Viabilidade do uso de salada de frutas minimamente processada como veículo de micro-organismos probióticos

• Autor(a) principal: Martins, Eliane Maurício Furtado
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/464
• topic: Micro-organismos probióticos; Salada de frutas; Escurecimento enzimático; DPPH; Carotenoides; Probiotics microorganisms; Fruit salad; Enzymatic browning; DPPH; Carotenoids; Morphology of microorganisms; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

Studies show that the vegetable matrix can carry probiotic cultures. Thus, the feasibility of using minimally processed fruit salads as a vehicle for L. rhamnosus HN001, L. acidophilus LA-5 and L. plantarum was the subject of this work. Moreover, we aimed to evaluate the effect of reducing compounds in order to retard the browning of fruits and determine the viability of probiotic bacteria in the product, verify its adhesion in fruits by electron microscopy (SEM) and determine the physico-chemical, vitamin C, carotenoids, microbiological and sensory characteristics of the salads during cold storage. We evaluated four antioxidants in fruit salad added of L. acidophilus. Analysis of polyphenol oxidase (PPO) and color were made. We also evaluated the viability of the probiotic cultures and accession by SEM. It was determined pH, acidity, soluble solids, texture, vitamin C, carotenoids, psychrotrophs, coliforms at 30 °C and 45 °C and Salmonella sp. in fruit salad. Hedonic scale of 9 points was used for sensorial analysis. There was significant difference (p <0.05) in PPO activity between control fruit salads and treated with ascorbic acid 1 % and 2 % and cysteine hydrochloride 0.5 % and 1 %. Ascorbic acid 1 % was selected as an inhibitor of browning of salad. The color of the fruit was affected by the processing and storage. The viability of L. acidophilus in salads containing inhibitor compounds at higher concentrations was above 7.43 log CFU/g until the fifth day of storage. It was further observed that L. rhamnosus was the culture of greater viability (p <0.05) in fruit salads, with 8.49 log CFU/g during product storage. It was observed by SEM that the tissues of fruit damaged by processing served as a shelter for probiotic cultures, which makes it an adhesion sites. We also observed a high number of L. rhamnosus, L. acidophilus and L. plantarum adhered to the surface of the fruit. There was greater adhesion of probiotic cultures in banana, apple and guava. It was also found that the addition of L. rhamnosus and L. plantarum did not alter the texture present in the fruit salad (p> 0.05). The fruit salad added of L. rhamnosus showed values of pH and acidity different from the control treatment (p <0.05). There was a reduction of vitamin C content over time, and salads containing L. rhamnosus showed a higher content of vitamin C (p <0.05) compared to control treatment, up to 72 hours of storage, because the fruits of this treatment were immersed in 1% of ascorbic acid, which contributed to enrich the fruit salad. No significant degradation (p> 0.05) of total carotenoids was observed during the storage period. The fruit salads containing probiotic cultures presented the counts of psychrotrophic microorganisms of at least 2.0 log CFU/g lower than salads control for 120 hours of storage at 8 °C. In addition, the salads were in agreement with the microbiological standards established by Brazilian law. The control fruit salads and containing L. rhamnosus were well accepted by consumers, with scores above 7.0, like moderately, in the nine point hedonic scale for the attributes color, flavor and overall liking. Therefore, fruit salads can be used as a promising vehicle for probiotic bacteria and represent an alternative to the consumption of functional foods for the population.