990 resultados para soy fermented product
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR
Influence of the combination of probiotic cultures during fermentation and storage of fermented milk
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to develop a new low-calorie symbiotic beverage made from yacon (prebiotic source) and soy extracts, containing probiotic Bifidobacterium animalis ssp. lactis BB-12. The synbiotic beverage was first produced with a range of sucrose concentrations in order to determine ideal sweetness by an acceptance test using a “just-about-right scale”. Sucrose was then replaced by sucralose or aspartame to produce sugar-free beverages. Characteristics including viable cell numbers, physicochemical properties, sensorial characteristics and fructooligosaccharides content were investigated. The ideal sweetness of the beverages with sucrose, aspartame and sucralose were 7.28%, 0.0486% and 0.0167%, respectively. Sucralose exhibited higher scores in acceptance test and was used to replace sucrose in the low-calorie symbiotic beverage. The synbiotic beverage exhibited counts of Bifidobacterium spp. of 108 CFU·mL-1 , sufficient condition to be considered probiotic. The chemical composition of the product was (g/100 g): 2.91 of protein, 1.41 of fat, 2.41 of total carbohydrate; 0.82 of FOS and 148.22 Kj of energy value. The synbiotic beverage developed in this study may be successful in health applications, due to their functional ingredients (soy, probiotic bacteria and yacon prebiotics) that can afford benefits to health or can present disease-preventing properties, beyond their inherent nutritional value. In addition this low-calorie beverage can be consumed by diabetic individuals and people concerned about the ingestion of calories.
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Introduction: In Brazil part of the production of ginger is of inadequate quality for export. The production of spirit from felt-over rhizomes is an alternative of great interest to producers of these rhizomes. Aim: Aiming to increase the value of felt-over rhizomes, this work aimed to study the use of ginger as a raw material for alcoholic beverage production. It was evaluated the effect of fermentation conditions on the components of fermented alcoholic, as well as, the quality of alcoholic distilled beverage of ginger. Methods: Dehydrated ginger passed by enzymatic hydrolysis-saccharification processes. The hydrolysate obtained was analyzed for sugar profile in HPLC. The alcoholic fermentation process followed the central composite rotational design for three factors: fermentation temperature (23 to 37ºC), time of fermentation (17 to 33 h) and concentration of inoculum (0.22 to 3.00%). The fermented alcoholic obtained was analyzed in HPLC for the contents of ethanol, methanol, glycerol and residual sugars. The distillated alcoholic beverage of ginger was analyzed for ethanol, methanol, acetaldehyde, ethyl acetate and higher alcohols in the gas chromatography (GC). In addition, copper content and acidity were analyzed Results: Sugar profile of the ginger hydrolysate revealed the presence of 77.8% of glucose. Data analysis of fermentation process showed influence of temperature on ethanol and methanol content of the fermented alcoholic of ginger. Time of fermentation had effect on glycerol content. All parameters of process had influence on residual sugars contents. The HPLC analysis has shown presence of methanol, ethyl acetate, aldehyde, acids, higher alcohols and esters in distilled alcoholic beverage of ginger. Conclusion: Fermented alcoholic of ginger with higher levels of ethanol can be obtained under the conditions of 1.5% w/w of inoculum, 30°C of temperature and 24 hours of fermentation time. In this condition of fermentation process the beverage of ginger had good quality.
