This study was concerned with the recovery of aroma compounds from aqueous solutions by pervaporation using poly(ether-block-amide) (PEBA) membranes. Three model aroma compounds (i.e., propyl propionate, C6-aldehyde and benzaldehyde) were used in the study to represent ester, aldehyde and aromatic aroma compounds, respectively. The effects of process conditions (i.e., feed concentration and operating temperature) on the pervaporation performance (in terms of permeation flux and selectivity) for aroma-water separations were investigated. It was found that both the aroma permeation flux and the selectivity were affected significantly by the feed aroma concentration. The aroma permeability was in the order of propyl propionate > C6-aldehyde > benzaldehyde, and the membrane selectivity for aroma/water separation followed the order of C6-aldehyde > propyl propionate > benzaldehyde. In general, the aroma flux was found to be proportional to the aroma compound concentration in the solution. In the concentration range (390-3,200 ppm) tested, the effect of temperature on the permeation flux followed an Arrhenius type of relation. The solubility and diffusivity of the aroma compounds in PEBA membrane, which determine their permeabilities through the membrane, were determined from the pervaporation and sorption/desorption data. It was shown that the solubility of the aroma compounds in the PEBA membrane generally followed the Henry’s law where the sorption uptake was proportional to the feed aroma concentration. Among the three aroma compounds studied, benzaldehyde was found to have the highest solubility selectivity in the PEBA membrane, followed by C6-aldehyde and propyl propionate. The solubilities of pure propyl propionate and water in PEBA membrane were also estimated; the solubility of pure propyl propionate was around 130 times higher than that of pure water. This confirmed that PEBA was an excellent organophilic membrane. The diffusivity of the aroma compounds through PEBA membrane was affected by the feed aroma concentration. From steady state pervaporation and equilibrium sorption data, the diffusivity was calculated on the basis of solution-diffusion model, and the diffusivity was shown to be linearly dependent on the feed aroma concentration. On the other hand, from the sorption kinetics data obtained from the time-dependent sorption experiments, the diffusivity was shown to be affected by the feed aroma concentration exponentially. The main reason may be that the simple form of the solution-diffusion model is unable to precisely describe the mass transport through the membrane during pervaporation. As an alternative to pervaporation where the liquid feed is in contact with the membrane and the mass transport involves permeation and evaporation (thus the word “pervaporation”), evaporation-permeation (or evapermeation, where the feed liquid is not in direct contact with the membrane and the mass transfer involves evaporation and then permeation) was also studied for aroma compound separation from water. It was shown that evapermeation was no better than pervaporation in terms of permeation flux and selectivity. This again demonstrated that the state of the membrane and the location for liquid-vapor phase change were important to the mass transport through the membrane. For aroma recovery from dilute aqueous solutions, batch pervaporation is often preferred. Batch pervaporation coupled with permeate decantation and water phase recycle was studied parametrically. It was demonstrated that compared to the conventional pervaporation, the aroma recovery can be enhanced by recycling the water phase from the permeate decanter to the feed for further recovery. In addition, unlike the conventional batch operation where the product concentration starts to decrease beyond certain time, the modified batch pervaporation allows a longer period of operation without compromising the product purity.

Šiame darbe atskleidžiami jutiminio marketingo sampratos ir esmės teoriniai aspektai, analizuojama jutiminių elementų sąveika bei kvapų naudojimo įtaka marketinge. Kvapų naudojimo pardavimams didinti praktika Lietuvoje yra nežinoma, todėl nuspręsta atlikti užsienio mokslininkų tyrimų analizę, kvapo naudojimo pardavimams didinti įvykdytų kampanijų pavyzdžių analizę. Dėl iškeltos hipotezės patvirtinimo arba paneigimo, jog kvapo naudojimas gali padidinti pardavimus, atliekamas trijų etapų eksperimentinis tyrimas. Tyrimo rezultatai nepatvirtina iškeltos hipotezės. Darbe yra įvardinami eksperimentinio tyrimo galimi trikdžiai. Taip pat yra pristatomi susisteminti kvapo naudojimo sprendimai įvairiose srityse bei apibendrintai pateikiami galimi kvapo naudojimo rezultatai. Autorės sudarytas kvapo naudojimo marketingo priemonių veiksmingumui didinti modelis pristato apibendrintą kvapų naudojimo algoritmą pagal vidinius, išorinius ir jutiminius veiksnius. / This paper deals with analyzing sensory marketing conception. Firstly, the theoretical aspects of senses and aroma marketing are examined. There aren‘t many projects implemented in Lithuania of using scents in marketing, especially using scents to increase sales. This reason conditioned to doing analysis of using scents to increase sales in retail according to foreigner’s scientists researches and realised campaigns of using scents in retail. In order to confirm or deny the hypothesis, that congruent scent can increase sales, an experiment had been carried out in Lithuania. Experiment results deny the hypothesis. The research identifies some potential interferences for an experiment. This paper shows the solutions of using scents in various areas and possible results that might occure. Also, it is done and introduced a model for using scents in marketing in case to increase it’s efficiency. This model is made of internal, external and additional forces analysis.

