Calcium fortified foodstuff

Abstract: A fortified foodstuff comprising a fortifying amount of a blend of calcium salts balanced with soluble and insoluble salts stabilised with a source of glucuronic acid and a process for its preparation which comprises forming a preparation of the blend of calcium salts, contacting this preparation with a source of glucuronic acid, and adding it to the foodstuff.

Description: FIELD OF THE INVENTION The present invention relates to the fortification of food and more particularly to the fortification of food with calcium. BACKGROUND OF THE INVENTION Calcium is an important element in human diets for adequate bone formation and maintenance as well as other metabolic functions, e.g. nerve transmission, blood clotting, proper cell function and muscle contraction. It is common practice to fortify food products with calcium sources which are either insoluble or soluble at around neutral pH. Many of the calcium sources currently used for fortification which are insoluble or substantially insoluble at around neutral pH, e.g. calcium carbonate, calcium phosphates, calcium citrate and other organic acid salts of calcium, result in precipitation and a chalky mouth feel. Other calcium sources which are soluble or substantially soluble at around neutral pH such as calcium chloride, calcium hydroxide and a few organic acid salts of calcium react with milk proteins resulting in undesirable coagulation and sedimentation. It is also common practice to stabilize or reduce the sedimentation of the calcium and milk proteins in the milk beverages fortified with calcium sources by adding carrageenans, pectins and/or other gums, but such materials impart an undesirably high viscosity to milk. Protein destabilisation, e.g. precipitation and coagulation, is mainly attributed to free calcium ions in the system. It would be highly desirable to have a calcium source to fortify milk beverages and other dairy based products without coagulation and sedimentation, with improved palatability. SUMMARY OF THE INVENTION We have developed a balanced mixture of soluble and insoluble calcium salts stabilised with a source of glucuronic acid which is capable of fortifying milk beverages and other dairy based products without coagulation and sedimentation, with improved palatability. According to the present invention, there is provided a fortified foodstuff comprising a fortifying amount of a balanced mixture of soluble and insoluble calcium salts stabilised with a source of glucuronic acid. DETAILED DESCRIPTION OF THE INVENTION The foodstuff may be a dairy based product such as a milk beverage, a confectionery product, ice cream or another beverage such as a juice. Examples of the soluble calcium salts are calcium lactate and calcium gluconate, calcium glycerophosphate, calcium chloride, etc. Examples of the insoluble calcium salts are tricalcium phosphate, dicalcium phosphate, calcium citrate and calcium carbonate. The weight ratio of soluble to insoluble salts may be from 1:3 to 3:1 and preferably from 1.5:2.5 to 2.5:1.5. The amount of the blend of calcium salts present in the fortified foodstuff may be from 0.05 to 5%, preferably from 0.1 to 2.5%, and more preferably from 0.2 to 1.0% by weight based on the weight of the foodstuff. The source of glucuronic acid may be gum ghatti but is preferably gum arabic. The amount of gum arabic present in the fortified foodstuff may be from 0.05 to 2.5%, preferably from 0.1 to 1.0%, and more preferably from 0.2 to 0.5% by weight based on the weight of the foodstuff. Although not wishing to be bound by theory, we believe that the glucuronic acid residues in gum arabic aid in suspending calcium by ionic binding without contributing significantly to viscosity. Advantageously, a carrageenan may be present which may be the lambda- or iotaform but is preferably kappa-carrageenan. The amount of carrageenan present in the fortified foodstuff may be from 0.005 to 0.1%, preferably from 0.1 to 0.05%, and more preferably from 0.02 to 0.04% by weight based on the weight of the foodstuff. The fortified foodstuff comprising a fortifying amount of a balanced mixture of soluble and insoluble calcium salts stabilised with a source of glucuronic acid may be prepared by forming a preparation of the blend of calcium salts, contacting this preparation with a source of glucuronic acid, and adding to the foodstuff. The blend of calcium salts and the source of glucuronic acid may be added in the form of aqueous solutions or suspensions or as dry powders. Advantageously, a carrageenan may be added to the foodstuff, preferably before the preparation of the blend of calcium salts is added to the foodstuff. The carrageenan may also be added to the foodstuff in the form of an aqueous solution or suspension or as a dry powder. If desired, the blend of calcium salts, the source of glucuronic acid, and optionally the carrageenan, may be co-driedand added as a powder. The drying may be carried out by various methods known to those skilled in the art. EXAMPLES The following Examples further illustrate the present invention. Example 1 The following solutions/suspensions are prepared: A. 1.155g of calcium lactate in 79.9ml water. B. 1.19g of calcium citrate in 50ml water. C. 0.52g of tri-calcium phosphate in 40ml water. D. The solutions/suspensions of A,B, and C are mixed for 10 minutes to give a calcium salt blend. E.2.5g of gum arabic are dispersed in 100g of water and hydrated thoroughly. F. 0.15g of kappa carrageenan (Sea Kem CM611) is added to 830g of skim milk with skim milk powder added for adjusting the milk solids to take into account the additional water of the solutions/suspensions in the final product. G. The calcium salt blend D is added to the gum solution E and mixed for 10 minutes. H. The calcium salt and gum arabic solution blend G is added to the milk and carrageenan blend F to prepare the final product and the pH adjusted to 6.6-7.0. The final product is UHT sterilised and homogenised. The milk was stable without any sedimentation during storage at 2° to 5°C and at room temperature. Example 2 A. 1.155g of calcium lactate, 1.19g of calcium citrate and 0.5g of calcium carbonate are dry blended. B. 0.15g of kappa carrageenan and 2.5g of gum arabic are added to 994.5g of cold milk. C. The calcium blend A is added to the blend of milk containing the carrageenan and gum arabic and the pH is adjusted to 6.6-7.0. The final product is UHT sterilised and aseptically filled. The milk was stable without any sedimentation during storage at 2° to 5°C and at room temperature. Comparative Example A A similar procedure to that described in Example 1 is followed but omitting the addition of the gum arabic and kappa carrageenan. The UHT sterilised and homogenised milk was not stable during processing and there was significant precipitation. Comparative Example B A similar procedure to that described in Example 2 is followed but omitting the addition of the gum arabic. The milk was stable during the processing but significant sedimentation occurred upon storage at 2° to 5°C after 5 weeks.

