Vitamin B2 content determination in liver paste by using acid and acid-enzyme hydrolysis

Background/Aim. Vitamin B2 is available in foodstuff in the form of coenzyme and in free form. For its content determination a few procedures should be performed (deliberation from a complex, extraction of free and deliberated form) and detection, identification and quantification. There is a particular problem in determination of vitamin B2 in the meat products. For a determination of total vitamin B2 content in liver paste two preparation procedures are compared: acid and acid-enzymatic hydrolysis. The aim of this study thus, was to compare the effectiveness of these two different procedures for vitamin B2 content determination in liver paste. Methods. High pressure liquid chromatography (HPLC) method with fluorescence detector, as specific and adequately sensitive for the foodstuff of a complex composition with a natural vitamin content, was used for determination of vitamin B2 in liver paste. Acid hydrolysis was performed with the application 0.1 M hydrochloric acid in a pressure cooker, and enzymatic hydrolysis was performed with the 10% takadiastase on 45 ºC within four hours. Ten samples of liver paste from the supply of the Serbian Army were examined. Separation was performed on the analytical column Nucleosil 50−5 C18 with mobile phase 450 ml CH3OH + 20 ml 5 mM CH3COONH4, and detection on the fluorescent detector with the variable wave length. Both methods were validated: examining a detection limit, quantification limit, specificity (because of a possible B2 vitamin interference with reagents), linearity of a peak area and standard concentration of B2 vitamin ratio in the range from 0.05 μg/ml to 2 μg/ml, precision for the 0.05 μg/ml concentration and recovery. Results. All the previously examined parameters validated both methods as specific, precise and reproductive, with a high recovery (98.5% for acid and 98.2% for acid - enzymatic hydrolysis), as well as linearity in a range that significantly superseded the expected content in the samples (r = 0.9994, and r = 0.99987). Hydrolysis procedures make a sample suitable for vitamin B2 determination. In the liver paste samples a high content of vitamin B2 was determined: 0.83 mg/100 g after acid hydrolysis, and 0.909 mg/100 g after acid-enzyme hydrolysis. There were statistically significantly higher values determined after the acid-enzyme hydrolysis (p < 0.05). Conclusion. Using acid-enzyme hydrolysis and separation instrument technique (liquid chromatography) with a fluorescent detector as detection system, statistically significantly greater vitamin B2 quantities were determined than after using acid hydrolysis procedure. Vitamin B2 content determined in ten liver paste samples was high (0.881 − 0.936 mg/100g) indicating that this meat product is a good vitamin B2 source

