Summary In this study, major types of flavonoids in 7‐day sprouts of five common buckwheat cultivars grown in Poland (Hruszowska, Kora, Panda, Luba and Emka) and wild tartary buckwheat were investigated. Results demonstrated that sprouts of common buckwheat cultivars and wild tartary buckwheat contained both known and a newly discovered flavonol: quercetin 3‐O‐galactosyl‐rhamnoside. An exceptionally high content of this flavonoid was found in cotyledons of wild tartary buckwheat (30.79 ± 0.14 mg g−1 DW), exceeding about 10 times level of rutin (3.16 ± 0.07 mg g−1 DW). The results are not consistent with the data published so far on the content of flavonoids in sprouts of tartary buckwheat. Higher levels of flavonoids were measured in cotyledons than in hypocotyls with the exception of anthocyanins, which were present in higher amounts in hypocotyls. Cotyledons of common buckwheat sprouts were rich in C‐glycosides of luteolin and apigenin, the total content of which exceeded ca. 5 times the concentration of rutin.

The effects of exogenously applied methyl jasmonate on content of biogenic amines: putrescine, spermidine, tyramine, cadaverine and 2-phenylethylamine in seedlings of common buckwheat (Fagopyrum esculentum Moench) were investigated. The studies have shown that methyl jasmonate stimulates the conversion of L-phenylalanine into 2-phenylethylamine and increases the endogenous levels of putrescine in hypocotyls and cotyledons of buckwheat seedlings. Simultaneous feeding the seedlings with L-phenylalanine and methyl jasmonate has indicated that conversion of L-phenylalanine into 2-phenylethylamine can be one of possible reasons, caused by the methyl jasmonate suppression of anthocyanins synthesis in hypocotyls. To our knowledge, the stimulation of conversion of L-phenylalanine into 2-phenylethylamine by methyl jasmonate, as found in the present study, is described for the first time in higher plants.

The aim of the study was to analyse the content of phenolic acids, total phenolic compounds, proanthocyanidins, and antioxidant capacity in cotyledons and hypocotyl of fi ve cultivars of common buckwheat (Fagopyrum esculentum Moench) sprout. This study presents the fi rst broad profi le of phenolic acids occurring in buckwheat microgreen seedlings. In the hypocotyl and cotyledons trans-cinnamic acid and its derivatives: o-, m-, and p-coumaric acids (2-, 3-, and 4-hydroxycinnamic), synapic acid (4-hydroxy-3,5-dimethoxycinnamic), caffeic acid (3,4-dihydroxycinnamic), and two isomers of ferulic acid (4-hydroxy-3-methoxycinnamic and 3-hydroxy-4-methoxycinnamic) have been identifi ed. Among the benzoic acid derivatives hydroxybenzoic, protocatechuic (3,4-dihydroxybenzoic), gallic (3,4,5-dihydroxybenzoic) and syringic (4-hydroxy-3,5-dimethoxybenzoic) were found in the organs. In addition to those mentioned, the organs of buckwheat sprouts contain chlorogenic acid as well. The contents of all analysed phenolics were substantially higher in the cotyledons than in the hypocotyl of buckwheat sprouts, except for chlorogenic and caffeic acids. Trans-cinnamic acid was the major phenolic acid in both organs. In the cotyledons, a signifi cant, positive linear correlation between the TEAC, ORAC, PLC-ACW values and content of total phenolic compounds, and also between DPPH and total phenolic acids were found. In the hypocotyl correlations between the DPPH, TEAC, and ORAC and proanthocyanidins content, between TEAC and total phenolic compounds, and between total phenolic acids and PCL-ACW were found.

The aim of study was to determine the effect of selected cultivation operations, such as nitrogenous fertilization (60, 90 kg N/ha), row spacing (62, 82, 102 cm), compaction of soil with wheels of farm aggregates (the numbers of passing 2×, 5×, 8×), on quality changes of two potato varieties (Irga and Ekra). The total protein content in the tubers of the tested potato varieties increased with the increase of the nitrogenous fertilization (90 kg N/ha). Genotype features of the tested potato tubers define the amino acid limiting the protein biological value (CS) to be leucine in Irga variety and isoleucine in Ekra variety. It is also genotype that influences the second limiting amino acid. It is the sum of sulphuric amino acids (Cys + Met) in respect to Irga variety and valine in respect to Ekra variety. The dose of 90 kg N/ha decreases the protein biological value (EAAI) of the tubers of Ekra variety, which is high in starch.Keywords: potato; tuber; total protein; biological value of protein; amino acids; nitrogen fertilization; row spacing; soil compaction Protein content in tubers is an important element of the evaluation of potato quality. Although when compared to other crop plants, potatoes contain a small amount of protein (2.0-2.5% f.m.), they are an important element of human and animal diet, due to high biological value of protein -very good amino acid composition (Ciećko et al. 1999). Potato protein is plant protein of high value for both humans and animals. Potato varieties are characterised by differentiated, genetically conditioned predisposition to protein accumulation in tubers. However, similarly to most quality characteristics, protein content can be modified by various factors, such as environment, soil and tillage (Mazurczyk and Lis 1999). The basic protein components are amino acids, which, similarly to nucleic acids, take part in all intracellular processes in living organisms. The amino acid composition of proteins is important from the nutrition point of view. The amino acid composition determination acids (exogenous), namely tryptophan, phenylalanine, lysine, treonine, methionine, leucine and valine, are valuable. These amino acids are necessary for all types of the examined animals. However, a rigid set of amino acids necessary for all animals cannot be applied because some of them may require specifically a certain type of an amino acid. The analysis of the amino acid composition of the potato protein makes it possible to classify the protein as full-value, as it contains a high amount of the essential amino acids, particularly lysine (Wieczer and Gonczarik 1977). MATERIAL AND METHODSThe experimental material consisted of the tubers of two varieties: edible Irga and industrial Ekra. A field experiment was carried out in the vegetation seasons of 1997-1999 at the Experimental Farm Station, Zawady and on the experimental field of the Department of Soil Cultivation and Plant Growing, Plant Production Institute of the University of Podlasie in Siedlce. The experiment was planned in...

The effect of methyl jasmonate (MJ) vapors on content of phenolic compounds: free phenolic acids, total quercetin, and total phenolics in etiolated buckwheat seedlings were studied. The data presented show that low concentration of MJ (10 -8 M) had no influence on trans-cinnamic acid (CA), but stimulated the accumulation of chlorogenic acid in hypocotyls and cotyledons of buckwheat seedlings. A moderate dose of MJ (10 -6 M) did not change the level of chlorogenic acid in the hypocotyls and cotyledons, but CA synthesis was promoted in cotyledons, whereas in hypocotyls no significant effect was found. Highest concentration of MJ (10 -4 M) caused small decline of CA in hypocotyls, but large stimulation of the acid production in cotyledons was noted. MJ had stimulatory effect on caffeic acid forming, but inhibited synthesis of vanillic acid in hypocotyls and cotyledons. Lowest concentration of MJ (10 -8 M) elicited accumulation of quercetin glycosides in both studied tissues of buckwheat seedlings, however at higher doses (10 -6 and 10 -4 M) did not affect the flavonol level. The obtained results suggest that nonequivalent influence of methyl jasmonate on the phenolics composition can be a result of various mechanisms of MJ uptake, transforming and/or its translocation in buckwheat hypocotyls and cotyledons. Decline of anthocyanins level in buckwheat hypocotyls caused by MJ cannot be explained by enhanced accumulation of quercetin glycosides or free phenolic acids, but probably by synthesis of other unknown phenolic compounds.