Claims: A fortified foodstuff comprising a fortifying amount of a balanced mixture of soluble and insoluble calcium salts stabilised with a source of glucuronic acid. A fortified foodstuff according to claim 1 wherein the foodstuff is a dairy based product, a confectionery product, ice cream or a beverage. A fortified foodstuff according to claim 1 wherein the soluble calcium salts are calcium lactate, calcium gluconate, calcium glycerophosphate or calcium chloride. A fortified foodstuff according to claim 1 wherein the insoluble calcium salts are tricalcium phosphate, dicalcium phosphate, calcium citrate or calcium carbonate. A fortified foodstuff according to claim 1 wherein the weight ratio of soluble to insoluble salts is from 1:3 to 3:1. A fortified foodstuff according to claim 1 wherein the amount of the blend of calcium salts present in the fortified foodstuff is from 0.05 to 5% by weight based on the weight of the foodstuff. A fortified foodstuff according to claim 1 wherein the source of glucuronic acid is gum arabic. A fortified foodstuff according to claim 1 wherein the amount of gum arabic present in the fortified foodstuff is from 0.05 to 2.5% by weight based on the weight of the foodstuff. A fortified foodstuff according to claim 1 wherein a carrageenan is present. A fortified foodstuff according to claim 1 wherein the amount of carrageenan present in the fortified foodstuff is from 0.005 to 0.1% by weight based on the weight of the foodstuff. A process for preparing a fortified foodstuff comprising a fortifying amount of a balanced mixture of soluble and insoluble calcium salts stabilised with a source of glucuronic acid which comprises forming a preparation of the blend of calcium salts, contacting this preparation with a source of glucuronic acid, and adding it to the foodstuff. A process according to claim 11 wherein the blend of calcium salts and the source of glucuronic acid are added in the form of aqueous solutions or suspensions or as dry powders. A process according to claim 11 wherein a carrageenan is added to the foodstuff. A process according to claim 13 wherein the carrageenan is added to the foodstuff in the form of an aqueous solution or suspension or as a dry powder. A process according to claim 11 wherein the blend of calcium salts, the source of glucuronic acid, and optionally a carrageenan, is co-dried and added as a powder.

Inventors: REDDY SEKHAR, VADEHRA DARAM VIR, WEDRAL ELAINE REGINA, ZYZAK LILI, REDDY, SEKHAR, VADEHRA, DARAM VIR, WEDRAL, ELAINE REGINA, ZYZAK, LILI
Applicants: NESTLE SA, SOCIETE DES PRODUITS NESTLE S.A.
Application year: 1998
Main classification: A23L1
IPC codes: A23C9, A23G3, A23L1, A23G9, A61K33