This thesis deals with the assessment of aroma active compounds in gooseberry and sensory analysis of it focusing on flavour. The theoretical part describes general characteristics, biological marks and properties of selected varieties, healing abilities, the active substances contained in gooseberry fruits and their use. The aim of the experimental part was to determine aroma-active substances contained in fruits of nineteen selected cultivars of gooseberry using SPME-GC-FID method. In total 45 volatile compounds were identified, among them 17 alcohols, 11 aldehydes, 6 ketones, 9 esters and 2 acids. For a better identification one sample (Captivátor variety) was also analysed using GC-MS with purge and trap extraction. Pentan-1-ol, hexanal, pentanal, ethylethanoate, ethylbutanoate, methylethanoate, methylbutanoate and ethanol were confirmed using mass spectra. Only several cultivars were selected for the assessment of overall sensory quality and palatability of fruits. Karmen and Remarka varieties were considered as the best samples by assessors.

No description available.

Kudzu (Pueraria lobata) is an edible vine from the legume family native to China but growing prolifically throughout the southeastern United States. Legumes are abundant in the beneficial compounds phytoestrogens, specifically isoflavones. This research analyzed Mississippi-grown kudzu roots, leaves, and flowers for antioxidant activity and total phenolic content and evaluated consumer acceptability of food products containing kudzu. Results indicated kudzu flowers, roots, and leaves contained phenolic compounds and the antioxidant activity amounts in flowers, roots, and leaves were 77.9%, 75.7%, and 56.5%, respectively. The dip products that were developed and evaluated were mayonnaise- and sour cream-based dips that contained either dried kudzu leaves or dried spinach and other seasonings. Healthier versions of dip products were developed using light mayonnaise and light sour cream and omitting salt. Consumer sensory panels evaluated appearance, aroma, flavor, texture, and overall acceptability of the dip samples using a 9-point hedonic scale. A randomized complete block design with three replications was used to determine if differences (p<0.05) in consumer acceptability existed among treatments. On average, the regular spinach dip was moderately liked and preferred (p<0.05) over the other dips. The regular kudzu dip was moderately liked and preferred (p<0.05) over the healthier kudzu and spinach dips. Cluster analysis partitioned consumers into five groups based on preference and acceptability of vegetable dips. Results indicated 39% of panelists rated the dips at like very much and did not differ (p>0.05) in their liking of dips, 42% preferred (p<0.05) the regular spinach dip and 50% liked all vegetable dips. A kudzu blossom jelly product was developed using kudzu flower liquid, sugar, pectin, and lemon juice. Consumer sensory panels evaluated the prepared jelly product, a purchased kudzu jelly, and a purchased scuppernong jelly. A randomized complete block design with three replications was used to determine if differences (p<0.05) in consumer acceptability existed among jellies. The purchased kudzu jelly was preferred (p<0.05) for overall acceptability (like moderately) compared to the prepared kudzu and scuppernong jelly, which were rated similarly between like slightly and like moderately.

Celiac disease is characterized by an allergic reaction to gluten that causes inflammation of the small intestine and can lead to malabsorption and malnutrition. Glutenree products are being developed that meet dietary needs of individuals with celiac disease. However, these products often lack whole grains and fiber. Fortification of glutenree products with flax can increase nutritional value and alleviate inflammation. Sensory analysis (N=152) was conducted to evaluate the acceptability of glutenree muffins with moderate (3.8%) and high (7.4%) amounts of added flax. Results indicated that consumers preferred (p<0.05) the muffin without flax or the highlax muffin more than the muffin with the moderatelax treatment. The highlax and control treatments were rated 6.7, between like slightly and moderately like; the muffins from the moderatelax treatment were rated 6.4 on a nine-point hedonic scale. Producers of glutenree products could potentially formulate muffins that include flax and are acceptable to consumers.

