Utilização de leveduras na produção de novas bebidas fermentadas

• Author(s): Oliveira, Pedro Miguel Rodrigues
• Date: 2009
• Persistent ID: http://hdl.handle.net/10400.5/1093
• Origin: Repositório da UTL
• Subject(s): tea; juice; alcoholic fermentation; yeast; chá; sumo; fermentação alcoólica; levedura
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Prista, Catarina Geoffroy; Dias, Maria da Conceição Loureiro
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia

The thesis main objective was to produce new and stable fermented sparkling beverages from fruit and infusions/teas, with yeast directed for gourmet restaurants. Ten fruits and eighteen infusions/teas were evaluated for organoleptic properties to choose the best potentially four sparkling beverages. Beverages were characterized for physico-chemical composition, pH, total acidity, ºbrix, soluble protein and phenolic compounds. Antimutagenic potential was analyzed by Ames test. Product shelf-life was established (15 days – juices; 30 days - infusions, at 4ºC) and microbiology analyses were done during the same period, while pH, ºbrix, total acidity, glucose, ethanol and pressure were monitored. RAPD-PCR allowed the microorganism’s strains identification in beverages. Esters, aldehydes, superior alcohols and phenolic compounds were detected by gas chromatography. Three focus group (32 people; ≥ 18 years old) were organized to evaluate beverage’s acceptability. It was concluded that these beverages were stable from the chemical and microbiological point of view. Its global sensorial appreciation was above the average for all four beverages (> 60% - infusions; > 80% - juices).