Calcium Chloride-Fortified Beverages: Threshold, Consumer Acceptability and Calcium Bioavailability
In the U.S., 90% of women, 60% of men, and over 50% of children consume less than the RDA for calcium. Calcium intake through dairy product consumption is declining as other beverages replace milk. Calcium fortification of water or flavored waters could increase calcium intake without impacting caloric intake.
The nutritional significance of calcium in bottled water is often questioned. The content in a serving for many brands of spring water is usually less than 2% of the Daily Value. However, mineral water and fortified water could have calcium contents high enough to show on a Nutrition Facts Label. The objectives of this study were to determine the sensory threshold of calcium chloride in water and flavored water, design an acceptable calcium-fortified beverage, and determine the bioavailability of calcium from calcium chloride-fortified drinking water in vitamin D-deficient rats.
Mineral content was determined for nine commercial bottled and flavored waters by atomic absorption spectrophotometry. Sensory detection thresholds of calcium chloride were determined in deionized water (DI), tap water, berry flavored water, and a sports beverage formulation using a five series ascending forced choice analysis. Ascending calcium chloride concentrations in the fortified drinks were evaluated by 30 panelists in duplicate trials. Ninety-eight consumers evaluated acceptability of de-ionized and flavored water with and without added calcium chloride.
Vitamin D-deficient diets of rats had either low (0.2%) or normal (0.5%) calcium content. After a 2-wk depletion phase, drinking water fortified with calcium chloride calculated to provide 0, 0.25, 0.5 or 1.0 times the usual calcium intake (estimated at 2.88 g/L) from diet was provided. Additional groups also had water fortified at 2 x usual dietary intake, but did not complete the study because of low feed and water intake. Some groups also had a water-soluble form of vitamin D added to the water.
Calcium concentration of the nine commercial products measured varied from 0.3 mg/L to 116 mg/L. Sensory thresholds for calcium chloride in drinks were: flavored water (857 ± 8.9 mg/L) > sport drinks (844 ± 9.8 mg/L) > DI- water (101 ± 3 mg/L) > tap water (93.5 ± 3mg/L), respectively. (On the basis of Ca, thresholds were flavored water (7.72 ± 0.08 mM) > sport drinks (7.60 ± 0.09 mM) > DI- water (0.91 ± 0.01 mM) > tap water (0.91 ± 0.01 mM), respectively.) Consumer acceptability scores were not different for water or flavored water with and without added calcium chloride (70 mg/L and 700 mg/L, or 0.63 and 6.31 mM, respectively) (p>0.05).
In the bioavailability study, the final serum vitamin D level indicated that the vitamin D in water was poorly available to the rats. Results showed that groups fed low dietary calcium and not supplemented with calcium in water had lower bone weight, bone ash weight, and bone ash calcium percentage, than did the rats supplemented with calcium in water. The deficient rats with no calcium and low vitamin D and those with highest Ca (2.88 g/L) in water all had lower final body weight than the control group (Ca and vitamin D in diet), and the groups with moderate water Ca (1.44 g/L). Body weight was correlated with food intake. For groups with 0.5% dietary Ca, bone weight, size, Ca, or breaking strength was not related to the Ca or vitamin D intake from water.
Calcium content in flavored drinks or water can be increased with calcium chloride without impacting acceptability. Regular consumption of calcium fortified water can significantly reduce the effect of low dietary Ca intake on bone growth and mineralization. The fortification of water has little additional effect on bones when dietary calcium is adequate.
Advisor:Dr. Jonathan Allen; Dr. Maryanne Drake; Dr. Timothy Sanders
School:North Carolina State University
School Location:USA - North Carolina
Source Type:Master's Thesis
Date of Publication:01/18/2005