Species trait shifts in vegetation and soil seed bank during fen degradation

Fens in Central Europe are characterised by waterlogged organic substrate and low productivity. Human-induced changes due to drainage and mowing lead to changes in plant species composition from natural fen communities to fen meadows and later to over-drained, degraded meadows. Moderate drainage leads to increased vegetation productivity, and severe drainage results in frequent soil disturbances and less plant growth. In the present article, we analyse changes in plant trait combinations in the vegetation and the soil seed bank as well as changes in the seed bank types along gradient of drainage intensity. We hypothesize that an increase in productivity enhances traits related to persistence and that frequent disturbance selects for regeneration traits. We use multivariate statistics to analyse data from three disturbance levels: undisturbed fen, slightly drained fen meadow and severely drained degraded meadow. We found that the abundance of plants regenerating from seeds and accumulating persistent seed banks was increasing with degradation level, while plants reproducing vegetatively were gradually eliminated along the same trajectory. Plants with strong resprouting abilities increased during degradation. We also found that shifts in trait combinations were similar in the aboveground vegetation and in soil seed banks. We found that the density of short-term persistent seeds in the soil is highest in fen meadows and the density of long-term persistent seeds is highest in degraded meadows. The increase in abundance of species with strong regeneration traits at the cost of species with persistence-related traits has negative consequences for the restoration prospects of severely degraded sites

Biodiversity and structure of spider communities along a metal pollution gradient

The objective of the study was to determine whether long-term metal pollution affects communities of epigeal spiders (Aranea), studied at three taxonomic levels: species, genera, and families. Biodiversity was defined by three indices: the Hierarchical Richness Index (HRI), Margalef index (DM) and Pielou evenness index (J). In different ways the indices describe taxa richness and the distribution of individuals among taxa. The dominance pattern of the communities was described with four measures: number of dominant species at a site, percentage of dominant species at a site, average dominant species abundance at a site, and the share of the most numerous species (Alopecosa cuneata) at a site. Spiders were collected along a metal pollution gradient in southern Poland, extending ca. 33 km from zinc and lead smelter to an uncontaminated area. The zinc concentration in soil was used as the pollution index.The study revealed a significant effect of metal pollution on spider biodiversity as described by HRI for species (p = 0.039), genera (p = 0.0041) and families (p = 0.0147), and by DM for genera (p = 0.0259) and families (p = 0.0028). HRI correlated negatively with pollution level, while DM correlated positively. This means that although broadly described HRI diversity decreased with increasing pollution level, species richness increased with increasing contamination. Mesophilic meadows were generally richer. Pielou (J) did not show any significant correlations. There were a few evidences for the intermediate disturbance hypothesis: certain indices reached their highest values at moderate pollution levels rather than at the cleanest or most polluted sites

Characteristics of technological quality, sensorial and shelf-life of pork with different pH

Celem pracy była analiza cech technologicznych, sensorycznych oraz trwałości mięsa pochodzącego od tuczników w zależności od pH końcowego. Badania przeprowadzono na materiale 50 tuczników pochodzących z krzyżowania loch mieszańców ras polskiej białej zwisłouchej i wielkiej białej polskiej z knurami hybrydami P76-PenArLan. Po uboju określono zawartość mięsa w tuszy oraz parametry charakteryzujące jakość mięsa bezpośrednio w próbkach mięśnia longissimus dorsi pobieranych za ostatnim żebrem. Określono: wartość pH po 45 min, 24 i 48 godz. od uboju, jasność barwy w 48. i 96. godz. post mortem w systemie CIE L*a*b*, wyciek naturalny i wskaźnik wydajności technologicznej „Napole”. Jakość sensoryczną mięsa (surowego i po obróbce termicznej) określono po 48 i 96 godz. od uboju metodą skalowania. W dniu uboju (0) oraz po 3, 6, 9, 12 i 15 dniach przechowywania mięsa wykonano analizy mikrobiologiczne w kierunku ogólnej liczby drobnoustrojów (OLD). Badaną grupę tuczników podzielono na 2 podgrupy: pierwszą grupę stanowiły tuczniki o pH24 poniżej 5,5 (36%), natomiast drugą tuczniki o pH24 powyżej 5,5. Mięso tuczników o niższym pH24 charakteryzowało się większym wyciekiem (o 2,4%), wyższą wartością składowej barwy b* w 48 godz. i składową a* w 96 godz., niższą marmurkowatością oraz wyższą akceptowalnością sensoryczną mięsa surowego. Uzyskano również wysoką zależność między pH mięsa a OLD (r = 0,74**).The aim of this study was to analyze technological characteristics, sensorial features and shelf life of meat from fatteners with different ultimate pH. The research study was based on a sample of 50 fatteners from the crossbreeding of Polish Landrace x Polish Large White with hybrids boars P76-PenArLan. After slaughter amount meat in carcass and other characteristics of raw meat from the Longissimus muscle taken from behind the last rib were analyzed. In the samples of meat pH of the meat after 45 minutes, 24 hrs and 48 hrs following slaughter, lightness of colour in 48 hrs and 96 hrs post mortem in the CIE L*a*b* system, natural drip, technological yield were determined. The sensory quality of raw and cooked meat after 48 hrs and 96 hrs post mortem was evaluated. In the day of slaughter and after 3, 6, 9, 12 and 15 days of storage microbiological analysis (total plate count) were done. Analyzed sample of fatteners on two groups were divided: fatteners with pH24 below 5,5 (36%) and second group fatteners with pH24 was above 5,5. Meat from fatteners described by pH24 < 5,5 characterized higher drip loss (2,4%), higher parameter b* of colour in 48 hrs and parameter a* in 96 hrs and higher acceptability of raw meat compared to group of fatteners with pH24 ≥ 5,5. Relationships between pH of meat and total plate count were found (r = 0,74**). Obtained results indicated further research on quality of culinary meat

