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<p>  </p> <p><strong>Background information:</strong> </p> <p>Lactose is a disaccharide found in milk and milk products. Lactose is digested by the enzyme lactase. Lactase non-persistence is a genetic trait in which individuals have low lactase activity. Approximately 70 percent of the world population is lactase non-persistent. It is a major cause of lactose maldigestion. An increase of 20 ppm hydrogen in breath within six hours of a lactose challenge dose (0.5 g of lactose per kg bodyweight) indicates lactose maldigestion. On the other hand, lactose intolerant individuals experience abdominal pain, bloating, diarrhea, and flatulence on consuming dairy. Therefore, lactose intolerant individuals avoid milk, which is a rich source of calcium. Consequently, lactose intolerance has been associated with reduced calcium intake and low bone mineral density. There are two mechanisms for lactose intolerance. The first mechanism is dependent on lactose dose and the second one is independent of lactose. Recently, A1 and A2 β-caseins have been associated with lactose intolerance. Studies conducted in China, New Zealand and Australia demonstrated fewer symptoms on consumption of milk containing only A2 β-casein as compared to milk containing both A1 and A2 β-casein. However, no study was conducted in the population residing in United States, where crossbred cows producing milk containing both A1 and A2 β-casein is the norm. Moreover, no study compared tolerance and digestion on consuming milk with different proportions of A1 and A2 β-casein. Lactose intolerant individuals can include A2 milk in their diet to meet the calcium requirement, if milk containing only A2 β-casein causes fewer symptoms and less maldigestion. </p> <p><strong>Objectives:</strong></p> <p>1. To determine if a single meal of A2 milk containing only A2 β-casein would be better tolerated, producing fewer GI symptoms and less maldigestion, than conventional milk containing 75 percent A1 β-casein and 25 percent A2 β-casein</p> <p>2. To determine if a single meal of Jersey milk containing 25 percent A1 β-casein and 75 percent A2 β-casein would produce less maldigestion and intolerance, than conventional milk containing 75 percent A1 β-casein and 25 percent A2 β-casein</p> <p>3. To determine if the gastric emptying time of milk containing only A2 β-casein and milk containing 75 percent A1 β-casein and 25 percent A2 β-casein was different </p> <p>4. To determine if inflammation, maldigestion and intolerance is lower with a two-week daily consumption of milk containing only A2 β-casein as compared to milk containing 75 percent A1 β-casein and 25 percent A2 β-casein</p> <p><strong>Methods:</strong> </p> <p>Three randomized, double-blinded, crossover trials were conducted. The first study was conducted to determine tolerance and digestion of milk containing different proportions of A1 β-casein and A2 β-casein in subjects residing in the United States. There were four milk interventions in the study: A2 milk (milk containing 100% A2 β-casein), Jersey milk (milk containing 25%/75% A1/A2 β-casein), conventional milk (milk containing 75%/25% A1/A2 β-casein) and lactose-free milk (milk containing 60%/40% A1/A2 β-casein). Lactose intolerance in subjects was determined using a Qualifying Lactose Challenge Symptom Score after a challenge milk dose of 0.5 g of lactose/kg bodyweight. Subjects were screened for lactose maldigestion with a six-hour Hydrogen Breath Test. Symptoms and madigestion response to a single meal of milk (dose calculated as 0.5 g of lactose/kg bodyweight) containing different proportions of A1 and A2 β-casein were determined in lactose intolerant subjects and lactose maldigesters. </p> <p>The second study was conducted to examine the difference in gastric transit between A2 milk and conventional milk in lactose maldigesters. Magnetic Resonance Imaging (MRI) technique was used to observe gastric emptying. Subjects rated abdominal pain after consumption of the two milk interventions using a six-point Likert scale.</p> <p>The final study was conducted to determine symptoms, maldigestion and inflammation due to consumption of A2 milk and conventional milk for fourteen days on a daily basis in lactose maldigesters. Subjects rated lactose intolerance symptoms every day during the fourteen days using a six-point Likert scale. Breath hydrogen, serum inflammatory markers and serum antioxidant concentrations were measured on day 15 after the two-week milk consumption.  