Flavour improvement of water solutions comprising bitter amino acids

The aim of this project was to improve taste of a liquid food product, comprising extremely bitter and unpalatable amino acids and one unrevealed ingredient. The amino acids were Lleucine, L-isoleucine, L-valine, L-threonine and L-lysine monohydrochloride. Experimental design was set up as a screeni...

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Detalles Bibliográficos
Autor principal: Lindqvist, Malin
Formato: Second cycle, A1E
Lenguaje:Inglés
Inglés
Publicado: 2011
Materias:
Acceso en línea:https://stud.epsilon.slu.se/2232/
Descripción
Sumario:The aim of this project was to improve taste of a liquid food product, comprising extremely bitter and unpalatable amino acids and one unrevealed ingredient. The amino acids were Lleucine, L-isoleucine, L-valine, L-threonine and L-lysine monohydrochloride. Experimental design was set up as a screening of water solutions comprising these ingredients (called BCAA solutions) and added ingredients with potential to improve flavour. BCAA solution with ingredients that were potential bitterness suppressors were evaluated in flavour, bitterness and/or palatability. Solutions of separate amino acids were also studied. Sensory panels comprised untrained assessors with varying capability of detecting bitterness. Palatability and bitterness were rated on hedonic scales in sensory analysis. Sensitivity to bitterness varies greatly between individuals, which together with varying preferences of bitterness and flavours caused significantly differing answers. This resulted in difficulties to obtain significant results using Tukey’s pair-wise comparison. A decreased content of leucine in the BCAA solution was indicated favourable, as well as replacing lysine monohydrochloride with lysine. Ingredients that indicated moderate bitterness reduction were aspartic acid and glutamic acid, both giving sour solutions but the latter being regarded as unpalatable. Ingredients indicated to reduce bitterness a little were carbonic acid, isomaltulose and some flavours. Opinions of bitterness reducing effect of flavours differed greatly, perhaps because of individual preferences or differences in bitterness sensitivity. The choice of water, more specifically the composition of minerals and salts, might considerably affect flavour qualities and bitterness of BCAA solution. The amino acid concentrations in the BCAA solution were probably too high for successful bitterness reduction using added ingredients in concentrations that would not alter flavour characteristics in any other undesired way. A promising alternative, that was not studied, would be to modify the branched chain amino acids (BCAAs) Leu, Ile and Val by acetylation of the N-terminal.