Fortification of cheese with vitamin D(3) using dairy protein emulsions as delivery systems

Vitamin D is an essential vitamin that is synthesized when the body is exposed to sunlight or after the consumption of fortified foods and supplements. The purpose of this research was to increase the retention of vitamin D(3) in Cheddar cheese by incorporating it as part of an oil-in-water emulsion using a milk protein emulsifier to obtain a fortification level of 280 IU/serving. Four oil-in-water vitamin D emulsions were made using sodium caseinate, calcium caseinate, nonfat dry milk (NDM), or whey protein. These emulsions were used to fortify milk, and the retention of vitamin D(3) in cheese curd in a model cheesemaking system was calculated. A nonemulsified vitamin D(3) oil was used as a control to fortify milk. Significantly more vitamin D(3) was retained in the curd when using the emulsified vitamin D(3) than the nonemulsified vitamin D(3) oil (control). No significant differences were observed in the retention of vitamin D(3) when emulsions were formulated with different emulsifiers. Mean vitamin D(3) retention in the model system cheese curd was 96% when the emulsions were added to either whole or skim milk compared with using the nonemulsified oil, which gave mean retentions of only 71% and 64% when added to whole and skim milk, respectively. A similar improvement in retention was achieved when cheese was made from whole and reduced-fat milk using standard manufacturing procedures on a small scale. When sufficient vitamin D(3) was added to produce cheese containing a target level of approximately 280 IU per 28-g serving, retention was greater when the vitamin D(3) was emulsified with NDM than when using nonemulsified vitamin D(3) oil. Only 58±3% of the nonemulsified vitamin D(3) oil was retained in full-fat Cheddar cheese, whereas 78±8% and 74±1% were retained when using the vitamin D(3) emulsion in full-fat and reduced-fat Cheddar cheese, respectively.