All the studies were registered at clinicaltrials.gov. </p> <p><strong>Results: </strong></p> <p>Results from the first study indicated that abdominal pain due to a single meal of A2 milk in lactose intolerant subjects was lower by twenty-three percent as compared to conventional milk (p=0.004, n=25). Similarly, there was a twenty-eight percent decrease in abdominal pain score on consumption of A2 milk as compared to conventional milk in lactose maldigesters (p=0.001, n=33). All the other symptoms were not different between A2 and conventional milk in lactose intolerant subjects and lactose maldigesters. A single meal of A2 milk reduced the total hydrogen production (p=0.04, n=33) by sixteen percent and total symptoms production (p=0.04, n=33) by eighteen percent in lactose maldigesters as compared to conventional milk. However, the total hydrogen and total symptoms produced were not different in lactose intolerant subjects between A2 and conventional milk. Similarly, individual GI symptoms, total symptoms and total hydrogen were not different between jersey and conventional milk in lactose intolerant subjects and lactose maldigesters.</p> <p>Results from gastric transit study indicated that volume of A2 milk in the stomach was higher by twenty-four percent at 30 (p=0.01, n=10), forty-six percent at 60 (p=0.002, n=10) and one hundred and sixty-one percent at 120 (p<0.001, n=10) minutes as compared to conventional milk in lactose maldigesters. </p> <p>Results from the last study suggested a fecal urgency score lower by thirty-three percent (p=0.033, n=10) in lactose maldigesters due to daily consumption of A2 milk for two weeks as compared to conventional milk. The other symptoms, inflammation markers, antioxidant and breath hydrogen production were not different between A2 and conventional milk due to two-week milk consumption.</p> <p><strong>Conclusion:</strong> </p> <p>Total intolerance symptoms and total hydrogen production were lower due to consumption of a single meal of A2 milk than conventional milk in lactose maldigesters. Gastric transit of A2 milk was slower as compared to conventional milk in lactose maldigesters. Daily consumption of A2 milk for two-weeks reduced fecal urgency as compared to conventional milk in lactose maldigesters. </p> <p>  </p>

Two experiments were conducted to examine the effects of type of milk (whole; nonfat; nonfat, 70% lactose-reduced) and type of egg (fresh, whole egg; egg substitute) on the quality of baked custards. The egg substitute was a combination of dried egg whit e solids, dried low-fat, low-cholesterol egg yolk solids, and xanthan gum. Custard formulations served as prototypes for use in studies conducted in the Department of Food Science and Technology, Virginia Tech. In those studies, the effects of processing parameters on the quality of the custards were examined. The goal of all the studies was to develop shelf-stable lactose-reduced custard mixes that have potential for use in the foodservice industry. In Experiment I, chemical, physical, and sensory characteristics of a dessert type baked custard, made with sucrose, were examined. In Experiment II, the same characteristics were examined for a cheese flavored, entree type custard made without sucrose. Results indicate that use of nonfat and nonfat, 70% lactose-reduced milk in place of whole milk decreased significantly total fat and cholesterol concentrations in both types of custard mixes. Lactose-reduced milk also decreased lactose and increased galactose concentrations. The egg substitute decreased total fat and cholesterol concentrations and increased protein concentration. In general, lactose reduction had little effect on the physical and sensory characteristics of both types of custards, but the egg substitute affected these characteristics. Custards made with the egg substitute had less intense yellow color and greater gel strength than those made with fresh, whole egg. These custards also were less bright and more uneven in color and had weaker egg flavor and aftertaste. Based on results of this study, development of a lactose-reduced custard is feasible. However, additional studies are needed to examine potential for use of the formulations in the foodservice industry. Because the mixes could be used as bases for other types of products, such as custard pies, filled pastries, and quiches, studies that focus on development of those products could help define the niche for the mixes in the foodservice industry. Because of the trend in today1s market for reduced-fat, reduced-cholesterol foods, additional studies could be done to examine the effects of various types of egg substitutes on the quality of the custards. / Master of Science

