Impregnação a vácuo de micro-organismos probióticos em goiaba minimamente processada

• Autor(a) principal: Rodrigues, Marcela Zonta
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2935
• topic: Lactobacillus rhamnosus; Lactobacillus plantarum; Vida de prateleira; Pressão de vácuo; Morfologia; Lactobacillus rhamnosus; Lactobacillus plantarum; Shelf life; Vacuum pressure; Morphology; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

Probiotic cultures are available to the consumer, especially in dairy products, but the interest in incorporating probiotics in other foods has increased in recent years. Thus, the matrices vegetables has become a good alternative to the incorporation of these micro-organisms. This research aimed to develop a probiotic food from guava using the technique of vacuum impregnation. The guava minimally processed, and then were impregnated under a vacuum pressure of 500 mm Hg using the control solution comprising citrate: citric acid, Lactobacillus acidophilus suspensions in citrate: citric acid and Lactobacillus plantarum in citrate: citric acid. The suspensions probiotic cultures initially contained 1010 CFU&#8901;mL-1. In order to determine the time vacuum ideal minimally processed guavas were impregnated with a suspension of L. plantarum evaluating five times (5, 10, 15, 20 and 30 minutes), and subsequently were counted viable bacteria adhered guavas. It was evaluated, too, the addition of L. acidophilus and L. plantarum in minimally processed guava vacuum impregnated by determining the viability of lactobacilli and the adherence by electron microscopy varredurra. Also determined pH, titratable acidity, soluble solids, color, weight loss, firmness, vitamin C, total carotenoids, total plate count of microorganisms mesophilic and psychrotrophic and Most Probable Number of coliforms at 35 °C and 45 °C throughout the shelf life of guavas. The time of impregnation influence the number L. plantarum adhered on guava (p<0.05) and the time 30 minutes was defined as the one with the highest score and used for the production of probiotic guava impregnated under vacuum. The viability of cultures probiotics in guavas remained constant (mean 8.64 CFU&#8901;g-1) until the tenth day of shelf life with no difference between the cultures studied (p>0.05). It was found by SEM that the plant tissue guava, honeycombed, damaged by processing facilitated the entry and served as shelter for the probiotic micro-organisms, confirmed the adherence of L. acidophilus and L. plantarum surface guava. The color of guava minimally processed was affected by vacuum impregnation stage and only the L * parameter was affected during the storage period (p<0.05). It was also found that the addition of probiotic cultures did not change (p>0.05) the physico-chemical (pH, titratable acidity, total soluble solids, weight loss, carotenoids and vitamin C) guava. However, the addition of micro-organisms affect the texture of the fruit. The storage period also influenced (p<0.05) the parameters of pH, acidity, weight loss and firmness. There was no significant degradation (p>0.05) of vitamin C and total carotenoids during the storage period. The addition of probiotic cultures in minimally processed guavas reduced (p<0.05) compared to the control treatment the count of micro-organisms aerobic mesophilic and psychrotrophic throughout the storage period. In addition, minimally processed guava met the microbiological standards for coliforms at 45 oC established by law. The minimally processed guavas control and containing L. acidophilus and L. plantarum were accepted by consumers, with grades above 6.0, like slightly, the nine-point hedonic scale for overall impression attributes, color, flavor and texture. Given the above, the minimally processed guavas added probiotic cultures can be an alternative to the consumption of functional foods.