In vitro ispitivanje adsorpcije vitamina B1, B2 i B6 na zeolit

Background/Aim. Zeolites are the hydratised alumosilicates of alcali and earthalcali cations, which have a long three-dimensional crystal structure. Preparations on the basis of zeolites are used for adsorption of organic and nonorganic toxic substances and they, also, find more and more use in veterinary and human medicine and pharmacy. The aim of this study was to evaluate the possibilities of zeolite to adsorb vitamins B1, B2 and B6 in acid and neutral solutions, as well as the characteristics of the process (saturability, reversibility and competitivness). Methods. The specific and sensitive HPLC method with fluorescent detector was used for determination of vitamins B1, B2 and B6. Analyte separation and detection were carried out by applying the reverse-phase method on column C18. An in vitro experiment was done by testing the influence of pH value (2 and 7), concentration of vitamin solution (1, 2 and 5 mg/L), the lenght of contact with zeolite (10-180 min) and cation competitiveness on the exchange capacity, which is achieved by media and zeolite contact, as well as a possible vitamins desorption through changing pH value of the solution at 37°C. Jon competitiveness was examined by adding commercial feed mixture (grower) with a defined content of the examined vitamines in zeolite solutions the pH = 2 and pH = 7. Results. Vitamins B1, B2 and B6 were stable in both pH=2 and pH = 7 solutions at 37°C, in the defined time intervals. In acid solution concentrations of vitamins significantly declined in the first 10 min, with no significant decline in further 30 min for all the three concentrations testch. In neutral solution, after the addition of 1% zeolite, decrease in vitamins concentrations was slightly lower than in acid solution, but also significant in the first 10 min of the contact with zeolite. It was found that zeolite, which adsorbed vitamins in acid solution, transferred in the neutral one released a significant quantity of adsorbed vitamins after 30 min of extraction on 37°C. Vitamins B1, B2 and B6 from a commercial feed mixture in pH = 2 solution, at 37°C, were significantly adsorbed on zeolite after 30 min of the contact (21.87%, 20.15% and 4.53%, respectively), while in neutral solution there was no statistically significant adsorption. Conclusion. Zeolite significantly adsorbs vitamins B1, B2 and B6 in acid and neutral solutions at 37°C, already in the first 10 min of the contact. Adsorption was irreversible, but partly reversible after changing pH from acid to neutral. This is a significant ions competition for adsorption on zeolite in neutral solution, so no statistically significant vitamins B1, B2 and B6 adsorption occurs, while in acid solution competition is less, thus zeolite significanthy adsorbs these vitamins, although in less degree than in conditions with no concurrent ions.Uvod/Cilj. Zeoliti su hidratisani alumosilikati alkalnih i zemnoalkalnih katjona koji imaju dugu trodimenzionalnu kristalnu strukturu. Preparati na bazi zeolita koriste se za adsorpciju toksičnih materija organskog i neorganskog porekla i nalaze sve širu primenu u veterinarskoj i humanoj medicini i farmaciji. Cilj ovog rada bio je ispitivanje sposobnosti zeolita da adsorbuje vitamine B1, B2 i B6 u kiselom i neutralnom rastvoru, kao i karakteristike tog procesa (saturabilnost, reverzibilnost i konkurentnost). Metode. Za određivanje vitamina B1, B2 i B6 korišćena je HPLC metoda, uz primenu fluorescentnog detektora. Separacija analita izvedena je primenom reverznofazne metode na koloni C18. U in vitro uslovima vršeno je ispitivanje uticaja pH (2 i 7), koncentracije rastvora vitamina (1, 2 i 5 mg/L), dužine kontakta sa zeolitom (0-180 min) i konkurentnosti katjona na kapacitet izmene koji se postiže u kontaktu medijuma i zeolita, kao i moguća desorpcija vitamina promenom pH vrednosti rastvora pri temperaturi od 37 °C. Uticaj konkurentnosti jona na stepen adsorpcije vitamina B1, B2 i B6 na zeolit ispitivana je dodavanjem standardne hrane za tov pilića sa definisanim sadržajem ispitivanih vitamina u rastvor zeolita pH = 2 i pH = 7. Rezultati. Vitamini B1, B2 i B6 bili su stabilni u rastvoru pH = 2 i 7 na 37°C, u vremenskom intervalu praćenja do 180 min. U kiselom rastvoru vitamina, dodatkom 1% zeolita, koncentracija vitamina značajno je opadala prvih 10 min, a nakon 30 minuta neznatno za sve tri posmatrane koncentracije. U neutralnom rastvoru, dodatkom 1% zeolita, sniženje koncentracije vitamina bilo je nešto manje nego u kiselom rastvoru, ali, takođe, značajno prvih 10 min. Ustanovljeno je da zeolit koji je adsorbovao vitamine u kiselom rastvoru prenet u neutralan rastvor, nakon 30 min ekstrakcije na 37°C, otpušta značajnu količinu adsorbovanih vitamina. Vitamini B1, B2 i B6 iz hrane u rastvoru pH = 2 na 37°C, posle 30 minuta kontakta, značajno su adsorbovali na zeolit (21,87%, 20,15% i 4,53%, redom), dok je u neutralnom rastvoru izostala njihova statistički značajna adsorpcija. Zaključak. Postoji značajna adsorpcija vitamina B1, B2 i B6 na zeolit u kiselom i neutralnom rastvoru na 37°C već posle 10 min kontakta. Adsorpcija je ireverzibilna u pojedinačnim rastvorima, a reverzibilna nakon promene pH rastvora iz kiselog u neutralan. U neutralnom rastvoru postoji značajna konkurentnost jona za adsorpciju vitamina B1, B2 i B6 na zeolit, pa ne dolazi do njihove statistički značajne adsorpcije, za raliku od kiselog rastvora u kome je konkurentnost manja i zeolit značajno adsorbuje ove vitamine, premda u znatno manjem stepenu od onog, u uslovima odsustva konkurentnih jona