Hos vuxna individer förekommer två fenotyper gällande produktionen av laktas, vilka kallas laktostolerans och laktosintolerans. Vid laktosintolerans produceras otillräckliga mängder laktas vilket framkallar symptom som magsmärtor och flatulens vid intagandet av mjölkprodukter. En enbaspolymorfism (LCT-13910C&gt;T) har kopplats till laktostolerans hos nordvästeuropéer och kan genotypas med smältkurveanalys i realtids-PCR. På Laboratoriemedicin vid Länssjukhuset Ryhov används idag en metod vid genotypning av LCT-13910C&gt;T där extraktion av DNA från blod krävs innan analys. Anledningen till detta är att DNA-polymeraset som ingår enzymmixen LightCycler® FastStart DNA Master HybProbe endast fungerar med rent DNA-templat. Med en annan enzymmix, Kapa Probe Force, ska analys kunna göras direkt på blod. För att utvärdera enzymmixen jämfördes resultat från befintlig metod och resultat från metod med Kapa Probe Force, gällande förmågan att identifiera genotyperna LCT-13910C/C, C/T och T/T samt med avseende på imprecision. Vid jämförelse mellan metoderna samstämde resultatet i avseende på genotyp till 100 % utifrån specificerade smälttemperaturer (Tm) för respektive genotyp angivna i kitet för primer/prober. Däremot syntes lägre fluorescensnivå på smältopparna i metod med Kapa Probe Force, men påverkade inte tolkning av smältkurvorna. En lägre prov-till-prov-variation sågs även i resultatet från metod med Kapa Probe Force gentemot befintlig metod. / Among adults two phenotypes are found with regards to production of lactase, these are termed lactase persistence and lactose intolerance. Lactose intolerance is characterized by a low production of lactase, which leads to symptoms such as stomach ache and flatulence after the consumption of dairy products. A single nucleotide polymorphism (LCT-13910C&gt;T) has been correlated with the occurrence of lactase persistence in northwestern Europeans. Genotyping of LCT-13910C&gt;T is possible with melting curve analysis in real time PCR. The currently used method for genotyping of LCT-13910C&gt;T at Ryhov County Hospital requires the extraction of DNA template from blood, due to the fact that the DNA-polymerase in the kit LightCycler® FastStart DNA Master HybProbe requires pure DNA template for analysis. With another DNA-polymerase, included in the kit Kapa Probe Force, analysis on crude samples such as pure blood should be possible. Evaluation of Kapa Probe Force included comparison of the results from both methods with regards to identification of genotypes LCT-13910C/C, C/T and T/T and with regard to imprecision. The results from Kapa Probe Force were 100 % consistent with the results from existing method and acquired melting temperatures (Tm) were all within the accepted ranges specified in the kit of primers and probes. The fluorescence of melting curves acquired with Kapa Probe Force was significantly lower, however this had no effect when it came to interpreting the results. A lower variation could also be seen between samples with Kapa Probe Force compared to existing method.

Darbo tikslas: įvertinti suaugusių Lietuvos gyventojų pieno ir pieno produktų vartojimo ypatumus ir žmonių, kurių laktazės aktyvumas yra sumažėjęs, mitybą. Uždaviniai: įvertinti Lietuvos gyventojų pieno ir pieno produktų vartojimo dažnį bei ryšį su socialiniais veiksniais; ištirti žmonių, turinčių sumažėjusį laktazės aktyvumą, pieno ir jo produktų vartojimo įpročius; įvertinti paros maisto davinio sudėtį, atsižvelgiant į laktazės aktyvumą. Tyrimo metodika. Tyrimą sudarė dvi dalys. Pirmojoje buvo vertinami suaugusių Lietuvos žmonių pieno ir jo produktų vartojimo ypatumai. Tiriamąjį kontingentą sudarė 3000 20-64 m. amžiaus Lietuvos gyventojų, atsitiktinai atrinktų iš Lietuvos gyventojų registro sąrašų. Jiems paštu buvo siunčiamas klausimynas, kurį užpildė 1763 gyventojai. Buvo analizuojamas pieno produktų vartojimo dažnis. Antrojoje dalyje buvo vertinama žmonių, turinčių