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A consumer and a trained descriptive panel was utilized to determine liking ratings and flavor profiles, respectively, for commercial brands of pre-stirred yogurt. Once the consumer and descriptive panel data was collected, the data was combined to determine the interrelationship of these two sets of data and to determine the conditions necessary to optimize the sensory characteristics of commercial yogurt. This study was broken down into two parts: (1) evaluation by a 90 to 182 member consumer panel and an 11 member descriptive panel for 14 strawberry and 6 lemon yogurt brands, and (2) correlation of the sensory measures of sweetness and sourness, and analytical measures of sugars and acids for 14 strawberry, 12 raspberry, 6 lemon, and 17 plain yogurt brands. Large sensory differences were found between yogurts for both flavors (strawberry and lemon) by both panels. Correlation and principal component analysis (PCA) indicated that two distinct groups of descriptors contributed to the liking of the yogurts: one associated with the fruity and sweetness characteristics, and the other related to the plain yogurt and sourness descriptors. Consumers based their overall liking ratings on fruit flavor, sweetness, sourness, and a balance of sweetness/sourness liking. Males and females rated samples differently by as much as one full scale value on a 9-pt. hedonic scale. Use of PCA to relate the two panels revealed that high consumer acceptance corresponded with the PC loaded with fruity and sweet characteristics while lower consumer acceptability was noted with high loadings on PC2 which was comprised of plain yogurt, acetaldehyde, and sourness descriptors. The results from the first part of the study indicate that to produce a highly acceptable yogurt, processors should strive to provide a balance between sweetness and sourness and provide enough fruit flavor to mask plain yogurt characteristics. In the second part of this study, titratable acidity and pH were measured for all the yogurts, while sugars were measured by HPLC only for the fruit flavored yogurts. Consumer overall liking was significantly correlated with sweetness intensity, sweetness:sourness (sw:so) ratio, and the summed impact of sweetness and sourness from the trained panel for strawberry and raspberry yogurt. No correlations between analytical measures and overall liking were found for any of the yogurts. A sw:so ratio greater than 1.0 for strawberry, and .8 for raspberry and lemon appeared necessary for high consumer acceptance. Generally, it was found that the sweeter the yogurt, the higher the consumer acceptance of fruit flavored yogurt. No relationships were found for any sensory and analytical measures for predicting the overall liking of plain yogurt. However, the best predictors of consumer liking of fruit flavored yogurt were the descriptive panel ratings. / Graduation date: 1991

Made available in DSpace on 2014-06-11T19:31:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-17Bitstream added on 2014-06-13T20:41:12Z : No. of bitstreams: 1 miguel_dp_dr_arafcf.pdf: 550018 bytes, checksum: 253df34d8ed9dba72685e94d0dcec852 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Esse estudo teve por objetivo o desenvolvimento de amostras de sorvete de “iogurte” simbiótico à base de extratos aquoso de soja e de yacon (Smallanthus sonchifolius) fermentado com Lactobacillus acidophilus CRL 1014. O L. acidophilus CRL 1014 foi caracterizado quanto à resistência ao pH e à sais biliares. Foram processadas formulações com diferentes proporções do extrato aquoso de yacon em substituição parcial ao extrato de soja, as quais foram submetidas à avaliações sensoriais para a definição da melhor combinação entre os extratos analisados. Também foi realizada a contagem de células viáveis do microrganismo em estudo na formulação selecionada. No processamento das amostras de “iogurte” foi verificado que quanto maior a quantidade de yacon presente nas diferentes formulações maior o tempo necessário para se atingir o pH estabelecido de 4,3, embora esse tempo tenha variado somente de 7,5 a 9,5 horas, exceto, para a formulação constituída somente por extrato de yacon, que ultrapassou o período de 10,5 horas sem ter o seu pH reduzido. A partir dos resultados obtidos nos testes sensoriais foi constatado que a formulação de “iogurte” contendo 100% de extrato de soja (sem extrato de yacon) obteve as maiores médias em termos absolutos para todos os atributos avaliados não diferindo da formulação com 75% de extrato de soja e 25% de extrato de yacon, sendo esta a selecionada para a etapa subseqüente deste estudo, uma vez que a formulação 1 não se caracteriza como sendo um produto simbiótico. A formulação 4 (iogurte com 25% de extrato de soja e 75% de extrato de yacon) foi a amostra que apresentou as menores médias em termos absolutos para todos os atributos avaliados. A contagem de células viáveis L. acidophilus CRL 1014 obtida para o “iogurte” simbiótico... / This study aimed to develop samples of symbiotic frozen yogurt with soybean and yacon (Smallanthus sonchifolius) fermented with Lactobacillus acidophilus CRL 1014. The L. acidophilus CRL 1014 was characterized for resistance to pH and bile salts. Formulations were processed with different proportion soybean water extract by adding yacon water extract, which were subjected to sensory evaluation to determine the best combination of the extract analyzed. The viable cells were counted in the formulation selected. In the processing of samples of yogurt was found that the higher concentration of yacon extract present in the different formulations increased the time required for the samples to reach the preset pH, although this time has varied only from 7.5 to 9.5 hours, except for the formulation consists of only yacon extract, which exceeded the period of 10.5 hours without having its pH reduced. From