Abstract:
Addition of acids to foods allows for enhanced food safety. Acids are the
primary form of defense against microbial contamination in refrigerated foods,
while use of acids in conjunction with heat or high hydrostatic pressure processing
lowers energy usage resulting in cost reduction. However, addition of acids to food
or beverage formulations often reduces palatability due to higher sourness and this
has limited the food industry's ability to better utilize them as preservatives. This
study was aimed at gaining a better understanding of sourness suppression and its
underlying mechanisms so that such limitations might be ultimately overcome.
This work was divided into three parts dealing with the suppression of the
sourness of citric, lactic and malic acids, as perceived by a trained sensory panel in
a) binary mixtures with sugars, b) binary mixtures with salts and c) tertiary
mixtures. The results of the first part showed that suppression was not mediated by
sugar molarity or weight, but was significantly influenced by its perceived
sweetness intensity in most cases. Sucrose and fructose were more effective than
glucose in suppressing acid sourness and the data supported a separate receptor
site/mechanism for glucose. Suppression was thought to have both central and
peripheral components.
In binary acid-salt mixtures sodium acetate (NaAc) affected the most
sourness reduction, along with the largest concurrent pH increase (above 4.4).
Sodium chloride (NaCl) mixtures showed significant suppression without a pH
increase. Sodium gluconate (NaGluc) mixtures showed moderate suppression with
citric and malic acids with pH increases remaining below 4.4, but showed little
effect on lactic acid sourness. Saltiness appeared to drive suppression only in the
case of NaCl, while pH change was responsible for reduction of sourness with
NaAc and NaGluc.
The tertiary trials indicated that a two-component multiple masker was
more effective when its components stimulated different (as opposed to similar)
receptors/receptor mechanisms in the taste system, irrespective of taste quality.
Furthermore, a two-component masker was more effective than each component
alone, and both components of a two-component masker did not have to be
effective individually for them to function together as an effective multiple masker.
