Writing in the Journal of Food Science, researchers from the Auckland University of Technology (AUT) in New Zealand report on the ability of cyclodextrins – in particular beta-cycodextrin – to block the certain flavour notes of goats milk by binding to the undesirable branched chain fatty acids (BCFAs) that are responsible for such flavour.
Using odour ranking trials, the research team found that concentrations of beta-cyclodextrin (beta-CD) between 0% and 0.35% “were increasingly effective” in reducing odours associated with ‘goaty’ flavour intensity – due to 4-methyloctanoic acid.
“Following a series of developmental experiments with 4-methyloctanoic acid ... it was found that beta-cyclodextrin was useful in masking goaty flavour in yogurts,” reported the authors, led by Owen Young of AUT.
The researchers explained that the fact that beta-CD is already certified safe for food use means that it could be used in commercial goat milk yogurts and similar products.
“If used in these products, the real or perceived nutritional advantages of goat milk would not lost to goaty flavour,” explained Young and his co-workers.
“Moreover, the market price for these products is higher and more variable than for pure milk, and so can more easily tolerate the costs of additives like cyclodextrins that improve eating quality,” they said.
‘Goaty’ flavour
Young and his team explained that goats milk has a different flavour from cow milk – due to certain branched-chain fatty acids in the in the triacylglycerols that make up the body and dairy fats of goats and sheep.
The progressive breakdown of these dairy fats during milk storage can create a ‘goaty’ flavour dimension.
“In goat cheeses, this characteristic flavour may be sought after by gourmets, but in whole milk the goaty flavour limits market possibilities in Western societies habituated to the relatively flavourless cow milk,” said the researchers.
Study details
The researchers used odour ranking trials in a yoghurt model to investigate the possibility of blocking the branched chain fatty acids – 4-methyloctanoic acid – responsible for the ‘goaty’ flavours.
Concentrations of beta-CD between 0% and 0.35% were found to be increasingly effective in reducing odours associated with the ‘goaty’ flavour.
Alpha-CD was also found to be effective in reducing the flavour notes, however gamma-CD was not, revealed the researchers.
In further investigations, Young and his team noted that an analytical panel showed the flavour of goat yogurt was reduced by addition of beta-CD – but only if added before heating and fermentation.
“A hedonic trial showed that consumers preferred unsweetened and sweet/vanilla-flavoured goat yogurt more when beta-cyclodextrin was included,” said the authors.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2011.02557.x
“Effects of Cyclodextrins on the Flavor of Goat Milk and Its Yogurt”
Authors: O.A. Young, R.B. Gupta,S. Sadooghy-Saraby