Element accumulation in boreal bryophytes, lichens and vascular plants exposed to heavy metal and sulfur deposition in Finland

Macronutrient (N, P, K, Mg, S, Ca), heavy metal (Fe, Zn, Mn, Cu, Ni, Cd, Pb) and Al concentrations in understorey bryophytes, lichens and vascular plant species growing in Scots pine forests at four distances from the Harjavalta Cu-Ni smelter (0.5, 2, 4 and 8 km) were compared to those at two background sites in Finland. The aim was to study the relationship between element accumulation and the distribution of the species along a pollution gradient. Elevated sulfur, nitrogen and heavy metal concentrations were found in all species groups near the pollution source. Macronutrient concentrations tended to decrease in the order: vascular plants>bryophytes>lichens, when all the species groups grew on the same plot. Heavy metal concentrations (except Mn) were the highest in bryophytes, followed by lichens, and were the lowest in vascular plants. In general, vascular plants, being capable of restricting the uptake of toxic elements, grew closer to the smelter than lichens, while bryophytes began to increase in the understorey vegetation at further distances from the smelter. A pioneer moss (Pohlia nutans) was an exception, because it accumulated considerably higher amounts of Cu and Ni than the other species and still survived close to the smelter. The abundance of most of the species decreased with increasing Cu and Ni concentrations in their tissues. Cetraria islandica, instead, showed a positive relationship between the abundance and Cu, Ni and S concentrations of the thallus. It is probable that, in addition to heavy metals, sporadically high SO(2) emissions have also affected the distribution of the plant species.     

Toxicological effects of dehydroabietic acid (DHAA) on the trout, Salmo gairdneri Richardson, in fresh water

Toxicological and physiological effects of dehydroabietic acid (DHAA), a major poison to fishes in pulp and paper mill effluents, were studied by two experiments with rainbow trout, Salmo gairdneri Richardson: in the first, fish were acutely exposed for 4 days to an average DHAA concentration of 1.2 mg l⁻¹ (Exp. I) and in the second for 30 days to an average of 20 μg DHAA l⁻¹ (Exp. II).Compared to the controls, fish of Exp. I displayed a decreased relative weight of liver, an increased blood haematocrit, and increased haemoglobin as well as plasma protein concentrations. The aspartate aminotransferase activity of heart muscle was significantly elevated, as was also the lactate dehydrogenase (LDH) of white muscle tissue. In the blood plasma, the proportion of muscle type LDH activity was simultaneously increased. UDP-glucuronyl-transferase activities of liver and kidney were strongly decreased. Results suggest an increased and altered use of body energy reserves, decreased plasma volume and impaired liver function.Fish of Exp. II showed an increased relative weight of spleen. In addition, liver and gill LDH shifted towards heart-type. We conclude that 20 μg l⁻¹ is close to the “minimum effective concentration” of DHAA to rainbow trout.     

Evaluation of a gas chromatographic method for detection of irradiation of chicken and a chicken meat product

A method was developed for the detection of irradiation of chicken and chicken meat products. The method consists of the extraction of fat from chicken skin or a chicken meat product, separation of hydrocarbons with an alumina column and gas chromatography (GC) and GC-mass spectrometry analyses of the hydrocarbons 16:2, 16:3, 17:1 and 17:2 formed from oleic, linoleic and stearic acids during irradiation. These hydrocarbons were only detected in irradiated samples at doses of 5 and 10 kGy. The mean concentrations of the hydrocarbons were linearly related to the dose levels of irradiation in the case of chicken fat. The concentrations of two of the hydrocarbons (16:2 and 17:1) gave the best correlation with dose. When a dose of 10 kGy was used, the concentrations of major degradation products were 1.5-5.0 mg/kg fat. The same relationship was not found in the case of chicken meat products because the amounts of hydrocarbons detected after irradiation with the same doses were similar. On the basis of this study it was clearly demonstrated that it is possible to judge analytically whether or not a chicken sample or a chicken meat product has been irradiated at doses of 5 or 10 kGy. It should also be possible to recognise samples irradiated with doses below 5 kGy.     