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Los objetivos principales de esta Tesis Doctoral fueron estudiar en 4 ensayos los efectos a) del procesado del maíz y la inclusión en los piensos de ingredientes de alta calidad como harina de pescado o fuentes de lactosa en lechones blancos b) inclusión en el pienso de diferentes productos derivados del haba de soja, con diferente contenido de proteína bruta (PB), tamaño de partícula y origen en lechones blancos e ibéricos y c) inclusión en el pienso de lechones ibéricos de ingredientes de alta calidad; forma de presentación del pienso y la duración del suministro del pienso prestárter sobre los parámetros productivos, la digestibilidad de los nutrientes, y las características morfológicas de la mucosa digestiva en lechones blancos e ibéricos recién destetados. En el experimento 1, los efectos de la complejidad del pienso prestárter sobre los parámetros productivos y la digestibilidad total aparente (TTAD) de los nutrientes fueron estudiados en lechones blancos recién destetados. Se utilizaron 10 tratamientos experimentales como resultado de 5 piensos prestárter (21 a 41 d de edad) y 2 piensos estárter (42 a 62 d de edad). Los piensos prestárter consistieron en un control negativo que incluía 40% de maíz crudo, 4% de harina de pescado y 7% de lactosa, un control positivo que incluía 40% de maíz cocido, 10% de harina de pescado, y 14% de lactosa, y 3 piensos adicionales con similares ingredientes que el pienso control positivo pero en los que a) 40% de maíz cocido fue sustituido por el mismo porcentaje de maíz crudo, b) se redujo el nivel de harina de pescado del 10 al 4%, y c) se redujo el nivel de lactosa del 14 al 7%. Cada tratamiento se replicó 6 veces (6 lechones/departamento). De 42 a 62 d de edad, la mitad de cada uno de los 5 piensos prestárter recibió un pienso estándar compuesto por harina de soja- maíz crudo y manteca y la otra mitad un pienso con similar perfil nutricional pero incluyendo un 20% de maíz cocido, 5% de harina de pescado, 1.3% de lactosa, 2% de concentrado de proteína de soja obtenido por fermentación y 1% de aceite de soja en lugar de harina de soja, maíz sin procesar y manteca. La complejidad del pienso no afectó a los parámetros productivos en ninguno de los periodos estudiados, pero el índice de diarreas durante la fase prestárter fue mayor en los lechones que recibieron el pienso control negativo que en los alimentados con cualquiera de los otros piensos (P<0.05). A los 30 días de edad (piensos prestárter), la digestibilidad de la materia orgánica (MO) y de la energía bruta (EB) fue menor (P<0.001) en los lechones que consumieron el pienso control negativo que en los lechones que consumieron cualquiera de los otros piensos. Sin embrago, la digestibilidad fecal de la PB no fue afectada. A los 50 días de edad (piensos estárter), la digestibilidad de los nutrientes fue similar en ambos piesnsos. Se concluye que la utilización de niveles elevados de ingredientes de alta calidad en los piensos no mejora los parámetros productivos de los lechones blancos en ninguno de los períodos estudiados. De 21 a 41 días de edad, el índice de diarreas se redujo y la digestibilidad de los nutrientes aumentó con la utilización de piensos de mayor calidad. Por lo tanto, la utilización de piensos con niveles elevados de ingredientes de calidad para reducir problemas digestivos y por lo tanto, mejorar los parámetros productivos podría estar justificada en algunos casos. En el experimento 2, se estudiaron los efectos de la inclusión en el pienso de harina de soja con diferente contenido de PB (44 vs. 49 % PB), la micronización de la harina de soja de alta proteína (AP-HS; 49% PB) y la utilización de concentrado de proteína de soja (CPS; 65% PB) sobre los parámetros productivos y la TTAD de los nutrientes en lechones blancos recién destetados de 28 a 63 días de edad. De 28 a 49 días de edad (fase I), hubo un pienso control positivo con un 10% de CPS, un pienso control negativo con 14.8% de harina de soja estándar (R-HS; 44% de PB) y otros 4 piensos que incluían 13.3% de AP-HS de origen Americano (USA) o Argentino (ARG) y molidas groseramente (980 μm) o micronizadas (80 μm). Cada tratamiento se replicó 8 veces (6 lechones/departamento). De 49 a 63 días de edad (fase II), todos los lechones recibieron un pienso comercial común en forma de harina. En el global de la fase I, el tratamiento experimental no afectó a ninguno de los parámetros productivos estudiados. Sin embargo, de 28 a 35 días de edad, los lechones alimentados con AP-HS micronizadas tuvieron un mejor índice de conversión (IC; 1.11 vs. 0.98; P<0.05) que los alimentados con AP-HS molidas groseramente. También, de 35 a 42 días de edad, los lechones que recibieron el pienso con AP-HS micronizada tendieron (P=0.08) a consumir más pienso que los lechones que consumieron el pienso con AP-HS molida. Durante la fase II (49 a 63 días de edad), cuando todos los lechones recibieron un pienso común, no se observaron diferencias en productividad de los lechones debido al tratamiento previo. En general, la digestibilidad de los nutrientes a los 35 días de edad fue mayor para los lechones que consumieron CPS que para los lechones que consumieron R-HS con los lechones que consumieron AP-HS en una posición intermedia. La digestibilidad de la PB fue mayor (P≤0.01) para el pienso que contenía CPS que para el promedio de los 5 tratamientos en base a HS. También, la digestibilidad de la MO y de la materia seca (MS) fue mayor para el pienso que contenía AP-HS micronizada o molida groseramente que para el pienso que contenía R-HS. La micronización de la AP-HS no tuvo efecto alguno sobre la digestibilidad de los nutrientes. Se concluye que cuando el CPS sustituye en el pienso a R-HS, la digestibilidad de la PB aumenta pero no tiene efecto alguno sobre los parámetros productivos. La utilización de AP-HS en sustitución de R-HS en el pienso mejora la digestibilidad de los nutrientes pero no afecta a los parámetros productivos. La utilización de harina de soja micronizada en los piensos mejora la eficiencia alimenticia durante la primera semana post-destete pero no tiene efecto alguno sobre la digestibilidad de los nutrientes. En general, la inclusión de productos derivados del haba de soja con un alto valor añadido (CPS o AP-HS) en el pienso presenta pocas ventajas en términos productivos al uso de AP-HS en lechones blancos recién destetados. En el experimento 3, se estudiaron los mismos productos de soja y piensos similares al experimento 2 en lechones ibéricos recién destetados. Además de los parámetros productivos y la TTAD de los nutrientes, en este ensayo se estudió también la digestibilidad ileal aparente (AID) de los nutrientes, así como las características histológicas y morfometría de la mucosa ileal. Cada uno de los 6 tratamientos fue replicado 6 veces (6 lechones/departamento). De 30 a 51 días de edad la fuente de harina de soja no afectó a los parámetros productivos, pero el índice de diarreas fue mayor (P<0.001) y la TTAD y AID de los nutrientes menor en los lechones alimentados con R-HS que en los alimentados con CPS o AP-HS. Sin embargo, no se encontró ninguna diferencia para éstos parámetros entre los piensos que contenían AP-HS y CPS. La TTAD de la MO (P=0.07) y de la EB (P=0.05) tendieron a ser mayores en los piensos basados en AP-HS micronizada que en los basados en AP-HS molida. La TTAD de la EB tendió (P<0.05) a ser mayor para la AP-HS de origen USA que para la AP-HS de origen ARG. Los lechones que consumieron R-HS presentaron villi de menor longitud (P<0.01) que los lechones que consumieron AP-HS o CPS, pero no se observaron diferencias en el caso de los lechones que recibieron los piensos que contenían AP-HS o CPS. Se concluye que la inclusión de AP-HS o CPS en el pienso en sustitución de R-HS reduce el índice de diarreas y mejora la digestibilidad de los nutrientes y las características morfológicas del íleon sin afectar a los parámetros productivos. La utilización de piensos basados en productos derivados del haba de soja con mayor valor añadido (CPS o AP-HS) en sustitución de la R-HS, mejora la TTAD de todos los nutrientes y reduce el índice de diarreas si llegar afectar a los parámetros productivos. En el experimento 4 