Health & Flavor

Figure 1. Composition of California Blue Elderberry

• Blue elderberries harvested from five farms in Yolo County in July and August of 2018 and 2019

• Berries analyzed for moisture, Brix, titratable acidity, pH, total anthocyanins, and total phenolics

Health-promoting compounds

Elderberries are often touted for high levels of “phenolics” or “antioxidants”, but what do these words really mean? 

Phenolic compounds are a group of compounds produced by plants that contain at least one “phenol group” (Figure 2).  Some phenolic compounds have multiple phenol rings, and these are “polyphenolics”. 

One class of polyphenolics is “flavonoids” which are characterized by a three ring structure, such as that seen in Figure 3. The three ring structure of flavonoids helps the molecule act as an antioxidant, which is a general term for any compound that can inhibit or reduce oxidation.

One type of flavonoid are anthocyanidins, which are called anthocyanins when a sugar molecule is attached to the compound, are plant pigments, often red, orange, and purple. These are the compounds that make elderberries a beautiful dark purple! Anthocyanidins are sensitive to pH, changing colors when in a more or less acidic environment. They can be unstable in processing due to high heat or long storage.

Another group of compounds within flavonoids, flavonols, are also found in elderberries. While not brightly colored like anthocyanins, they can act as powerful antioxidants and impart some biological benefits. 

Elderberries are known for their high levels of phenolics and anthocyanins, which can help support the immune system^1,2. These phytochemicals have also been shown to have some antiviral and anti-bacterial characteristics, further increasing the use of elderberry products to fight against colds or flus.

Other elderberry components

As expected for a berry, elderberries also have sugars, mainly glucose and fructose. These contribute a sweet taste to elderberry products. The main organic acids found in elderberries are citric acid (the main acid in citrus fruits) and malic acid (the main acid in apples). Elderberries also contain ascorbic acid, or Vitamin C, which can also act as an anti-oxidant, though the content can vary from 5 to 26 mg/100g fresh fruit³. Other important components of elderberry are fiber and minerals such as potassium, phosphorous, calcium, and magneiusm⁴.

Aroma compounds

The flavor of elderberries is more than just the sweetness from sugar and tartness from the acid. There are also volatile compounds that contribute to the complex aroma of elderberries. The volatile compounds have been investigated in the European and American elderberries, and the work is underway to compare the California blue elderberry to these other subspecies. The aroma compounds are typically divided into several groups: characteristic elderberry, flowery, fruity, grassy, agrestic, and miscellaneous^5,6. For European elderberries, the “characteristic” compounds are dihydroedulan, β-damascenone, and sometimes, ethyl-9-decenoate. The other compounds are a variety of alcohols, aldehydes, ketones, esters, heterocycles, hydrocarbons, and acids. The terpenoids and norisoprenoids have also been investigated in European elderberries throughout the ripening period, which found compounds such as dihydroedulan, limonene, and p-cymene tend to decrease over the ripening stage of berries⁷. 

Composition of Blue Elderberries Grown in Hedgerows Compared to Literature on Black Elderberries

1. Range determined from Ozgen et al. (2010), Lee and Finn (2007), and Thomas et al. (2013)
2. Range determined from Veberic et al. (2009), Mikulic-Petkovsek (2016), Lee and Finn (2007)

Blue Elderberry Organic Acids and Sugar Summary

Blue elderberries harvested from hedgerows on farms near Davis, CA were evaluated for their organic acid and sugar concentrations. Four farms were harvested in 2018 and five farms were harvested in 2019. The main acids present were citric acid and malic acid, like other elderberry subspecies. Citric acid is present in roughly double the concentrations of malic acid. Sugars present were glucose and fructose, with glucose being about double the levels of fructose. There was some variability in the concentration of these compounds between the different farms evaluated in this study in addition to variation between the two years the berries were harvested. The compounds were evaluated using high performance liquid chromatography (HPLC).

Organic acid and sugar concentrations in blue elderberry in California

Handout: Nutritional Attributes of Elderberry Varieties

References

(1)       Lee, J.; Finn, C. E. Anthocyanins and Other Polyphenolics in American Elderberry (Sambucus Canadensis) and European Elderberry (S. Nigra) Cultivars. J. Sci. Food Agric. 2007, 87, 2665–2675.

(2)       Veberic, R.; Jakopic, J.; Stampar, F.; Schmitzer, V. European Elderberry (Sambucus Nigra L.) Rich in Sugars, Organic Acids, Anthocyanins and Selected Polyphenols. Food Chem. 2009, 114 (2), 511–515.

(3)       Kaack, K.; Austed, T. Interaction of Vitamin C and Flavonoids in Elderberry (Sambucus Nigra L.) during Juice Processing; 1998; Vol. 52.

(4)       Vulic, J. J.; Vracar, L. O.; Šumic, Z. M. Chemical Characteristics of Cultivated Elderberry Fruit. Acta Period. Technol. 2008, 39, 85–90.

(5)       Vitova, E.; Divisova, R.; Sukalova, K.; Matejicek, A. Determination and Quantification of Volatile Compounds in Fruits of Selected Elderberry Cultivars Grown in Czech Republic. J. Food Nutr. Res. 2013, 52 (1), 1–11.

(6)       Jensen, K.; Christensen, L. P.; Hansen, M.; Jrgensen, U.; Kaack, K. Olfactory and Quantitative Analysis of Volatiles in Elderberry (Sambucus Nigra L) Juice Processed from Seven Cultivars. J. Sci. Food Agric. 2001, 81 (2), 237–244.

(7)       Salvador, A. C.; Rudnitskaya, A.; Silvestre, A. J. D.; Rocha, S. M. Metabolomic-Based Strategy for Fingerprinting of Sambucus Nigra L. Berry Volatile Terpenoids and Norisoprenoids: In Fl Uence of Ripening and Cultivar. J. Agric. Food Chem. 2016, 64, 5428–5438.