sumažėjusį laktazės aktyvumą, mityba. Tiriamąjį kontingentą sudarė asmenys, kurie kreipėsi į KMUK konsultacinės poliklinikos gastroenterologą dėl virškinimo sistemos sutrikimų. Taikant greitąjį laktazės testą, jiems buvo nustatytas laktazės aktyvumas, atlikta 24 val. mitybos ir anketinė apklausa. Tyrime dalyvavo 54 žmonės. Rezultatai. Ketvirtadalis tiriamųjų (22,7 proc. vyrų ir 26 proc. moterų) atsakė, kad negeria pieno. Didelė gyventojų dalis (35 proc. vyrų ir 28,1 proc. moterų) gėrė natūralų kaimišką pieną. Liesą pieną gėrė labai maža gyventojų dalis (6 proc.). Ketvirtadalis gyventojų teigė visai nevalgantys... [toliau žr. visą tekstą] / Aim: to evaluate the consumption of milk and milk products among Lithuanian adult population and the diet of patients with lactose intolerance. Objectives: to assess the frequency of consumption of milk and milk products among Lithuanian adult population in relation to social factors; to analyze the habits of milk and milk products consumption as well as mean daily energy and nutrient intake of the patients with lactose intolerance. Methods: for evaluation of the consumption of milk and milk products a national random sample of 3000 inhabitants of Lithuania aged 20-64 has been taken out of National Population Register. The questionnaires were mailed to selected persons. 1763 persons filled in the questionnaire. Second part of the study was carried out in Kaunas University Hospital. Fifty four patients with dyspeptic symptoms underwent upper gastrointestinal endoscopy. Quick lactose test was used for assessment of hypolactasia. Diet was evaluated using 24 h recall and food frequency questionnaire. Results: One fourth of respondents (22.7 percent of men and 26 percent of women) reported that they do not consume milk at all. High-fat milk was consumed by 35% of men and 28% of women. Only 6% of respondents indicated the usage of low-fat milk. High-fat milk was more often consumed by men, if compared to women; by older women, if compared to younger ones; by low educated people, if compared to high educated; by city inhabitants, if compared to rural ones. A quarter of the... [to full text]

Os alimentos funcionais probióticos e/ou prebióticos estão em grande expansão no mercado e encontram-se disponíveis em diversas formas de apresentação, principalmente como produtos lácteos, na forma de iogurtes e leites fermentados. Porém, aproximadamente 70% da população mundial tem seu consumo ameaçado, em virtude da incapacidade de produzir a enzima &#946;-galactosidase em quantidades suficientes para a digestão de lactose, característica esta que torna esses indivíduos intolerantes a esse açúcar. O arroz (Oryza sativa) é um cereal consumido por cerca de dois terços da população mundial, que apresenta um baixo sabor residual e que faz parte da cultura alimentar de diversos países, inclusive o Brasil. Suas propriedades favorecem o seu uso em géis, pudins e sobremesas, principalmente devido à sua aparência, sabor suave, além de resultar em certos efeitos benéficos à saúde, como prevenção e controle de doenças crônicas, também consequentes da presença de proteínas hipoalergênicas. O presente trabalho teve como objetivo desenvolver um produto novo que sirva de alternativa para indivíduos intolerantes à lactose - uma sobremesa não láctea potencialmente simbiótica à base de arroz, elaborada com a adição da cultura ABT (composta dos microrganismos comprovadamente probióticos Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis Bb-12 e da cultura starter Streptococcus thermophilus) e com os ingredientes prebióticos inulina e fruto-oligossacarídeo (FOS) e enriquecida com cálcio e com isolado protéico de soro de leite. Três tratamentos foram realizados (em triplicata): T1 (sobremesa não fermentada), na qual o produto final foi diretamente resfriado, sem a sua fermentação prévia, T2 (sobremesa fermentada) na qual se aguardou a fermentação por parte da cultura adicionada (a 37 &#176;C/ 2 horas) e T3 (controle), sem a adição da cultura. Os produtos foram mantidos a 4-5 &#176;C por até 21 dias. As sobremesas foram avaliadas sensorialmente por provadores não treinados, após 7, 14 e 21 dias de armazenamento, através de teste de aceitabilidade, com escala hedônica de nove pontos. Também foram monitorados o pH, a firmeza instrumental (em analisador de textura TA-XT2) e a viabilidade de Bb-12, La-5 e Streptococcus thermophilus