Desenvolvimento de bebidas fermentadas a partir de subprodutos da indústria da castanha

• Author(s): Costa, Daniel Filipe Cortês
• Date: 2015
• Persistent ID: http://hdl.handle.net/10400.5/10933
• Origin: Repositório da UTL
• Subject(s): Koji; Sake; chestnut byproducts; Aspergillus oryzae; saccharomyces cerevisiae
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Prista, Catarina Geoffroy
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia

The food industry is an increasingly demanding industry, regarding both quality and safety. Consumers are keen to satisfy their needs and preferences, and the industry try hard to satisfy them, by producing new products resulting from competition among companies and innovation capacity. Fermented foods and beverages are among some of the most popular innovative products, because they frequently ally functional properties to surprise and variety. The main objective of this work was to develop and optimize a fermented drink produced from by-products of the chestnut industry centred on the ancestral rice saké methods. The production method for this drink was based on the simultaneous utilization of a mold (Aspergillus oryzae) as koji and yeasts (Saccharomyces cerevisiae). During this process, starch is hydrolysed by amylases produced by the mold, resulting in more simple sugars that will be fermented by the yeast producing ethanol. Preliminary assay were performed in order to determine which were the best elements to produce a tasty beverage. We tested different formulations, varying the type of koji, the type /proportion of substrate to ferment and the yeast strain. After testing 16 formulations, the most adequate one was determined, using koji produced from rice, raw chestnut as substrate and the yeast strain Saccharomyces cerevisiae CBS 436, which added a very aromatic profile to the final product. It reached an alcohol content of 13,25% (vol/vol). Sensory analysis performed by a non-trained panel of consumers moderately liked the concentrated and the diluted version of the selected beverage, both in terms of taste, colour and flavour (values between 6 and 7, in a scale of 1 to 9). However, in terms of acceptance by the tasters in the sensory analysis they show a buying intention near the indifference (values of 2.96875 for sample A and 3.03125 sample B, a scale of 1 to 5).