Chemical composition and quality of sea buckthorn (Hippophae rhamnoides L.) berry processing products
Keywords: Hippophae rhamnoides L., oil, resistance to oxidation, berry press cake, juice
AbstractResearch on the quality of sea buckthorn (Hippophae rhamnoides L.) berry processing products was done at Vytautas Magnus University Agriculture Academy in 2019. For the studies, the juice was squeezed from the defrosted sea buckthorn berries, and was stored in the refrigerator until separated into three fractions: solids, oil (oil No. 1) and juice. The berry cake remaining after squeezing the juice was dried and filled with unrefined sunflower oil. After 2 weeks, the oil (oil No. 2) was separated from the cake. The aim of the research was to determine the chemical composition and quality indices of sea buckthorn berry processing products. The content of soluble solids, titratable acidity, vitamin C and total carotenoid content were determined by standard methods in sea buckthorn juice, solids, berry press cake and in oil No. 1 and No. 2. The acid value, iodine value, peroxides value, induction period and colour of sea buckthorn berry oil No. 1 and No. 2 were determined. The research data were analysed by the factorial analysis of variance (ANOVA). Arithmetical means and standard deviation of the data were calculated. Statistical reliability was assessed by Fisher’s LSD test (P < 0.05). The results showed that the solids had 1.3-fold higher soluble solids content, 1.1-fold higher vitamin C, 2.5-fold total carotenoid content and 1.0-fold higher titratable acidity compared to juice. Oil No. 1 was characterized by a 1.88-fold bigger content of vitamin C and 2.9-fold higher titratable acidity. The total carotenoid content was 8.7% higher in oil No. 2. Oil No. 1 was less resistant to oxidative degradation because the induction period of this oil was shorter by 0.45 h and for a 26% higher amount of free fatty acids. However, a 12% higher peroxide content was found in oil No. 2. Oil No. 1 was brighter; the intensity of red and yellow colour of this oil was more intense.