Título:	Eficácia da água ozonizada no controle de microrganismos em morango (Fragaria x ananassa Duch.) e efeito na qualidade físico-química durante o armazenamento
Autor(es):	Ferreira, Wallas Felippe de Souza
Orientador(es):	Alencar, Ernandes Rodrigues de
Assunto:	Microorganismos Ozonização Morango
Data de publicação:	31-Mar-2017
Data de defesa:	21-Fev-2017
Referência:	FERREIRA, Wallas Felippe de Souza. Eficácia da água ozonizada no controle de microrganismos em morango (Fragaria x ananassa Duch.) e efeito na qualidade físico-química durante o armazenamento. 2017. xxiii, 104 f., il. Dissertação (Mestrado em Agronomia)—Universidade de Brasília, Brasília, 2017.
Abstract:	The objective of this work was to evaluate the effect of ozone gas dissolved in water under different conditions and combinations on deteriorating and pathogenic microorganisms and possible effects on the physical-chemical quality of the stored strawberry. Two experiments were carried out in the present work: the first experiment evaluated the influence of pH on the ozonated water efficiency in controlling microorganisms and possible changes in the physical-chemical quality of the stored strawberry; In the second experiment the efficiency of the ozonated water in different combinations of concentration and time of immersion in the control of microorganisms and possible changes in the physical-chemical quality of the stored strawberry were evaluated. Strawberries of the "Portola" variety were purchased from a producer in the administrative region of Brazlândia – Distrito Federal. To evaluate the influence of pH on ozonated water, strawberries were divided into six batches, three batches in which the ozone gas was dissolved in the water at a concentration of 21 mg L-1 for 15 min of bubbling and three batches in which were not ozonated, Corresponding to the treatments: ozonized distilled water with pH 3.0 and ozone concentration in water of 0.11 mg L-1, ozonated distilled water with pH 6.5 and ozone concentration in water of 0.08 mg L-1, ozonated distilled water with pH 8.7 and ozone concentration in the water of 0.04 mg L-1; The other three treatments were control, distilled waters with pH’s of 3.0, 6.5 and 8.7. In order to reach pH 3.0, citric acid was used and sodium bicarbonate was used for pH 8.7, pH 6.5 was not altered. The immersion time in all treatments was 5 min. After this stage the strawberries were stored in a cold room at 5 °C. The fruits were analyzed on the day of ozonation (time zero) and every two days until day six of storage. In the microbiological stage, the presence of Salmonella spp., Total coliforms, E. coli, molds and yeasts and aerobes mesophiles, all expressed in log (UFC g-1), were evaluated. The qualitative variables evaluated were: fresh weight loss, pH, total titratable acidity, soluble solids content, ratio and staining. A completely randomized design was used in a 6x4 factorial scheme, with six treatments and four storage periods (0, 2, 4 and 6), with three replications. Initially, analysis of variance and regression analysis were performed. It was found that pH influenced the efficiency of ozonated water in the control of undesirable microorganisms in strawberries during storage. As regards the physico-chemical quality of strawberries, ozonated water was able to delay the loss of fresh mass, maintain pH levels, total soluble solids, titratable total acidity, ratio and color variables. To evaluate the efficiency of the ozonated water at different concentrations and with an immersion time of 7.5 min, strawberries were divided into three lots: ozone gas dissolved in water at a concentration of 45 mg L-1 and bubbled for 40 min, ozone gas dissolved in water at a concentration of 20 mg L-1, and lastly the last batch was not subjected to immersion in ozonated water. The strawberries were then stored in a cold room at 5 °C. The fruits were analyzed on the day of ozonation (zero time) and every three days until day nine of storage. The stages of microbiological analysis and physical-chemical quality of the strawberries were identical to those of the first experiment. A completely randomized design was used in a 3x4 factorial scheme, with three treatments and four storage periods (0, 3, 6 and 9), with three replications. Initially, analysis of variance and regression analysis were performed. The ozonated water was efficient in the control of microorganisms, especially with regard to aerobic mesophiles. Regarding the physico-chemical quality of the stored strawberries, the ozonated water did not significantly affect the loss of fresh mass, pH, total soluble solids, total titratable acidity, ratio and color variables. It was concluded from the results obtained in the two experiments that the use of ozonated water can become a promising method in the control of microorganisms and in the maintenance of the physico-chemical quality of stored strawberries.
Unidade Acadêmica:	Faculdade de Agronomia e Medicina Veterinária (FAV)
Informações adicionais:	Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2017.
Programa de pós-graduação:	Programa de Pós-Graduação em Agronomia
Licença:	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
DOI:	http://dx.doi.org/10.26512/2017.02.D.23159
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