The proteic nitrogen in alcoholic fermentation and influence in cachaça quality

Author(s)

Elisangela Marques Jeronimo

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2004-08-10

Examining board members

Gil Eduardo Serra; Dejanira Franceschi de Angelis; Maria das Graças Cardoso; Evelyn de Souza Oliveira; Lúcia Regina Durrant; Marcia Edilamar Pulzatto; Helena Maria André Bolini

• Advisor: Gil Eduardo Serra

Abstract

Studies on the addition of nitrogen source in alcoholic fermentation have been conducted using nitrogen fertilizers as ammonium sulphate, superphosphates and urea, but applied for alcohol production. In small sugarcane distilleries the sugarcane juice complementation with nitrogen can constitute a benefical practice in yeast multiplication and cellular growth, and also for the improvement of fermentation yield and productivity. Mineral nitrogen sources, many times show controversial results. Several authors verified that the a nitrogen complex source, influenced the ethanol yield, yeast biomass and other alcoholic fermentation parameters. The goal of this work is to evaluate the influence of sugarcane juice clarification on proteic nitrogen content of juice, and by otherhand the addition of proteic nitrogen souce - yeast extract on the fermentation parameters and volatile compounds produced. The sugarcane juice clarification reduced the cellular multiplication, without affecting the cell viability, and endanger yeast recycling for a new fermentation. The proteic nitrogen additions enhanced cellular viability and ensure yeast recycling operation. Higher levels of proteic nitrogen affected the synthesis of volatile superior alcohols, increasing propilic formation and reducing isobutilic and isoamilic alcohol. Proteic nitrogen addition also reduced fermentation time. Considering the sensory analysis importance in the brandies quality evaluation and research, the work included a study for to investigate the alcoholic concentration influence and of the acidity in the sugarcane liquor sensory perception profile by the provers, about the equalities or differences detection in the product aroma and flavor typical attributes sensory evaluation. It was going used a sugarcane spirit recently-distillate, which was going submitted at dilution and acidification with succinic acid, originating four samples for proofs. It concluded that the alcoholic concentration and the acidity didn¿t influence the brandy typical attributes sensory evaluation. The sugar cane spirit dilution doesn¿t contribute for greatest of the differences perception between two samples, neither at acidity variation masked the attributes sensory expression due to the represented sugarcane liquor secondary components mostly for aldehyde, superior alcohols, esters and organics acid. Finally, also was study the proteic nitrogen influenced positively the cell viability, and can ensure yeast recycling operation. It was also observed a reduction in fermentation time. The proteic nitrogen addition in the juice didn¿t affect the sensory acceptance of sugarcane liquor, and also didn¿t result in different levels of volatile compounds. Assimilable forms of proteic nitrogen can be helpfull on the optimization of alcoholic fermentation (AU)

• FAPESP's process: 00/07628-5 - Treatment of sugarcane juice by different strains of yeasts in the productivity and quality of the liquor
• Grantee: Elisangela Marques Jeronimo Torres
• Support Opportunities: Scholarships in Brazil - Doctorate