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.

Polyphenol compounds are very important components of cider -they are responsible for the colour and the bitterness and astringency balance of cider. The polyphenolic profile of apples and apple drinks is influenced by several factors: apple variety, climate, maturity, and technological processes applied. This research paper concerns the influence of apple variety on the phenolic compounds and sensory properties of cider. Fermentation of 12 varieties of apple juice with Saccharomyces cerevisiae yeast '71B-1122' (Lalvin, Canada) was performed in a laboratory of the Faculty of Food Technology of the Latvia University of Agriculture. The total phenol content (TPC) was determined according to the Folin-Ciocalteu spectrophotometric method. Individual phenolic compounds were analysed using HPLC. Sensory properties (clarity, the apple, fruit and yeast aroma, the apple and yeast taste, sourness, astringency, and bitterness) were evaluated by trained panelists using a line scale. Special attention was paid to the use of dessert apples for the production of cider. The most important sensory properties of cider are the aroma and taste of apples and fruit. All cider samples showed the intensity of apple aroma ranging from 5.3 to 7.6 points, and higher results were obtained for cider from the variety 'Auksis' apples. The TPC in cider samples varied from 792.68 to 3399.78 mg L -1 : Among crab apples, the highest TPC was detected in ciders made from the 'Hyslop' and 'Riku' varieties, whereas among dessert apples, the highest TPC was detected in ciders made from the 'Antonovka' variety. Among the twelve phenols identified in cider samples, chlorogenic acid and caffeic acid were the dominating ones. Variation in the sensory properties of ciders was dependent on the physicochemical composition of the apples used.

Abstract-Many of the compounds present in potato are important because of their beneficial effects on health, therefore, are highly desirable in the human diet. The orange and yellow colour of the tuber flesh is due to carotenoids. The aim of this research was to determine the content of total phenolic content and carotenoids in relationship with the colour of organically and conventionally cultivated potato varieties before and after period of storage. In the research 31 potato samples of 12 potato varieties were analyzed on total carotenoid, total phenolic content and colour. Obtained results show that there was significant influence on carotenoid content between different cultivation environments (p<0.05) and between varieties (p<0.05). Total phenolic content significantly varies both per variety (p<0.001) and storage conditions (p<0.001).

Beer is a complex mixture - over 400 different compounds have been characterized in beer. Significant health and product quality promoting benefits have been attributed to its bioactive secondary metabolites such as phenolics. Polyphenols and phenolic acids present in beer are natural antioxidants. The aim of the research was to characterize the bioactive compounds in Latvian barley beer, such as phenolic acids and flavanols. In an experiment, different lager-type beers produced in Latvia were analysed. The total phenolic content was determined spectrophotometrically according to the Folin-Ciocalteu colorimetric method and expressed as gallic acid equivalents. Individual phenolic compounds were determined using high performance liquid chromatography (HPLC). The antioxidant potential of beer was analyzed by the 2,2-diphenyl-1-picrylhydraziyl (DPPH) radical assays and expressed as micromoles of Trolox equivalents. The research showed that the total phenolic content of dark beer samples (320.8-863.6 mg GE L-1) was mostly higher than that of the light beers (300.9-475.2 mg GE L-1). In total, eleven phenols were determined in the analysed samples. Also the sum of individual phenolics in dark beer samples was higher than in the light beer brands. All beer samples exhibited a strong DPPH radical scavenging activity: from 441.3 to 1064.2 μmol TE L-1 for the light beer samples, and from 726.2 to 1748.7 μmol TE L-1 for the dark beer. The research suggests that composition of beer phenolic compounds was not dependent on the type of beer - light or dark.

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