The effect of micronization (at 130 and 150 °C) as a potential heat treatment to reduce ‘beany’ aroma and flavor of cooked chickpea (Cicer arietinum) and green lentil (Lens culinaris) flours was investigated. A simultaneous distillation solvent extraction method was developed to extract key volatile compounds with potential contribution to ‘beany’ aroma and flavor notes in micronized pulse flours and analyzed by gas chromatography-mass spectrometry. Concentrations of volatile compounds such as pentanol, hexanal, 2-hexenal, hexanol, heptanal, furan-2-pentyl, 2-octenal, nonanal, 2,4 decadienal, and 2,4- undecadienal were significantly (P<0.05) decreased with micronization. Low fat burgers fortified with 6% micronized chickpea and green lentil flours showed significantly higher acceptability for aroma, flavor, texture, color and overall acceptability (p<0.05) compared to non-micronized samples in a consumer acceptability test with 101 consumers. In addition, fatty acid analysis of burgers showed burgers containing micronized pulses had higher level of linoleic and linolenic acid content.

The effect of micronization (at 130 and 150 °C) as a potential heat treatment to reduce ‘beany’ aroma and flavor of cooked chickpea (Cicer arietinum) and green lentil (Lens culinaris) flours was investigated. A simultaneous distillation solvent extraction method was developed to extract key volatile compounds with potential contribution to ‘beany’ aroma and flavor notes in micronized pulse flours and analyzed by gas chromatography-mass spectrometry. Concentrations of volatile compounds such as pentanol, hexanal, 2-hexenal, hexanol, heptanal, furan-2-pentyl, 2-octenal, nonanal, 2,4 decadienal, and 2,4- undecadienal were significantly (P<0.05) decreased with micronization. Low fat burgers fortified with 6% micronized chickpea and green lentil flours showed significantly higher acceptability for aroma, flavor, texture, color and overall acceptability (p<0.05) compared to non-micronized samples in a consumer acceptability test with 101 consumers. In addition, fatty acid analysis of burgers showed burgers containing micronized pulses had higher level of linoleic and linolenic acid content.

Pervaporation is a selective membrane technique in which a liquid feed mixture is separated by means of partial vaporization through a non-porous perm-selective membrane. This method can be used for the recovery of heat sensitive aroma compounds to avoid them from thermal damage in beverage industries. The main objective of this study was to determine the effects of feed temperature (30, 40, 50&deg / C), composition (different model solutions, strawberry essence), concentration (50, 100, 150 ppm) and permeate pressure (4, 8 mbar) on the recovery of aroma compounds of strawberry by pervaporation in terms of mass flux and selectivity. In addition, it was aimed to optimize the extraction conditions (extraction time, temperature, agitation speed, strawberry matrix) of Solid-phase microextraction (SPME), which is used for the analysis of strawberry aroma compounds. Optimum results for SPME were obtained at 40&deg / C, 700 rpm for 30 min and no matrix effect was observed. Pervaporation experiments were performed using a hydrophobic membrane, PERVAP 1070 (PDMS). As the feed temperature increased, the mass flux and selectivity increased and the total mass flux followed an Arrhenius type relation. Decreasing downstream pressure increased both total flux and selectivity, while increase in feed concentration led to higher organic fluxes but lower selectivities. In general, PERVAP 1070 showed a higher selectivity towards Methyl butyrate (MTB) than Ethyl butyrate (ETB) and MTB flux was affected negatively by the presence of ETB in the feed solution. Pervaporation experiments were also performed with a strawberry essence and strawberry model solution. The selectivities of MTB and ETB were negatively affected by the presence of other aroma compounds.

