Nadezhda Petkova

European cinquefoil (Potentilla reptans L.) (Rosaceae) is very common in the Central Europe and Balkan Peninsula. Since ancient times the European cinquefoil have been traditionally used in herbal medicine for treatment of tooth ache, ulcers and inflammation of the throat, as well as certain forms of cancer, infections due to bacteria, fungi and viruses, diarrhea, diabetes mellitus and other ailments. Most species of genus Potentilla contain hydrolysable tannins, proanthocyanidins, flavonoids and triterpenes as bioactive substances. The aim of this study was to establish the most suitable condition for extraction of biologically active substances from Potentilla reptans aerial parts. The influence of the time of the ultrasonic extraction and solvent concentration (ethanol-water) in different ratio over the extraction process was studied. The optimal conditions for the extraction of biologically active substances from European cinquefoil were as follow: 40% ethanol-water as solvent system and extraction time 45 min in ultrasonic bath with frequency 35 kHz. Under these conditions the maximum values of total polyphenols content, total proanthocyanidins and total hydrolysable tannins (60.2 mg GAE/ g dw, 93.1 mg LE/100g dw, 101.3 mg TAE /g dw) were obtained.

Tests under field conditions were conducted on the biofertilizer Kompovet and the biological pesticides Neem Oil and Neem Cake on the Gergana cucumber variety and Ismalia F 1 zucchini variety. Trials were carried out in 2015-2016, in the village of Kostievo near Plovdiv. The treated variants accumulated more biomass, formed a greater number of female flowers and gave higher yield (by 29.3% and 32.7% respectively) in relation to the control. The plants treated with organic products showed better ecological plasticity to the extremely high summer temperatures. The resulting vegetables contained high values of sugars, carotenoids and chlorophylls compared with the untreated variants and they werе natural sources of phytonutrients of an antioxidant potential. The fruits of the treated zucchini variants showed the highest values of total phenols and performed the highest in vitro antioxidant activity evaluated by the DPPH and FRAP methods. The applied biological pesticides (insecticides and nematicides) increased the resistance to some soil pathogens – root-knot nematodes. ВЪВЕДЕНИЕ Прогресивното нарастване на използването на химични торове за повишаване на добивите в съвременното зеленчукопроизводство води до

Carob, Ceratonia siliqua, is cultivated for ornamental and industrial purposes in many Mediterranean countries. This study assessed carob pulp and syrup, a rich source of carbohydrates and sugars, by evaluating content of reducing sugars and total sugars in carob pulp before extraction of syrups. We identified the sugar content before and after treatment by using thin-layer (TLC) and high performance liquid chromatography with refractive index detection (HPLC-RID). It was established that total sugars increased with extraction and heat treatment. Sucrose (34.2 g/100 g dry weight; dw), glucose (11.1 g/100 g dw) and fructose (6.5 g/100 g dw) were the major sugars identified and quantified in pulp of the Turkish carob. Ceratonia siliqua pods of Turkish origin produced higher levels of total and of reducing sugars (fructose and sucrose) than did the pods from Bulgaria. The carbohydrate content in the syrup prepared from Turkish carob pods was highest, with the sucrose content especially reaching up to 45 g/100 g dw. The data are discussed in terms of nutritional and energy value of the carob pod. The carob and obtained products (flour or syrup) are identified as highly caloric and as a prospective energy source alternative to cocoa and its products. UDC Classification: 543.6 DOI: http://dx.doi.org/10.12955/cbup.v4.855

Alginic acids are perspective biopolymers with significant application in food technologies and pharmaceuticals. The aim of the current research was to synthesized environment-friendly alginic acid derivatives (methylated and amidated alginic acids with the different ratio of M/G blocks in the polysaccharide backbone) by ultrasound irradiation. The newly synthesized derivatives were characterized by the degree of esterifi-cation (DE), degree of amidation (DA) and their structure were elucidated by FT-IR spectroscopy. Their physi-cochemical properties were also evaluated. Methyl esters of two alginic acids were characterized with DE 49 and 82 % respectively, while their amidated derivatives reached DA to 53 %. The methylated alginic acid with (M/G) ratio: 61:39 showed the promising results future application as a foaming agent. The obtained results showed the significant improvement of rheological properties of methylated alginates with increase of DE, and decrease of emulsifying properties after amidation of alginate methyl esters, respectively.

Polysaccharide inulin was isolated by different methods comprised conventional, accelerate solvent extraction (ASE), ultrasound – assisted extraction (UAE), and microwave extraction (MWE) from Helianthus tuberosus L. tubers. The resulting carbohydrate presented tasteless, white, dry powder. The isolated inulin was characterized in terms of yield, degree of polymerization (DP), melting point, water activity (aw), reducing groups and total fructose content. The structure of polysaccharide was confirmed by IR-FT spectroscopy. The yield varied in range of 12-24%, as the highest was obtained by MWE (da se promeni !!!). The highest DP was evaluated to be 45, as reducing groups not exceeded 1,8 %. Melting point was established in the range of 178-182 oC. The IR-FT spectra revealed the presence of typical bands for inulin structure - 817, 873 and 937cm-1 with terminated α-D-glucose residue.

