Evaluation of starters cultures of yeasts in jackfruit seeds fermentation and their effects on chocolate aroma

Author(s)

Amanda Cristina Marabesi

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2018-08-03

Examining board members

Solange Guidolin Canniatti Brazaca; Severino Matias de Alencar; Luiz Humberto Gomes

• Advisor: Solange Guidolin Canniatti Brazaca

Abstract

Currently the world demand of cocoa exceeds it\'s supply, leading the research and development of substitutes. Study recently conducted evidenced a potential substitute by subjecting hard jackfruit seeds to fermentation, drying and roasting processes, resulting in the production of volatile compounds to those of cocoa. However, the fermentative process was carried out with the natural microbiota, which makes it impossible to direct the production of interests compounds. Thus, the aim of the present work was the application of starter cultures of two microrganisms isolated from the cocoa beans fermentation (Kluyveromyces marxianus e Saccharomyces cerevisiae) in the fermentative process of hard jackfruit seeds, the monitoring of the fermentative mass characteristics, the microbiological characterization, and evaluation of volatile compounds produced. In the first chapter are presented the data refering to the first stage of the project, which involved the fermentation in three lots, containing a treatment without yeast inoculation (control) and two inoculated treatments, KM with K.marxianus, and MIX with K.marxianus and S. cerevisiae. In this chapter it was also evaluated the fermentative mass characteristics throughout the fermentation process (pH, exsudation, soluble solids, titratable acidity and temperature), the nutrients consumption (sugars and proteins), the production of ethanol and organic acids (acetic acid and lactic acid) and the characterization of mineral content. Differences were observed in the parameters for the treatments, mainly due to the acceleration of the fermentation in the MIX treatment, which influenced in the volatile compounds production. Also it was evidenced the presence of yeasts, lactic acid bacteria and acetic acid bacteria throughout the process. In chapter two are presented the results obtained in the second stage of the project, which involved the analysis of volatile compounds production and the aromatic profile similar to cocoa, evidencing the maximization of some volatile compounds production that confer chocolate aroma, in the presence of MIX of starters cultures, indicating their potential use in the hard jackfruit fermentation. (AU)

• FAPESP's process: 16/09594-9 - Use of starter culture of yeast in seed fermentation of hard jackfruit and its effect on chocolate flavour
• Grantee: Amanda Cristina Marabesi
• Support Opportunities: Scholarships in Brazil - Master