Zugl.: Bonn, Univ., Diss.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Yeast strains contend with numerous stresses during winemaking. An inability to perceive and initiate the physiological changes needed to adapt to stress, has been linked to slow or incomplete (residual sugar > 4 g/L) fermentations. Wine yeast strains differ in genotype; this is manifested as differences in their stress tolerance, and fermentation performance. The first goal of this study was to evaluate how the initial sugar (200 or 240 g/L) and nitrogen (50, 100, 250, or 400 mg/L) content, and the fermentation temperature (15°C or 20°C) affected the fermentation performance of 17 commercial wine yeast strains. Fermentation performance was evaluated based on the fermentation kinetics (lag phase, maximum fermentation rate and total weight loss by CO2 evolution), residual sugar content and yeast dry weight. The results demonstrate that the fermentation performances of commercial yeast cultures are significantly and differently affected by initial nitrogen and sugar levels, as well as the fermentation temperature. Additionally, excess nitrogen had a negative impact on the fermentation kinetics and sugar consumption. Nitrogen deficiency is a common cause of slow and incomplete fermentations, as it affects yeast growth and thus fermentation rates. Nitrogen supplements are routinely added at the onset of fermentation, reducing the risk of problematic fermentations. Therefore characterising the fermentative ability of a strain over a range of oenologically relevant conditions, could aid winemakers in selecting a yeast strain capable of fermenting a grape must (of known sugar and nitrogen levels) to completion at the desired fermentation temperature. Investigations on fermentation related stress generally focus on its influence on fermentation rate and sugar consumption. However, from a winemaking perspective, the strain’s ability to produce the desired volatile aroma compounds is equally important. Yet, literature provides little insight into the influence stress has on the volatile aroma profile; this is surprising as wine aroma is closely linked to wine quality and consumer liking. The final goal of this study was to evaluate changes to the volatile aroma profiles produced by five commercial yeast strains, in response to hyperosmotic and temperature stress. The concentrations of the aroma compounds were quantified using a gas chromatograph coupled to a flame ionization detector. The results show that hyperosmotic and temperature stress caused significant changes in the levels of a number of aroma compounds. Furthermore, the changes observed differed among the evaluated strains, as well as for the fermentation stress treatments studied. Future aims should be directed towards the potential application of yeast strain selection as a means to avoid problematic fermentations in grape must; in addition to the further characterisation of the relationship between stress and the resultant volatile aroma profile in wine. / AFRIKAANSE OPSOMMING: Gisrasse moet verskeie stresfaktore afweer tydens die wynmaak proses. Die onvermoë van ‘n wyngis om stres waar te neem en die nodige fisiologiese veranderinge te inisieer om aan te pas by die strestoestande word met slepende of onvolledige fermentasies (met ‘n residuele suiker van meer as 4 g/L) geassosieer. Wyngisrasse verkil in genotipe; wat as groot verskille in die graad van strestoleransie, en dus ook fermentasie sukses geopenbaar word. Die eerste doelwit van hierdie studie was om te evalueer hoe die suiker (200 of 240 g/L) en stikstof (50, 100, 250, of 400 mg/L), asook die fermentasie temperatuur (15°C of 20°C) die fermentasie prestasie van 17 kommersiële wyngiskulture beïnvloed. Die sukses van fermentasie is geëvalueer op grond van fermentasie kinetika (sloerfase, maksimum fermentasiespoed en totale gewigsverlies as CO2 verlies), die residuele suiker inhoud en die gis droë massa. Die resultate demonstreer dat die fermentasie sukses van kommersiële giskulture beduidend en verskillend beïnvloed word deur die aanvangsstikstof en – suikerkonsentrasies, asook die fermentasie temperatuur. Daarbenewens, wanneer stikstof in oormaat teenwoordig is kan dit ‘n negatiewe impak op fermentasietempo en suiker metabolisme hê. Beperkende vlakke van stikstof ‘n algemene oorsaak van slepende of onvolledige fermentasies, aangesien stikstof die groei en gevolglik ook die fermentasiespoed