Influence of the addition of raspberry seed extract on changes in the volatile pattern of stored model breakfast cereal

Laboratory-prepared muesli-type breakfast cereal (mixture of oat flakes, wheat flakes, corn flakes, hazelnuts, raisins, sunflower seeds, and flax seeds) was subjected to accelerated storage test at 60 degrees C with or without the addition of red raspberry seed extract. The oxidative changes in muesli resulting in the formation of secondary oxidation products were evaluated using solid phase microextraction (HS-SPME) and solvent-assisted flavor evaporation (SAFE) to isolate volatiles and GC-MS and chromatography-olfactometry to quantify them and determine the key odorants. During 14 days of storage the total amount of volatile compounds changed from 1.0 mg/kg, in freshly prepared muesli, to 32 mg/kg after storage. The predominant compound was hexanal; its content during storage increased 20-fold, reaching 17 mg/kg. Red raspberry seed extract addition limited the rate of lipid oxidation, and the total amount of volatiles was estimated at 11 mg/kg and that of hexanal at almost 5 mg/kg. An elevated temperature of the storage test also influenced the crucial flavor compounds determined using aroma extract dilution analysis (AEDA). The flavor dilution factor (FD) values for volatile lipid oxidation products were lower in samples with red raspberry seed extract added.     

In vitro efficacies of phosphorolytic enzymes synthesized in mycelial cells of Aspergillus niger AbZ4 grown by a liquid surface fermentation

Activities of phytase, a pH 6.0 optimum nonspecific phosphomonoesterase and phosphodiesterase assayed toward bis(p-nitrophenyl)phosphate (phosphodiesterase I) and against p-nitrophenylphosphorylcholine (phosphodiesterase II), were partially purified from mycelial extracts of Aspergillus niger AbZ4 cultivated on a molasses medium by a liquid surface fermentation method. After elimination of phosphate from the medium, 7.3- and 3.5-fold enhancements in specific activities of phytase and phosphodiesterase II were observed. Efficacies of mycelial protein fractions in dephosphorylating a wheat-based broiler feed were determined in vitro according to a procedure that simulated digestion in the intestinal tract of poultry. The addition of 0.052 mg of protein from fractions, each of which was high in either pH 6.0 optimum phosphomonoesterase, phosphodiesterase I, phosphodiesterase II, or phytase per gram of a feed sample resulted in the enhancement of phosphorus release by 10, 11, 27, and 88%, respectively. In the presence of an excess of commercial phytase, the addition of the mycelial fraction high in phytase increased the dephosphorylation rate by 56%. The fraction high in phosphodiesterase II enhanced feed dephosphorylation by 8% in the presence of an excess of commercial phytase and commercial acid phosphatase.     

The Impact of Dredging Deep Pits on Organic Matter Decomposition in Sediments

In this study, the results of investigations of organic matter decomposition in natural and dredged areas of the inner Puck Bay (Baltic Sea) are presented. The dredging of relatively deep pits causes environmental problems. Researched post-dredging pits are sediment traps in which 3 times more organic carbon (C_org), 3.5 times more total nitrogen (N_tot), about 1.5 times more organic phosphorus (P_org) and 1.7 times more total phosphorus (P_tot) accumulate as compared to the non-dredged regions; they are also characterized by very intensive decomposition of organic matter. About 42, 44, 95 and 50% of the annual load of, respectively, C_org, N_tot, P_org and P_tot undergo decomposition in the dredged area, whereas the respective values for natural seabed are ca. 11, 44, 41 and 21%. Reduction of nitrogen in the pit occurs mainly through ammonification, while in the natural areas of seabed denitrification prevails. In non-dredged sediments, 84% of the released nitrogen comes from denitrification whereas in the pit, it is only 18%. Organic matter degradation in the pit sediments manifests itself by a 7-fold increase in the phosphate flux into near-bottom water as compared to natural seabed. The observed phosphate flux originated from the organic matter as well as from the decomposition of inorganic phosphorus compounds. Periodically, sulphate reduction in the pit sediments resulted in hydrogen sulfide occurrence.     

Washing agents from sewage sludge: efficiency of Cd removal from highly contaminated soils and effect on soil organic balance

Purpose

To compare Cd removal from different soils with three washing agents recovered from sewage sludge (dissolved organic matter (DOM), soluble humic-like substances (HLS), soluble humic substances (SHS)). Also, to investigate how washing with these agents changes soil organic-matter composition (OM).