Ispitivanje uticaja zeolita na sadržaj vitamina B6 u mesu brojlera - validacija metode

Zeolites are crystal, hydrated aluminosilicates of alkali-metal and alkaline-earth-metal cations which possesses 'infinite' three-dimensional crystaline structure, and are characterized with an ability of losing and accepting water and interchanging some of their own constitutional cations. Zeolites are more and more used in veterinary and human medicine. As a dietary supplement, they have been present on the European market since 1998. Zeolite-based products are used to adsorb aflatoxins and prevent aflatoxicosis, as well as appearance of aflatoxins residues in eggs, poultry meat, beef, mutton and pork. The aim of this paper was to determinate, using HPLC method with fluorescent detection, the content of vitamin B6 in meat of poultry fed with: commercial feed for broilers' fattening; commercial feed for broilers' fattening with the addition of 0,2% of zeolite, i.e. to investigate whether the persence of zeolite in feed has any influence on resorption and total vitamin B6 content in poultry meat. For this purpose an experiment on 30 broiler chicken was set. During 6 weeks, control group was fed with commercial broiler chicken fattening mixture, while 0,2% of zeolite was added to the experimental group's commercial mixture. After six weeks vitamin B6 content was determined by ion-pair reverse-phase HPLC method with fluorescence detector, after acid and enzymatic meat samples hydrolysis. Results show that, after adding 0,2% of zeolite to chicken diet, there was no statistically significant difference in vitamin B6 content in meat of experimental group, compared with the control group of broiler chicken. Investigation of zeolite adsorption ability of vitamin B6 gave significant contribution to the studies of the possibilities of its application in poultry production from the aspect of obtaining meat that fulfills all hygienic and nutritional requirements. .U veterinarskoj i humanoj medicini zeoliti nalaze sve širu primenu. Kao dijetetski suplementi nalaze se na tržištu Evrope od 1998. godine. Preparati na bazi zeolita koriste se radi adsorpcije aflatoksina i sprečavanja aflatoksikoze, kao i pojavljivanja rezidua afl atoksina u jajima i mesu živine, goveda, ovaca i svinja. Cilj ovog rada je bio da se ustanovi da li zeolit utiče na resorpciju, odnosno koncentraciju vitamina B6 u mesu nakon njegove primene u ishrani brojlera. U tu svrhu je dizajniran ogled na 30 brojlera. Tokom 6 nedelja brojleri kontrolne grupe hranjeni su komercijalnom smešom za tov brojlera, dok je eksperimentalna grupa brojlera dobijala komercijalnu smešu, uz dodatak 0,2 posto zeolita. Posle toga je određivan sadržaj vitamina B6 u mesu primenom jonoizmenjivačke reverzno-fazne HPLC metode sa fluorescentnim detektorom, nakon kisele i enzimske hidrolize uzoraka mesa. Rezultati ukazuju da se nakon dodavanja 0,2 posto zeolita smešama za ishranu brojlera ne ispoljava statistički značajna razlika u sadržaju vitamina B6 u mesu ogledne u odnosu na meso kontrolne grupe brojlera.

