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| Author(s): |
Adriana Diaz Toni Fabbri
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Pesquisas Energéticas e Nucleares (IPEN/BT) |
| Defense date: | 2014-06-10 |
| Examining board members: |
Susy Frey Sabato;
Alexandre Bera;
Wilson Aparecido Parejo Calvo;
Lúcia Scott Franco de Camargo Azzi Collet;
Leonardo Gondim de Andrade e Silva
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| Advisor: | Susy Frey Sabato |
| Abstract | |
Immunocompromised individuals are susceptible to acquiring serious diseases from contaminated food, by having a low number of defense cells. As a result of this fact, they have an extremely restricted diet, avoiding any food that represents microbiological hazards. Irradiation is one of the few technologies that ensure the safety and quality of food, controlling pathogenic microorganisms without significantly affecting any organoleptic attribute. Based on dietary restriction in relation to fresh produce, this work was designed to study the effect of ionizing radiation (gamma rays) over fruit salad for immunocompromised individuals. For such, minimally processed fruits and fruit salad were subjected to doses of 0.5; 1.0; 1.5; 2.0 and 3.0 kGy and analyzed along with control samples (non irradiated). Analyzes were performed in the physicochemical (color, texture, titulabre total acidity, pH, water activity, total soluble solids and soluble sugars), microbiological (coagulase positive staphylococci, yeasts and molds count, count of aerobic bacteria, total coliforms, E. coli and Salmonella) and sensorial (acceptance testing and tastings) fields, besides the application of questionnaires with head of nutrition in hospitals to understand the practices of immunocompromised diet. The results showed that irradiation at the dose of 3.0 kGy was effective in eliminating microorganisms from fruit salad, ensuring the microbiological safety within the levels required by law. Regarding the physicochemical results, changes in color and texture with the increase in the dose of radiation were observed. Results of pH, acidity, total soluble solids and water activity values showed fluctuations mainly due to intrinsic factors of the fruit, while fruit salads irradiated with doses of 3.0 kGy, showed a tendency to get more sweet than the control samples, obtaining good sensorial acceptability. Furthermore, the results of questionnaires conducted in hospitals reported a need to incorporate fresh foods in the nutritional diet of immunocompromised individuals, as well as the creation or establishment of nutritional protocols in the country for that field. Thus, based on microbiological, physicochemical and sensorial results, it can be concluded that fruit salads may be indicated for the consumption of immunocompromised individuals, if treated with the dose of 3.0 kGy and produced with Good Manufacturing Practices, in compliance with the criteria of production from raw material to the end product. (AU) | |