Name: Clara Suprani Marques
Type: MSc dissertation
Publication date: 23/02/2018
Advisor:

Namesort descending Role
PATRICIA CAMPOS BERNARDES Advisor *

Examining board:

Namesort descending Role
ANTONIO MANOEL MARADINI FILHO External Alternate *
JOEL CAMILO SOUZA CARNEIRO Internal Examiner *
JUSSARA MOREIRA COELHO Internal Examiner *
PATRICIA CAMPOS BERNARDES Advisor *
PATRÍCIA FONTES PINHEIRO External Examiner *
POLLYANNA IBRAHIM SILVA Internal Alternate *

Summary: Essential oils have an interesting antimicrobial activity. Given that they are natural products derived from plants, their use as food preservative has been the subject of many studies. However, their strong odor and poor stability in presence of light, heat and oxygen may limit their application in foods. The complexation with β-cyclodextrin (β-CD) can be used as a method to overcome this drawbacks, protecting the biocompounds and improving their applicability. Therefore, one of the aims of this research was to characterize and investigate the antimicrobial activity of essential oils of leaves of Pimenta dioica (PDEO) and basil (BEO) as well as obtain their inclusion complexes with β-CD by two methods (kneading and freeze-drying) and two different molar ratios (1:1 and 2:1 essential oil:β-CD), with further characterization of the inclusion complexes and investigation of their antimicrobial activity. The other aims encompassed choosing the best inclusion complex for the elaboration of an antimicrobial sachet to be used as a preservative system for a ready-to-eat salad subjected to different washing treatments and stored for six days at 7 ºC. The washing treatments were: control or no sanitization (NS), ultrasound (US), sodium dichloroisocyanurate (SD), sodium dichloroisocyanurate associated with ultrasound (SD+US), peracetic acid (PA) and peracetic acid associated with ultrasound (PA+US). Physicochemical, microbial and sensorial parameters of the salad were investigated. Additionally, the sanitizing treatments applied and the sachet were evaluated against the pathogen Listeria monocytogenes, intentionally inoculated on the vegetables surface. β-Myrcen, eugenol and d-limonen were the majority compouds found in PDEO, which showed a higher antimicrobial activity against all microorganisms tested than BEO (methyl chavicol and linalool as majoritary compounds). Eight inclusion complexes were obtained in total and complexation for both essential oils was achieved and assured by thermal analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. PDEO inclusion complexes prepared by kneading, in both molar ratios, showed the best in vitro antimicrobial activity, and the inclusion complex PDEO 2:1 was chosen for sachet elaboration. No substantial physicochemical changes in salad were caused by the sanitizing treatments applied or the presence of the sachet. A slight weight loss was observed over storage time, but it remained lower than 1%. The sanitizing treatments SD, SD+US and PA were the best against psychrotrophic bacterias and acid latic bacterias. Against molds and yeasts, SD and SD+US reached the greatest log reduction, and PA+US showed more efficacy than PA alone. Against L. monocytogenes, SD, SD+US and PA+US provided the best results. Under the tested conditions, the sachet antimicrobial activity wasn't observed when applied on food system. Besides, the salads stored alongside sachets were the least accepted by consumers.

Access to document

Acesso à informação
Transparência Pública

© 2013 Universidade Federal do Espírito Santo. Todos os direitos reservados.
Alto Universitário, s/nº - Guararema, Alegre - ES | CEP 29500-000