Determination of the lipophilicity of 2҆'-Hydroxychalcones by RP-HPLC method [Određivanje lipofilnosti 2'-hidroksihalkona primenom RP-HPLC metode]

Lipophilicity of twelve synthesized chalcones, whose ring B is a ortho, meta or para monosubstituted with alkyl, oxyalkyl groups or halogens was determined by reverse phase liquid chromatography, using octadecyl-functionalized (RP-18) silica gel as a stationary phase and two-component mixture of methanol/water as a mobile phase. Linear dependence of log k' values of the volume fraction of methanol in the mobile phase was determined for all analyzed compounds, with high coefficient of correlation (r > 0.99). Extrapolation of the line to 0% methanol concentration resulted in the capacity factor of chromatographic system where water is the mobile phase (log k(w)). For five standard substances, chemically similar to chalcones, log kw values were determined under experimental conditions and they were correlated with logP values of those compounds available in the literature. log P-EXP values of synthesized chalcones were calculated on the basis of the created standard curve. In order to estimate the relevance of the experimentally obtained log P values for chalcones, correlation of log P-EXP values with the log P values obtained through various computational procedures was performed using linear regression analysis. Statistical parameters of dependence showed that the best matching of the results had been achieved with ChemOffice program, suggesting that this program is suitable for calculating logP values of newly-synthesized chalcones, as well as of compounds structurally similar to chalcones

Comparative review of the nutritional value of cold-pressed pumpkin (cucurbita pepo l.) Seed oil of different origins

The objective of this study was to investigate the nutritional value of seven samples of cold pressed pumpkin oil of different origins and influence of seed origin on the content of the most important bioactive components. Four samples of a pumpkin oil is obtained by cold pressing of the seeds of domestic and Austrian varieties, and three samples of cold pressed oils were obtained from the seeds of unknown origin, taken by free choice in the market. As indicators of the nutritional values are determined by the composition and content of fatty acids, tocopherols and sterols. In the composition of the fatty acid were oleic dominant (34.2 +/- 0.09-43.9 +/- 0.04%) and linolenic fatty acid (30.8 +/- 0.09-46.9 +/- 0.015%). This study confirmed that the oil pumpkin dominant beta+gamma-tocopherol, whose contents ranged from 34.65 +/- 0.03 to 44.59 +/- 0.69 mg/100 g. We determine the composition and content of Delta(7)-phytosterols, especially for specific oil pumpkins. It was detected five Delta(7)-sterols: spinasterol, Delta(7,22,25)-stigmastatrienol, Delta(7,25)-stigmastadienol, Delta(7)-stigmasterol and Delta(7)-avenasterol. Dominant content was Delta(7,22)-stigmastadienol or spinasterol with 39.98 to 50.31% of the total content of sterols

The content of antioxidants in sunflower seed and kernel

The primary objective of this research was to determine differences among investigated sunflower genotypes and whether the analyzed hybrids could be sources of phenols and tocopherols important for storage stability of sunflower seeds and their derived products. DPPH• radical scavenging activity, the content of phenolic components and tocopherols (α-, β-, γ-, and δ-) in seeds and kernels of three sunflower hybrids were analyzed. In the present study, six different phenolic compounds were separated by the HPLC analysis. Chlorogenic acid was the most abundant phenol. The chlorogenic acid content strongly correlated with total phenols (r=0.93). Other marked phenolics were caffeic acid, ferulic acid, rosmarinic acid, myricetin and rutin. The total tocopherols were significantly higher (P lt 0.05) in kernels than in seeds of all sunflower hybrids. Concentrations in sunflower seeds ranged from 200.67 to 220.05 μg/g and from 256.62 to 267.49 μg/g in sunflower kernels where α-tocopherol was the dominant isomer in all samples. The α-tocopherol content was 98% of averaged of the total tocopherols in all analysed samples. All these nutrients with antioxidant properties influenced the capacity of DPPH• scavenging. Accordingly, sunflower kernels had a higher DPPH• scavenging activity, and a higher nutritive value than sunflower seeds

