UC Davis

The blue elderberry (Sambucus nigra ssp. cerulea) is a fruit-bearing shrub native to the western region of North America. Compared to the well-studied European black elderberry (S. nigra ssp. nigra) and the American elderberry (S. nigra ssp. canadensis), this subspecies has not been thoroughly analyzed and thus is not used in commercial products. The composition of the fruit and flower, particularly the phenolic profile, was studied for the first time. The blue elderberry has a significantly lower level of anthocyanins than the other subspecies but contains cyanidin 3-sambubioside and cyanidin 3-glucoside like European elderberry. The elderflower of the blue elder is unique in terms of phenolic and volatile profile. Isorhamnetin 3-rutinoside was the dominant phenolic compound in the elderflower, unlike rutin in European and American elderflower. Furthermore, methyl eugenol was one of the most concentrated volatile compounds in the elderflower, a compound that has not been identified in other studies on the European elderflower. These studies have provided more information on the native plant, which has several environmental benefits such as improving air and soil quality when planted in hedgerows, which may facilitate more use of the fruit and flower in commercial products. Chapter 1 presents information on the composition of the blue elderberry, including the sugar, and acid content of the fruit, and the phenolic profile of the blue elderberry. Chapter 2 explores the elderflower of the blue elderberry, investigating the volatile and phenolic profile of the flower. Chapter 3 examines the cyanogenic compounds as well as the impact of thermal processing on the important phenolic compounds present in blue elderberry juice.