the results obtained in the sensory tests it was showed that the formulation of yogurt containing 100% of soy extract (no yacon extract) had the highest average in absolute terms for all sensory attributes and there was no significant difference between the formulation with 75% soy extract and 25% of yacon extract, this being selected as a basis for this study, since the formulation 1 is not characterized as a synbiotic product. Formulation 4 (yogurt with 25% of soy extract and 75% of yacon extract was a sample showing the lowest means in absolute terms for all attributes. The viability of L. acidophilus CRL 1014 obtained for the synbiotic yogurt 1.8 x 109 were above the recommended level from 106 to 107 CFU / mL, thus satisfying the criteria established for probiotic foods. From the tests of resistance to acidic conditions and to bile salts, it was found that L. acidophilus CRL 1014, despite having a time delay, was able to grow... (Complete abstract click electronic access below)

ABSTRACT Stirred yogurt is a cultured dairy product produced by mixed cultures of lactic acid bacteria. It is a semi-viscous liquid whose rheological properties are major quality determinants. These are influenced by several manufacturing factors such as heat treatment of the yogurt milk. Improvement of the properties of stirred yogurt made under different manufacturing conditions was the key focus in this research. The research included an investigation of the key factors involved in the development of nodulation which is an unsightly defect, as consumers expect stirred yogurt to have a smooth consistency. This research consisted of three main experimental parts: 1. Effect of different heat treatments on the properties of stirred yogurt; 2. Factors involved in nodulation in stirred yogurt; and 3. The physical and chemical nature of nodules. The types and levels of heat treatment have a major influence on the properties of stirred yogurt. In this study, yogurt milk was treated at pasteurization and UHT conditions. The milk heated at pasteurization, 80-95oC, and UHT, 130-145oC, conditions had similar levels of whey protein denaturation, approximately 85-99%, while the milk treated at low temperature for a long time, 65oC for 4 hr, had a significantly lower level of denaturation (~55%). Yogurt made from milk pasteurized at 85oC for 30 min and 92oC for 7 min and UHT treated milk at 130-145oC for 5 s had similar hardness and viscosity while yogurt made from milk treated at 65oC for 4 hr had significantly lower hardness and viscosity than corresponding yogurts from high heat treatments. In addition, the water-holding capacity and syneresis of yogurts made from either pasteurized or UHT milk were not significantly different. Yogurt (made from either pasteurized or UHT-treated milk) enriched with non-dairy ingredients, gelatin, inulin and sugar, showed higher hardness, viscosity, water-holding capacity than yogurt made with only dairy ingredients. These yogurts also showed no syneresis. This can be largely attributed to the gelatin which improves the texture, binds additional water and prevents syneresis. The formation of nodules in yogurt has been reported to be influenced by several factors. In this study, the heat treatment of the yogurt milk, the types and levels of sugar added, and the type of starter cultures were found to significantly influence the level of nodulation in the stirred yogurts. Severe pasteurization heat treatments, at temperatures < 100ºC, caused more nodules than mild heat treatments at temperatures in this range. The type of heat treatment was also important, with yogurt made from UHT-treated milk showing much less nodulation than yogurt made from pasteurized. This was observed when the levels of whey protein denaturation in the pasteurized and UHT milk were similar, indicating that the extent of whey protein denaturation alone is not a major factor in the development of nodules. Sucrose added either before or after heat treatment of yogurt milk also affected the extent of nodulation. Increasing the amount of added sucrose from 0 to 6.5% caused correspondingly higher numbers of nodules. In addition, there was a positive synergistic effect between heat treatment and sugar addition on nodulation; the highest numbers of nodules appeared when the yogurt milk was severely heated and sugar was added at the highest level, 6.5%. Addition of lactose or fructose instead of sucrose did not promote nodule formation while glucose caused nodulation in a similar manner to sucrose. The use of different starter cultures affected the numbers of nodules; yogurts made with the culture ABT 10 had much less nodulation than those made with ABT5 and ABT6, even under heating conditions and sugar addition conducive to nodule development. The amount of exopolysaccharide (EPS) produced by the starter cultures, ABT5 and ABT10, did not correlate with the extent of nodulation in the yogurt. Disturbance during yogurt fermentation by changing the temperature (from 37 to 42 or 45 to 42oC) when the gel was forming increased the numbers of nodules while refrigerated storage of yogurt and altering the pH during heat treatment (from pH 6.46 to 6.90) did not affect the number of nodules. Ultrasonication of the yogurt milk caused a reduction in the numbers of nodules in the yogurt. This was attributed to disruption of clumps of starter culture bacteria, thus preventing excessive localised build-up of acid around the bacterial clumps which could form the nucleus of nodules. The major conclusions from this study are that heat treatment of the yogurt milk and the level and type of added sugar are important factors affecting the extent of nodulation of stirred yogurt. Other factors such as the type of starter culture bacteria and their degree of clumping are also significant. Optimisation of these factors would allow yogurt manufacturers to minimise nodulation in stirred yogurt.