Estimating the possibility of isolating high quality culinary meat on the basis of fattener meatiness and colour and pH measurments using cluster analysis

Celem pracy była ocena możliwości wyboru mięsa kulinarnego o wysokiej jakości i spełniającego oczekiwania konsumentów na podstawie oceny mięsności tuczników oraz instrumentalny pomiar parametrów barwy i pH mięsa. Badania przeprowadzono na materiale 90 tuczników pochodzących z krzyżowania loch mieszańców ras Polskiej Białej Zwisłouchej i Wielkiej Białej Polskiej i loch linii Naïma z knurami hybrydami P76-PenArLan. W tuszach określono mięsność, grubość słoniny, grubość schabu, zmierzono pH po 1, 3, 24 i 48 h post mortem, zmierzono parametry barwy mięsa (w systemie CIE L*a*b*), wyciek naturalny oraz wydajność mięsa w gotowaniu. Określono także jakość sensoryczną mięsa po obróbce cieplnej (tj. zapach, ton barwy, kruchość, soczystość i intensywność smaku gotowanego mięsa). Wyniki opracowano statystycznie obliczając współczynniki korelacji prostej, wielorakiej i kanonicznej celem oszacowania zależności pomiędzy zmierzonymi parametrami i badanymi cechami. Mięso kulinarne wysokiej jakości wyodrębniono stosując analizę skupień – metodą k-średnich. Obliczenia wykonano stosując program Statistica Pl 6.0. Uzyskane wyniki wskazują na możliwość wykorzystania wyników oceny mięsności tuczników prowadzonej w zakładach mięsnych i parametrów barwy (L i a) oraz pomiaru pH48, w celu wyodrębnienia na etapie produkcji, mięsa kulinarnego charakteryzującego się bardzo dobrą jakością w zakresie cech sensorycznych, takich jak kruchość, soczystość i smakowitość oraz niewielkim wyciekiem i odpowiednią wydajnością w obróbce cieplnej. Wykazano także, że wymienione cechy charakteryzujące jakość mięsa kulinarnego były determinowane w około 70 % przez mięsność tuszy oraz zastosowane do diagnozowania parametry barwy i pH końcowe mięsa.The objectives of the research were to estimate the possibility of choosing the high quality culinary meat that meets the consumer expectations, on the basis of fattener meatiness, and to instrumentally measure the meat parameters: colour and pH. The study was conducted on a group of 90 fatteners descending from crossing sows of the Polish Landrance and the Polish Large White and Naïma lines with P76-PenArLan boars-hybrids. In the carcasses under analysis: meatiness, backfat thickness, and LD muscle thickness were determined, the pH level after 1, 3, 24 and 48 hours post mortem was measured, as were the following parameters: colour indicators (under the CIE L*a*b system), natural drip loss, and meat cooking yield. Furthermore, sensory quality of thermally processed meat (i.e. aroma, tone of the colour, tenderness, juiciness, and intensity of cooked meat flavour) were assessed. The results were statistically analyzed by computing simple, multivariate, and canonical correlation coefficients for the purpose of evaluating the dependencies among the parameters measured and meat characteristics analyzed. High quality culinary meat samples were isolated using a cluster analysis under the k-average method. Statistical computations were performed using a Statistica Pl 6.0 software. The results obtained prove that it is possible to apply outcomes of the assessment, conducted in meat plants, of fattener meatiness, as well as of the parameters of colour (L* and a*), and of pH48 measurements for the purpose of isolating culinary meat, as early as during the stage of producing it. The isolated meat should be characterized by a very good quality of its sensory characteristics, such as: tenderness, juiciness, and flavour, further: by a low drip loss, and a proper cooking yield being thermally treated. It was also proved that about 70% of the meat features characterizing culinary meat were determined by the carcass meatiness, colour parameters & final pH value used to assess meat

The use of wheat fiber of varying fiber length to improve the quality of meat products made from defective meat

