Spectophotometric evaluation for the stability of the ascorbic acid from the sweet briar (Rosa Canina) and white sea buckyhorn (Hyppophae Rhamnoides)

Abstract

The nutritional value of the products obtained from sweet briar and white sea buckthorn comes from the complexity of their chemical composition. It is remarkable that these fruits contain such a great concentration of ascorbic acid (AA). Our researches on this matter show that the ascorbic content is higher in proportion with the white sea buckthorn than in the sweet briar (sweet briar: 190 mg/100g versus white sea buckthorn: 618mg/100g dry matter). At the same time our research points out the usefulness of the modern extraction methods used to obtain the extracts of sweet briar and white sea buckthorn. The purpose of the paper is also to study spectro-photometrically, on a pure system and from the mentioned extracts, the ascorbic acid stability. Consequently, we studied the dynamics of the ascorbic acid towards different solvents used in extraction: water, trichloroacetic acid (TCA) and acetic acid both in the presence and in the absence of light. On the other hand, the influence of the pH variation on the ascorbic acid stability was taken into account, both towards the pure solution of ascorbic acid and towards the extracts of sweet briar and white sea buckthorn. The spectrophotometric experimental results pointed out the high stability of the ascorbic acid when the extraction reactive was the acetic acid. In this context, the stability of the ascorbic acid from the extracts of sweet briar and white sea buckthorn, towards the acetic acid used as extraction reactive proved to be the best at pH = 2,903 for white sea buckthorn and at pH = 3,264 for sweet briar, in the absence of light.