In vitro study of vitamins B1, B2 and B6 adsorption on zeolite

Background/Aim. Zeolites are the hydratised alumosilicates of alcali and earthalcali cations, which have a long three-dimensional crystal structure. Preparations on the basis of zeolites are used for adsorption of organic and nonorganic toxic substances and they, also, find more and more use in veterinary and human medicine and pharmacy. The aim of this study was to evaluate the possibilities of zeolite to adsorb vitamins B1, B2 and B6 in acid and neutral solutions, as well as the characteristics of the process (saturability, reversibility and competitivness). Methods. The specific and sensitive HPLC method with fluorescent detector was used for determination of vitamins B1, B2 and B6. Analyte separation and detection were carried out by applying the reverse-phase method on column C18. An in vitro experiment was done by testing the influence of pH value (2 and 7), concentration of vitamin solution (1, 2 and 5 mg/L), the lenght of contact with zeolite (10-180 min) and cation competitiveness on the exchange capacity, which is achieved by media and zeolite contact, as well as a possible vitamins desorption through changing pH value of the solution at 37°C. Jon competitiveness was examined by adding commercial feed mixture (grower) with a defined content of the examined vitamines in zeolite solutions the pH = 2 and pH = 7. Results. Vitamins B1, B2 and B6 were stable in both pH=2 and pH = 7 solutions at 37°C, in the defined time intervals. In acid solution concentrations of vitamins significantly declined in the first 10 min, with no significant decline in further 30 min for all the three concentrations testch. In neutral solution, after the addition of 1% zeolite, decrease in vitamins concentrations was slightly lower than in acid solution, but also significant in the first 10 min of the contact with zeolite. It was found that zeolite, which adsorbed vitamins in acid solution, transferred in the neutral one released a significant quantity of adsorbed vitamins after 30 min of extraction on 37°C. Vitamins B1, B2 and B6 from a commercial feed mixture in pH = 2 solution, at 37°C, were significantly adsorbed on zeolite after 30 min of the contact (21.87%, 20.15% and 4.53%, respectively), while in neutral solution there was no statistically significant adsorption. Conclusion. Zeolite significantly adsorbs vitamins B1, B2 and B6 in acid and neutral solutions at 37°C, already in the first 10 min of the contact. Adsorption was irreversible, but partly reversible after changing pH from acid to neutral. This is a significant ions competition for adsorption on zeolite in neutral solution, so no statistically significant vitamins B1, B2 and B6 adsorption occurs, while in acid solution competition is less, thus zeolite significanthy adsorbs these vitamins, although in less degree than in conditions with no concurrent ions.Uvod/Cilj. Zeoliti su hidratisani alumosilikati alkalnih i zemnoalkalnih katjona koji imaju dugu trodimenzionalnu kristalnu strukturu. Preparati na bazi zeolita koriste se za adsorpciju toksičnih materija organskog i neorganskog porekla i nalaze sve širu primenu u veterinarskoj i humanoj medicini i farmaciji. Cilj ovog rada bio je ispitivanje sposobnosti zeolita da adsorbuje vitamine B1, B2 i B6 u kiselom i neutralnom rastvoru, kao i karakteristike tog procesa (saturabilnost, reverzibilnost i konkurentnost). Metode. Za određivanje vitamina B1, B2 i B6 korišćena je HPLC metoda, uz primenu fluorescentnog detektora. Separacija analita izvedena je primenom reverznofazne metode na koloni C18. U in vitro uslovima vršeno je ispitivanje uticaja pH (2 i 7), koncentracije rastvora vitamina (1, 2 i 5 mg/L), dužine kontakta sa zeolitom (0-180 min) i konkurentnosti katjona na kapacitet izmene koji se postiže u kontaktu medijuma i zeolita, kao i moguća desorpcija vitamina promenom pH vrednosti rastvora pri temperaturi od 37 °C. Uticaj konkurentnosti jona na stepen adsorpcije vitamina B1, B2 i B6 na zeolit ispitivana je dodavanjem standardne hrane za tov pilića sa definisanim sadržajem ispitivanih vitamina u rastvor zeolita pH = 2 i pH = 7. Rezultati. Vitamini B1, B2 i B6 bili su stabilni u rastvoru pH = 2 i 7 na 37°C, u vremenskom intervalu praćenja do 180 min. U kiselom rastvoru vitamina, dodatkom 1% zeolita, koncentracija vitamina značajno je opadala prvih 10 min, a nakon 30 minuta neznatno za sve tri posmatrane koncentracije. U neutralnom rastvoru, dodatkom 1% zeolita, sniženje koncentracije vitamina bilo je nešto manje nego u kiselom rastvoru, ali, takođe, značajno prvih 10 min. Ustanovljeno je da zeolit koji je adsorbovao vitamine u kiselom rastvoru prenet u neutralan rastvor, nakon 30 min ekstrakcije na 37°C, otpušta značajnu količinu adsorbovanih vitamina. Vitamini B1, B2 i B6 iz hrane u rastvoru pH = 2 na 37°C, posle 30 minuta kontakta, značajno su adsorbovali na zeolit (21,87%, 20,15% i 4,53%, redom), dok je u neutralnom rastvoru izostala njihova statistički značajna adsorpcija. Zaključak. Postoji značajna adsorpcija vitamina B1, B2 i B6 na zeolit u kiselom i neutralnom rastvoru na 37°C već posle 10 min kontakta. Adsorpcija je ireverzibilna u pojedinačnim rastvorima, a reverzibilna nakon promene pH rastvora iz kiselog u neutralan. U neutralnom rastvoru postoji značajna konkurentnost jona za adsorpciju vitamina B1, B2 i B6 na zeolit, pa ne dolazi do njihove statistički značajne adsorpcije, za raliku od kiselog rastvora u kome je konkurentnost manja i zeolit značajno adsorbuje ove vitamine, premda u znatno manjem stepenu od onog, u uslovima odsustva konkurentnih jona