TESIS PARA OPTAR AL GRADO DE MAGÍSTER EN MARKETING / Pamela Catalina Castro Contreras [Parte I], Hernán Patricio Palma Calderón [Parte II] / En el siguiente informe se exponen antecedentes que permiten re-enfocar el posicionamiento del yogurt Activia de Danone. Activia, es un yogurt que da fe de ayudar con los problemas de tránsito lento presentados principalmente por mujeres. Sin embargo, luego de ver cuestionado su atributo principal en un programa de televisión, la imagen del producto y las ventas del mismo se vieron afectadas sin lograr revertir la situación. Gracias a los antecedentes expuestos se busca renovar la marca, otorgándole un nuevo posicionamiento basado en estudios de consumidor y sus hábitos, lo que nos permitirá generar una nueva estrategia capaz de retomar en el corto plazo los niveles de penetración alcanzados por la marca en sus inicios en nuestro país. Luego de un análisis de la competencia, perfil de marca y arquetipos encontrados, se pretende definir las directrices y plan de acción a ejecutar, con el fin de recuperar el espacio perdido luego del programa de televisión “Contacto”, emitido por Canal 13, donde se cuestionó la calidad del producto, sus beneficios y además se le atacó sobre su procedencia e ingredientes, lo que dio pie a éste Plan de Marketing. Lo expuesto a continuación cuenta con una primera fuente, estudios de mercado realizados por la empresa Kantar Worldpanel a través de su metodología de panel de consumidores, lo que otorga data cuantitativa y cualitativa. / Luego de conocer el contexto en que se encuentra Activia y la categoría Yogurt, nuestro plan de Marketing se basa en el atributo descubierto que posee la marca, más allá del tránsito es el sabor, lo rico que resulta para el consumidor y lo variado de sus sabores, dejando como de forma anexa esta cualidad de ser light o sano a la vez. Para esto, nos enfocaremos en los consumidores que llamamos “consientes” quienes están perfectamente identificados desde su estrato hasta el canal de preferencia para hacer sus compras vs el promedio, desprendiéndose tres acciones: Brand Awareness, Penetración de nuevos hogares y fidelización. La primera es netamente comunicacional, enfocada en los atributos que queremos darle a la marca actualmente, mientras que para las acciones de penetración y fidelización se implementarán acciones que abarcan desde el canal de venta, pasando por la distribución hasta llegar a la implementación de precios. Como sabemos que la penetración es la variable más ligada al crecimiento de Share, nuestro objetivo mínimo es lograr mayor penetración, recuperando en un año la que teníamos años anteriores, pero ahora desde estos nuevos hogares obteniendo como resultado un crecimiento en las ventas cercanas al 17%.

Diploma thesis is divided into two parts: theoretical and practical. The literary review is related to classification and chemical composition of yogurts and technological procedures in yogurt production. There is also a chapter on methods and application of sensory analysis in food industry. The aim of thesis was to evaluate three samples of yogurts differing in composition of strawberry mixture using the sensory profile and preference test. Questionnaire survey on consumer habits was a part of the research. The evaluators were students of the Faculty of Agriculture at the University of South Bohemia in České Budějovice and schoolchildren of Elementary School in Velešín.