e a população de contaminantes, no produto recém-preparado (1 dia) e após 7, 14 e 21 dias de armazenamento. Adicionalmente, a determinação de pH foi realizada durante a elaboração dos produtos e a composição centesimal foi efetuada no produto mantido congelado. A sobremesa T1 (não fermentada) apresentou redução de pH durante os 21 dias de armazenamento, enquanto que T2 (fermentada) e T3 (controle) não diferiram significativamente (p>0,01). A firmeza de T2 foi ligeiramente menor (entre 0,46 N - dia 1 e 0,23 N - dia 21) que a de T1 (entre 0,55 N - dia 1 e 0,25 N - dia 21). A avaliação sensorial revelou que as sobremesas desenvolvidas obtiveram notas entre 6,4 e 7,4, sendo que não foram detectadas diferenças significativas (p<0,05) na preferência entre os diferentes tratamentos realizados e para os diferentes dias de armazenamento, com exceção do tratamento T3 ao 14º dia, o qual obteve notas significativamente inferiores aos demais. A viabilidade de Bb-12 foi superior à de La-5 em ambos os tratamentos adicionados de cultura ABT. Entretanto, a fermentação influenciou cada microrganismo de modo distinto. A viabilidade de La-5 foi maior em T1, tendo diminuído de 8,1 log UFC/g (dia 1 - pH 5,1) para 7,3 log UFC/g (dia 21 - pH 4,9), enquanto que Bb-12 apresentou viabilidade ligeiramente superior em T2, tendo diminuído de 8,8 log UFC/g (dia 1 - pH 4,7) para 8,1 log UFC/g (dia 21 - pH 4,5). Em T2, a população de La-5 foi inferior a 5,0 log UFC/g após 21 dias de armazenamento. A população de S. thermophilus se manteve superior a 8,0 log UFC/g durante todos os períodos, em ambos os tratamentos. A sobremesa não láctea à base de arroz potencialmente simbiótica desenvolvida apresenta boas perspectivas como alimento funcional e obteve boa aceitação por parte dos provadores. A fabricação do produto não fermentado poderia ser a sobremesa de escolha, de preparo mais curto, levando-se em consideração as questões econômicas envolvidas durante a sua produção. O estudo sugere que cada cepa deve ser testada separadamente, quanto ao comportamento no produto, em diferentes condições. Sugere, ainda, que a inclusão da etapa fermentativa na preparação de uma sobremesa pode afetar diferentemente cepas probióticas distintas. / Functional foods containing probiotic strains and/or prebiotic ingredients are available in different forms, and most of them are dairy products, such as yogurts and fermented milk. Nevertheless, the milk content in these products may restrict their intake by a considerable proportion (approximately 70%) of the worldwide population that is incapable of producing &#946;-galactosidase in enough quantity for digesting lactose. Rice (Oryza sativa) is an alternative crop with low residual taste, which is extremely abundant, being the basic food for more than half of world´s population. Its properties favor its use in puddings and desserts, mainly due to its appearance, light taste, and resulting in certain beneficial effects to health, such as prevention and control of chronic diseases, also due to the hypoallergenic proteins present. This study aimed to develop a new product to serve as an alternative for individuals who are lactose intolerant - a non-dairy rice-based potentially synbiotic dessert, prepared with the addition of an ABT culture (containing Bifidobacterium animalis subsp. lactis Bb-12, Lactobacillus acidophilus La-5, and Streptococcus thermophilus), with inulin and fructo-oligosaccharide (FOS), and enriched with calcium and milk whey protein isolate. Three different trials were prepared (in triplicates): T1 - without the previous fermentation stage after the addition of the ABT culture, and directly cooled for storage; T2 - desserts were previously fermented, at 37 °C for 2h, after the addition of the culture; and T3 (control) - without the addition of culture. The products were stored at 4-5 °C for up to 21 days. The desserts were submitted to sensory evaluation by an untrained panel, employing the acceptability test, with a 9-point structured hedonic scale, after 7, 14 and 21 days of storage. Moreover, pH, and instrumental firmness (TA-XT2 texture analyzer), and viability of Bb-12, La-5, and Streptococcus thermophilus, and populations of contaminants were also monitored during the storage period (days 1, 7, 14, and 21 of storage) for each trial. In addition, pH was also determined during production, and chemical composition proceeded