Lolita Tomsone, Zanda Kruma, Ruta Galoburda and Thierry Talou
Horseradish is a perennial plant with significant antioxidant properties, and it contains about 0.2% to 1.0% of essential oil, mainly sinigrin, sinigrin-derived allylisothiocyanate and diallylsulphide. The aim of the study was to determine composition of volatile compounds of horseradish (A. rusticana L.) roots depending on the genotype. Volatiles from fresh horseradish roots of nine genotypes were extracted using solid phase microextraction with DVB/Car/PDMS fibre and were further analysed using gas chromatography-mass spectrometry. The volatile compounds were identified by comparing their mass spectra with mass spectral libraries (Nist98) and by calculating linear retention indexes and comparing them with the literature data. The studied horseradish genotypes differed both in the quantitative and qualitative content of aroma compounds. Totally 15 volatile compounds were detected, and their highest amount was found in genotype G12B. The main aroma compound of all horseradish samples was allylisothiocyanate, which formed 64-82% of the total identified volatile compounds. The obtained results were compared with those found in the literature. All horseradish samples contained significant amounts of phenylethylisothiocyanate (4-18%) that is formed from glucosinolate - gluconasturtin. The study revealed that genotype has great influence on the content of volatiles in horseradish roots.
Bouchra Sayed-Ahmad, Evita Straumīte, Mārtiņš Šabovics, Zanda Krūma, Othmane Merah, Zeinab Saad, Akram Hijazi and Thierry Talou
Fennel (Foeniculum vulgare L.) is an aromatic plant belonging to Apiaceae family widely cultivated elsewhere for its strongly flavoured leaves and seeds. Fennel seeds are of particular interest as a rich source of both vegetable and essential oils with high amounts of valuable components. However, residual cakes after oil extraction were typically considered as byproducts, in the present framework, the potential added value of these cakes was studied. The aim of this study was to investigate the effect of addition of fennel cake and seeds to protein bread quality. In the current research, a single-screw extruder, which is a solvent-free technique, was used for fennel seed oil extraction. For the protein bread making, fennel seed and cake flour in concentrations from 1 to 6% were used. Moisture, colour L*a*b*, hardness, total phenolic concentration, DPPH radical scavenging activity, and nutritional value of protein bread were determined. The addition of fennel cake and seeds had significant (p < 0.05) effect on bread crumb colour and hardness attribute, whereby the bread became darker and harder in texture than the control. Moreover, higher antioxidant activity and total phenolic concentration were observed for both protein breads enriched with fennel cake and seed flour. The overall results showed that addition of fennel cake and seed had beneficial effects on phenolic concentration, antioxidant activity and quality of protein bread. This result suggests also that added value of fennel seeds oil by-products could be increased by their utilisation in bread production.