se estudiaron los efectos del contenido de PB y la complejidad del pienso, la presentación física y la duración del suministro del pienso prestárter sobre los parámetros productivos y la TTAD de los nutrientes en lechones ibéricos recién destetados de 28 a 63 días de edad. Hubo 12 tratamientos experimentales con 2 tipos de pienso (AC; calidad alta y BC: calidad media), 2 presentaciones del pienso (gránulo y harina) y 3 duraciones de suministro del pienso prestárter (7, 14 y 21 días). Desde los 7, 14 y 21 días de experimento (dependiendo del tratamiento), hasta los 35 días, todos los lechones recibieron un pienso comercial en forma de harina. Cada uno de los tratamientos fue replicado 3 veces (6 lechones/departamento). En el global del experimento, la ganancia media diaria (GMD; P<0.05) y el consumo medio diario (CMD; P<0.01) fue menor en los lechones que recibieron el pienso AC que para los que recibieron el pienso de BC, si bien el IC no se vio afectado. La granulación del pienso prestárter no afectó a los crecimientos pero mejoró la eficiencia alimenticia. La utilización del pienso prestárter de 0 a 21 días de prueba mejoró el IC (P<0.05), pero redujo la GMD (P<0.01) en comparación con la utilización de éste pienso solo durante 7 o 14 días. El índice de diarreas tendió a ser mayor (P=0.06) en los lechones alimentados con los piensos AC que en los alimentados con los piensos BC. Asimismo, el índice de diarreas fue superior en los lechones que recibieron el pienso en gránulo que los que los recibieron en harina (P<0.001). Además, el índice de diarreas fue superior en los lechones que recibieron el pienso prestárter durante 14 o 21 días que en los que lo recibieron solo durante 7 días (P<0.01). De 28 a 49 días de edad, la GMD y el IC no se vieron afectados por la complejidad del pienso, pero la presentación en gránulo o el aumento en la duración de suministro del pienso prestárter mejoró el IC (P<0.01). También, en este periodo el índice de diarreas fue mayor en lechones alimentados con piensos granulados que aquellos alimentados con piensos en harina. Asimismo, fue superior para los lechones alimentados con el pienso prestárter durante 14 o 21 días que para los que recibieron éste pienso solo durante 7 días (P<0.01). De 49 a 63 días de edad, los lechones que previamente habían recibido piensos BC crecieron más que los que recibieron piensos AC (P<0.001). Asimismo, los lechones que recibieron el pienso prestárter durante 21 días comieron (P< 0.001) y crecieron menos (P<0.05) presentando una peor eficacia alimenticia (P<0.05) que los lechones que lo recibieron solo durante 7 14 días. La digestibilidad de la MO fue mayor en los lechones alimentados con los piensos AC que en los alimentados con piensos BC (P<0.05). La granulación del pienso mejoró la digestibilidad de los principales nutrientes. Los piensos prestárter AC mejoraron la digestibilidad de los nutrientes pero no la eficiencia alimenticia en lechones ibéricos de 28 a 63 días de edad. La granulación del pienso mejoró la eficiencia alimenticia. El aumento del suministro del pienso prestárter de 7 a 21 días mejoró la eficiencia alimenticia pero redujo la GMD. Por lo tanto, la utilización de piensos granulados de alta calidad durante el periodo prestárter es recomendable en lechones ibéricos, pero solo durante la primera semana post-destete. ABSTRACT The main objectives of this PhD Thesis were to study the effects of a) heat processing (HP) of corn and inclusion of high quality ingredients of animal origin such as fish meal (FM) and dried milk products in the diet, b) inclusion of different soy products varying in crude protein (CP) content, particle size, and origin of the beans in diets for conventional white and Iberian weanling pigs, and c) effects of ingredient quality, feed form, and duration of supply of the phase I diets on growth performance, nutrient digestibility, and intestinal morphology of weanling pigs. In experiment 1, the effect of diet complexity on total tract apparent digestibility (TTAD) and growth performance was studied in piglets from 21 to 62 d of age. There were 10 experimental treatments which