Submitted in fulfilment of the academic requirements for the Degree in Master's in Food Science and Technology, Durban University of Technology, 2017. / Pigeon pea (Cajanus Cajan) is consumed in many parts of Africa as a source of protein and carbohydrate. It is underutilised and mainly grown for subsistence. Researching on pigeon pea may enhance value addition and increase its utilization. In this study, a non-dairy probiotic yoghurt was prepared from pigeon pea milk. Yoghurt samples were prepared, using 100% pigeon pea milk, pigeon pea/soy milk in the ratio 50:50 and 100% soy bean milk. The yoghurts were inoculated with yoghurt starter cultures and divided into two equal parts. One part inoculated with Propionibacterium freudenreichii was referred to as probiotic yoghurt, while the other part served as the control. The nutritional, sensory and some functional properties of the yoghurt were determined. The microbiological quality of yoghurt samples stored at 4, 10 and 21°C, respectively, for 4 weeks, were monitored and analysed for aerobic spores’ formers, E. coli, total plate counts, mould and Propionibacterium freudenreichii weekly. The protein contents of the yoghurt samples varied from 4.54-5.85% for 100% soymilk and 100% pigeon pea yoghurt respectively. The probiotic yoghurt showed slightly lower protein content than pigeon pea yoghurt alone. All the yoghurt samples had considerably high total solids (16.04-17.41%) and were fairly good sources of amino acids. Essential amino acids in the yoghurt samples were comparable to the FAO/WHO (2007) recommended amino acid requirement for adults. Anti-nutritional factors of yoghurt samples were significantly lower (P≤0.05) than their milk counterparts, which may be attributed to the fermentation process. Probiotic yoghurt samples showed higher firmness than non-probiotic samples. Total plate counts (log 7.01- 7.46 CFU/ml) samples stored for 2 weeks at 4° C were similar. Predominant organisms were LAB and Propionibacterium freudenreichii. Storage temperature of yoghurt samples had an influence on the total plate count and LAB. Total plate count and LAB significant increased approximately by log 2 CFU/ml for the first two weeks of storage. However, moulds and E. coli were not detected in all samples. Beyond 2 weeks of storage, there was significant decline in total plate counts and LAB, while mould grew and increased. Aerobic spore formers and moulds were observed in the control yoghurt. However, E. coli was not found in all yoghurt samples throughout storage period. The pH of the milk in which yoghurt mixtures were formulated, ranged from pH 7 to 6.8 for pigeon pea and soymilk declined significantly as a result of acidification. Decline in pH at 4, 10 and 21°C was significant (p≤0.05) with the rate higher at 21, 10 than 4° C. Decline in pH resulted in increased TTA values over storage temperatures and periods. Samples stored at 21°C and 10°C had significantly higher TTA values than samples stored at 4° C. The colour values evaluated were recorded as L*, b*, a* and ∆E* during 4 weeks storage at 4, 10 and 21° C. Significantly high values (p≤0.05) were recorded for L* yoghurt samples with soymilk. The colour scale defines positive (red) and negative (green) for a* and b* positive (yellow) and negative (blue). All a* values both positive and negative were less than 3. There was no negative value recorded for b*. Colour difference ∆E* values trends increased as storage time and temperature increased. There were significant (p≤0.05) differences between samples stored at same and different storage temperatures and periods. Water holding capacity was significantly different (p≤0.05) in all the yoghurt samples stored at 4, 10 and 21°C for 4 weeks. Formulation with 100% soymilk recorded higher values. Soy yoghurt and probiotic yoghurts (100 %) showed higher water holding capacity compared to pigeon pea yoghurt and pigeon pea/soymilk yoghurt. The addition of Propionibacterium freudenreichii did not significantly affect sensory properties of the yoghurts. Acceptable yoghurt was produced from pigeon pea with comparable quality to soy which serves as control. Proximate composition was comparable to previous reports. Microbial quality and profile of all the yoghurt samples were similar. The absence of pathogenic bacteria in all the yoghurt samples confirm their safety. Soy yoghurt was most acceptable amongst the yoghurt samples but all the samples had comparable ratings, and these ratings are within commercially acceptable range (4 to 9) for yoghurt. Storage at 4oC should be the most acceptable, as storage at 21oC encourage proliferation of contaminant / M

En el presente estudio de prefactibilidad se muestra la viabilidad técnica, económica y financiera de implementar una empresa productora y comercializadora de yogurt en Lima Metropolitana. En el primer capítulo, Estudio Estratégico, se realiza el análisis del macro y micro entorno, en el cual se concluyó que más del 30% de la población peruana se concentra en Lima Metropolitana y que se presenta una tendencia creciente en el consumo de productos naturales y nutritivos. Así mismo se define la visión, misión y objetivos de la empresa. Además, se desarrolla la estrategia de diferenciación del negocio luego de realizar la matriz FODA. En el Estudio de Mercado se da a conocer el sector de lácteos especialmente la categoría de yogurt regular. Luego se definen los segmentos en los cual se divide el yogurt regular, de los cuales se escoge el segmento Entero debido a que representa el 77% de la división regular. Posterior a ello, se selecciona el mercado objetivo a través del análisis de variables geo demográficas, psicográficas y conductuales. Así mismo se estudia fuentes primarias y secundarias que reflejan el crecimiento de la demanda de yogurt. Para determinar la oferta, se estudian las empresas con mayor representación en el mercado, así como su crecimiento para los próximos años. Al culminar el capítulo se determina la demanda insatisfecha y la demanda para el proyecto en un horizonte de cinco años complementando con el plan de marketing para nuestro producto. En el tercer capítulo, Estudio técnico, se determina la localización óptima de la planta de producción y oficina de la empresa. Luego, se establece el proceso productivo y los requerimientos de materia prima, mano de obra y servicios para el correcto funcionamiento de la empresa. Por otro lado, se definen las características físicas del local, se realiza la distribución de planta y el dimensionamiento de las áreas. Finalmente se realiza la evaluación ambiental y social del proyecto. En el Estudio Legal y Organizacional, se define el tipo de sociedad y se detallan los impuestos y normas legales que aplican a una empresa del sector bebidas no gasificadas. Luego, se describe la estructura organizacional de la empresa, se determinan las funciones del personal. Asimismo, se definen los servicios que serán presentados por empresas terceras.

