Cover Image,Volume 75, Issue 3

The front cover image is based on the Research Article Does winter supplementary feeding affect deer damage in a forest ecosystem? A field test in areas with different levels of deer pressure by Zbigniew Borowski et al., DOI: 10.1002/ps.5131 . Image Credit: Karol Zub.

     

Fermentation as a bio-process to obtain functional soybean flours

The effect of fermentation on the antioxidant compounds [vitamins C and E, total phenolic compounds (TPC), and reduced glutathione (GSH)], and antioxidant capacity [superoxide anion scavenging activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), inhibition of phosphatidylcholine (PC) peroxidation, and Trolox equivalent antioxidant capacity (TEAC)] of soybean (Glycine max cv. Merit) was studied. Fermentation was carried out in solid state in cracked seeds inoculated with Aspergillus oryzae, Rhizopus oryzae, Bacillus subtilis, and Lactobacillus plantarum and in liquid state either in cracked seeds or milled soybean flours fermented naturally by only the microorganisms present in the seeds or by inoculation with L. plantarum. Vitamin C was not detected in the studied samples. Fermentation caused a decrease in vitamin E activity, except when cracked seed was fermented with A. oryzae, R. oryzae, or B. subtilis that increased 31, 30, and 89%, respectively. Fermentation produced an increase in TPC content and did not affect or reduce the GSH content. Fermentation decreased SOD-like activity drastically, while PRTC increased except when it was carried out naturally in cracked seed. TEAC values rose sharply when soybeans were fermented with B. subtilis. Processed soybean extracts inhibited PC peroxidation in comparison with the control assay. On the basis of the results obtained, the relative contributions of vitamin E, TPC, and GSH to antioxidant capacity were calculated and results showed a very high TPC contribution and a low contribution of GSH and vitamin E activity. Optimum results for functional soybean flours were achieved when fermentation was carried out with B. subtilis inoculum.     

Effect of processing on the antioxidant vitamins and antioxidant capacity of Vigna sinensis Var. Carilla

Cowpea (Vigna sinensis L. var. Carilla) flours obtained by fermentation with inoculum Lactobacillus plantarum (PF) or with the natural microorganisms present in the flour (NF) and subsequent heat treatment in an autoclave were prepared to study the effect of fermentation on the antioxidant vitamin content and on the antioxidant capacity. Bacterial counts and pH values, vitamins C and E, carotenoids, glutathione (GSH), superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), lipid peroxidation in unilamillar liposomes, and Trolox equivalent antioxidant capacity (TEAC) were evaluated in raw and processed cowpea flours. gamma-Tocopherol and delta-tocopherol were found in raw cowpea, whereas vitamin C and carotenoids were not detected. An increase in the vitamin E activity was observed in PF, whereas vitamin C and carotenoids were not detected in fermented cowpea flours. Fermentation or heat treatment in an autoclave after fermentation produced processed cowpea flours with lower PRTC, glutathione content, and SOD-like activity than those of the raw seeds. However, those processes increased the capacity to inhibit the lipid peroxidation in unilamellar lipoposomes and TEAC. According to the results obtained in this study, the fermentation of cowpeas (naturally or with L. plantarum) and fermentation and subsequent heat treatment in an autoclave are good processes to obtain functional cowpea flours having higher antioxidant capacity than the raw legume.     

Thermally initiated solvent-free radical modification of beech (Fagus sylvatica) wood

A procedure for rapidly modifying beech wood using a thermally initiated solvent-free grafting system was examined. In the modification, butyl acrylate and butyl methacrylate were used as vinyl monomers. Free radicals were generated from 2,2′-azobis(2-methylpropionitrile) or benzoyl peroxide at 103 and 180 °C by contact heating of the modified material. Chemical changes in the material were investigated by FTIR and X-ray photoelectron spectroscopies. The modification resulted in decreased surface wetting of the material manifested by increased water contact angles. The hardness of the resultant material decreased, while its color changed by the effect of temperature. It was shown that the approach allowed for efficient thermal-initiated modification of wood with rapid contact heating.     

Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean

The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P<0.05). Moreover, we noticed significant increases of equol and para-ethyl-phenol in the blood plasma of the early-pregnant heifers (P<0.05). In contrast, in the blood plasma of the late-pregnant heifers, we did not find an increase in the isoflavone metabolite concentrations compared with the early-pregnant heifers (P>0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.     