Chemical composition and nutritive potential of Cichorium intybus L. leaves from Montenegro

The leaves of chicory (Cichorium intybus L.) plant have been used for centuries in Montenegro and other Mediterranean countries as a vegetable in salads, sauces and other types of appetizers and meals. The wild and cultivated chicory leaves from different location in Montenegro were analysed regarding several nutrients, major and trace element and vitamin composition using standard methods of analysis. The results of the study indicated that chicory leaves were rich in total dietary fiber and mineral content and had low energy value. Also, they were potential sources of useful nutrients such as potassium, calcium, manganese, iron, and vitamin A, with the average content of 391.9, 164.7, 0.55, 2.33 and 0.47 mg / 100 g in fresh leaves, respectively. Wild plants were superior to the cultivated ones regarding carbohydrate, calcium and manganese content. Origin of the chicory leaves significantly influenced most of the analyzed parameters

Antioxidant activity, phenolic profile, chlorophyll and mineral matter content of corn silk (Zea mays L): Comparison with medicinal herbs

Yellow, green, pinky and purple colored corn silk were harvested 5 and 25 days after emergence and compared with six medicinal herbs for total phenolics, flavonoids, anthocyanins, proanthocyanidins, chlorophylls, as well as antioxidant activity. The phenolic acid, flavonoid and mineral matter profiles of corn silks were also determined. Corn silks at the silking stage are much more suitable for use as a natural source of phenolic compounds than silks at the R4 dough stage. The content of total phenolic and flavonoid compounds in fresh silk was higher by about 2- to 4-fold than in the silk at the R4 dough stage and by about 1.2- to 2.6-fold than in the most investigated herbs. The most abundant phenolic compounds were hydroxycinnamic acid ester and luteolin derivative i.e. 3-O-caffeoylquinic acid and maysin, respectively. A high potassium content and antioxidant activity of silk are associated with its health benefit properties