Storage of olives (Olea europaea L.) under CO2 atmosphere: liquid chromatography-mass spectrometry characterization of indices related to changes in polyphenolic metabolism

Olives (Olea europaea cv. Chondrolia) were stored under a CO2 atmosphere immediately after harvesting for a period of 12 days. Samples obtained at 24-h intervals were analyzed by HPLC to identify components that may reflect changes in the biochemical behavior of the tissue. Four substances were shown to undergo significant fluctuations during storage, while their evolution was found to be different in olives stored under CO2 from those stored under regular atmospheric conditions (control). On the basis of data provided by liquid chromatography-electrospray ionization mass spectrometry, these substances were tentatively identified as hydroxytyrosol glucoside, demethylated ligstroside aglycone, ibotalactone A methyl ester, and verbascoside. The data are discussed in relation to the effect of postharvest treatments of olives for purposes of manipulating their polyphenolic content and plausible development of novel debittering processes.     

Towards sweet cherry (<Emphasis Type="Italic">Prunus avium</Emphasis> L.) breeding: phenotyping evaluation of newly developed hybrids

An increasing demand for cherry production (Prunus avium L.) in Greece led to the development of new high quality sweet cherry cultivars. Self-incompatibility in cherry is one of the most challenging issues for the species’ cultivation and top breeding priority. Τhe present study focuses on the development of new hybrids with improved traits such as productivity, fruit size, organoleptic characteristics and self-compatibility. For this purpose, thirty different cultivars were crossed and produced hybrids that were evaluated according to 34 morpho-physiological characteristics. The results were analyzed using the XLSTAT (version 2014.1) software and a dendrogram was constructed using the agglomerative hierarchical clustering method. Optimal hybrid clustering was achieved when characteristics of great economic importance such as fruit shape and size, growth habit and days to blooming were included in the analysis. Based on the results, new sweet cherry hybrids with the special character of self-compatibility were developed. Our findings provide crucial new information for sweet cherry future breeding programs and cultivation.     

Optimization of pheromone trapping method for click beetles (<Emphasis Type="Italic">Agriotes</Emphasis> spp.) in Greece

Field studies were performed to survey and monitor Agriotes spp. (Coleoptera: Elateridae) click beetles in Greece. A pitfall type trap made of durable plastic and loaded with pheromone lures for different Agriotes species was employed in field sites in 2006 and 2007. The diversity of Agriotes species in arable crops in central Greece seems to be rather limited. The two species trapped in this study, A. rufipalpis and A. litigiosus, had quite different temporal patterns. In both years A. rufipalpis was captured in high numbers, beginning early in the spring and declining progressively later on. In 2006 but not in 2007, there were A. rufipalpis trap captures in early summer. Trap captures for A. litigiosus remained at low levels in both fields and only in mid-summer was there an increase in the number of adult captures. Pheromone dose had a significant effect in trap captures for both species, whereas old baits and new ones were equally attractive. The simple trap used in the present study loaded with the optimal pheromone and dose would be suitable for surveying and monitoring and even mass trapping of click beetles.     

Production economics of the emerging private fish farming industry in Bulgaria

The production economics of the emerging Bulgarian private carp and trout farming industry were assessed by surveying a representative sample of 20 private and state-controlled farms as well as visiting the National Fresh Water Fish Research Institute, the state-owned fish feed production plant and a fish processing plant.The major constraints for the development of profitable fish farming were found to be the lack of capital and the insecurity of tenure, which nonetheless, do not serve to discourage new entrants into the industry. The expected gross margin per tonne of carp produced in reservoirs or earth ponds is USD 487, while a tonne of trout farmed in concrete raceways shows a gross margin figure of USD 525. State-owned trout farms are only available for outright purchase at auctions, whereas carp farms may be rented, but only for a short term.Fish farmers could benefit from organizing themselves into producer groups in order to improve marketing and secure quality inputs. In particular, there is scope to source quality dry fish diets on both economic and environmental grounds.An extension advisory service is needed to support inexperienced new entrants and researchers should urgently evaluate what seem to be the most cost-effective methods of production.     