from frozen samples. Trial T1 (non fermented) showed a decrease in pH during the whole storage period of 21 days, whereas T2 (fermented), and T3 (control) did not change significantly (p>0,01). T2 presented a slightly lower firmness (between 0.46 N - day 1, and 0.23 N - day 21) than T1 (between 0.55 N - day 1, and 0.25 N - day 21). The sensory evaluation revealed that the desserts obtained grades between 6.4 and 7.4, and no differences (p<0,05) for sensory acceptability between the trials, and the different days of storage were observed, except for trial T3 on the 14th day, which obtained significantly lower grades, when compared to the others. Viability of Bb-12 was higher than of La-5 in both trials with ABT culture. Nevertheless, the fermentation stage had implications on growth in different ways for each microorganism. Viability of La-5 was significantly higher (p<0.05) in T1, decreasing from 8.1 log cfu/g (day 1 - pH 5.1) to 7.3 log cfu/g (day 21 - pH 4.9), whereas viability of Bb-12 was just slightly higher in T2, decreasing from 8.8 log cfu/g (day 1 - pH 4.7) to 8.1 log cfu/g (day 21 - pH 4.5). Trial T2 revealed La-5 populations below 5.0 log cfu/g, after 21 days of storage. S. thermophiles maintained population above 8.0 log cfu/g during all storage times for both trials. This study indicated that the non-dairy rice-based potentially synbiotic dessert developed has a great potential as a functional food, and was well accepted by the panelists. The production of the non-fermented dessert could be the best choice, for economical questions and because of the shorter time during the production. This study suggests each strain must be evaluated independently for a specific product and condition. Moreover, the inclusion of a fermentation stage during production may affect the viability of probiotic strains in different ways.

Os alimentos funcionais probióticos e/ou prebióticos estão em grande expansão no mercado e encontram-se disponíveis em diversas formas de apresentação, principalmente como produtos lácteos, na forma de iogurtes e leites fermentados. Porém, aproximadamente 70% da população mundial tem seu consumo ameaçado, em virtude da incapacidade de produzir a enzima &#946;-galactosidase em quantidades suficientes para a digestão de lactose, característica esta que torna esses indivíduos intolerantes a esse açúcar. O arroz (Oryza sativa) é um cereal consumido por cerca de dois terços da população mundial, que apresenta um baixo sabor residual e que faz parte da cultura alimentar de diversos países, inclusive o Brasil. Suas propriedades favorecem o seu uso em géis, pudins e sobremesas, principalmente devido à sua aparência, sabor suave, além de resultar em certos efeitos benéficos à saúde, como prevenção e controle de doenças crônicas, também consequentes da presença de proteínas hipoalergênicas. O presente trabalho teve como objetivo desenvolver um produto novo que sirva de alternativa para indivíduos intolerantes à lactose - uma sobremesa não láctea potencialmente simbiótica à base de arroz, elaborada com a adição da cultura ABT (composta dos microrganismos comprovadamente probióticos Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis Bb-12 e da cultura starter Streptococcus thermophilus) e com os ingredientes prebióticos inulina e fruto-oligossacarídeo (FOS) e enriquecida com cálcio e com isolado protéico de soro de leite. Três tratamentos foram realizados (em triplicata): T1 (sobremesa não fermentada), na qual o produto final foi diretamente resfriado, sem a sua fermentação prévia, T2 (sobremesa fermentada) na qual se aguardou a fermentação por parte da cultura adicionada (a 37 &#176;C/ 2 horas) e T3 (controle), sem a adição da cultura. Os produtos foram mantidos a 4-5 &#176;C por até 21 dias. As sobremesas foram avaliadas sensorialmente por provadores não treinados, após 7, 14 e 21 dias de armazenamento, através de teste de aceitabilidade, com escala hedônica de nove pontos. Também foram monitorados o pH, a firmeza instrumental (em analisador de textura TA-XT2) e a viabilidade de Bb-12, La-5 e Streptococcus thermophilus e a população de contaminantes, no produto recém-preparado (1 dia) e após 7, 14 e 21 dias de armazenamento. Adicionalmente, a determinação de pH foi realizada durante a elaboração dos produtos e a composição centesimal foi efetuada no produto mantido congelado. A sobremesa T1 (não fermentada) apresentou