Néctar de cupuaçu adicionado de proteína de soja e probióticos e avaliação de seus efeitos in vivo em ratos wistar induzidos a lesões pré neoplásicas

• Ano de defesa: 2014
• Autor(a) principal: Pelais, Ana Carla Alves
• Orientador(a): Ramos, Afonso Mota
• Banca de defesa: Vieira, érica Nascif Rufino , Binoti, Mirella Lima
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Cupuaçu; Proteínas de soja; Probióticos; Lesão pré-neoplásica; Ratos com animais de laboratórios
• Palavras-chave em Inglês: Cupuassu; Soy protein; Probiotics; Pre-neoplastic lesion; Rats with laboratory animals
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/498

The viability of using probiotic microorganisms in non-dairy matrices as nectars and fruit juices has been successfully evaluated by many researchers. Thus, this work aimed to develop a nectar based on cupuassu pulp (18.5 %, 20 %, 30 %, 40 %, and 41.5 %) and soybean protein (0.7 g, 1 g, 1.75 g, 2.5 g, and 2.8 g) containing probiotic with evaluation of their effects in vivo on Wistar rats induced to pre-neoplastic lesions. In the best formulation, L. acidophilus LA-3 (T 1 ), L. paracasei BGP1 (T 2 ), and the L. acidophilus LA-3/L. paracasei BGP1 (T 3 ) mixture were added resulting in three treatments in addition to control without probiotic. Physicochemical analysis, microbiological, and sensory evaluation were performed in the various trials of nectar; based on the optimized formulation, the monitoring of the beverage was made for 28 days of storage at 4 °C by means of physicochemical characteristics, probiotic viability, and in vitro resistance to the gastrointestinal conditions. Concomitantly, the beverages were administered to Wistar rats groups by gavage at a rate of 3 mL/kg body weight/day for a period of 10 weeks. As inducing agent of the colon pre-neoplastic lesions, 1.2 dimethylhydrazine (DMH) was used. During the experimental period, fresh feces were collected from animals for determining pH, Lactobacillus spp., and Bifidobacterium spp. At the end of the experiment after euthanasia, samples of blood, cecum's feces, liver, and colon were prepared to determine serum, volatile fatty acids, and hepatosomatic index, and for quantification of Aberrant Crypt Foci (ACF). Results showed that the prepared nectars were according to the recommended microbiological standards of the current law. In relation to the physicochemical standards, it was observed that increasing the concentration of cupuassu pulp caused a linear increase in titratable acidity and ascorbic acid content and consequently reduced the pH value. Nectars had good sensory acceptability, with mean scores above 5.0 for flavor attributes and overall impression and above 2.0 for the purchasing behavior. Based on obtained results, testing at 20% of cupuassu pulp and 2.5 g of soy protein were suggested as the best formulation, in which probiotic cultures were added. There was no significant difference (p > 0.05) among treatments for evaluated color parameters. Although acidity increase and pH reduction during the four storage weeks were observed, the viability of the used cultures was maintained in at least 7.0 Log UFC.mL -1 in all nectars throughout the storage period. The T 1 nectar showed the lowest survival at the end of the in vitro gastrointestinal simulation with 3.35 Log UFC.mL -1 , while T 2 and T 3 were more tolerant to stress with scores of 6.13 and 5.35 Log UFC.mL -1 , respectively. In sensory evaluation, control and T 1 treatments had the best acceptance, possibly due to the lower presented acidity. On in vivo assay, results suggest that ingestion of probiotic nectar did not exert a protective effect on the formation of ACF in all evaluated groups. Volatile fatty acids also showed no difference (p > 0.05) among the groups fed with the beverage. Fecal pH decreased only from the seventh week of the experimental period, while the count of Lactobacillus ssp. and Bifidobacterium spp. showed no significant differences (p > 0.05) among the experimental groups during the studied period. total cholesterol, high-density lipoprotein (HDL), and low density lipoprotein (LDL) did not differ (p > 0.05) in the groups fed with the beverage compared to the control groups. The no significant effect of the beverage at the evaluated parameters in animals treated with dimetilhidrazina (DMH) can be possibly attributed to the experiment duration.