Materials and methods

Sandy clay loam (S1) and clay (S2) highly contaminated with Cd (300 mg kg^?1) were washed with DOM, HLS, or SHS solutions at various pHs, and with various washing times and washing modes (single or double). Cd distribution and OM composition were determined (including content of humic substances (HS), fulvic fraction (FF), labile humic acids (L-HA), and stable humic acids (S-HA)).

Results and discussion

Cd removal proceeded with pseudo-second-order kinetics. Equilibrium was reached in 30 min (S1) and 60 min (S2). DOM, HLS, and SHS removed 75–82% of Cd from S1, and 80–87% from S2. The most mobile fraction of Cd was removed after one wash. S2 retained more OM, including HS, than S1. Although washing did not change the HA/FF ratio in most variants, washing with DOM and HLS increased the percentage of L-HA in both soils. Washing with SHS increased S-HA content in both soils, but the percent content of S-HA was similar to that in the unwashed soil.

Conclusions

DOM, HLS, and SHS derived from sewage sludge can effectively remediate clay and sandy clay soils highly contaminated with Cd. Washing with an SHS solution can increase the content of the most stable carbon forms (HA), which is beneficial for carbon sequestration in remediated soils.

     

Comparison of spectrophotometric and electrochemical methods for the evaluation of the antioxidant capacity of buckwheat products after hydrothermal treatment

This paper reports the use of spectrophotometric and voltammetric methods for the determination of the antioxidant capacity of buckwheat and its products originated from a technological line of a buckwheat roasted groats producer. 80% methanol extracts from raw and roasted buckwheat and groats and hulls obtained from roasted buckwheat were used. The spectrophotometric methods included (1) free radical scavenging activities of the extracts against ABTS*+ radical cation (TEAC) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH RSA) and (2) determination of reducing capacity by the means of Folin-Ciocalteu reagent (FCR) application. The radical scavenging activities of the extracts were also investigated using a voltammetric assay. Moreover, the flavonoids profiles of the studied materials were provided. Buckwheat roasting caused a decrease in TEAC, DPPH RSA, and FCR reducing capacity by 70%. The lowest TEAC, DPPH RSA, and FCR reducing capacities were noted for roasted groats. Both DPPH RSA and TEAC methods were highly positively correlated with the FCR reducing capacity assay (r = 0.98 and r = 0.99). Cyclic voltammograms of analyzed buckwheat extracts were useful for evaluation of the antioxidant capacity. The total charge below the anodic current waveform was correlated with the data obtained by TEAC (r = 0.770), DPPH RSA (r = 0.88), and FCR reducing capacity (r = 0.81). The changes in the antioxidant capacity of buckwheat and its products followed the changes in flavonoids composition. In particular, the concentration of flavonoids was related to measurements by cyclic voltammetry.     

Organic matter effects on phosphorus sorption in sandy soils

Phosphorus (P) sorption processes in soils contribute to important problems in agriculture: a deficiency of this plant nutrient and eutrophication in aquatic systems. Soil organic matter (SOM) plays a major role in sorption processes, but its influence on P sorption remains unclear and needs to be elucidated to improve the ability to effectively manage soil P. The aim of this research was to investigate the influence of SOM on P sorption. The study was conducted in sandy soil profiles and in topsoils before and after removal of SOM with H₂O₂. The results were interpreted with the Langmuir and Freundlich isotherms. Our results indicated that SOM affected P sorption in sandy soils, but that P sorption also depended on specific soil properties (e.g. values of the degree of P saturation (DPS), P sorption capacity (PSC) and pH) often related to land use. Removal of SOM decreased PSC in most of the topsoils tested; other soil properties became important in controlling P sorption. An increase in P desorption observed after SOM removal indicated that SOM was potentially that soil constituent which increased P binding and limited P leaching from these sandy soils.     

