The impact of the agrochemical properties of soil on the chemical composition of Jerusalem artichoke flowers

Abstract

The objective of this research was to investigate and to evaluate the chemical composition of Jerusalem artichoke flowers grown in different soils. Quality analysis was carried out in the laboratories of the Institute of Agricultural and Food Science of Vytautas Magnus University. The following agrochemical parameters of the soil were determined using standardized methods: pHKCl, the amount of soil humus, mineral nitrogen, mobile phosphorus (P) and potassium (K). The chemical composition of different parts of Jerusalem artichoke flowers (disk florets and ray florets) were evaluated by the standard method: the content of carbohydrates (inulin and total saccharides content), minerals (N, P, K, Ca, Fe, Na, Zn, Mg). Electronic nose (Alpha M. O. S.) measurement technologies were used to recognize and identify the flower fragrance (volatile organic compounds). Processing of the research data was carried out through the application of the analysis of variance (ANOVA), using the computer software Statistica 10. The research results showed that the substantially highest amount of inulin was determined in the disk florets (0.339%, D. M.) of Jerusalem artichoke grown in the soil with the medium humus and medium available potassium amount. The content of total soluble saccharides of different parts of Jerusalem artichoke flowers varied from 2.54 to 4.11% of disk florets and from 0.55 to 0.81% of ray florets. The highest amount of macroelement potassium (3.1%, D. M.) was detected in Jerusalem artichoke flowers grown in the soil with the medium amount of humus and the medium amount of mobile potassium. Volatile organic compounds in Jerusalem artichoke flowers were determined as a complex mixture of esters, alcohols, terpenes, sulphur and other compounds. Esters as volatile compounds prevailed in Jerusalem artichoke flowers. Methyl acetate and ethyl 2-methylbutyrate with fruity, grape odour were the predominant esters group compounds as well as dimethyl trisulfide – sulfur compound in Jerusalem artichoke flowers. The investigated aroma profile of flowers shows that they have fruity-like odour.