Sensory Characteristics of Salt Substitute Containing L-Arginine
Dietary salt restriction is a common approach recommended by physicians in the treatment and prevention of hypertension. Salt substitute is a potential alternative. The most popular salt substitute is KCl, having similar physical properties to NaCl. Because of the higher molecular weight of cations (K+), KCl imparts undesired bitterness and metallic aftertaste. L-arginine has been found to have the bitterness-suppression property. Therefore, it may be used in the mixture of salt substitutes.
In the first study, NaCl and four salt substitute solutions consisting of KCl, NaCl, and L-arginine, were developed at 0.5%, 1%, and 1.5% w/v. A discriminative test was performed to determine (1) the effectiveness of L-arginine in masking the bitterness perception of KCl, (2) saltiness perception of mixed salt solutions against NaCl solution, and (3) sensitivity of the simple ranking test vs. the R-index tests for evaluating bitterness and saltiness perception. The differences of saltiness perception of aqueous mixed salt against NaCl solution existed based on the non-parametric Friedmans test and the R-index test. The samples were not significantly different in terms of bitterness based on both techniques. Therefore, L-arginine could mask the bitterness of KCl.
In study two, eleven formulations of the mixture of NaCl/KCl/L-arginine were developed using a mixture design. The consumer study was performed to determine sensory attributes driving acceptance and to optimize the formulation. Consumers (n=385) evaluated the products, following a balanced incomplete block design. Bitterness was the discriminating attribute. Overall liking was identified as the attribute influencing consumer acceptability. The formulation containing 56-100% NaCl, 0-44% KCl, and 0-5% L-arginine would yield product acceptability score 1.0 unit less than that of NaCl. Consumers were able to discriminate the saltiness and the bitterness between formulations of salt solutions (100% NaCl vs. 35% NaCl, 65% KCl), using the triangle test with a corrected beta binomial distribution.
L-arginine could partially mask the bitterness of KCl. However, development of the proportion of KCl/NaCl/L-arginine obtained from mixture design, and the application of salt substitute in foods would be worth further study. Moreover, the heat and cold stability of L-arginine in the salt substitutes should be investigated.
Advisor:Beilei Ge; Zhimin Xu; Witoon Prinwawiyatkul
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Date of Publication:11/16/2006