for analyzing other finished food containers (e.g. plastic trays, boxes, etc.) or packaging materials of a different nature (multilayer plastic films, biodegradable materials, composites, etc.).     

Sensory Profiles for Dried Fig (Ficus carica L.) Cultivars Commercially Grown and Processed in California

A trained sensory panel evaluated the 6 fig cultivars currently sold in the California dried fig market. The main flavor and aroma attributes determined by the sensory panel were “caramel,” “honey,” “raisin,” and “fig,” with additional aroma attributes: “common date,” “dried plum,” and “molasses.” Sensory differences were observed between dried fig cultivars. All figs were processed by 2 commercial handlers. Processing included potassium sorbate as a preservative and SO₂ application as an antibrowning agent for white cultivars. As a consequence of SO₂ use during processing, high sulfite residues affected the sensory profiles of the white dried fig cultivars. Significant differences between dried fig cultivars and sources demonstrate perceived differences between processing and storage methods. The panel‐determined sensory lexicon can help with California fig marketing.