van gis beïnvloed. Stikstofaanvullings word dikwels tot druiwemos toegevoeg aan die begin van gisting, wat die risiko van probleemfermentasies verlaag. Dus kan die karakterisering van die fermentasievermoë van ‘n gisras vir ‘n reeks wynkundig relevante kondisies die wynmaker help om ‘n gisras te selekteer wat in staat is om ‘n druiwemos (waarvan die suiker en stikstofvlakke bekend is) droog te gis by die gewenste temperatuur. Meeste studies wat fermentasieverwante stress ondersoek, fokus op die die invloed daarvan op fermentasietempo en suikerverbruik. Van ‘n wynmaakperspektief is die gis se vermoë om die gewensde vlugtige aroma komponente te produseer egter ewe belangrik as die vermoë om fermentasie te voltooi. Tog verskaf die literatuur min insig tot die invloed van stres op die vlugtige aromaprofiel; wat verbasend is aangesien die aromaprofiel ‘n belangrike faktor is van die waargenome wynkwaliteit en daarom ook verbruikersvoorkeur. Die finale doelwit van hierdie projek was om die veranderinge tot die vlugtige aromaprofiel geproduseer deur vyf kommersiële gisrasse in reaksie op hiperosmotiese stres en temperatuur stres te evalueer. Die konsentrasies van die aromakomponente is gekwantifiseer deur gas chromatografie gekoppel aan vlam‐ioniserende deteksie. Die resultate wys dat hiperosmotiese‐ en temperatuur stres beduidende veranderinge meebring in die vlakke van ‘n aantal aromakomponente. Verder is die waargenome veranderinge ook verskillend vir die geëvalueerde gisrasse, asook vir die verskille stresbehandelings wat ondersoek is. Toekomstige studies behoort gerig te wees op die toepassing van gis seleksie om potensiële probleemfermentasies in druiwemos te voorkom; asook die verdere karakterisering van die verhouding tussen omgewingstresfaktore en die gevolglike vlugtige aromaprofiel in wyn.

Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-26Bitstream added on 2014-06-13T20:30:17Z : No. of bitstreams: 1 kamimura_h_me_arafcf.pdf: 1354920 bytes, checksum: ff4a5c6aed9b30ab6727c5843dacbe13 (MD5) / O suco de laranja é um produto de grande importância para a economia nacional, tendo papel relevante na pauta de exportações brasileiras. A maior parte da produção brasileira de laranja é destinada à produção de suco concentrado congelado – FCOJ, que é predominantemente exportado para a Europa e América do Norte. O processamento do suco envolve as etapas de extração, filtração, concentração, mistura e de resfriamento. O tratamento térmico empregado na etapa de concentração para redução do volume de água, redução da carga microbiana e inativação enzimática, também é capaz de favorecer reações que alteram a composição do suco e promovem alterações sensoriais e degradação da vitamina C, além de arrastar e degradar compostos voláteis importantes para o sabor do suco. Os objetivos deste trabalho foram reunir informações referentes ao processamento do FCOJ e aos fatores relacionados às alterações de qualidade que podem ocorrer durante o processamento, avaliar o suco de laranja das principais etapas do processamento do FCOJ, de forma a avaliar as etapas mais críticas em relação às alterações no perfil sensorial e perda de qualidade e avaliar a atividade antioxidante total (AAT), os compostos fenólicos totais (TPC) e as características físico-químicas do suco de laranja das etapas do processamento do FCOJ. O suco de laranja das principais etapas do processamento do FCOJ foi avaliado por 12 julgadores selecionados e treinados utilizando a análise descritiva quantitativa (ADQ). Foram gerados 21 descritores para aparência (5), aroma (6), sabor (8) e textura (2). O suco das etapas de extração e filtração foram caracterizados por alta intensidade de sabor doce, aroma e sabor natural, aroma e sabor cítrico e aroma e sabor óleo, com perfil sensoriais semelhantes. O suco da etapa de extração também foi caracterizado por gomos, tanto... / Orange juice is a important product to the national economy, with great relevance to the Brazilian exportations. The majority of Brazilian orange production is used in the frozen concentrated orange juice (FCOJ) production, which is mainly exported to North America and Europe. The FCOJ processing covers the extraction, filtration, concentration, blend and cooling steps. The heat treatment used in the concentration step to reduce the water activity, favors reactions that drastically changes the juice composition and promotes sensory changes, ascorbic acid degradation, and