Comparison of Quality Changes in Eurasian Perch (Perca fluviatilis L.) Fillets Originated from Two Different Rearing Systems during Frozen and Refrigerated Storage.

The current knowledge on how different Eurasian perch rearing systems impact the final fillet quality is scant. Therefore, two domestic storage conditions were investigated-10 months frozen (-20 °C) and 12 days refrigerated (+4 °C) storage conditions-in order to determine (i) how the choice of rearing system affects fillets quality during different processing conditions and (ii) if oxidative changes and other quality parameters were interactive. For the proposed idea, proteome analysis, oxidative changes, and some quality parameters were considered in this study. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) indicated a higher loss of protein in the frozen fillets from ponds (PF) than the fillets from recirculating aquaculture systems (RAS) (RF). Western blot showed a higher protein carbonyls level in RF compared to PF, which was confirmed by the total protein carbonyls during frozen storage. PF indicated less liquid loss, hardness, and oxidation progress than RF in both storage conditions. The biogenic amines index (BAI) in the fillets from either origin showed acceptable levels during storage at +4 °C. Furthermore, the n-3/n-6 ratio was similar for both fillets. The deterioration of fillets during frozen storage was mainly caused by formation of ice crystals followed by protein oxidation, while protein oxidation was the main concern during refrigerated storage confirmed by principal component analysis (PCA) analysis.

PARV4 found in wild chimpanzee faeces: an alternate route of transmission?

Human parvovirus 4 (PARV4, family Parvoviridae, genus Tetraparvovirus) displays puzzling features, such as uncertain clinical importance/significance, unclear routes of transmission, and discontinuous geographical distribution. The origin, or the general reservoir, of human PARV4 infection is unknown. We aimed to detect and characterize PARV4 virus in faecal samples collected from two wild chimpanzee populations and 19 species of captive non-human primates. We aimed to investigate these species as a potential reservoir and alternate route of transmission on the African continent. From almost 500 samples screened, a single wild Pan troglodytes schweinfurthii sample tested positive. Full genome analysis, as well as single ORF phylogenies, confirmed species-specific PARV4 infection.

Adenovirus infection in savanna chimpanzees (Pan troglodytes schweinfurthii) in the Issa Valley, Tanzania.

Adenoviruses are a widespread cause of diverse human infections with recently confirmed zoonotic roots in African great apes. We focused on savanna-dwelling chimpanzees in the Issa Valley (Tanzania), which differ from those from forested sites in many aspects of behavior and ecology. PCR targeting the DNA polymerase gene detected AdV in 36.7% (69/188) of fecal samples. We detected five groups of strains belonging to the species Human mastadenovirus E and two distinct groups within the species Human mastadenovirus C based on partial hexon sequence. All detected AdVs from the Issa Valley are related to those from nearby Mahale and Gombe National Parks, suggesting chimpanzee movements and pathogen transmission.

Effect of variety on content of bioactive phenolic compounds in common elder (Sambucus nigra L.).

The inflorescence of common elder (Sambucus nigra L., Adoxaceae) is known to be rich in phenolic compounds. The content of five selected phenolic compounds (rutin, chlorogenic acid, isoquercitrin, isorhamnetin-3-O- rutinoside and dicaffeoylquinic acid) was determined in methanolic extracts from flowers and floral stems by HPLC in samples obtained from 20 varieties of S. nigra cultivated in Czech Republic. In all samples, there were determined rutin (11-54 mg/g), chlorogenic acid (23-46 mg/g), isoquercitrin (0.6-18 mg/g), isorhamnetin-3-O-rutinoside (3-10 mg/g), calculated on air-dried material. The content of dicaffeoylquinic acid was 0-13 mg/g of air-dried material. The amount of the analysed compounds in floral stems was lower than the flowers. The results are a unique set of information on the content of main phenolics in the inflorescence of cultured elderberry varieties.

New adenoviruses from new primate hosts - growing diversity reveals taxonomic weak points.

