The Effects of Processing on the Nutritional Benefits of Fruit: Grapes, Raisins, and Papaya

Each component of a food can serve a beneficial, neutral or harmful function within the food and after consumption. Changes that occur during food, digestive, or absorptive processing modify the human nutritional potential of a food by changing food components or interactions between food components. This hypothesis was tested with grapes and raisins to explore changes due to drying on serum antioxidant capacity, with papaya pulp to improve availability and human nutrition potential using multiple processing methods, and with individual components found in food and serum to evaluate interactions and synergistic potential. There is a long-term antioxidant benefit to consuming a serving of grapes or raisins in addition to a free-living, varied diet. However, within two hours after consuming bagels and grapes or raisins, there was an environment of increased oxidation in serum. Repeated exposure to postprandial oxidation may be a long-term contributor to cardiovascular disease. Improving availability of nutrient dense foods could help combat postprandial oxidation. Papaya is nutrient dense, but not readily available in a processed form. Producing a papaya pulp beverage that retains its fresh flavor and nutritional value is not possible with traditional pasteurization. Combining moderate irradiation and mild heat resulted in a better tasting, nutritionally optimized papaya pulp beverage meeting microbiological and enzyme standards for a refrigerated product. Chemical changes that occur as papaya undergoes processing led to the hypothesis that there may be certain combinations of chemicals that would provide more effective antioxidative benefits than others. Combining individual phenols, sugars and ascorbic acid at concentrations found in honey and papaya in increasingly complex mixtures suggested some combinations had synergistic potential. Similar results were found after simulated digestion. Serum-achievable concentrations of a separate set of compounds also suggested synergistic potential. These results support our hypothesis. The changes that occur during processing can affect the human nutritional potential of food and interactions are important. Further study is needed to understand these complex changes and interactions.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Parker, Tory L.

Contributors dc:contributor

• Nicki Engeseth

• Agriculture, Food Science and Technology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3337883

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/87899