Chemical composition of the water extract of young spruce (<em>Picea abies</em> (L.) Karst) shoots

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>Young shoots of spruce are a natural resource that have been used as a remedy or a food ingredient for a long time. Although, it cannot be harvested from the forest without the permission of the landowner, it could be exploited more. Almost third of Finnish forests resources is spruce, forming enormous reservoir for the spruce shoots and more refined spruce shoot products.</p><p>Lactic acid bacteria is one of the most, if not the most, used group of microbes in the food industry. In our earlier growth experiments the water extract from young spruce shoots had an enhancing effects in the growth of some strains of Lactobacillus species. Particularly, Lactobacillus plantarum grew better and had shorter lag time, when growth medium contained spruce shoot extract. To apprehend better, what could generate an effect seen with the growth of the bacteria, we analyzed the chemical composition of the water extract of the spruce shoots.</p><p>For the evaluation of the chemical composition of the spruce shoot water extract chromatographic, capillary electrophoretic and spectrophotometric methods were used. Sugars and sugar alcohols were measured with the capillary electrophoresis (CE), glucose and inositol respectively being of most abundant. Also non phenolic acids and inorganic cations were analyzed with the CE. Quinic acid was the main non phenolic acid detected, and of the inorganic cations K, Mg, Ca, Ni, Zn and ammonium were recognized from the extract.</p><p>Antioxidant capacity (reduction potential) of 772mg GAE/L was measured for the extract using spectrophotometric method of Folin-Ciocalteu. To analyze phenolic compounds, chromatographic methods developed for the detection of catechins, proantocyanidin, phenolic acids and stilbenoids were utilized. Main catechins in the water extract were the catechin and epicatechin. Type B dimers were the most apparent of the proantocyanidins. The extract contained several benzoic and cinnamic acid derivatives, but protocatechuic acid and p-coumaric acid were the most apparent ones. Of the stilbenoids trans and cis forms of piceid, sugar derivative of resveratrol, and astringin were the most abundant.</p><p>Future research will focus on, whether Lactobacillus bacteria will metabolize one or more of these detected compounds found when in growth with the extract.</p></div>