Quantitative taste evaluation of total enteral nutrients

The purpose of this study was to evaluate quantitatively the taste of the various total enteral nutrients marketed in Japan using human gustatory sensation tests and an artificial taste sensor. In the human gustatory sensation test, four basic taste intensities (sweetness, saltiness, sourness, and bitterness), as well as 15 kinds of palatability scales, were evaluated according to the semantic differential (SD) method. Among 15 palatability items, the item; difficult to drink/easy to drink, was adopted as an overall palatability since it shows the highest factor loading by factor analysis. The overall palatability was found to be highly positively correlated with sweetness and sourness, but negatively correlated with bitterness and saltiness. Addition of a flavour to the amino acid-based enteral nutrient Aminoleban(R)EN significantly improved its palatability. This effect is presumably due to sour components of the flavour, such as citric acid, which reduce the bitterness intensity of branched-chain amino acids in the product. The sweetness and sourness intensities predicted by the taste sensor showed a high correlation with the results obtained in the human gustatory sensation tests. The taste sensor was able to predict the overall palatability of the total enteral nutrients with high accuracy. The products could be classified into three groups (peptide-based, amino-acid-based, and protein-based) by principal component analysis using sensor output of 8 channels. The products could be also classified into four groups; peptide-based, amino-acid-based, and protein-based and flavor addition group by principal component analysis using sensor output of channels 1, 3, 4 and 7, which are specific to basic tastes. The taste sensor could therefore be useful in predicting the taste or palatability of total enteral nutrients, and could contribute to attempts to improve compliance for such products and for enteral nutrients.