changes the volatile compounds important to the aroma and flavor of the juice. The aim of this work was to gather informations regarding the FCOJ processing and the factors related with the juice quality changes during the processing, to evaluate the orange juice from the main steps of the FCOJ processing, in order to identify the most critical steps regarding the sensory changes and loss of quality using QDA and to evaluate the total antioxidant activity (TAA), the total phenolic compounds (TPC) and the physicochemical characteristics of the orange juice from the steps of the FCOJ processing. The orange juice from the main steps of the FCOJ processing was evaluated by 12 selected and trained judges using QDA. 21 descriptors were generated for appearance (5), aroma (6), flavor (8) and texture (2). The juices from the extraction and filtration steps were characterized by high intensity of sweet aroma, natural aroma and flavor, citric aroma and flavor, and oil aroma and flavor, with similar profile. The juice from the extraction step was also characterized by vesicles from both appearance and texture. The juice from the concentration, blend and cooling steps were characterized by high intensity of cooked aroma and flavor, with similar profile. The sensory profile of the orange juice was noticeably affected... (Complete abstract click electronic access below)

O café solúvel aglomerado é produto da aglomeração do café solúvel em pó. A sua produção envolve etapas de processo cujas variações térmicas modificam qualitativamente e quantitativamente a fração de compostos voláteis responsáveis pelo aroma e sabor do produto acabado. A indústria de bebidas de café considera o sabor e aroma de cereal como um defeito na produção de café solúvel aglomerado. Desta forma, este trabalho objetivou aplicar o planejamento experimental para avaliação dos parâmetros de processo da produção de café solúvel aglomerado em escala industrial. Os efeitos destes parâmetros nos componentes voláteis do café e na intensidade do gosto de cereal foram avaliados através do planejamento fracionário 24-1 com resolução IV. As variáveis independentes estudadas foram temperatura do queimador (TQ), fluxo de ar de processo (FA), temperatura da seção quente do leito (TL) e pressão de vapor (PV). Os resultados do planejamento experimental deram-se pela utilização de análise sensorial conduzida por equipe treinada para a detecção do aroma e sabor indesejado. Adicionalmente, os compostos voláteis foram extraídos pela técnica microextração em fase sólida com amostragem no headspace (HS-MFES), identificados e quantificados por cromatografia gasosa acoplada a espectrometria de massa (CG-EM). O efeito dos fatores estudados foi avaliado mediante análise de variância (ANOVA) com nível de significância de 90% e os resultados expressos por gráficos de pareto. A análise de componentes principais (ACP) foi realizada com o intuito de identificar dentre os compostos que podem conferir sabor e aroma de cereais aqueles tem a maior contribuição e quais as condições de processo ideias para evitar a formação do sabor e aroma de cereal. De acordo com ACP foi constatado que piridina, 2-metoxi-4-vinilfenol, 2,3-dimetilpirazina, 2,5-dimetilpirazina, 2,6-dimetilpirazina, 4-metiltiazol, pirazina, 2-metoxifenol, 4,5-dimetiltiazol contribuem para formação do sabor e aroma de cereal. Também indicou que a aglomeração deve ocorrer conforme TQ=215ºC, FA=250rpm, TL=120ºC e PV=1,2 x100KPa. / The agglomerated instant coffee is the product of the powder instant coffee agglomeration. Its production involves stages of processes whose thermal variations change qualitatively and quantitatively the volatile compounds fractions responsible for the aroma and flavor of the finished product. The coffee beverage industry considers the cereal like flavor and aroma as a fault in the production of the agglomerated instant coffee. In this way, this study had as the aim to apply experimental plan to evaluate the parameters of the processes of the agglomerated instant coffee production on an industrial scale. The effects of those parameters in the coffee volatile components and in the intensity of the cereal taste were evaluated through the fractional 24-1 with resolution IV. The independent variables studied were the burner temperature (BT), the process air flow (AF), the temperature of the fluidized bed hot section (LT) and the steam pressure (SP). The results of the