Date of Award

Summer 8-21-2015

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Food Science and Human Nutrition

Advisor

Brian Perkins

Second Committee Member

Rodney Bushway

Third Committee Member

Jason Bolton

Abstract

The following liquid chromatographic (LC) method developments and applied research studies were done using two complex food matrices, potatoes and elderberries, which are common to the state of Maine. Potatoes are Maine’s largest agricultural crop, a staple food in most U.S. households, and are, from an analytical standpoint, considered a complex matrix due to the high starch content that can be difficult to remove without degrading or removing nutrients in the process. Elderberries are an emerging crop in the U.S. because of their antioxidant and anti-viral properties and are found growing wild, throughout Maine. Elderberries are also considered a complex matrix because of the large number of compounds naturally present in the berries, including a range of flavonoids. Many flavonoids have similar chemical structures to vitamin C, which makes removing them without degradation or removing the vitamin C difficult. Both methods described in this thesis were created for use with high performance liquid chromatography and use Tris(2-carboxyethyl)phosphine Hydrochloride (TCEP) as the reducing agent.

The experiments that follow the method development for these matrices center around accurate nutrient reporting and interest in nutrient variation. The potato method was applied to a research question of inter-variation in vitamin C content in a single, consume- available purchase package of potatoes. For this study eight different varieties of potatoes were purchased from a local supermarket and measured for ascorbic acid, dehydroascorbic acid, and total vitamin C concentrations. The results showed a significant variation between potatoes from the same purchase package. The variety with the largest variation in total vitamin C had concentrations ranging between 3.90 – 23.38 mg/100g. Additional research on other commercially available individual produce will allow the USDA to report nutrient ranges for foods as opposed to the single nutrient content, as are currently listed in the National Nutrient Database for Standard Reference.

The applied elderberry experiment focused on whether wild elderberries grown in different locations throughout Northern and Central Maine have significant differences in vitamin C content. For this study fourteen frozen elderberry samples and seventeen freeze-dried elderberry samples were used, all collected throughout Northern and Central Maine. Samples were measured for ascorbic acid, dehydroascorbic acid, and total vitamin C. Results show significant variation in total vitamin C levels between samples grown in different locations.

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