ISSN 2285-1364, ISSN CD-ROM 2285-5521, ISSN ONLINE 2285-1372, ISSN-L 2285-1364
 

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Gabriel MUSTĂŢEA, Mona Elena POPA, Mioara NEGOIŢĂ

Acrylamide is a chemical compound first detected in food in 2002 by the Swedish National Food Administration (NFA) and the University of Stockholm. Acrylamide was added on the list of substances of very high concern and was also classified as a probable carcinogenic substance to humans. Acrylamide is mainly formed in the Maillard reaction when asparagine reacts with the reducing sugars, especially glucose and fructose that are present in food. This usually takes place during high temperature processing of food: frying, baking, roasting and grilling. This work presents a review of scientific literature published between 2003 and 2014 presenting different methodologies and experimental approaches to reduce acrylamide levels in bakery products. The main pathways for acrylamide mitigation in bakery products take into account three important issues: raw materials, recipes and food processing conditions.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Mioara VARGA

In this paper, we discuss about an application of Analysis of Variances from biology. We are interested to determine the effect of adding the NaCN (sodium cyanide) on the uptake in vitro of a particular amino acid by intestinal preparations from certain species of fish. First, we introduce some theoretical notions about this statistical method; we present the most important calculation formulas and the way they are used for comparing the treatment means in case of an experiment with k treatments, b blocks and n replicates per treatment per block. Afterwards, we consider a twotreatment experiment (with and without NaCN) and the results obtained for three replicates from each of the 4 species of fish are expressed asμ mol g−1dry weight per 20 min period. After we calculate the sums of observational data per sub-class, per treatment and grand totals, we determine the elements from the table of analysis of variances (sums of squares, degrees of freedom, the error mean square) and we use the Fisher test for establishing the conclusions. Then we find that the difference between treatment means is 0,49, thus with 95 % confidence probability, we may state that the addition of the NaCN to the medium reduces uptake by 0,68μ mol g−1dry weight per 20 min period.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Dasha MIHAYLOVA, Lidiya GEORGIEVA, Atanas PAVLOV

The aim of the present research was to make a comparison between two Bulgarian commercial forms of Rosa canina L. for herbal preparations in terms of the possible benefits by oral intake. The plant samples were investigated for their antioxidant activity and the bioactive substances. The total phenolic content of the extracts was evaluated as well. Four reliable methods (DPPH, ABTS, FRAP and CUPRAC assays) for antioxidant activity assessment were applied. The highest results were recorded by the FRAP assay.The plant Rosa canina is known as wealthy source of carotenoids and organic acids, therefore fat soluble β-carotene, lycopene and lutein in addition to water soluble malic, citric, fumaric and ascorbic acids were evaluated by HPLC-methods. According the conducted assays the tested samples have similar composition. Lutein concentration in both tested extracts was calculated as 6.9 μg/g DW. Lycopene and β-carotene were determined to be 13.91 and 12.18 μg/g DW and 27.14 and 22.83 μg/g DW, respectively. HPLC determination of organic acids showed that the amount of citric acid in the extracts was 7343 and 6583 μg/g DW and fumaric acid content in both samples was 30 μg/g DW. The size of the plant particles used for the extraction seems to contribute significantly to the exhibited activity.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Evelina GHERGHINA, Florentina ISRAEL-ROMING, Daniela BALAN, Gabriela LUTA, Vasilica SIMION, Marta ZACHIA

Bakery products constitute an important part of the human diet, providing a high quantity of carbohydrates, but also proteins, dietary fibres, B group vitamins and minerals. Consumption of whole grain foods means high intake of dietary fibre and micronutrients, which has been associated with a reduced risk of coronary heart disease, diabetes, obesity and some forms of cancer. The aim of the present study was to appreciate the nutritive value of some bakery products by assessment of content in thiamine and α-tocopherol. The researches were performed on common products made with wheat or rye flour and on some enriched products obtained by adding different ingredients of vegetal origin, such as olives, onion, garlic or seeds. These supplementary ingredients were used to improve the taste and to diversify the range of bakery products. In the same time, their addition results in obtaining healthier food. α-Tocopherol content was analysed by HPLC method and thiamine content was determined by spectrofluorometric method. The obtained results showed a higher content of thiamine in the enriched products comparing to the traditional ones. Moreover, the analysis indicated an improvement of α-tocopherol content, although the bakery products usually contain low amounts of this vitamin.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Marius Cristian BODA

The study was carried to survey a total of 60 samples of canned meat (20 samples of canned pork, 20 samples of canned meat with sauce and 20 canned fish).The samples were obtained from local markets in Bath city and Wiltshire County within the United Kingdom, during three months January – March 2015. The samples were relocated to laboratory and kept at room condition (temperature and humidity). Thus, the scope of the present study was to conduct bacteriological measurements for the quality control of canned meat stored at 20°C for up to 15 days. In this paper, variations of the cans integrity are analysed to reveal the correlation between cans structure and the evolution of the spoilage organisms developing in food cans, semi-finished goods meat product and on fish packed meat. The study was focused on analysing the growth behaviour of the spoilage flora in the processed meat product, and on liquid medium rather than in fresh meat. Based on these analyses it was observed that all cans that are damaged deeply, more than cans that are superficial scratched, had a growth of microbiological spoilage. The bacteriological examinations of external surface showed negative results, so there no pathogenic microorganisms attached to the surface, but some presence of moulds was highlighted in this study.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Carmen Madalina CISMASIU