Abstract The inulin-type fructans, inulin and fructooligosaccharies (FOS), are part of dietary fibers for production of functional foods with improved health benefits. The increasing application of these components in food technology needs reliable methods for their analysis and control. The aim of the current review is to present and compare the main analytical methods for inulin determination in food products. This study summarizes not only the common applied spectrophotometric and enzymatic methods, but also describes in details chromatographic techniques-HPLC, GC and TLC, IR-FT and real time 1 H NMR spectroscopy. Some of suggested analytical assays, especially spectrophotometric, enzymatic and HPLC-RID methods are applied for routine analysis in analytical practice for monitoring of some process in food technology and control in food labeling. Special attention has been paid to nondestructive IR-FT spectroscopy that reveals the potential to identify the presence of inulin by typical for β-→1 glycosidic bond. Some typical shifts are shown for structure elucidation or hydrolysis of inulin by NMR spectroscopy.

Dandelion (Taraxacum officinale L. Weber ex F.H. Wigg.) roots were traditionally used in folk medicine worldwide due
to its antidiabetic, choleretic, antirheumatic and diuretic properties. The aim of the current study was to determinate
the biologically active substances in 95% ethanol and subsequent water extracts from dandelion roots and to evaluate
their antioxidant activities. The carbohydrate composition was analyzed by the resorcinol assay, TLC and HPLC-RID
methods. The total phenolic contents (TPC), total flavonoids (TF) and total dihydroxycinnamic derivatives contents
were determined by Folin–Ciocalteau method, aluminium chloride colorimetric assay and Arnow’s reagent,
respectively. In vitro antioxidant activities of the extracts were estimated using ferric-reducing/antioxidant power
(FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assays. In spring harvested dandelion roots the
total fructan content were established to be in range 17-19 % dw. The low molecular carbohydrate fraction presented
by glucose, fructose, sucrose, 1-kestose and nystose dominated in 95 % ethanol extracts. The subsequent water extracts
demonstrated the highest inulin content (12% dw), while TPC, TF and total dihydroxycinnamic derivatives contents
were reported to be 9.2 mg GAE/g, 1.7 mg QE/g and 13.7 mg chlorogenic acid derivates/g dw, respectively. These
extracts showed the highest antioxidant activity for both the DPPH (82.1 mM TE/g) and FRAP (52.9 mg mM TE/g)
assays. Therefore, the subsequent water extracts possessed the highest antioxidant capacity, which positively correlated
with the phenolic content. The results of current investigation demonstrate that dandelion root is a valuable source of
dietary fibers and natural antioxidants and could be successfully used in foods with the potential to improve digestion
and prevent from oxidative stress related diseases.

The aim of the current study was to investigate the carbohydrate composition, total phenolic content and in vitro antioxidant activities of 70 % (v/v) ethanol extracts obtained from fruits and leaves of three Morus species: white mulberry (Morus alba), black mulberry (Morus nigra) and red mulberry (Morus rubra) grown in Bulgaria. The carbohydrate content was determinated by spectrophotomeric, TLC and HPLC-RID methods. The total phenolic content was analyzed by Folin–Ciocalteau method. The antioxidant activities of above mentioned extracts were evaluated by DPPH and FRAP assays. From the obtained results, monosaccharides fructose and glucose were found to be the main sugars in all investigated extracts, as their content reached to 3.0 g/100 g fw in fruits and 0.6 g/100g fw in leaves. M. alba and M. rubra fruits were evaluated as a natural source of prebiotic, due to the presence of 1-kestose, nystose and inulin. The absence of sucrose in all mulberry fruit extracts was also established. The total phenolic content was reported to be the highest in black and red mulberry leaves, as their values reached up to 2 mg GAE/g fw. The extracts from M. nigra leaves demonstrated the highest antioxidant activity for both assays: for DPPH were 10.9 mM TE/g fw and for FRAP – 6.0 mM TE/g fw, respectively. The current research was the first comprehensive study for detailed analysis of carbohydrate composition and antioxidant properties of three mulberry species grown in Bulgaria. Therefore, mulberry fruits and leaves could be assumed as a rich source of biologically active substances with great importance for human nutrition.

Elecampane (Inula helenium L.) is herb from the Compositae family known as a rich source of biologically active compounds, especially inulin and eudesmane-type sesquiterpene lactones. Until now no detailed characteristics of inulin obtained from this plant have been done. The current research aimed to obtain this polysaccharide form elecampane dry roots by application of ultrasound-assisted extraction procedure and to elucidate its structure and physico-chemical properties. The isolated substance presented white tasteless powder with the melting point 178.5-181 °C, the angle of optical rotation (c=0.5; H2O), fructose content 93.3 % and reducing groups 2.9 %. Elecampane inulin was characterized as high molecular with average degree of polymerization (DP) 30 - 33 and the molecular weigh 5 kDa. The protein content in the polysaccharide fraction was below 1 %. The IR-FT spectra were characterized with typical bands for inulin structure - 817, 873 and 933 cm-1 that showed the presence of β 2→1 glycoside bond.

During the current investigation experiments for the preparation of alginate beads with aqueous solutions of sodium alginate, calcium lactate or
calcium dichloride and dietary fiber in different concentrations: inulin with varying degrees of polymerization, wheat bran and amidated apple pectin were
carried out. The sodium alginate solutions were at constant concentration 3%, while calcium salts in 7% were applied for bead formation. It was proven that the
rupture force of alginate beads was always higher than the pure model system regardless of the chemical structure of dietary fibers used. In the result of the
carried research the dependence at a certain concentration was established.