Evaluation of a portable glucose meter for use in cattle and sheep

Background: In farm animal practice, determination of blood glucose concentration under field conditions is often necessary. Objective: As there is no portable glucose meter device developed for use in farm animals, the analytical accuracy of a portable glucometer designed for people was evaluated for its use in cattle and sheep. Methods: Blood samples from 90 cattle and 101 sheep were used in the study. Glucose concentration was determined in whole blood immediately after blood collection from the jugular vein with the One Touch Vita portable glucometer and in serum with an enzymatic colorimetric method. The agreement between methods was assessed by Passing and Bablok regression analysis. The precision and the accuracy of the measurements were determined using the concordance correlation coefficient. Results: There was a strong linear relationship between the glucose values obtained using the portable glucometer and those obtained by the bench method in both cattle and sheep. Precision was 95% for cattle and 88% for sheep, whereas accuracy was 92% and 99%, respectively. The mean glucose values obtained using the portable glucometer were significantly lower by 8.3% in cattle and 3.2% in sheep than those determined by the bench method. Conclusion: The One Touch Vita portable glucometer can be used in clinical practice to determine blood glucose concentrations in cattle and sheep, but reference intervals (RI) must be corrected to allow for negative bias. Based on these equations the RI for blood glucose in cattle and sheep using the portable glucometer were corrected to 1.84–4.17 and 2.41–4.35 mmol/L, respectively.     

Chemical Evaluation of Compost Produced at a Large Greek Mechanical Biological Treatment Plant: Metal Availability and Phytotoxicity

ABSTRACT

The present work investigates the impact of municipal solid waste mechanical separation and industrial composting on the metal content of composts and assesses the availability of Cu, Cd, Cr, Pb, and Zn at different maturation stages of compost produced at the largest mechanical biological treatment plant in Greece. Substantial metal contamination of composts was found to take place within the industrial facility, attributed to segmentation and sorption mechanisms during composting. In fresh compost, Zn is present in mobile fractions (41%), Cu is mostly held on the less mobile organic phases (57%), Cd is mostly present in bioavailable forms (51%), whereas Pb and Cr are associated with less mobile phases, such as Fe-Mn oxides and organic molecules. Cd, Cu, and Zn migrate to more inert phases during compost maturation, paralleled by the decrease of overall metal leachability. Cu and Pb concentrations (mg kg^?1) exceeded the permissible limits in both composts (Fresh: Cu: 213 ± 48, Pb: 128 ± 69; Mature: Cu: 263 ± 1, Pb: 158 ± 29) and water leachates (Fresh: Cu: 106 ± 4, Zn: 126 ± 13; Mature: Cu: 50 ± 0.50, Zn: 118 ± 20). Nevertheless, toxic effects were not observed in monocot, dicot, or aquatic biosensor plants as indicated by radicle and shoot growth and visual quality ratings. Since metal availability in composts is related to their leaching potential, metal speciation studies should be conducted in leachates for the appropriate characterization of industrial composts.     

Mono- and duoculture of juvenile sharpsnout seabream Diplodus puntazzo (Cetti) and gilthead seabream Sparus aurata L. in a recirculated water system

Although the growth of intensively reared sharpsnout seabream Diplodus puntazzo (DP) has been suggested to improve in duoculture with gilthead seabream Sparus aurata (SA), the stocking ratio for most effective duoculture rearing has not been investigated. For this purpose, juvenile D. puntazzo (1.68±0.011 g) and S. aurata (1.43±0.007 g) were reared in duplicated groups of 165 specimens each, in two monoculture (100% DP, 100% SA) and four duoculture combinations (80% DP–20% SA, 60% DP–40% SA, 40% DP–60% SA, 20% DP–80% SA) for 96 days under recirculated water system conditions. Both species exhibited the highest growth when stocked at 20% and the poorest growth when stocked at 80%. For each species, no major differences for coefficient of weight variation and carcass proximate composition were detected. As the percentage of stocked S. aurata increased, D. puntazzo aggressiveness and weight variability of whole population were reduced, while total biomass, food consumption and food conversion ratio were increased. The results obtained are discussed in relation to fish behaviour and social interactions. From the fish farming point of view, it is indicated that under the present experimental conditions, juvenile S. aurata should be reared in monoculture and D. puntazzo in duoculture 40% DP–60% SA.