Date of Award

Spring 5-6-2016

Level of Access

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Food and Nutrition Sciences

Advisor

L. Brian Perkins

Second Committee Member

Rodney Bushway

Third Committee Member

Denise Skonberg

Additional Committee Members

Beth Calder

Christina Khoo

Abstract

Elderberry (Sambucus sp.) fruit is a healthful food with a variety of reported curative properties and is among the richest sources of anthocyanic pigmentation, which are the primary factors for its commercial use. Although a variety of value-added elderberry products are available to consumers, it is questionable as to which product form contains the highest nutrient levels and color stability characteristics, and represents the best value to consumers. It was the objectives of this research to evaluate a variety of commercial elderberry products, and to develop a value-added elderberry product with enhanced nutrient and color stability.

The first part of this research evaluated the nutrient and color stability of several value-added elderberry products (syrups, tinctures, concentrates, capsules, lozenges, dried fruit, powder) throughout 10 weeks of accelerated temperature (32° C) storage. Most of the products contained appreciable amounts of anthocyanins and other nutrients, which generally exceeded the values observed within raw elderberry fruit. However, the elderberry tinctures contained low levels of anthocyanins, proanthocyanidins, and sugars; high levels of moisture/alcohol, and displayed poor nutrient and color stability throughout storage. The elderberry syrups, capsules, and lozenges generally displayed favorable phytochemical and color stability characteristics. Kerr Elderberry Concentrate and NP Nutra® Elderberry P.E. 10:1 powder contained substantial amounts of phytochemicals and pigmentation, which demonstrates their value within wholesale food markets.

The second part of this research determined the nutrient and color stability effects of copigment additives (rosemary extract, tannic acid, black carrot color, purple sweet potato color, enzymatically modified isoquercitrin) within elderberry tinctures throughout 6 weeks storage at 21° C. The results did not demonstrate effective copigmentation among any of the tinctures with copigment additives, which was likely due to the high ethanol content of the tinctures. All of the copigment additives contributed to increased phenolic contents and antioxidant activity within the tinctures, and black carrot and purple sweet potato color additives caused significant (p≤0.05) effects to the L*a*b* color values, monomeric anthocyanins, color density, and polymeric color of the tinctures. The results demonstrated that elderberry anthocyanins degraded into colorless products prior to converting into brown colored anthocyanin-tannin products throughout storage.

Share