Preparation and comparative release characteristics of three anthocyanin encapsulation systems

Bilberries (Vaccinium myrtillus L.) and their major polyphenolic constituents, anthocyanins, have preventive activities inter alia against colon cancer and inflammatory bowel diseases. However, anthocyanins are sensitive to environmental conditions; thus their bioavailability in the gastrointestinal tract is an important determinant of their in vivo activity. In the study reported here, the potential benefits of encapsulating an anthocyanin rich bilberry extract (BE) on anthocyanin stability were investigated. Nonencapsulated BE and three different BE loaded microcapsule systems were incubated in simulated gastric fluid (SGF) and fed state simulated intestinal fluid (FeSSIF). After exposure to these media, released anthocyanins were identified and quantified by HPLC with UV/Vis detection. Although a rapid release of anthocyanins was observed within the first 20 min, encapsulation of anthocyanins doubled the amount of available anthocyanins after 150 min of incubation. These results illustrate the ability of encapsulation to inhibit early degradation of anthocyanins in the intestinal system.     

Climate Change as the Primary Cause for pH Shifts in a High Alpine Lake

Chemical and biological sedimentary records of a high alpine lake were used to reconstruct palaeoecological conditions and compared with two centuries of instrumental temperature measurements. Air temperature determined the lake water pH throughout the past 200 yr almost regardless of the level of atmospheric deposition. Our data suggest a strong climate forcing of the acid-base balance in sensitive high-altitude lakes. Their physico-chemical conditions and biota strongly depend on the duration of ice and snow cover which is significantly different between warm and cold periods. Beside changes in weathering rates, in-lake alkalinity generation and water-retention time, delayed freezing in autumn and earlier ice-out dates with a shorter duration of CO₂ over-saturation could be crucial for the tight temperature-pH coupling.     

Effects of Preparation Temperature on Gelation Properties and Molecular Structure of High‐Amylose Maize Starch

In this study, 3% aqueous high‐amylose maize starch (Hylon VII) dispersions were heated to temperatures of 140–165°C. The onset and rate of gel formation was observed using a small‐strain oscillation rheometer as a function of temperature from 90 to 25°C. The gel formation clearly began earlier in high‐amylose starch paste preheated at lower temperatures, but the rate of gelation was slower and the resulting gel was weaker in comparison with starch pastes preheated at higher temperatures. In addition, the structure of the final gels was studied using large deformation compression measurements. The most rigid gel structure on the basis of small and large deformation tests was obtained for high‐amylose starch gel preheated to 150–152°C, depending on the type of measurement. The rate of gelation was also fastest in that temperature range. High‐amylose gels heated to higher temperatures lost their rigidity. The molecular weight distribution of starch molecules was measured by size‐exclusion chromatography. Heating caused extensive degradation of amylopectin, which had a great effect on amylose gel formation and the final gel properties of high‐amylose maize starch. Micrographs of Hylon VII gels showed that phase separation of starch components visible in light microscopy occurred on heating to higher temperatures.     

The effect of a single prolonged milking interval on inflammatory parameters, milk composition and yield in dairy cows

A technical stop in automatic milking systems may result in a severely prolonged milking interval (PMI) with subsequent impact on milk somatic cell count (SCC). This study investigated the inflammatory reaction, milk composition and yield during SCC peak observed in composite milk after exposing cows to a single PMI of 24h. At the first milking after the PMI, a sharply increased proportion of milk polymorphonuclear leukocytes (PMN) but marginally increased SCC were observed. The peak in SCC was not seen until morning milking day 2 after the PMI, notably, concomitantly with a decreased PMN proportion. An increase in blood lactose, milk bovine serum albumin and serum amyloid A (SAA) and a drop in milk alpha lactalbumin (ALA) were seen concomitantly with the peak in PMN. All parameters mentioned, had returned to base line after day 2. The changes in SCC and SAA had the longest duration. Lactate dehydrogenase in afternoon milk was decreased during the whole study as was also afternoon milk yield. Interleukin-1β could not be detected in milk at any time. SAA and ALA, respectively, may influence chemotaxis and the changed concentrations observed after the PMI might have contributed to the increased migration of PMN to milk.     