resulted from the combination of 5 phase I (21 to 41 d of age) and 2 phase II (42 to 62 d of age) diets. The 5 phase I diets consisted of a negative control diet that contained 40 % raw corn, 4% FM, and 7% lactose (LAC); a positive control diet that contained 40 % HP corn, 10% FM, and 14% LAC, and 3 extra diets that used similar ingredients to those of the positive control diet but in which a) 40% of HP corn was substituted by raw corn, b) 4% FM rather than 10% FM, and c) 7% LAC instead of 14% LAC were included in the diet. Each treatment was replicated 6 times (6 pigs per pen). From 42 to 62 d of age, half of the pens of each of the 5 phase I treatments received a standard soybean meal (SBM)–native corn–lard diet wheras the other half received a diet with similar nutrient profile but that included 20% HP corn, 5% FM, 1.3% lactosa, 2% fermented soy protein concentrate, and 1% soybean oil in substitution of variables amounts of non-processed corn, SBM, and lard. Dietary treatment did not affect piglet performance at any age, but the incidence of post-weaning diarrhea (PWD) was higher during phase I in piglets fed the negative control diet than in piglets fed any of the other diets (P<0.05). At 30 d of age (phase I diets), the TTAD of organic matter (OM) and gross energy (GE) was lower (P<0.001) in pigs fed the negative control diet than in pigs fed the other diets but CP digestibility was not affected. At 50 d of age (phase II diets), dietary treatment did not affect TTAD of any dietary component. It is concluded that the use of high quality ingredients at high levels in the diet did not improve growth performance of piglets at any age. From 21 to 41 d of age, PWD was reduced and nutrient digestibility was increased in pigs fed the more complex diets. Consequently, the inclusion of high levels of high quality ingredients in piglet diets to maximize growth performance might not be justified under all circumstances In experiment 2, the effect of CP content (44 vs. 49 % CP) of SBM, micronization (fine grinding) of the high CP SBM (HP-SBM; 49% CP), and soy protein concentrate (SPC; 65% CP) on TTAD and growth performance was studied in conventional white piglets from 28 to 63 d of age. From 28 to 49 d of age (phase I), there was a positive control diet that included 6.5% CP from SPC and a negative control diet that supplied the same amount of CP as regular SBM (R-SBM; 44% CP) of Argentina (ARG) origin. The other 4 diets included the same amount of dietary CP from 2 sources of HP-SBM (USA or ARG origin), either ground (990 μm) or micronized (60 μm). Each treatment was replicated 8 times (6 pigs per pen). From 49 to 63 d of age (phase II), all pigs were fed a common commercial starter diet. For the entire phase I, type of soy product included in the diet did not affect growth performance of the pigs. However, from 28 to 35 d of age pigs fed the micronized HP-SBM had better feed conversion ratio (FCR; 0.90 vs. 1.01; P<0.05) than pigs fed the ground HP-SBM. Also, from 35 to 42 d of age, average daily feed intake (ADFI) tended to be higher (P=0.08) for pigs fed the micronized HP-SBM than for pigs fed the ground HP-SBM. During phase II, when all the pigs received the same diet, no differences among treatments were observed. In general, the TTAD of nutrients at 35 d of age was higher for the SPC than for the R-SBM diet with the HP-SBM diets being intermediate. The TTAD of CP was higher (83.8% vs. 81.9%; P≤0.01) for the SPC diet than for the average of 5 SBM containing diets. Also, the digestibility of OM and dry matter (DM) was higher (P<0.01) for the HP-SBM, either ground or micronized, than for the R-SBM diet. Micronization of the HP-SBM did not affect nutrient digestibility. It is concluded that when R-SBM was substituted by SPC, CP digestibility was improved but no effects on growth performance were observed. The use of HP-SBM in substitution of R-SBM in the diet improved nutrient digestibility but did not affect piglet performance. The inclusion of micronized HP-SBM in the diet improved FCR during the first week post-weaning but did not affect TTAD of nutrients. Therefore, the