Identifier

etd-11152006-145418

Degree

Master of Science (MS)

Department

School of Nutrition and Food Sciences

Document Type

Thesis

Abstract

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 Friedman’s 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.

Date

2006

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Witoon Prinwawiyatkul

Included in

Life Sciences Commons

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