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| Author(s): |
Cecilia Geraldes Martins
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2008-10-17 |
| Examining board members: |
Mariza Landgraf;
Bernadette Dora Gombossy de Melo Franco;
Laercio Goularte;
Maria Aparecida Azevedo Pereira da Silva;
Anna Lucia Casañas Haasis Villavicencio
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| Advisor: | Mariza Landgraf |
| Abstract | |
With the increase in the consumption of fresh vegetables and the globalization of the market for fresh fruits and vegetables, the concern with foodborne diseases associated with these products has also increased. In Brazil, the production of organic vegetables has increased approximately 40% per year in the last decade. Considering the above, 108 samples of irradiated, minimally processed, organic watercress from producers in the region of Sao Roque, Sao Paulo, were collected through November 2005 to March 2007, to assess the microbial ecology and vitamin C content. Samples of organic watercress collected at the farm level and at the industry level showed populations higher than 3,0 UFC/g for aerobic mesophilic, psychrotrophic, Pseudomonas spp, fecal coliforms and E. coli. Salmonella, E. coli O157:H7 and L. monocytogenes were not detected along the production chain. Comparing the minimal process and the combination of minimal process and irradiation, the combination was more efficient since even the lower dose (1 kGy) was sufficient to reduce the population of the various groups of microorganisms. The ascorbic acid, dehidroascorbic acid and vitamin C content varied at all stages of minimal processing as well as with the exposed doses of irradiation (1, 2 and 3 kGy). The population of L. monocytogenes decreased approximately 4.5, 5.5, and 5.9 log cycles, depending on the exposed doses, throughout the shelf life of irradiated minimally processed organic watercress. Similar behavior was showed by the Salmonella population. Sensory evaluation results showed that previous knowledge or none by consumers does not interfere with the acceptance and intention of purchase of irradiated minimally processed organic watercress. Thus the process of irradiation to improve the microbiological quality of minimally processed organic watercress is feasible provided that Good Agricultural Practice, Good Practice Production and Good Irradiation Practice are followed. (AU) | |