Identifier

etd-0711103-093202

Degree

Master of Science (MS)

Department

School of Nutrition and Food Sciences

Document Type

Thesis

Abstract

Age-related macular degeneration (AMD) is a physiological condition that affects the elderly, diabetic patients, and leads to loss of vision. There are no effective therapies for AMD. The role of nutrition in preventing AMD is receiving strong scientific scrutiny. Lutein and zeaxanthin have been identified as dietary strategies that can delay the onset of AMD. Consumption of at least six milligrams of lutein per day has been reported to delay the onset of AMD by as much as 43%. However, most available food sources contain such low levels of lutein that it would be difficult to meet the daily requirement. It would require 2 lbs of corn, 16 lbs of tomatoes, or one salad bowl of kale to meet the minimum daily requirement. As a result, food fortification with lutein extract is appealing to health conscious consumers. The objective of this study was to prepare an oil in water emulsion containing at least 6 mg of lutein per serving size (one tablespoon) as a daily source of lutein. Random Centroid Optimization was applied to find the best conditions for preparing a stable emulsion. Experimental parameters included: lutein concentration (0.010-0.020 %w/w); pH (3.5-4.7); phosphatidylglycerol (0.018-0.1 %w/w); whey protein (1.5-3.5 %w/w); and corn oil (15-25 %w/w). Emulsions were prepared and turbidity measurements were determined as a function of half-life stability in minutes. Absorbance was measured at 500 nm for 10 min. The same measurements were carried out using the best values for four factors obtained from the RCO program. Emulsion stability was evaluated by heating samples at 90 oC from 5 to 30 min to check for oil separation. Emulsion samples were also shaken at 700 rpm for 30 min. Size distribution and zeta potential of emulsion droplets were measured, using zetameter. After 9 experiments in the first cycle and 4 experiments in centroid cycle, optimal conditions for the preparation of a stable lutein-enriched emulsion were: corn oil: 20 %, phosphatidylglycerol (0.018 %w/w), pH: 4.55, lutein concentration: (0.015 %w/w), and whey proteins concentration 2%.

Date

2003

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Jack Losso

Included in

Life Sciences Commons

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