The knowledge of the closest human relatives of human adenoviruses (AdVs) such as adenoviruses found in nonhuman primates is still limited, despite the growing importance of adenoviruses in vaccine development, gene and cancer therapy. We examined 153 stool samples of 17 non-human primate species and detected adenoviral DNA sequences of DNA polymerase (DPOL) gene in 54 samples (35%), originating from 12 out of 17 primate species. We further sequenced 15 hexon gene fragments and based on the phylogenetic analysis we propose two new provisional species SAdV-H and SAdV-I. Our study shows extensive diversity of adenoviral strains forming separate clades often from closely related host species from old world monkeys suggesting the existence of new species of AdVs and shows the necessity for clear ICTV guidelines for final establishment of so far provisional AdV species.

A comparative molecular survey of malaria prevalence among Eastern chimpanzee populations in Issa Valley (Tanzania) and Kalinzu (Uganda).

BACKGROUND: Habitat types can affect vector and pathogen distribution and transmission dynamics. The prevalence and genetic diversity of Plasmodium spp. in two eastern chimpanzee populations-Kalinzu Forest Reserve, Uganda and Issa Valley, Tanzania-inhabiting different habitat types was investigated. As a follow up study the effect of host sex and age on infections patterns in Kalinzu Forest Reserve chimpanzees was determined. METHODS: Molecular methods were employed to detect Plasmodium DNA from faecal samples collected from savanna-woodland (Issa Valley) and forest (Kalinzu Forest Reserve) chimpanzee populations. RESULTS: Based on a Cytochrome-b PCR assay, 32 out of 160 Kalinzu chimpanzee faecal samples were positive for Plasmodium DNA, whilst no positive sample was detected in 171 Issa Valley chimpanzee faecal samples. Sequence analysis revealed that previously known Laverania species (Plasmodium reichenowi, Plasmodium billbrayi and Plasmodium billcollinsi) are circulating in the Kalinzu chimpanzees. A significantly higher proportion of young individuals were tested positive for infections, and switching of Plasmodium spp. was reported in one individual. Amongst the positive individuals sampled more than once, the success of amplification of Plasmodium DNA from faeces varied over sampling time. CONCLUSION: The study showed marked differences in the prevalence of malaria parasites among free ranging chimpanzee populations living in different habitats. In addition, a clear pattern of Plasmodium infections with respect to host age was found. The results presented in this study contribute to understanding the ecological aspects underlying the malaria infections in the wild. Nevertheless, integrative long-term studies on vector abundance, Plasmodium diversity during different seasons between sites would provide more insight on the occurrence, distribution and ecology of these pathogens.

Changes in the Content of Biogenic Amines and Fatty Acids in High Pressure-Processed Carp Flesh (Cyprinus carpio).

Biogenic amine and fatty acid contents were determined in vacuum-packed fillets of common carp (Cyprinus carpio). Samples were pressure treated at 300 and 500 MPa and were stored at 3.5 and 12°C for up to 28 days (control, 0 MPa) and 70 days (pressure-treated). The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine, and phenylethylamine) were determined. Putrescine and cadaverine were influenced by all factors (temperature, pressurization level, and time of storage). Tyramine content was the most sensitive indicator of the improper status of sample; levels exceeding 10 mg/kg indicated both the loss of meat freshness and temperature abuse, in spite of persisting good sensory indices. Neither storage temperature nor pressurization level had a statistically important effect on the contents of fatty acids. Only polyunsaturated fatty acids decreased slightly if the storage time exceeded 42 days.

Biogenic amines formation in high-pressure processed pike flesh (Esox lucius) during storage.

The effects of vacuum packaging followed by high pressure processing on the shelf-life of fillets of pike (Esox lucius) were examined. Samples were pressure-treated at 300 and 500 MPa and stored at 3.5 and 12 °C for up to 70 days. The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined. Putrescine showed very good correspondence with the level of applied pressure and organoleptic properties. Polyamines spermidine and spermine did not show statistically significant changes with the level of applied pressure and the time of storage. Increased cadaverine and tyramine contents were found in samples with good sensory signs, stored for longer time and/or kept at 12 °C, thus indicating the loss of freshness. Tryptamine and phenylethylamine were not detected in pressure-treated samples kept at 3.5 °C. Histamine was not detected in samples of good quality.