Hard cider is an alcoholic beverage made from fermented apple juice. Its popularity has grown rapidly since the early 2000s and is expected to grow to a billion-dollar industry by 2022. However, unlike beer and wine, there are few popular resources and little scholarly research on the sensory attributes of ciders and how consumers perceive them. Thus, the purpose of this study was to categorize and describe the sensory and visual product attributes of ciders made in Virginia, USA using a rapid sensory evaluation method with untrained panelists known as a free sorting task. Specifically, panelists (N=65) first evaluated, sorted into groups, and described ciders (K=18). Then panelists (N=63) sorted photo sheets of cider labels and packaging according to how they expected the products would taste and at what occasion they would be most inclined to drink each cider. The data were analyzed with DISTATIS to produce compromise similarity maps, with bootstrapped confidence intervals to identify significant differences between products. Classical text analysis was used to evaluate the sensory descriptions used by assessors during the sorting task and project terms onto the similarity map. Panelists identified and described distinct sensory styles and attributes among the ciders evaluated. Consistent patterns in what occasion panelists might consume a cider emerged, providing a first-look into how cider might be valued based on packaging and label. / Master of Science in Life Sciences / Hard cider is a beverage made from fermented apple juice. Its popularity has grown rapidly since the early 2000s and is expected to grow to a billion-dollar industry by 2022. However, there are few popular resources and little scholarly research on the sensory attributes of ciders and how consumers perceive them. The purpose of this study was to categorize and describe the sensory and visual product attributes of ciders made in Virginia using sorting tasks with untrained panelists. Specifically, panelists (N=65) first evaluated, sorted into groups, and described ciders (K=18). Panelists (N=63) then sorted photo representations of cider labels and packaging according to how they expected the products would taste and at what occasion they would be most inclined to drink each cider. The data were analyzed with DISTATIS, an extension of multidimensional scaling, to produce product similarity maps with confidence intervals to identify significant differences between products. Classical text analysis was used to evaluate the sensory descriptions used by assessors during the sorting task and project terms onto the product maps. Panelists identified and described distinct sensory styles and attributes among the ciders evaluated. Consistent patterns in what occasion panelists might consume a cider emerged, providing a first look into how cider might be valued based on packaging and label. The findings act as a first step in understanding how consumers may describe and perceive hard cider and will aid in future sensory research on consumer liking, purchase intent, and acceptance of hard cider.

Ce travail a pour objectif de caractériser et analyser le bruit de frottement des étoffes textiles généré lors de l’activité d’un individu (marche et course). Le présent travail apporte une contribution pour la caractérisation physique du bruit de frottement grâce à des paramètres physiques du son (bruit) et grâce à une nouvelle méthode de traitement du signal sonore des étoffes textiles, la transformée en S (transformée de Stokwell). L’évaluation sensorielle du bruit a été menée grâce à des panélistes entraînés en appliquant la méthode d’Analyse Descriptive Quantitative. Dans ce cadre, l’influence de l’armure d’étoffes en coton écru sur les propriétés sonores a été analysée. La corrélation entre les paramètres mécaniques des tissus qui décrivent l’état de surface et la compression de l’étoffe (mesurés par la chaîne de mesure Kawabata Evaluation System) et le niveau sonore global du bruit de frottement a été effectuée. Une corrélation entre le niveau sonore et les descripteurs sensoriels a été également menée. Le bruit d’une veste d’homme, confectionnée en deux types de prototypes présentant des variantes de manches, a été analysé en situation réelle, dans une chambre anéchoïque.Selon le traitement des signaux sonores, l’armure sergé 3 est la plus bruyante avec un niveau sonore, une amplitude du maximum les plus importants, pour les deux vitesse de frottement (marche et course), et une fréquence de maximum se trouvant dans la zone fréquentielle pour laquelle l’oreille humaine est la plus sensible. L’armure satin 4 est la plus ‘furtive’ avec un niveau sonore, une amplitude du maximum la moins importante et une fréquence correspondant importante et moins perceptible. Les résultats obtenus par l'analyse sensorielle sont cohérents avec les résultats obtenus en terme instrumental. Les panélistes qui participent à l'évaluation du bruit de frottement des étoffes textile ont perçu le bruit du satin 4 comme le bruit le plus sourd et le plus homogène, alors que le bruit du sergé 3 a été perçu comme le bruit le plus énergique et le plus disharmonique. Les modèles établis expriment que le niveau sonore augmente en fonction de la rugosité de surface et diminue en fonction de la résilience et de l'énergie de compression. Ainsi, plus que le niveau sonore est important, plus que le bruit est perçu plus polyphonique et plus grattant. Les bruits générés par le frottement de la veste avec les deux types de manche sont similaires en termes instrumental et sensoriel. / This work aims to characterize and analyze the frictional noise of textile materials generated during the activity of a subject (walking and running). This work contributes to the physical characterization of frictional noise characterized by physical parameters of sound (noise) and thanks to a new method of treatment of the acoustic signal, Stokwell-transform. Sensory evaluation of frictional noise was conducted by trained panelists using the Quantitative Descriptive Analysis method. In this context, the influence of the weave patterns of raw cotton fabrics on sound properties was analyzed. Correlations between the mechanical parameters of the fabric which describe the surface and the compressional proprieties of fabrics (measured by the Kawabata Evaluation System) and the sound level of the frictional noise were conducted. Correlations between the noise level and sensory descriptors were also conducted. The sounds of a man's jacket, fabricated in two types of prototypes with sleeves variants were analyzed in situation case, in an anechoic room. According to the treatment of acoustic signal, the twill 3 weave pattern is the noisiest one with a most important level sound and highest amplitude for the two types of movement (walking and running). The satin 4 weave pattern, which is the less noisy, presents a sound level and its highest amplitude is the less important. The frequency of highest amplitude is less important for twill 3 than satin 4. The results obtained by sensory analysis are coherent with the results obtained by instrumental characterization. The subjects participating to sensory evaluation of frictional noise of these fabrics perceived that the noise of satin 4 as the most muffled and most homogeneous noise, while the noise of twill 3 was perceived as the most dynamic and the most disharmonic one. Proposed models express that the sound level increases with the surface roughness and decreases with the resilience and the compression energy. The more sound level is important, the more the noise is perceived as polyphonic and scratching. The noise generated by the friction of the jacket with the two types of sleeves is similar whatever the evaluation.

