A cost analysis of encapsulated spray-dried milk fat.
Anhydrous butter oil or cream was encapsulated in all-purpose flour, modified cornstarch, or sucrose and then spray-dried. We estimated the processing cost for a plant designed to produce 57,000 kg/d (125,000 lbs/ d) of encapsulated milk fat powder. Powder with a 50% milk fat content could be produced for about $0.23/kg plus the cost of the butter oil or cream, the encapsulant selected, and the other ingredients. Spray-drying of milk fat improved ease of handling and reduced storage costs.
Particle Structures of Encapsulated Milkfat Powders
Abstract Emulsions of milkfat (cream or anhydrous butteroil), carbohydrate (sucrose, modified starch or all-purpose flour), nonfat dry milk and mono- and di-glycerides as emulsifying agents were prepared and spray dried, yielding free-flowing powders containing 400, 500 or 600 g/kg milkfat. Structural features of the powders were evaluated by optical and scanning electron microscopy. Powder particles were generally spherical in shape, with particle size distributions ranging from 20 to 120 μm; surface morphology of the particles could be related to the encapsulant used. Butteroil was more readily encapsulated than cream in all cases; butteroil-containing powders contained less extractable fat than did those made with heavy cream. Milkfat was distributed in the walls of the powder particles when modified starch was the encapsulant; these particles contained occluded air in their cores, which could be detrimental to long-term storage. Powders with all-purpose flour as the encapsulant showed loose matrices enclosing large fat droplets, demonstrating structural weakness. Fat droplets were enclosed without central voids within the capsules when sucrose was the encapsulant; with less than 6 g/100g extractable fat, sucrose encapsulated milkfat powders were structurally stable, suggesting good resistance to air/oxygen diffusion during storage.
Evaluation of antioxidants by a rapid polarographic method
A simple, rapid, precise, and reproducible method and an adaptable apparatus for polarographic measurement of lipid peroxidation and antioxidant activity is described. This method measures antioxidant activity within a few min time as compared to the hours or days needed for several widely used methods. Peroxidation rates were measured for different lipids as a function of amount of lipid, and amount of biocatalyst. The method is applicable to the detection and measurement of the antioxidant effects exhibited by weak antioxidants and has been satisfactorily used for the measurement of the antioxidant activity of different concentrations of powerful antioxidants.