Detecting ingested plant DNA in soil-living insect larvae

Although a significant proportion of plant tissue is located in roots and other below-ground parts of plants, little is known on the dietary choices of root-feeding insects. This is caused by a lack of adequate methodology which would allow tracking below-ground trophic interactions between insects and plants. Here, we present a DNA-based approach to examine this relationship. Feeding experiments were established where either wheat (Triticum aestivum) or maize (Zea mays) was fed to Agriotes larvae (Coleoptera: Elateridae), allowing them to digest for up to 72 h. Due to the very small amount of plant tissue ingested (max = 6.76 mg), DNA extraction procedures and the sensitivity of polymerase chain reaction (PCR) had to be optimized. Whole-body DNA extracts of larvae were tested for the presence of both rbcL and trnL plastid DNA using universal primers. Moreover, based on cpDNA sequences encoding chloroplast tRNA for leucine (trnL), specific primers for maize and wheat were developed. With both, general and specific primers, plant DNA was detectable in the guts of Agriotes larvae for up to 72 h post-feeding, the maximum time of digestion in these experiments. No significant effect of time since feeding on plant DNA detection success was observed, except for the specific primers in maize-fed larvae. Here, plant DNA detection was negatively correlated with the duration of digestion. Both, meal size and initial mass of the individual larvae did not affect the rate of larvae testing positive for plant DNA. The outcomes of this study represent a first step towards a specific analysis of the dietary choices of soil-living herbivores to further increase our understanding of animal-plant feeding interactions in the soil.     

Connectivity in Heterogeneous Landscapes: Analyzing the Effect of Topography

Animal response to landscape heterogeneity directs dispersal and affects connectivity between populations. Topographical heterogeneity is a major source of landscape heterogeneity, which is rarely studied in the contexts of movement, dispersal, or connectivity. The current study aims at characterizing and quantifying the impacts of topography on landscape connectivity. We focus on ‘hilltopping’ behavior in butterflies, a dispersal-like behavior where males and virgin females ascend to mountain summits and mate there. Our approach integrates three elements: an individual-based model for simulating animal movements across topographically heterogeneous landscapes; a formula for the accessibility of patches in homogenous landscapes; and a graphical analysis of the plots of the simulation-based vs. the formula-based accessibility values. We characterize the functional relationship between accessibility values and landscape structure (referred to as ‘accessibility patterns’) and analyze the influence of two factors: the intensity of the individuals’ response to topography, and the level of topographical noise. We show that, despite the diversity of topographical landscapes, animal response to topography results in the formation of two, quantifiable accessibility patterns. We term them ‘effectively homogeneous’ and ‘effectively channeled’. The latter, in which individuals move toward a single summit, prevails over a wide range of behavioral and spatial parameters. Therefore, ‘channeled’ accessibilities may occur in a variety of landscapes and contexts. Our work provides novel tools for understanding and predicting accessibility patterns in heterogeneous landscapes. These tools are essential for linking movement behavior, movement patterns and connectivity. We also present new insights into the practical value of ecologically scaled landscape indices.     

Genetic variation among <Emphasis Type="Italic">Fusarium</Emphasis> isolates from onion,and resistance to <Emphasis Type="Italic">Fusarium</Emphasis> basal rot in related <Emphasis Type="Italic">Allium</Emphasis> species

The aim of this research was to study levels of resistance to Fusarium basal rot in onion cultivars and related Allium species, by using genetically different Fusarium isolates. In order to select genetically different isolates for disease testing, a collection of 61 Fusarium isolates, 43 of them from onion (Allium cepa), was analysed using amplified fragment length polymorphism (AFLP) markers. Onion isolates were collected in The Netherlands (15 isolates) and Uruguay (9 isolates), and received from other countries and fungal collections (19 isolates). From these isolates, 29 were identified as F. oxysporum, 10 as F. proliferatum, whereas the remaining four isolates belonged to F. avenaceum and F. culmorum. The taxonomic status of the species was confirmed by morphological examination, by DNA sequencing of the elongation factor 1-α gene, and by the use of species-specific primers for Fusarium oxysporum, F. proliferatum, and F. culmorum. Within F. oxysporum, isolates clustered in two clades suggesting different origins of F. oxysporum forms pathogenic to onion. These clades were present in each sampled region. Onion and six related Allium species were screened for resistance to Fusarium basal rot using one F. oxysporum isolate from each clade, and one F. proliferatum isolate. High levels of resistance to each isolate were found in Allium fistulosum and A. schoenoprasum accessions, whereas A. pskemense, A. roylei and A. galanthum showed intermediate levels of resistance. Among five A. cepa cultivars, ‘Rossa Savonese’ was also intermediately resistant. Regarding the current feasibility for introgression, A. fistulosum, A. roylei and A. galanthum were identified as potential sources for the transfer of resistance to Fusarium into onion.     

