As natural food products and colorants are on the verge of a new era, anthocyanins are of particular interest because of their known antioxidant power, beautiful color, and relative stability in high acid foods. This study focuses on the Peruvian berry Berberis boliviana, rich in phenolics and non-acylated anthocyanins (9 and 7% dry weight, respectively)
Our objective was to determine color and pigment stability using different levels of Berberis boliviana whole fruit addition in comparison to purple carrot acylated anthocyanin extracts throughout various yogurt fat matrices.
Yogurt samples with 0, 2, and 4% fat contents were colored using 10 and 20mg of Berberis boliviana anthocyanins. Yogurt samples were compared with FD&C Red 40, Betalaines, and Purple Carrot anthocyanin treatments, along with a negative control yogurt sample (no color added). All treatments were stored at 4ºC for 1, 7, 14, 30, 45, and 60 days. Yogurt color (CIELab, chroma, and hue angle) was measured with a Hunter ColorQuest. Anthocyanin and phenolic degradation kinetics was evaluated using the pH differential method and Folin Ciocalteau methods, respectively. Qualitative changes were monitored by HPLC coupled to a MS and PDA detectors.
Initial color of the yogurt treatments containing Berberis boliviana anthocyanins showed very similar color characteristics (L=65, a*=12, b*=-6, chroma=14, and hue angle=335º) to commercial blueberry yogurt (L=65, a*=10, b*=-3.5, chroma=10.5, and hue angle=341º) colored with FD&C Red 40 and Blue 1. Color and pigment stability was achieved in both acylated and non-acylated anthocyanins throughout the study and was related to the fat content of the matrix. The added stability of acylated pigments did not result in a marked difference throughout the shelf life of the yogurt (typically 30 days).
Addition of Berberis boliviana whole fruit to yogurt resulted on an attractive and marketable added value product with acceptable stability for commercial applications.The IFT FoundationThe Tinker Field Research Grant Foundatio