No description available.

Doctor of Philosophy / Department of Human Nutrition / Delores H. Chambers / A green tea descriptive sensory lexicon was developed by a highly trained panel, which identified, defined, and referenced 31 flavor attributes of green tea. The attributes were categorized as “green” (asparagus, beany, Brussels sprout, celery, parsley, spinach, green beans, and green herb-like), “brown” (ashy/sooty, brown spice, burnt/scorched, nutty, and tobacco), “fruity/floral” (fruity, floral/perfumy, citrus, and fermented), “mouthfeel” (astringent and tooth-etching), “basic tastes” (overall sweet and bitter), and other attributes (almond, animalic, grain, musty/new leather, mint, seaweed, and straw-like). Using the green tea lexicon, the flavor differences that exist among a wide range of green teas (n=138) produced in various countries were determined. Roast-processed teas were mostly responsible for brown-related flavors and steam-processed teas were mostly responsible for green-related flavors. Aroma analyses of green tea showed that the concentration of volatile compounds were much lower than stated in the literature. Brown, brown-related attributes, bitterness, and astringency became stronger and green and green-related attributes become weaker as the brewing time lengthened (1, 2, 5, and 20 min) and the water temperature increased (50, 70, 95°C). The flavor characteristics of roast-processed, steam processed, or roast-steam-processed Korean green teas differed only in their characterizing green flavors. The flavor and aroma of green teas change after sequential brewings. Green teas in leaf form can be brewed four times: the first two brews providing stronger flavor and aroma characteristics whereas the third and fourth brews will provide milder flavor and aroma characteristics. The flavor and aroma change in green teas that are stored over two years were observed at 3, 6, 12, 18, and 24 months after their original packaging dates. Green tea changes minimally during the first year of storage and only slightly more during the first two years of storage. Consumer studies and descriptive evaluations were conducted to understand what green tea flavor characteristics influence US consumers' liking. Twelve green tea samples were evaluated by three consumer groups from Korea, Thailand, and the United States. The current research suggests that familiarity plays a role in tea acceptance. However, various flavor profiles may be acceptable to consumers who are familiar with other flavors of green tea.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Brandy has a high alcohol content of at least 36% alcohol by volume and a complex volatile chemical structure. Due to this, the sensory evaluation of brandy is challenging to execute and must be carefully managed to avoid panellists’ sensory and mental fatigue. Although rapid sensory profiling methods, such as projective mapping (PM), are commonly used for fast moving consumer goods, it was unclear whether these methods could accommodate the difficulties associated with brandy evaluation. The primary objective of this study was to validate PM, also called Napping®, as a reliable tool for brandy evaluation. Two variations of PM were tested: global napping (GN) where products are evaluated based on overall sensory perception, and partial napping (PN) where the product perception is broken down in to separate sensory modalities, in this case appearance, aroma and in-mouth sensations. Several practical aspects of PM were investigated in order to optimise the method for brandy evaluation and to gain understanding into practical methodological aspects that have not been fully understood at the onset of this study. The results showed that both GN and PN delivered reliable results, but that PN was more reproducible and better suited to larger sample sets (10 products). The concept of in-mouth sensations was found to be ineffective in extracting useful information on mouthfeel differences in the product set and that retronasal flavour should be separated from basic tastes and mouthfeel. A verbal instruction to the panellists was sufficient to obtain reliable information on mouthfeel differences; it was not necessary to use black glasses or nose-clips to eliminate the influence of appearance and flavour perception. In response to the insufficient reproducibility of GN, the sorting method was tested and validated as a suitable screening method that delivered reliable product maps of larger sample sets (10 products) in one replication, compared to GN which has to be replicated several times. A recent hypothesis states that the elongated horizontal dimension of a rectangular PM tasting sheet could be used to elicit more prominent product differences, while tasting sheets without an elongated axis, such as circles or squares, could be used to bring forth more subtle differences. This hypothesis was challenged by testing