Effect of high-pressure treatment on biogenic amines formation in vacuum-packed trout flesh (Oncorhynchus mykiss).

The effects of vacuum packaging followed by high pressure processing on the shelf-life of fillets of rainbow trout (Oncorhynchus mykiss) were examined. Samples were pressure-treated at 300 and 500 MPa and were stored at 3.5 and 12 °C for up to 28 days (control--0 MPa) and 42 or 70 days (pressure-treated; 12 and 3.5 °C resp.). The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined. Putrescine, cadaverine and tyramine showed very good correspondence with the level of applied pressure and organoleptic properties. Samples of very good quality contained less than 10 mg/kg of each of these amines. Polyamines spermidine and spermine did not show statistically significant changes with the level of applied pressure and the time of storage. Tryptamine, phenylethylamine and histamine (with the single exception of a sample stored for 70 days) were not detected in pressure-treated samples kept at 3.5 °C.

Effect of low-dose irradiation on biogenic amines formation in vacuum-packed trout flesh (Oncorhynchus mykiss).

The effects of vacuum packaging followed by high-energy electron beam irradiation on the shelf-life of fillets of rainbow trout (Oncorhynchus mykiss) were examined. Samples were irradiated at doses of 0.25, 0.50, 0.75, 1.0 and 2.0kGy. The control and treated packs were stored at 3.5°C for up to 28, 42, 70 and 98days (control - 0, 0.25, 0.50 and >0.50kGy respectively). The content of seven biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine and tryptamine) were determined. Putrescine, cadaverine and tyramine showed very good correspondence with the irradiation dose and organoleptic properties. Samples of good quality contained less than 10mg/kg of each of these amines. The polyamines spermidine and spermine did not show statistically significant changes with the irradiation dose and the time of storage. With few exceptions, histamine was not detected in the samples treated with radiation. Tryptamine was not detected in any of the samples.

Concentration of biologically active polyamines in rabbit meat, liver and kidney after slaughter and their changes during meat storage and cooking.

The concentration of putrescine (PUT), spermidine (SPD) and spermine (SPM) was determined in chilled meat and kidneys of 18 rabbits and in liver of 12 animals 24h after slaughter. Very low PUT concentrations were detected only in kidneys. Mean SPD levels were 2.2, 2.2, 61.7 and 32.7mgkg(-1) in saddle, leg, liver and kidneys, respectively. The respective SPM concentrations were 14.7, 8.0, 115 and 88.4mgkg(-1). SPD and SPM losses of about one third of the initial levels were apparent in saddles stored at -18°C for 8months. Losses of both polyamines of about 15-20% of the initial concentrations were found in saddles stored aerobically at +2°C for up to 9days. Stewing of saddles caused significant SPD and SPM losses of about 20-25%, while upon roasting and pan-roasting without oil a decrease of about 50% of the initial concentration was observed.

Concentration of biologically active polyamines in meat and liver of sheep and lambs after slaughter and their changes in mutton during storage and cooking.

Putrescine (PUT), spermidine (SPD) and spermine (SPM) concentrations using a UPLC method, in chilled mutton, lamb and livers 24 h after slaughter were determined. PUT concentrations were quantifiable only in some samples. Mean SPD concentrations were 4-6, 13.5 and 16.8 mg kg-1 in the meats, sheep and lamb livers, respectively. The respective SPM concentrations were 17-25, 128 and 79 mg kg-1. SPD and SPM losses of about one fifth and half of the initial level, respectively, were apparent in mutton loins stored at -18°C for 6 months. Significant losses of SPD and SPM were found in mutton loins stored aerobically, vacuum-packaged or in a modified atmosphere at +2°C. Boiling and stewing of mutton legs caused SPD and SPM losses of about 40% and roasting of about 60% of the initial content.

Determination of quercetin glycosides and free quercetin in buckwheat by capillary micellar electrokinetic chromatography.

