LASER-LIGHT SCATTERING AND MICROSCOPIC PROPERTIES OF MILKFAT GLOBULESIN SWISS CHEESE WHEY LOW-DENSITY LIPID-CONTAINING FRACTION

Improved utilization of cheese whey, a by-product of cheese manufactur e, is a major concern of rite cheese industry. Large amounts of whey a nd whey products al-e used as nutritional and functional ingredients b y the food and dairy industry.However: the residual lipids that remain in the whey interface with the manufacture of whey; protein concentra tes by ultrafiltration processing and also adversely affect the functi onal properties and flavor stability of whey protein concentrate and o ther dried whey products. Information on the size and microstructure o f residual whey lipid particles should allow the food industry to deve lop new and improved processing technologies to remove them from whey and utilize them as a novel food ingredient. Residual whey lipid front Swiss cheese whey has been fractionated by high speed centrifugation into: (a) low-density lipid-containing fraction (LDLF); (b) medium-den sity lipid-containing fraction (MDLF); and (c) high-density lipid-cont aining fraction (HDLF). Our objective for this study was to investigat e the size and microstructural properties of the smallest-sized LDLF p articles recover-ed from Swiss cheese whey by high-speed centrifugatio n using laser light scattering spectrophotometry (LLSS), light microsc opy and scanning electron microscopy. LLSS results revealed that the s ize of LDLF particles ranged from < 0.1-about 4 mu m with a predominan ce in the larger sizes. Light microscopy size results for LDLF particl es agreed with LLSS results and also confirmed their globular microstr ucture. Electron micrographs further confirmed the size and provided m ore detailed information on the microstructural properties of LDLF par ticles.