Anthocyanin is an antioxidant found in the skin of cranberries. Concentrations of anthocyanin increase as the berries ripen. Demand for berries with high antioxidant content is very high due to their therapeutic qualities. Consequently, the accurate evaluation of anthocyanin (TAcy) content has a direct impact on the market value of cranberries. In keeping with the recommendations of the Cranberry Institute in Massachusetts, TAcy is currently measured in the lab using a chemical method that takes 15 minutes and uses a large quantity of product. In summer 2007, after several years of research, Atoka Cranberries asked INO for help in exploring alternative methods in order to reduce operating costs and improve measurement reliability.
Our specialists took advantage of anthocyanin’s red pigmentation to develop a color vision system capable of predicting TAcy on the basis of color concentration. They designed a multiview image capture station and developed a color calibration method. Data was collected then analyzed to determine the relationship between color and TAcy content. A feasibility study yielded promising results. A second phase of testing is now being planned to verify the applicability of our results on samples from the next harvest (fall 2008).
A portable version of the TAcy detection system could help producers choose the optimal time for harvest.