redução de pH durante os 21 dias de armazenamento, enquanto que T2 (fermentada) e T3 (controle) não diferiram significativamente (p>0,01). A firmeza de T2 foi ligeiramente menor (entre 0,46 N - dia 1 e 0,23 N - dia 21) que a de T1 (entre 0,55 N - dia 1 e 0,25 N - dia 21). A avaliação sensorial revelou que as sobremesas desenvolvidas obtiveram notas entre 6,4 e 7,4, sendo que não foram detectadas diferenças significativas (p<0,05) na preferência entre os diferentes tratamentos realizados e para os diferentes dias de armazenamento, com exceção do tratamento T3 ao 14º dia, o qual obteve notas significativamente inferiores aos demais. A viabilidade de Bb-12 foi superior à de La-5 em ambos os tratamentos adicionados de cultura ABT. Entretanto, a fermentação influenciou cada microrganismo de modo distinto. A viabilidade de La-5 foi maior em T1, tendo diminuído de 8,1 log UFC/g (dia 1 - pH 5,1) para 7,3 log UFC/g (dia 21 - pH 4,9), enquanto que Bb-12 apresentou viabilidade ligeiramente superior em T2, tendo diminuído de 8,8 log UFC/g (dia 1 - pH 4,7) para 8,1 log UFC/g (dia 21 - pH 4,5). Em T2, a população de La-5 foi inferior a 5,0 log UFC/g após 21 dias de armazenamento. A população de S. thermophilus se manteve superior a 8,0 log UFC/g durante todos os períodos, em ambos os tratamentos. A sobremesa não láctea à base de arroz potencialmente simbiótica desenvolvida apresenta boas perspectivas como alimento funcional e obteve boa aceitação por parte dos provadores. A fabricação do produto não fermentado poderia ser a sobremesa de escolha, de preparo mais curto, levando-se em consideração as questões econômicas envolvidas durante a sua produção. O estudo sugere que cada cepa deve ser testada separadamente, quanto ao comportamento no produto, em diferentes condições. Sugere, ainda, que a inclusão da etapa fermentativa na preparação de uma sobremesa pode afetar diferentemente cepas probióticas distintas. / Functional foods containing probiotic strains and/or prebiotic ingredients are available in different forms, and most of them are dairy products, such as yogurts and fermented milk. Nevertheless, the milk content in these products may restrict their intake by a considerable proportion (approximately 70%) of the worldwide population that is incapable of producing &#946;-galactosidase in enough quantity for digesting lactose. Rice (Oryza sativa) is an alternative crop with low residual taste, which is extremely abundant, being the basic food for more than half of world´s population. Its properties favor its use in puddings and desserts, mainly due to its appearance, light taste, and resulting in certain beneficial effects to health, such as prevention and control of chronic diseases, also due to the hypoallergenic proteins present. This study aimed to develop a new product to serve as an alternative for individuals who are lactose intolerant - a non-dairy rice-based potentially synbiotic dessert, prepared with the addition of an ABT culture (containing Bifidobacterium animalis subsp. lactis Bb-12, Lactobacillus acidophilus La-5, and Streptococcus thermophilus), with inulin and fructo-oligosaccharide (FOS), and enriched with calcium and milk whey protein isolate. Three different trials were prepared (in triplicates): T1 - without the previous fermentation stage after the addition of the ABT culture, and directly cooled for storage; T2 - desserts were previously fermented, at 37 °C for 2h, after the addition of the culture; and T3 (control) - without the addition of culture. The products were stored at 4-5 °C for up to 21 days. The desserts were submitted to sensory evaluation by an untrained panel, employing the acceptability test, with a 9-point structured hedonic scale, after 7, 14 and 21 days of storage. Moreover, pH, and instrumental firmness (TA-XT2 texture analyzer), and viability of Bb-12, La-5, and Streptococcus thermophilus, and populations of contaminants were also monitored during the storage period (days 1, 7, 14, and 21 of storage) for each trial. In addition, pH was also determined during production, and chemical composition proceeded from frozen samples. Trial T1 (non fermented) showed a decrease in pH during the whole storage period of 21 days, whereas T2 (fermented), and T3 (control) did not change significantly (p>0,01). T2 presented a slightly lower firmness (between 0.46 N - day 1, and 0.23 N - day 21) than T1 (between 