W niniejszej pracy badano wpływ różnych preparatów błonnika pszennego (Promacel WF 200 oraz WF 1000) na podwyższenie jakości kiełbasy białej parzonej wyprodukowanej z mięsa normalnego oraz mięsa kwaśnego (ASE). Zastosowano dodatek dwóch preparatów błonnika o zróżnicowanym stopniu rozdrobnienia w ilości 1,5 % w stosunku do masy farszu. Warianty doświadczalne bez dodatku preparatu stanowiły próby kontrolne. W wyprodukowanych kiełbasach oznaczono wydajność po procesie obróbki cieplnej, zbadano ich podstawowy skład chemiczny oraz poddano je ocenie sensorycznej. Na podstawie wyników przeprowadzonych badań wykazano istotny wpływ mięsa wadliwego (ASE) oraz dodatku błonnika pokarmowego na jakość produktów. Dodatek preparatu błonnika typu WF 1000 w próbkach z udziałem mięsa normalnego wpłynął na poprawę cech sensorycznych, tj. soczystości i ogólnej jakości kiełbas. Zastosowanie obu preparatów w przypadku kiełbasy wyprodukowanej z mięsa ASE wpłynęło na istotne obniżenie wydajności, soczystości, smakowitości oraz ogólnej jakości tego typu wędlin. Wykazano więc, że podwyższenie jakości wyrobów mięsnych poprzez dodatek preparatów błonnika jest możliwe tylko w przypadku, gdy surowiec mięsny odznacza się dobrą jakością. Celem wyprodukowania wędlin wysokiej jakości należy jednak stosować dodatek preparatów błonnikowych o odpowiednich parametrach. Do podwyższenia jakości wędlin powinien być stosowany preparat błonnika zawierający jak najwięcej długich włókien, które mają dużą zdolność zatrzymywania wody.The objective of the study was to compare the effect of different wheat fibre preparations (Promacel WF 200 and WF 1000) on the quality enhancement of white steamed sausage made from normal and acidic meat (ASE). Two fibre preparations of different particle size degree were applied; their amount was 1.5 % of the stuffing mass. The experimental variants without the preparations added constituted control samples. In the final products, the cooking yield and basic chemical composition were determined; also, those products were sensory assessed. Based on the results of the analyses performed, a significant impact was found of defective meat and the dietary fibre added on the quality of products. The preparation of fibre type WF 1000 added to the meat samples containing the RFN meat improved the sensory features, i.e. the juiciness and overall quality of the sausages. Moreover, the two preparations used in the sausages made from the ASE meat caused the cooking yield, juiciness, palatability, and the overall quality of those cold cuts to significantly deteriorate. Thus, it has been proved that it is possible to enhance the quality of meat products by adding fibre preparations only in the case when the raw meat material is characterized by a good quality. In order to produce high quality cold meat cuts, the fibre preparations of proper parameters should be added. To enhance the quality of cold meat cuts, a fibre preparation should be added that contains as much long fibres as possible for those long fibres have a high water-holding capacity

Evaluation of protein aggregation in cooked meat

International audienceThe effect of meat cooking on protein aggregation was measured in pig M. Longissimus dorsi. Muscles were aged 4 days in air and then cooked at 100 degrees C for 10 or 30 min. Meat was ground in a KCl solution and the whole extract was delipidated with a mixture of butanol and di-isopropyl ether in a 40:60 v/v ratio. Protein aggregation induced by cooking was evaluated with a laser granulometer, which enabled reliable and reproducible characterisation of particle size distributions, and particle shape distributions using automated imaging techniques. Cooking significantly decreased the level of big particles, while the number of small particles remained stable. Cooking also affected the form and size of the particles. In order to better understand the mechanisms implicated in the aggregation process the level of protein oxidation and the protein surface hydrophobicity were evaluated in parallel with the granulometry measurements. Significant correlations were observed between the granulometry parameters and some of the protein oxidation indices. The protein surface hydrophobicity was also correlated with the granulometry parameters demonstrating the impact of thermal denaturation on the aggregation process

Characteristic of slaughter value and meat quality of three synthetic pig lines

The aim of the study was to evaluate the quality of meat in different lines of pigs with consideration of the intramuscular fat level of the longissimus muscle. The research was conducted on 60 pigs from three pig lines, P76, Redone and Galia, (20 gilts in each group), slaughtered at ca. 105 kg live weight. The percentage meat in the carcass and hot carcass weight were estimated. Samples were taken from the longissimus muscle. The pH value after 1, 3 and 24 h post mortem, natural drip loss, cooking yield and parameters of meat colour were measured. Furthermore, fat level and glycolytic potential (GP) of the muscle were determined. Intramuscular fat level was determined chemically, and marbling on the basis of sensory evaluation according to a Japanese photographic standard. The results showed significant differences between lines in slaughter value of carcasses and for pH3, pH24, GP, colour parameters and marbling of raw meat. The P76 line was characterised as the most meaty line with satisfactory meat quality. The Redone line was characterised by meat with the highest intramuscular fat content and marbling.Keywords: Meat quality, intramuscular fat, P76, Redone, Galia, swin