Production and biological evaluation of aroma compounds by the biotrasnformation of carotenoids

Author(s)

Ana Paula Dionísio

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2010-02-08

Examining board members

Glaucia Maria Pastore; Mário Roberto Maróstica Junior; Stanislau Bogusz; Paulo Roberto Nogueira Carvalho; Gorete Ribeiro de Macedo

• Advisor: Glaucia Maria Pastore

Abstract

The biotransformation of carotenoids is a field of growing interest to the flavor industry, once the compounds obtained can be labeled as "natural", with high industrial applicability and that may present, in many cases, interesting biological properties. Chapter 1 reviews a variety of techniques developed till the present days for the oxidation of terpenes, especially monoterpenes and ß-carotene, to volatile compounds. In sequence, Chapter 2 deals with the screening of microorganisms from natural sources rich in ß-carotene. Among more than 400 strains evaluated, 60 exhibited a potential for biotransformation of carotenoids, as evidenced by a characteristic degradation halo formed around the colonies inoculated on a plate containing ß-carotene. Afterwards, the solid phase microextraction technique (SPME) was used to extrain and concontrate the aroma compounds produced by the selected strains, and the analysis were conduced by GC-FID and GC-MS. The study of the variables involved in the biotransformation of ß- carotene by the LB398APD strain is reported in Chapter 3. For this, a Placket-Burman (PB16) was initially performed for the screening of the variables, and following the experimental design process, a 22 factor with the significant parameters selected in the PB was performed. In sequence, Chapter 4 shows the use of alternative culture media for the biomass development by the LB398APD strain. The microorganism demonstrated a development in the cassava wastewater media higher than in the conventional media, and the optimum system conditions were achieved by using 60 % of cassava wastewater, 30 °C and 300 rpm (biomass production in 24 hours = 4.6 gL-1). In addition to the tests using ß-carotene as substrate, other terpenes were also tested with some fungal strains, and this biotransformation is reported in Chapter 5. Carvone and carveol were obtained when limonene was used as the sole carbon source. The use of Paecilomyces sp. seems to be the first report in literature for biotransformation assays. Finally, Chapter 6 deals with some in vitro studies with carotenoids derived aroma compounds. The promising results create the possibility for such compounds to be used as "functional flavors (AU)