X-ray characterization of starch-based solid foams

Wide- and small-angle X-ray scattering (WAXS and SAXS) and X-ray microtomography were used to study the structure of brittle, solid foams made by extrusion of whole grain barley flour and additional whey protein isolate (WPI) and polydextrose (PD). The structure of the extrudates was described in a coarse way from nano- to microscale, and the effects of additives were discussed. The additives were observed to affect the structure in many scales, for instance, by inducing differences in the crystal structure of starch and in the microscale pore structure observed with both SAXS and X-ray microtomography. The most significant effects were introduced by WPI, but these were highly reduced in the presence of PD. Differences were also seen in lamellar structures of starch, which were probably formed due to retrogradation and observed with SAXS in powder samples soaked in water before the measurements.     

Processing of pharmaceutical materials by electrospraying under reduced pressure

Context: Electrospraying was used in drug particle production.

Objective: The aim of the research was to evaluate the possibilities to produce drug particles with desired pharmaceutical properties by electrospraying. In particular, the effect of drying pressure on particle properties was studied.

Materials and methods: A poorly water soluble model drug (budesonide) was dissolved in chloroform, and the solution was atomized by electrospraying. Following this, the charged droplets were neutralized and dried in a drying chamber. The pressure in the drying chamber was varied. The dried particles were collected and analyzed.

Results: The pressure reduction had a slight impact on particle size distribution. The particles produced in reduced pressure turned out to be notably more porous than the particles produced in atmospheric pressure. The pressure reduction also affects the degree of crystallinity of the product. The dissolution of the particles produced in reduced pressures was faster to a certain extent than that of the particles produced in atmospheric pressure.

Discussion and conclusions: A setup for electrospraying materials in a reduced pressure was presented. The pressure reduction had a notable impact on particle morphology. The possibilities to tailor the particle properties during electrospraying were studied.     

Persistence of probiotic strains in the gastrointestinal tract when administered as capsules, yoghurt, or cheese

Most clinical studies of probiotics use freeze-dried, powdered bacteria or bacteria packed in capsules. However, probiotics are commercially available in various food matrices, which may affect their persistence in the gastrointestinal tract. The objective of the study was to compare oral and faecal recovery during and after administration of a combination of Lactobacillus rhamnosus GG and LC705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium animalis subsp. lactis Bb12 as capsules, yoghurt, or cheese. This randomized, parallel-group, open-label trial (n = 36) included a 4-week run-in, 2-week intervention, and 3-week follow-up period. Participants consumed 10¹⁰ cfu/day of probiotic combination and provided saliva and faecal samples before, during, and after the intervention. Strain-specific real-time PCR was used to quantify the strains.L. rhamnosus GG was the only probiotic strain regularly recovered in saliva samples. During the intervention period it was recovered in the saliva of 88% of the volunteers at least once. No difference was found between the yoghurt and cheese groups. At the end of the intervention, L. rhamnosus GG and LC705 counts were high in faecal samples of all product groups (8.08 and 8.67 log₁₀ genome copies/g, respectively). There was no matrix effect on strain quantity in faeces or the recovery time after ceasing the intervention. For P. freudenreichii subsp. shermanii JS and B. animalis subsp. lactis Bb12, a matrix effect was found at the end of the intervention (P < 0.01 and P < 0.001, respectively) and in the recovery time during follow-up (P < 0.05 for both). Yoghurt yielded the highest faecal quantity of JS and Bb12 strains (8.01 and 9.89 log₁₀ genome copies/g, respectively). The results showed that the administration matrix did not influence the faecal quantity of lactobacilli, but affected faecal counts of propionibacteria and bifidobacteria that were lower when consumed in cheese. Thus, the consumption of probiotics in yoghurt matrix is highly suitable for studying potential health benefits and capsules provide a comparable means of administration when the viability of the strain in the capsule product is confirmed.