Stability of Carotene and Phenols of Sea Buckthorn (Hippophae rhamnoides L.) Juice with Pomace during Storage
Sea Buckthorn (SB) juice is rich in biologically active compounds. It has considerable health benefits; thus, it can serve as functional food ingredient. The aim of this study was to determine and compare the total content of polyphenols, antioxidant capacity (FRAP), soluble solid content, pH value, β-carotene content and colour parameters (L*, a*, b*) in berry juice of cultivar 'Leikora' Sea Buckthorn (SB) (Hippophae rhamnoides L.). The treatment was made as control sample of Sea Buckthorn juice (C), and Sea Buckthorn juice with 0.5 % (P0.5); 1 % (P1); 2 % (P2) dried pomace of Sea Buckthorn. The samples were stored at room temperature for physicochemical analysis at interval of 2 months for a total period of 14 months.
According to our results, the β-carotene (C to P2 was 3.71, 4.82, 5.49 and 6.52 mg 100 mL−1) as well as the antioxidant capacity of the samples increased with the growth of the pomace content. During storage, degradation occurred in the polyphenol content and antioxidant capacity, but the β-carotene content increased. The increase of the β-carotene content was 94.6 % (C) and 32.7 % (P0.5). The smaller reduction in antioxidant compounds was the higher the sample of pomace content is. The FRAP and total polyphenol values measured during storage confirm that the pomace has antioxidant effect. There is a close correlation between the two parameters, including a positive correlation (r=0.8614), which indicates that a significant part of the antioxidant capacity of buckthorn is due to the presence of different polyphenols.