Whipping creams are oil-in-water emulsion which by whipping can be formed to a foam by the incorporation of air into the system. Traditionally whipping creams are made out of milk but today imitation whipping creams based on vegetable fat has gained a large share of the marked due to their many benefits compared to traditionally whipping creams. Imitation whipping creams are both cheaper and more flexible than traditionally creams. By vary the characteristics of the fat system and the cream recipe the properties of the imitation creams can be adapted to fit the purpose of a specific product. The aim of this thesis was to increase the understanding of how different types of fat systems and other ingredients affect the properties of imitation whipping creams based on vegetable fat. This was done by studying three vegetable fat systems with different physicochemical properties. The properties of the fat systems were characterized and the three fat systems were then used for making different imitation whipping creams. The properties of the creams were characterized and the properties of the fat systems and the creams were assessed and compared with each other. The study showed that the fat characteristics that generally seem to have the highest impact on the properties of whipping creams are the structure, the solid fat content and the crystallization temperature of the fat. A fat solution with a hard structure, a high crystallization temperature and a high solid fat content at a wide range of temperatures overall seem to provide the whipping creams with the best properties. This as these fat properties provide the creams with a high foam stability, a high overrun and a short whipping time. This study has also shown that other ingredients than the fat systems provide the creams with diverging properties. This is best shown by the results of the freeze-thaw stability which indicate that a recipe with a high amount of sugar seem to provide the whipping creams with good freeze-thaw stability. Other properties of the whipping creams also seem to be very much influenced by other ingredients than the fat systems but further studies are needed to provide clarity to the complexity of the interplay of the ingredients in whipped creams.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / There is a great concern of consumers with health, food safety and nutritional value of foods that come with even more interest in sau-hum- ming, nutritious and great use food products. Aimed to evaluate the effect of seasonality and industrial heat treatment on fatty acids of milk and the biological response of rats on diets of different lipid sources submitted or not to physical activity profile. In assessing the effect of climate station and heat treatment on fatty acid profile of milk samples were collected (in natura, pasteurized and sterilized) for 11 consecutive months in the Rio Grande do Sul Dairy Industry. Samples were subjected to extraction lipids and after the determination of fatty acid profiles in gas chromatography, using patterns of fatty acids. The bioassay was conducted for a period of 52 days, we used 36 adult male Wistar rats, divided into 6 treatments of six animals each and were fed diet AIN- 93M, varying the source of lipids and regular physical activity: DCSA normolipídica control, with soybean oil and no physical activity; DCCA normolipídica control with soy oil and physical activity; DMSA fat with butter and no physical activity; DMCA fat with butter and physical activity; DGSA fat with hydrogenated vegetable fat and no physical activity; DGCA fat diet with hydrogenated vegetable fat and physical activity. We investigated the effect of treatments on feed intake, weight gain, feed conversion, feed efficiency ratio, weight, liver, kidneys, heart, epididymal fat digestibility of diets, blood parameters (total COL, HDL, TG, GLI , ALB, ALT, AST, urea, creatinine, IL-1, IL-6, IL-10, TNF-α, IFN-γ and PCRus) and the histology of the aortic arch. The sterilization of milk caused reduction of docosanoic fatty acids, conjugated linoleic acid (cis-9, trans-11) and eicosapentaenoic ratio PUFA: SFA. The seasonal variation caused in octadecatrienoic fatty acids, conjugated linoleic acid (cis- 9, trans-11), docosadienoic acid, and eicosapentaenoic ratio PUFA: SFA. The experimental diets interfere with the feed intake, weight gain, feed conversion ratio, feed efficiency coefficient, epididymal fat weight and total cholesterol blood parameters, alanine transaminase, aspartate transaminase, IL-1, IL-6 and IL-10. Physical activity influence on blood triglyceride, creatinine, IL-1, IL-6 and IL-10. The interaction between diet and physical activity was significant for TNF-α and INF-γ. From the results it can be concluded that the heat-treated milk (pasteurization and sterilization) produced in four seasons show variations in the fatty acid profile. The concomitant fat diet with regular physical activity promotes normal development and maintenance of experimental animals. / Existe uma grande preocupação dos consumidores com a saúde, segurança alimentar e valor nutricional dos alimentos com isso surgem interesse por produtos alimentícios ainda mais saudáveis, nutritivos e de grande aproveitamento. Objetivou-se avaliar o efeito da sazonalidade e do tratamento térmico industrial no perfil de ácidos graxos do leite e a resposta biológica de ratos com dietas de diferentes fontes lipídicas submetidos ou não à atividade física. Na avaliação do efeito da estação climática e do tratamento térmico no perfil de ácidos graxos, foram coletadas amostras de leite (in natura, pasteurizado e esterilizado) durante 11 meses consecutivos em Indústria de Laticínios do Rio Grande do Sul. As amostras foram submetidas a extração de lipídios e após a determinação do perfil de ácidos graxos em cromatografia gasosa, empregando-se padrões de ácidos graxos. O ensaio biológico foi conduzido por um período de 52 dias, utilizou-se 36 ratos Wistar machos adultos, distribuídos em 6 tratamentos de 6 animais cada, que receberam ração AIN-93M, variando a fonte de lipídeos e a prática regular de atividade física: DCSA controle normolipídica, com óleo de soja e sem atividade física; DCCA controle normolipídica, com de óleo de soja e com atividade física; DMSA hiperlipídica, com manteiga e sem atividade física; DMCA hiperlipídica, com manteiga e com atividade física; DGSA hiperlipídica, com gordura vegetal hidrogenada e sem atividade física; DGCA dieta hiperlipídica, com gordura vegetal hidrogenada e com atividade física. Investigou-se o efeito dos tratamentos sobre o consumo de ração, ganho de peso, conversão alimentar, coeficiente de eficiência alimentar, peso fígado, rins, coração, gordura epididimal, digestibilidade das dietas, parâmetros sanguíneos (COL total, HDL, TG, GLI, ALB, ALT, AST, uréia, creatinina, IL-1, IL-6, IL-10, TNF-α, IFN-γ e PCRus), bem como a histologia do arco aórtico. A esterilização do leite ocasionou diminuição dos ácidos graxos docosanóico, linoléico conjugado (cis-9, trans-11), eicosapentanóico e na relação PUFA:SFA. A sazonalidade causou variação nos ácidos graxos octadecatrienóico, linoléico conjugado (cis-9, trans-11), docosadienóico, eicosapentaenóico e relação PUFA:SFA. As dietas experimentais interferiram no consumo alimentar, ganho de peso, conversão alimentar, coeficiente de eficiência alimentar, peso da gordura epididimal e nos parâmetros sanguíneos de colesterol total, alanina transaminase, aspartato transaminase, IL-1, IL-6 e IL-10. A atividade física influenciou nas concentrações sanguíneas de triglicerídeos, creatinina, IL-1, IL-6 e IL-10. A interação entre dieta e atividade física foi significativa para TNF-α e INF-γ. Através dos resultados pode-se concluir que os leites submetidos a tratamentos térmicos (pasteurização e esterilização) produzidos nas quatro estações do ano apresentam variações no perfil de ácidos graxos. As dietas hiperlípidica concomitante com a prática regular de atividade física promovem a manutenção e desenvolvimento normal dos animais experimentais.