Abstract: (14488 Views)
The red color of pomegranate juice is primarily associated with anthocyanin pigment. Studies showed that anthocyanin has low stability during processing and storage time and color of pomegranate juice decreased significantly over time. Copigmentation between Anthocyanins and copigments such as phenolic acids and flavonoids, is the main color stabilizing mechanism and is regarded today as one of the significant factors of structure stabilization, colorant of Anthocyanin under in vivo conditions. Anthocyanin copigmentation gives brighter, stronger and more stable colors than those expressed by anthocyanin alone. The objective of this study was to compare the effects of Ferulic acid and Tannic acid in concentrations of 230, 460, and 920 mg/lit on the color stability and sensory acceptance of pomegranate juice kept in 5°C during 60 days of storage. In order to investigate the color stability, change in absorption maximum wavelength (Δλmax) and change in maximum absorbance (ΔAmax), Total color difference (ΔE), and total anthocyanin content, all treatments and control were evaluated by spectrophotometer, hunterlab colorimeter, and HPLC respectively in day 1,10,20,30, and 60 in 5°C. Furthermore, the sensory acceptance level of samples was evaluated by trained panelists in first and 60th day in 5°C. The results showed that Total anthocyanin content, Redness (a*), maximum absorbance (Amax), and absorption maximum wavelength (λmax) in treated samples with 230, 460, and 920 mg/lit of Ferulic acid and in treatment with 920 mg/lit Tannic acid increased significantly (P<0.05) during storage period of 60 days compare with the control. Increase in Ferulic acid and Tannic acid concentration decreased the sensory acceptance significantly (P<0.01), Also in treatments with 230, 460, 920 mg/lit of Ferulic acid, the sensory acceptance was higher compared to similar concentrations.
Received: 2013/01/26 | Accepted: 2013/01/26 | Published: 2013/01/26