Successful biodegradation process of different complexes required attention to biological parameters (such as choice of microorganisms), control of the chemical and physical environment (pH, redox potential, temperature and metallic ions) and consideration of the metal mines condition. In this context, the present paper presents the study regarding the main interactions between acidophilic bacteria and toxic metal ions can occur through active processes, involving the metabolic sequences of living microorganisms or passive processes, independent of cellular metabolism. The acidophilic bacterial cultures used in the degradation experiments of organic compounds were selected on the basis of their capacity to hydrolyse the starch in the presence of different inorganic forms of heavy metal ions The heterotrophic bacterial capacity by producing organic acid was very high, which confirm the adaptation of these populations to higher concentrations of heavy metallic ions. Comparative results bring an improved bacterial growth and sensitivity to specific environmental conditions and bacterial populations although the effect is not maintained after longer times. Our analysis regarding the efficiency of extracellular enzymes from Acidiphilium populations shows continuous agitation conditions (21 days) in the presence of 2-3g/l starch induce an increased extracellular hydrolytic activity (50-60%) when sulphates is present in the environment.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Mirela C. IORDAN, Ioan I. ARDELEAN

In this paper there are present the results concerning chemical parameters and the rate of metabolic activity of activated sludge in Constanta Nord waste water plant. Special emphasis is focused on time evolution of nitrates, ammonium, phosphorus concentrations and chemical oxygen demand in inlet, waste water and outlet, purified water. These results are discussed in correlation with metabolic activity of active sludge microbiota measured as the rate of resazurine reduction, and microscopic images obtained both in bright field and in epifluorescence microscopy. The results open inter alia the possibility to use the rapid method of resazurine reduction (15-20 minutes) to assess the activity of activated sludge microbiota and to correlate it with standardized, but timeconsuming (hours to 5 days) methods, thus increasing the possibility to take good operational decisions in shorter time.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Nadezhda PETKOVA, Ivan IVANOV, Stanka TOPCHIEVA, Panteley DENEV, Atanas PAVLOV

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.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Cornelia NICHITA, Georgeta NEAGU, Ana CUCU, Catălin CEAUŞ

A systematic scientific research for useful bioactivities from medicinal plants is now considered to be a rational approach in nutraceutical, drug research and food. A sustainable development of extractive biotechnological processes from herbal species can be achieved by classical method and also by supercritical fluid extraction(SFE). This paper is presenting the obtaining of some selective extracts from Rosmarinus officinalis L. species, with dual function of ingredients and antioxidants for food products. The fresh and dried leaves of Rosmarinus officinalis are frequently used as a food preservative and in traditional Mediterranean cuisine as a flavoring agent. Classical Soxhlet method and supercritical fluid extraction (SFE) method with CO2 and ethanol cosolvent were applied for obtaining the Rosemary officinalis L. extracts. The herbal extracts have been investigated by UV-Vis spectroscopy for quantitative determination of the total polyphenols and flavonoids content, polyphenolcarboxylic acids and rosmarinic acid, according to Romanian and European Pharmacopoeia. In addition to this, four SFE extracts and four Soxhlet extracts were screened for their radical-scavenging capacities and antioxidant activities by various in vitro, non cellular assays, respectively chemiluminescence method in an luminol hydrogen peroxide system, and DPPH (2,2-diphenyl-1- picrylhydrazyl) radical-scavenging. The results revealed excellent correlation between the antioxidant capacity and the amount of active constituents of extracts (rosmarinic acid, total polyphenols and flavonoids content, polyphenolcarboxylic acids).

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Roxana-Mădălina STOICA, Ovidiu POPA, Liliana-Claudia BLASS, Narcisa BĂBEANU

The latest world trends in scientific research are directed towards the production and application of secondary metabolites. The plant of the genus Capsicum produces a fruit (chilli pepper) with unique bioactive compounds. Pepper fruits are a rich source of metabolites with potential health-promoting properties, for example carotenoids (provitamin A), ascorbic acid (vitamin C), tocopherols (vitamin E), capsaicinoids and flavonoids. Capsaicinoids are the compounds responsible for the hot, spicy flavour presented by many varieties of peppers. There were identified over 20 compounds, capsaicin analogues, of which most important (>95%, w/w) are: capsaicin, dihydrocapsaicin, nordihydrocapsaicin, homodihydrocapsaicin, homocapsaicin. Capsaicinoid extraction from peppers is typically performed using organic solvents, however, the extraction efficiencies can vary with peppers, their parts and pre-extraction processing. A major component of this group is capsaicin. This study involves extraction of capsacinoids from three varieties cultivated in Romania. Capsaicinoids were identified in all extracts with concentration ranging from 0.5 to 0.8% (dry weight) and the best results were obtained with 96% ethanol as solvent.

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