rectangular, square and round tasting sheet shapes. Although differences were observed between the shapes in terms of product configuration and panellist performance, the practical value of using different tasting sheet shapes to obtain specific information could not be established. The impact of high alcohol content and product complexity on panellist performance in PM was tested and it was concluded that product complexity did influence the panellists’ performance, particularly for high alcohol products. It was also found that prior knowledge of a products’ high alcohol content influenced the panellists’ descriptive language to include more alcohol-related terms. A new panellist performance measure was developed, namely the Relative Performance Index (RPI). This measure can be used to monitor trained panellists’ performance in the PM task more effectively to thereby ensure reliable results. The outcomes of this study extended the brandy sensory evaluation toolbox. Practical measures were identified that can be used to overcome the challenges associated with the sensory evaluation of complex high alcohol products. / AFRIKAANSE OPSOMMING: Met ‘n alkohol inhoud van mintens 36% alkohol per volume en ‘n komplekse vlugtige chemise samestelling is brandewyn ‘n uitdagende produk om sensories te evalueer. Maatreëls moet in plek gestel word om te verhoed dat sensoriese paneellede nie uitgeput raak nie om sodoende betroubare resultate te verseker. Hoewel vinnige sensoriese toetsmetodes, soos projeksiekartering (PM) en sortering, gereeld gebruik word vir die evaluasie van vining bewegende verbruikersgoedere was dit weens die voorafgenoemde redes onduidelik of die metodes geskik sou wees vir brandewynevaluasie. Die oorhoofse doelwit van hierdie projek was om PM, ook genoem Napping®, te valideer as ‘n geskikte metode vir die sensoriese evaluering van brandewyn. Twee variasies van PM is ondersoek: oorhoofse kartering (GN) waar die produkte op grond van ‘n algehele sensoriese waarneming evalueer word, en gedeeltelike kartering (PN), waar die verskillende sensoriese waarnemingsmodaliteite afsonderlik gemeet word. In hierdie geval is voorkoms, aroma en algehele binne-mondse ervaring gemeet. Verskeie aspekte van GN en PN is ondersoek ten einde die metodes vir brandewynevaluasie te optimiseer asook lig te werp op praktiese metodologiese aspekte waaroor daar nog onsekerheid was by die aanvang van hierdie studie. Die resultate het getoon dat beide GN en PN betroubare inligting oor brandewyn kan oplewer, maar dat PN meer herhaalbaar en beter geskik is vir groter produkstelle (10 produkte). Dit is egter bevind dat die konsep van algehele binne-mondse waarneming nie doeltreffend was om mondgevoelverskille tussen produkte uit te lig nie. Smaak- en mondgevoelwaarnemings moet liefs onderskei word van binne-mondse geurwaarneming. Dis bevind dat dit voldoende is om hierdie onderskeid deur skriftelike instruksies tot die paneel te bewerkstelling en dat die gebruik van swart glase en neusknippies nie nodig was om betekenisvolle inligting oor mondgevoel te bekom nie. Na aanleiding van die swak herhaalbaarheid van GN, is sortering getoets en gevalideer as ‘n geskikte siftingsmetode wat betroubare produkkaarte van groot produkstelle (10 produkte) kan oplewer met slegs een evaluasie, teenoor GN waarvoor meer as een sessie benodig word. ‘n Onlangse hipotese stel dat die langer horisontale dimensie van reghoekige PM proekaarte gebruik kan word om meer prominente verskille tussen produkte uit te wys, terwyl proekaarte sonder verlengde asse, soos sirkels en vierkante, gebruik kan word om meer subtiele verskille uit te wys. Hierdie hipotese is bevraagteken deur reghoekige, vierkantige en ronde PM proekaarte teenoor mekaar te toets. Hoewel die resultate vanaf die verskillende proekaarte effens verskil het in terme van produk konfigurasie en die paneel se taakverrigting, kon die praktiese waarde van die gebruik van produkkaarte met verskillende vorms om spesifieke inligting te bekom nie bevestig word nie. Die impak van hoë alkohol en produkkompleksiteit op paneellede se PM taakverrigting is ondersoek. Dit is bevind dat produkkompleksiteit wel hul taakuitvoering beinvloed, en dat hierdie invloed groter is vir hoë alkohol produkte. Dit is ook gevind dat paneellede se beskrywende taalgebruik beïnvloed om meer alkoholverwante woorde in te sluit word indien hul kennis dra van ‘n produk se hoë alkohol inhoud. ‘n Nuwe vaardigheidsberaming vir die meet van paneellede se taakverrigting is ontwikkel, naamlik die Relatiewe Taakverrigtingsindeks (RTW). Dit kan gebruik word om paneellede se vaardigheid in PM meer doeltreffend te monitor en sodoende betroubare resultate te verseker. Die uitkomste van die studie het die poel beskikbare metodes vir die sensoriese evaluering van brandewyn suksesvol verbreed en praktiese maatreëls is geidentifiseer om die uitdagings van ‘n komplekse hoë alkohol produkte te oorkom.