inclusion of added value soy products (SPC or micronized SBM) in the diet presents little advantage in terms of growth performance over the use of HP-SBM in pigs weaned at 28 d of age. In experiment 3, the effects of the same sources of soy protein used in experiment 2 on TTAD and growth performance of crossbreed Iberian pigs from 30 to 61 d of age were studied. In addition, the apparent ileal digestibility (AID) of nutrients and mucosa ileum morphology were also determined. Dietary treatment did not affect growth performance of the pigs at any age but from 30 to 51 d of age (phase I diets), PWD was higher (P<0.001) and the TTAD and AID of all nutrients were lower for pigs fed the R-SBM diet than for pigs fed the HP-SBM or the SPC diets. However, no differences between the HP-SBM and the SPC containing diets were detected for digestibility of any dietary component. The TTAD of OM (P=0.07) and GE (P=0.05) tended to be higher for the micronized HP-SBM than for the ground HP-SBM and that of GE was higher (P<0.05) for the USA meal than for the ARG meal. Pigs fed R-SBM had lower villus height (P<0.01) than pigs fed HP-SBM or SPC but no differences in ileal mucosal morphology were detected between SPC and HP-SBM containing diets. It is concluded that feeding the HP-SBM or SPC in substitution of R-SBM reduced PWD and improved nutrient digestibility and ileal morphology in piglets as compared with feeding the R-SBM, but had no effect on growth performance. The inclusion in the diet of added value soy products (micronized SBM or SPC) in substitution of the R-SBM increased the TTAD of all nutrients and reduced PWD but had no advantage in terms of growth performance over the use of ground HP-SBM. In experiment 4, the effect of CP content and ingredient complexity, feed form, and duration of feeding of the phase I diets on growth performance and TTAD of nutrients were studied in Iberian pigs from 28 to 63 d of age. There were 12 dietary treatments with 2 type of feeds (HQ; higher quality and LQ; medium quality), 2 feed forms (pellets vs. mash), and 3 durations of supply (7, 14, and 21 d) of the phase I diets. From d 7, 14, or 21 (depending on treatment) to d 35 of experiment, all pigs received a common diet in mash form. Each treatment was replicated 3 times (6 pigs/pen). For the entire experiment, average daily gain (ADG; P<0.05) and ADFI (P<0.01) were lower with the HQ than with the LQ phase I diets but FCR was not affected. Pelleting of the phase I diets did not affect ADG but improved FCR (P<0.01). Feeding the phase I diets from d 0 to 21 improved FCR (P<0.05) but decreased ADG (P<0.01) as compared with 7 or 14 d of feeding. Post-weaning diarrhea tended to be higher (P=0.06) for pigs fed the HQ diets than for pigs fed the LQ diets and for pigs fed pellets than for pigs fed mash (P<0.001). Also, PWD was higher for pigs fed the phase I diet for 14 or 21 d than for pigs fed this diet for 7 d (P<0.01). From d 0 to 21, ADG and FCR were not affected by feed quality but feeding pellets or increasing the duration of feeding the phase I diets improved FCR (P<0.01). Also, in this period PWD was higher with pellets than with mash and for pigs fed the phase I diets for 14 or 21 d than for pigs fed this diet for only 7 d (P<0.01). From d 21 to 35, pigs previously fed the LQ diet had higher ADG than pigs fed the HQ phase I diets (P<0.001). Also, pigs that were fed the phase I diets for 21 d had lower ADG (P<0.05) and ADFI (P< 0.001) and poor FCR (P<0.05) than pigs fed these diets for 7 or 14 d. Organic matter digestibility was higher for pigs fed the HQ phase I diets than for pigs fed the LQ phase I diets (P<0.05). Pelleting improved TTAD of all nutrients (P<0.01). It is concluded that HQ phase I diets increased TTAD of nutrients but not feed efficiency of Iberian pigs from d 28 to 63 d of age. Also, pelleting improved nutrient digestibility and feed efficiency. Increasing the duration of supply of the phase I diets from 7 to 21 d improved feed efficiency but reduced ADG. Therefore, the use of LQ phase I diets in pellet form for no more than 7 d after weaning is recommended in Iberian pigs.