experimental plan were made by the use of sensory analysis performed by a trained team for the detection of the undesired aroma and flavor. Additionally, the volatile compounds were extracted by solid-phase microextractiontechniquewithsampling in theheadspace (HS-SPME), identified and quantified by gas chromatography coupled to mass spectrometry (GC-MS). The effect of the factors studied was evaluated by variance analysis (ANOVA) with significance level of 90% and the results showed by Pareto charts. The principal components analysis (PCA) was made with the aim to identify, among several compounds, those that implies on more cereal flavor and aroma, those which major contribution and which ideal process conditions could be used to reduce the cereal flavor and aroma development. According to PCA, it was found that pyridine, 2-metoxi-4-vinylphenol, 2,3-dimethylpyrazine, 2,5-dimetylpyrazine, 2,6-dimethylpyrazine, 4-methyltiazol, pyrazine, 2-methoxyphenol, 4,5-dimethylthiazol contribute to the development of the cereal flavor and aroma. It was also found that the agglomeration must be according to TQ = 215°C, AF=250 rpm, LT=120°C and EPV = 1,2 x 100 KPa.

Orientador: Leonardo Pezza / Banca: Jose Anchieta Gomes Neto / Banca: Edilene Cristina Ferreira / Banca: Aristeu Gomes Tininis / Banca: Eder Tadeu Gomes Cavalheiro / Resumo: A qualidade do café e sua peculiaridade é intrinsicamente dependente de diversos fatores, dentre eles espécies/cultivares, origem geográfica, tipos dos grãos, colheita, processamento pós-colheita, torrefação e armazenamento. No presente trabalho revela-se a complexidade da relação entre a qualidade e composição aromática do café. Muitos aspectos abordados continuam sem ser totalmente elucidados, dentre eles, origem geográfica e processamento pós-colheita, enquanto outros, podem ser melhor compreendidos, tais como influência de espécies, qualidade de grãos e condições de armazenamento. No presente estudo alguns aspectos tais como origem geográfica, tipos dos grãos e torrefação foram avaliados e correlacionados através da composição volátil utilizando-se ferramentas de análise multivariada. Em todos os casos foram analisadas a composição volátil dos grãos de café através da técnica de Headspace-SPME. A correlação entre compostos voláteis e os fatores analisados foi constatada e, permitindo-se assim a elaboração de modelos discriminantes para a diferenciação de amostras de diferentes origens geográficas, grau de torrefação e selos de qualidade (tipos de grãos). Identificou-se também compostos voláteis marcadores de origem geográfica (macrorregiões e microrregiões), grau de torração e qualidade dos grãos. Dentre os marcadores voláteis encontrados no estudo o 2-metilbutanal é o marcador mais versátil, por ser considerado importante em todos os testes de discriminação geográfica, c... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The quality of the coffee is dependent on several factors, among them species / cultivars, geographical origin, types of beans, harvesting, post-harvest processing, roasting and storage. In the present work the complexity of the relationship between the quality and aroma composition of the coffee was revealed. Many aspects remain to be fully elucidated, including geographic origin and post-harvest processing, while others may be better understood, such as species influence, grain quality, and storage conditions. In the present study, some aspects such as geographic origin, grain types and roasting were evaluated and correlated through the volatile composition using multivariate analysis tools. In all cases, the volatile composition of the coffee bean was analyzed using the Headspace-SPME technique. The correlation between volatile compounds and the mentioned factors was verified, allowing the elaboration of discriminant models for the differentiation between samples of different geographic origins, degree of roasting and quality seals (beans types). Volatile compounds were identified from geographic origin (macro-regions and micro-regions), degree of roasting and grain quality. Among the volatile markers suggested in the study, 2-methylbutanal is the most versatile marker found, because it is considered important in all geographical discrimination tests, compounds such as 2-ethylpyrazine and 2,5-dimethylpyrazine are important markers for both geographical origin and degree of... (Complete abstract click electronic access below) / Doutor