L'objectif de la thèse est de contribuer à l'explicitation du lien au terroir, dans le cas de vins d'Appellation d'Origine Contrôlée. À ce lien au terroir correspond une typicité, qui correspond à des propriétés remarquables et partagées pour un groupe humain de référence. Le lien causal entre typicité et terroir a été étudié en prenant comme élément d'étude le chantier de vendange et les vinifications associées. La composition phénolique des vendanges, et leur aptitude à être extraits lors de la vinification ont permis de mieux interpréter le lien causal étudié. La représentation conceptuelle de la typicité, qui engendre des choix techniques, a été mise en évidence, du point de vue des critères sensoriels d'appartenance et des critères sensoriels de distinction. Cette représentation conceptuelle est en générale consensuelle, et les principaux facteurs du terroir, explicatifs du lien, correspondent au milieu physique. La représentation perceptuelle a été étudiée, permettant de mettre en évidence des descripteurs d'appartenance et de distinction, et de les hiérarchiser vis à vis de la perception globale de la typicité. Cette représentation est moins consensuelle. Les principaux facteurs du terroir, explicatifs du lien, correspondent aux actes techniques, en particulier la date de vendanges et la durée de cuvaison.Une évolution de la composition de la vendange en fonction du niveau de maturité a été mise en évidence d'un point de vue histologique, mais son interprétation est incomplète. L'aptitude des proanthocyanidines à être extraits, en fonction du niveau de maturité des baies est fortement corrélé à la perception globale de la typicité. Dans le cas de vins revendiquant un lien au terroir, certaines représentations de la typicité sont partagées, et engendrent des choix techniques (date de vendange, durée de cuvaison). L'importance de ces choix peut être démontré par l'étude de la composition de la vendange en composés phénoliques. Cependant, il existe un écart entre la typicité en tant que concept et la typicité telle qu'elle est sensoriellement perçue. / The aim of this work is to contribute to highlight the terroir effect, in the case of wines from delimited origin. The typicality is the result of the terroir effect and corresponds, to remarkable and shared properties for a human group of reference. The causal link between typicality and terroir was studied by taking into account the harvest date and the associated wine makings. The phenolic composition of the grape at harvest, and their extractability during the wine making made it possible to better interpret the studied causal link. The conceptual representation of the typicality, which generates technical choices, was highlighted, from the point of view of the sensory criteria of similarity and of distinction. This conceptual representation is in general consensual, and the main factors of the terroir, which explain the causal link, correspond to the soil and climate. The perceptual representation was studied, descriptors of similarity and distinction were highlighted, and theses descriptors were organized with respect to the global perception of the typicality. This representation is less consensual than conceptual one. The main factors of the terroir, which explain the causal link, correspond to the technical acts, particularly the harvest date and the vatting duration.Composition of the harvest, according to the level of maturity was highlighted from a histological point of view, but its interpretation was unfinished. The aptitude of the proanthocyanidins for being extracted, according to the level of maturity is strongly correlated for the global perception of the typicality. For wines related to terroir, some typicality representations are shared, and lead to technical choices (harvest date, duration of vatting). These choices are explained by the harvest composition. However, there is a difference between the typicality as a concept and the typicality as sensory perception.