Suitability of plant physiological methods to estimate the transpiration of agricultural crops

Transpiration is the main part of the water balance in the system soil-plant during the vegetation period. Its determination or calculation is essential for modeling of soil moisture content or solute transport. Transpiration is difficult to quantify because it is influenced by the atmosphere, the soil, and the plants. This paper describes the potential and limitations of plant physiological methods (sap flow, gas exchange, leaf water potential) to estimate the transpiration. A weighable lysimeter was used as reference method. Results are shown for corn [Zea mays L.] and rape [Brassica napus L.]) for the years 1998 and 1999. At days without rain the diurnal transpiration rates, determined by the plant physiological methods and by the lysimeter differ by less than 12%. The results demonstrate that the plant physiological methods applied are important for an understanding of the complex transpiration process. Limitations lie in the difficulties in up-scaling, and the impossibility of measurements of the absolute actual transpiration rates of agricultural crops for longer periods like months or years.     

Effect of Addition of Different Acetic Acid Concentrations on the Quality of Marinated Herring

This study investigated the effect of acetic acid concentrations from 3 to 8% on the physicochemical and sensory quality of marinated Atlantic and Baltic herring from fresh and frozen-thawed material. The increased concentration of acetic acid was found to exert a strong impact on decreased sensory scores, weight yield, and pH value as well as on an increased brightness parameter of meat. In turn, moisture, protein hydrolysis products (PHB), total volatile bases (TVB) content, and hardness parameter were affected by the higher addition of acid to a lesser extent. Enhanced protein hydrolysis was observed only at acetic acid concentration of 5% or 5–8%, whereas there was a decrease in the content of TVB only at an acid concentration of up to 4–5%. The marinated frozen-thawed fillets, compared to the fresh ones, required a greater addition of acid in the brine, by 1.5%, to reach a similar pH value. The freezing of fish contributed also to a decrease of PHB and free hydroxyproline, along with an increased concentration of acetic acid. The marinades from frozen-thawed herring contained more TVB, had worse color, and hardness parameters, as well as less yield.     

Short rotation willow coppice biomass as an industrial and energy feedstock

In order to increase the yield of short rotation willow coppice cultivated on agricultural land and to improve the biomass quality as an industrial and energy feedstock, particular consideration should be devoted to proper location and to the cultivation of woody plants. This paper presents the yield of five new cultivars of willow coppice and the relationship between the chemical composition of biomass and the plant harvest cycle. The Tur cultivar has been shown to have the highest mean productivity of 21.5 t of d.m. ha⁻¹ year⁻¹. In a three-year harvest cycle, the cultivar also gave biomass with the highest cellulose:lignin ratio (2.14). The significantly highest yield of dry biomass from the cultivars under study (20.5 t of d.m. ha⁻¹ year⁻¹) was achieved in a three-year harvest cycle. It was lower by 3.4% on average in a two-year harvest cycle and lower by 17.2% in a one-year harvest cycle as compared to a three-year cycle. As the harvest cycle was extended, the biomass quality in terms of its chemical composition improved. The biomass obtained in a three-year cycle contained the highest amount of cellulose (44.6% of d.m.) and the lowest amount of lignin (21.8% of d.m.). The results indicate that the agrotechnical factors, including the cultivar and the harvest cycle, affect not only the yield, but also the qualitative features of short rotation coppice willow biomass.     

The role of neurokinin A and its receptor in the regulation of prolactin secretion by the anterior pituitary of cyclic pigs

In pigs, plasma prolactin concentration markedly changes during the oestrous cycle and the regulation of its secretion is very complex. The contribution of neurokinins in this process has not been sufficiently delineated. The aim of the study was to examine the effects of neurokinin A (NKA) on prolactin synthesis and secretion in cyclic gilts. The expression of NKA precursor (Ppta) and receptor (Tacr2) genes as well as NKA and TACR proteins content in the porcine pituitaries (days 2–3, 9–10, 12–13, 15–16 and 19–20 of the cycle) was determined. Furthermore, the in vitro influence of NKA on the expression of prolactin (Prl), dopamine receptor (D2r), TRH receptor (Trhr) genes and prolactin secretion by the porcine pituitary cells (days 9–10, 15–16 and 19–20 of the cycle) was assessed. The expression of Ppta and Tacr2 as well as NKA and TACR proteins in the pituitary tissue has been changing throughout the oestrous cycle. NKA affected in vitro the expression of studied genes and prolactin secretion depending on the stage of the cycle, dose of NKA and/or duration of the cell incubation. Altogether, the study indicates that NKA is engaged in the modulation of prolactin secretion in the pig during the oestrous cycle.