Zur energetischen Bewertung von Nichtstärke-Polysacchariden beim Geflügel

Der tierische Organismus verfügt über keine Verdauungsenzyme, um Polysaccharide mit β-glykosidischer Bindung zu hydrolysieren. Deshalb gelten Nichtstärke-Polysaccharide (NSP) als intestinal unverdaulich und können im tierischen Organismus lediglich durch mikrobielle Aktivität hydrolysiert und damit über die Bildung flächtiger Fettsäuren für das Tier nutzbar gemacht werden. Entscheidend für die energetische Ausbeute ist vor allem der Ort und das Ausmaβ der mikrobiellen Aktivität. Während beim Wiederkäuer das Verdauungssystem primär auf die mikrobielle Zerlegung des Futters ausgerichtet ist, ist die energetische Verwertbarkeit von NSP beim Schwein begrenzt (z.B. Müller und Kirchgessner 1983a; Kirchgessner und Müller 1991). In der Geflügelernährung werden faserarme Mischfutter eingesetzt, so daβ NSP bislang in der energetischen Bewertung von Futtermischungen, z.B. bei der Energieberechnung durch die WPSA-Formel nicht berücksichtigt werden. Vorangegangene Untersuchungen (J AMROZ et al. 1998a,b) zeigten allerdings, daβ NSP beim Geflügel etwa zur Hälfte durch Mikroorganismen abgebaut und in flächtige Fettsäuren überführt werden. Die vorliegende Arbeit verfolgte das Ziel, aus Messungen der Verdaulichkeit von NSP sowie der Bildung flächtiger Fettsäuren den energetischen Nutzen von NSP beim Geflügel abzuschätzen. Die Untersuchungen schlossen dabei drei verschiedene Spezies ein, nämlich Hähnchen, Enten und Gänse.     

Viability of diploid and triploid larvae of Siberian sturgeon and bester hybrids

The aim of the present study was to produce Acipenser baeri× (Huso huso×Acipenser ruthenus) hybrids in a diploid and triploid state and to study their viability in comparison with the A. baeri from the fish farm stock. A heat shock (37°C) in the 18th minute after fertilization was applied to induce triploidy. The survival rate and the ploidy level of the hybrids obtained were studied. The mortality of triploid hybrids was approximately twice as high as the mortality of diploid hybrids. No significant difference in the survival rate between Siberian sturgeon and their diploid hybrid with bester was noted. Cytogenetic analysis was performed by preparing chromosomes from the gill epithelium. The results showed that all studied fish from the heat‐shocked group were triploid.     

Meiotic gynogenesis affects the individual and gonadal development in sterlet Acipenser ruthenus

Larval growth and gonadal differentiation of gynogenetic sterlet Acipenser ruthenus were studied. The gynogenetic fish were produced by activation of albino sterlet eggs with UV‐irradiated sperm (collected from healthy coloration specimens), following by a heat shock of 34°C. Embryos were reared at 18.0 ± 0.5°C in a recirculation system and initially fed with Artemia sp. for 4 weeks and then fed with formulated feed. During the experiment, the length and weight of fish were recorded for the gynogenetic and control groups. Additionally, the analysis of gonadal sex differentiation was conducted with a 2‐week interval at 289, 303, 317, 331, 345 and 373 DPH. The mean body weight of the control group was significantly higher (p < .05) than the gynogenetic group only at 345 and 373 DPH, while the mean total body length was significantly higher at 331 and 345 DPH (p < .05). The gonad investigation was started at 289 DPH, and ~80% of females were found in the gynogenetic group during the trial period while the number of females and males was similar at 303, 331 and 373 DPH in the control group. The first symptoms of morphological differentiation appeared at 289 DPH, and the final shaping macroscopic structure of the gonad took place earlier in females than in males.     

Rearing river lamprey <Emphasis Type="Italic">Lampetra fluviatilis</Emphasis> (L.) larvae under controlled conditions as a tool for restitution of endangered populations

A method for actively protecting river lamprey and increasing the number of river lamprey populations is presented as protocol of rearing stocking material. The objective of the study was to accommodate lamprey larvae during the most critical life period under controlled conditions until they reach a sufficient size, which will increase their chances to survive in the natural environment. The eggs obtained from wild breeders were incubated in Weiss’s jars at the water temperature of 12 °C. The larvae were reared in tanks set up in closed recirculating aquaculture systems. During the rearing period, the water temperature was 20 °C and the density of larvae was 150 individuals per 1 dm² of bottom. In the initial rearing phase, the main focus was on the type of feeds and the nourishment method. It was determined that the most suitable feed type was Artemia nauplii combined with Hikari dry food. Additionally, the type of substrate was tested under controlled conditions. In this case, the optimum one was composed of sand of the grain size between 0.3 and 0.5 mm. The experiment proved that it is possible to successfully conduct river lamprey larvae rearing under controlled conditions. The growth rates are comparable to or better than those achieved under natural conditions. After 30 days of the rearing period, the lamprey larvae were 25 mm long. The results create a possibility to develop a technology for the restitution of river lamprey and other lamprey species, which are endangered throughout the world.