A simple and reliable method for determination of quercetin glycosides and free quercetin in buckwheat flower, leaves, stems and achenes was developed. The method consists of flavonoid extraction from freeze-dried homogenous material in 50% v/v methanol solution and in presence of an antioxidant, cleaning of extract and analyte isolation using SPE. Analytical step uses capillary micellar electrokinetic chromatography. The working ranges, LOD and LOQ, recovery, precision and measurement uncertainty were calculated. The method is suitable for samples from buckwheat. The highest content of rutin was found in flowers of both kinds of buckwheat (99,400 mg/kg in F. esculentum, 108,000 mg/kg in F. tataricum). The free quercetin occurs in flowers and achenes of F. esculentum, whereas flowers and achenes of F. tataricum contained quercitrin.

Chromatographic methods for determination of S-substituted cysteine derivatives--a comparative study.

A novel HPLC method for determination of a wide variety of S-substituted cysteine derivatives in Allium species has been developed and validated. This method allows simultaneous separation and quantification of S-alk(en)ylcysteine S-oxides, gamma-glutamyl-S-alk(en)ylcysteines and gamma-glutamyl-S-alk(en)ylcysteine S-oxides in a single run. The procedure is based on extraction of these amino acids and dipeptides by methanol, their derivatization by dansyl chloride and subsequent separation by reversed phase HPLC. The main advantages of the new method are simplicity, excellent stability of derivatives, high sensitivity, specificity and the ability to simultaneously analyze the whole range of S-substituted cysteine derivatives. This method was critically compared with other chromatographic procedures used for quantification of S-substituted cysteine derivatives, namely with two other HPLC methods (derivatization by o-phthaldialdehyde/tert-butylthiol and fluorenylmethyl chloroformate), and with determination by gas chromatography or capillary electrophoresis. Major advantages and drawbacks of these analytical procedures are discussed. Employing these various chromatographic methods, the content and relative proportions of individual S-substituted cysteine derivatives were determined in four most frequently consumed alliaceous vegetables (garlic, onion, shallot, and leek).

Rutin and total quercetin content in amaranth (Amaranthus spp.).

The aim of the study was to confirm the presence of rutin, one of the most common quercetin glycosides, and other quercetin derivatives in plants of genus Amaranthus, to investigate the influence of the species and variety on rutin distribution in the plant and content changes during growing season. The rutin content was determined by micellar electrokinetic capillary chromatography in individual plant parts at the beginning of the growth, at the flowering stage and at the maturity stage of five Amaranthus species. The total quercetin content was determined by micellar electrokinetic capillary chromatography too. The rutin content in amaranth ranged from 0.08 (in seeds) to 24.5 g/kg dry matter (in leaves). Comparison of the determined total quercetin content and the calculated content of quercetin released from rutin did not prove important presence of quercetin or other quercetin derivatives than rutin. Only amaranth leaves sampled at the maturity stage probably contained quercetin or quercetin derivatives. Significant differences in the rutin content were established among species and as well varieties. Amaranthus hybrid and A. cruentus were the best sources of rutin.

Quantitative determination of S-alk(en)ylcysteine-S-oxides by micellar electrokinetic capillary chromatography.

A novel method for determination of S-alk(en)ylcysteine-S-oxides by capillary electrophoresis has been developed and validated. The method is based on extraction of these sulfur amino acids by methanol, their derivatization by fluorenylmethyl chloroformate and subsequent separation by micellar electrokinetic capillary chromatography. Main advantages of the new method are simplicity, sensitivity, high specificity and very low running costs, making it suitable for routine analysis of a large number of samples. Employing this method, the content of S-alk(en)ylcysteine-S-oxides was determined in 12 commonly consumed alliaceous and cruciferous vegetables (e.g. garlic, onion, leek, chive, cabbage, radish, cauliflower and broccoli). The total content of these amino acids in the Allium species evaluated varied between 0.59 and 12.3mg g(-1) fresh weight. Whereas alliin was found only in garlic, isoalliin was the major S-alk(en)ylcysteine-S-oxide in onion, leek, chive and shallot. On the other hand, the cruciferous species analyzed contained only methiin in the range of 0.06-2.45mg g(-1) fresh weight.