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The current success of soy foods is driving soy ingredient manufacturers to develop innovative products for food manufacturers. One such innovation is separating the soy proteins glycinin and beta-conglycinin to take advantage of their individual functional and nutritional properties. Precipitation by acidification is a low-cost method for separating these two proteins. Separation is achieved by preferentially precipitating glycinin at pH ~ 6 while beta-conglycinin remains in solution. Understanding the particle formation during protein precipitation is important as it can influence the efficiency of the precipitation process as well as subsequent downstream processes such as the particle-liquid separation step, usually achieved by centrifugation. Most of the previous soy protein precipitation studies are limited to precipitation at pH 4 as this is the pH range most commonly used in the commercial manufacturing of soy protein isolates. To date, there have been no studies on the particle formation during precipitation at pH > 5.Precipitation of soy protein is generally thought to occur by the rapid formation of primary particles in the size range of 0.1 - 0.3 microns followed by aggregation of these particles via collision to aggregates of size about 1 - 50 microns. The formation of the primary particles occurs on a time scale much shorter than that of the overall precipitation process (Nelson and Glatz, 1985). This study shows that precipitation of soy protein is indeed rapid. At high pH levels, binary liquid-liquid separation occurs forming a protein-rich heavy phase. The protein-rich phase appears as droplets which can be coalesced to form a uniform bulk layer under centrifugation forces. Upon lowering the pH level by the addition of acid, further protein is precipitated as amorphous material which binds the droplets together to form aggregates of amorphous precipitates. Liquid-liquid separation has been observed in many protein solutions but this phenomenon has only scarcely been reported in the literature for soy proteins. It presents an exciting opportunity for an innovative product. Features of the liquid-phase protein such as protein yield and purity will be characterized.
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A research work entitled: “Microbiological analysis of traditionally fermented milk (Ikivuguto) sold in Kinigi Sector of Musanze District,” was carried out at Higher Learning Institution of Applied Sciences (INES-Ruhengeri) Laboratory of Microbiology located near Volcanoes in the Northern Province of Rwanda. The main objective of this work was to determine the microbiological quality of traditionally fermented milk, which is consumed by Kinigi Center local people. The hypothesis was to analyze if traditionally fermented milk commercialized in Kinigi restaurants contained pathogenic bacteria such as fecal coliforms and Escherichia coli , in addition to staphylococci and yeasts. Milk samples were collected from Kinigi sector and examined in the microbiology laboratory in order to assess the microbiological quality and safety of traditionally fermented milk in rural areas. The samples were analyzed qualitatively and quantitatively for the microbes found in fermented milk sold in Kinigi Center, and the results were as follows: 7.21x107 CFU/ml for total counts; 3.89x107 CFU/ml for Lactobacillus ; 2.77x107 CFU/ml for yeasts; 1.196x105 CFU/ml for total coliforms; 9.63x104 CFU/ml for fecal coliforms and 8.92x103 CFU/ml for staphylococci. Biochemical tests were carried out and the results showed that identified pathogens were E. coli, Providencia alcalifaciens , and the staphylococci group. It was found that fermented milk contained genera and species of Staphylococcus haemolyticus , Staphylococcus aureus , Staphylococcus intermedius , Staphylococcus xylosus and Staphylococcus saprophyticus . Findings showed that the commercial milk samples were cross-contaminated by different pathogens from environment. These contaminations could have been due to improper handling, presence of flies, soil erosion, dust from atmosphere, as well as contaminated milk vessels or pots, stirrers and unpasteurized water. It was concluded that local farmers and milk retailers did not adhere to required hygienic conditions for milk safety. In this regard, the sold traditional fermented milk does not meet health and safety standards because people did not respect good manufacturing practices. The hypothesis and main objective were confirmed, because traditionally fermented milk of Kinigi was cross-contaminated before consumption. Thus, it would be better to train farmers in the areas of product hygiene, sanitation and safety during milking, processing and marketing.
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Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL
Resumo:
The behavior of the hydroxyl units of synthetic goethite and its dehydroxylated product hematite was characterized using a combination of Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) during the thermal transformation over a temperature range of 180-270 degrees C. Hematite was detected at temperatures above 200 degrees C by XRD while goethite was not observed above 230 degrees C. Five intense OH vibrations at 3212-3194, 1687-1674, 1643-1640, 888-884 and 800-798 cm(-1), and a H2O vibration at 3450-3445 cm(-1) were observed for goethite. The intensity of hydroxyl stretching and bending vibrations decreased with the extent of dehydroxylation of goethite. Infrared absorption bands clearly show the phase transformation between goethite and hematite: in particular. the migration of excess hydroxyl units from goethite to hematite. Two bands at 536-533 and 454-452 cm(-1) are the low wavenumber vibrations of Fe-O in the hematite structure. Band component analysis data of FTIR spectra support the fact that the hydroxyl units mainly affect the a plane in goethite and the equivalent c plane in hematite.