0.55 N - day 1, and 0.25 N - day 21). The sensory evaluation revealed that the desserts obtained grades between 6.4 and 7.4, and no differences (p<0,05) for sensory acceptability between the trials, and the different days of storage were observed, except for trial T3 on the 14th day, which obtained significantly lower grades, when compared to the others. Viability of Bb-12 was higher than of La-5 in both trials with ABT culture. Nevertheless, the fermentation stage had implications on growth in different ways for each microorganism. Viability of La-5 was significantly higher (p<0.05) in T1, decreasing from 8.1 log cfu/g (day 1 - pH 5.1) to 7.3 log cfu/g (day 21 - pH 4.9), whereas viability of Bb-12 was just slightly higher in T2, decreasing from 8.8 log cfu/g (day 1 - pH 4.7) to 8.1 log cfu/g (day 21 - pH 4.5). Trial T2 revealed La-5 populations below 5.0 log cfu/g, after 21 days of storage. S. thermophiles maintained population above 8.0 log cfu/g during all storage times for both trials. This study indicated that the non-dairy rice-based potentially synbiotic dessert developed has a great potential as a functional food, and was well accepted by the panelists. The production of the non-fermented dessert could be the best choice, for economical questions and because of the shorter time during the production. This study suggests each strain must be evaluated independently for a specific product and condition. Moreover, the inclusion of a fermentation stage during production may affect the viability of probiotic strains in different ways.

Actuellement, 70 % de la population mondiale est concernée par la baisse génétiquement programmée de l’activité de la lactase. Pour ces sujets, la consommation de lactose peut entrainer de sévères troubles digestifs. Les produits diététiques étudiés, réhydratés à l’aide de lait par le consommateur, sont donc potentiellement source d’inconforts. La première partie de ce projet s’est par conséquent attachée à développer des moyens permettant l’obtention de produits convenant à la majorité de la population intolérante au lactose. Dans le même temps, de plus en plus conscient du lien étroit liant alimentation, santé et bien être, le consommateur tend depuis quelques années à modifier ses habitudes alimentaires. Cela se traduit par un intérêt grandissant pour les aliments « santé ». La formulation de tels produits se heurte toutefois encore au manque de connaissances quant à la biodisponibilité de certains macro et micronutriments. Ce projet à visée industrielle propose par conséquent d’optimiser la digestibilité de l’amidon et des protéines contenus dans différents produits diététiques destinés à remplacer l’intégralité de la ration journalière. Pour ce faire, la digestibilité de différentes sources d’amidon (blé, maïs, maïs cireux, manioc, pomme de terre, riz et riz cireux) et de différentes protéines (caséines, concentrat de protéines de lait, isolat de protéines de pois, poudre de blanc d’œuf, concentrat de protéines sériques et isolat de protéines de soja) a été étudiée in vitro et comparée / Currently, 70% of the world population is affected by the genetically programmed decline in lactase activity. For these subjects, lactose consumption can cause severe digestive disorders. The studied dietetic products, usually rehydrated with milk by the consumer before use, are hence a potential source of digestive discomfort. The first part of this project deals therefore with development ways in order to obtain suitable products for the majority of lactose intolerant population. Laterraly, increasingly aware of the close link between food and health, consumers tend to change their eating habits. This is reflected by a growing interest in "healthy" foods. The formulation of these products is however still hampered by a lack of knowledge about some macro and micronutrients bioavailability. This industrial project aims to maximize the digestibility of starch and protein contained in dietary products replacing the entire daily ration. The digestibility of different starch sources (wheat, corn, waxy maize, cassava, potato, waxy rice and rice) and different food proteins (caseins, milk protein concentrate, pea protein isolate, egg white powder, whey protein concentrate and soya protein isolate) has thus been studied and compared in vitro

published_or_final_version / Paediatrics / Master / Master of Philosophy