Master of Science / Department of Food Science / Karen A. Schmidt / Milk proteins are excellent sources of sulfur-containing amino acids methionine and cysteine, in particular whey proteins. Cysteine is synthesized from methionine by γ-cystathionase. However, cysteine has to be included in the diets of certain subpopulations due to diminished γ-cystathionase activity. Cysteine, a heat- liable amino acid, may lose bioavailability during thermal processing. The objective of this research was to enhance cysteine content in yogurt while maintaining its quality. First, yogurt mixes were formulated to a total solids content of 12.5% with nonfat dry milk (NDM) (N) or a combination of NDM (10%) and whey protein isolate (WPI) (2.5%) (W), and processed at 70°C (20 min) (70) or 90°C (7 min) (90). Yogurt was prepared and maintained at 4oC for 60 days. Three replications were performed and data were analyzed using SAS®. The W mixes had 65%, 32% and 190% more cysteine, true protein and whey protein contents respectively, compared to N mixes prior to processing. However in day 1 yogurt, the highest cysteine content (398.3 mg/L) was found in the W70 yogurt and its gel quality was comparable to the N90 yogurt except for firmness. During a 60 day storage period the W70 and N90 were similar in gel quality except for firmness. Secondly, a hedonic test was done on the W70 (HC) and N90 (LC) yogurts which had been reformulated to contain sugar and vanillin. One replication was performed and data were analyzed using SAS®. The LC and HC yogurts did not vary in liking of flavor (6.1), aftertaste (6.1) and overall acceptability (6.3) corresponding to the words of “like slightly” when compared. However, the appearance of the LC yogurt was liked more than the HC yogurt (6.7 vs. 6.1) whereas the thickness of HC yogurt was liked more than the LC yogurt (6.4 vs. 5.8). These results suggest that addition of WPI along with lower process treatment resulted in yogurt with enhanced cysteine; however, further studies may be needed to optimize the WPI addition to improve the visual characteristics of the yogurt for consumer acceptance.

Master of Science / Food Science Institute -- Human Nutrition / Delores H. Chambers / This research aimed to determine the sensory characteristics of commercially-available plain yogurts and examine how three "more sustainable" prototypes compared. Three experimental non-fat set-style yogurts were provided – one control and two samples that differed in fermentation time. These shortened fermentation times could result in energy reductions and potentially substantiate a “sustainable” marketing claim, a concept gaining traction with consumers. Twenty-six commercially-available yogurts varying in percent milk fat, milk type (organic or conventional), and processing (set-style, stirred, or strained/Greek-style) were also included. Using descriptive sensory analysis, a six-person highly-trained panel scored the intensity of 25 flavor, six texture, four mouth feel, and two mouth coating attributes on a 15-point numerical scale. Three replications were conducted, and all samples were tested at least 10 days prior to the end of their shelf-lives. The samples differed for 19 flavor and all texture, mouth feel, and mouth coating attributes. Cluster analysis indicated approximately seven flavor and five texture (texture, mouth feel, and mouth coating combined) clusters, resulting in 15 unique combinations of flavor and texture. Although no legal definitions exist for “sustainable,” the prototypes’ sensory characteristics were comparable to those of top-selling yogurts indicating potential market viability. This research also demonstrated potential growth opportunities. Despite the current diversity, several combinations of flavor and texture were not represented.