Carbon Sequestration in Kiwifruit Orchard Soils at Depth to Mitigate Carbon Emissions

Management practices designed to increase carbon sequestration via perennial tree crops are potential tools to mitigate the consequences of climate change. Changes in orchard management could enable growers to meet eco-verification market demands for products with a low carbon footprint and potentially exploit the emerging business opportunity in carbon storage, while enhancing the delivery of ecosystem services that depend on soil carbon stocks. However, there is no standard methodology to verify any potential claims of carbon storage by perennial vine crops. We developed a robust methodology to quantify carbon storage in kiwifruit orchards. Soil carbon stocks (SCS) were determined in six depth increments to 1 m deep in two adjacent kiwifruit blocks, which had been established 10 (“young”) and 25 (“old”) years earlier. We used a space-for-time analysis. Our key results were the young and old kiwifruit block stored about 139 and 145 t C/ha to 1 m depth. Between 80–90 percent of the SCS were stored in the top 0.5 m, and 89–95 percent in the top 0.7 m; there was no significant difference between the SCS in row and alley to a depth of 0.5 m; a CV of 5–15 percent indicates that 4–10 cores are needed for 80 percent confidence in the estimated SCS; we recommend separating each core into the depths 0–0.1, 0.1–0.3, 0.3–0.5, and 0.5–1 m to allow the assessment of SCS dynamics; we detected a weak spatial pattern of the SCS only for the old kiwifruit block with a range of about 3 m. A sampling bay along a vine row should have a maximum length of 3 m. We then assessed SCS in more than sixty kiwifruit orchards throughout New Zealand. They stored on average 174.9 ± 3 t C ha^?1 to 1 m depth. On average, 51 percent of the SCS down to 1 m depth were stored in the top 0.3 m, which is the standard depth according to the Kyoto protocol. About 72 percent of the SCS to 1 m depth were captured when increasing the sampling depth to 0.5 m. These results underscore the necessity to analyze SCS in an orchard to at least 0.5 m deep. Using the same methodology to 1 m deep, we determined SCS in two wine grape vineyards on shallow, stony alluvial soils. We found a difference between vineyard and adjacent pasture SCS of nearly 16 t/ha. As the vines are 25 years old, this equates to carbon sequestration rates of 640 kg ha^?1 yr^?1. Our results of the space-for-time analysis also showed that all sequestration had occurred below 0.5 m. Therefore, we decided to sample C to a greater depth. In a 30-year old kiwifruit orchard and an adjacent pasture, SCS was measured to 9 m deep. In the kiwifruit orchard, we found a sequestration rate of 6.3 tons of C per hectare per year greater than in the adjacent pasture that was the antecedent land use.     

Detection of key factors in the extraction and quantification of lycopene from tomato and tomato products

The analytical process of lycopene extraction and photometrical determination was critically examined for raw tomato and processed tomato products by means of a 2 IV (15-10) Plackett-Burman experimental design in order to identify the key factors (KFs) involved. Fifteen apparent key factors (AKFs) reported in the literature were selected: sample weight (X1); volume of extraction solution (X2); antioxidant concentration (BHT, X3); neutralizing agent concentration (MgCO 3, X4); light presence during lycopene extraction (X5), homogenization velocity (X6) and time (X7), agitation time (X8), and temperature (X9) during the extraction process; water volume for separation of polar/nonpolar phases (X11); presence of inert atmosphere throughout the process (X12); time (X13), temperature (X14), and light presence (X10) during separation of phases and time delay for reading (X15). In general, higher lycopene concentrations in samples led to a higher number of key factors (KF). Thus, for raw tomato (lycopene range 1.22-2.29 mg/100 g) no KF were found, whereas for tomato sauce (lycopene range from 5.80 to 8.60 mg/100 g) one KF (X4) and for tomato paste (lycopene range from 35.80 to 51.27 mg/100 g) five KFs (X1, X2, X4, X11, and X12) were detected. For lycopene paste, X1 and X2 were identified as the KFs with the greatest impact on results, although in fact the X1/X2 ratio was the real cause. The results suggest that, with increased processing, the physical and chemical structure of lycopene becomes less important since the identified KFs explain almost 90% of variability in tomato paste but only 32% in raw tomato.     

Organic carbon sequestration in earthworm burrows

Earthworms strongly affect soil organic carbon cycling. The aim of this study was to determine whether deep burrowing anecic earthworms enhance carbon storage in soils and decrease C turnover. Earthworm burrow linings were separated into thin cylindrical sections with different distances from the burrow wall to determine gradients from the burrow wall to the surrounding soil. Organic C, total N, radiocarbon (¹⁴C) concentration, stable isotope values (δ¹³C, δ¹⁵N) and extracellular enzyme activities were measured in these samples. Anecic earthworms increased C stocks by 270 and 310 g m^?2 accumulated in the vertical burrows. C-enrichment of the burrow linings was spatially highly variable within a distance of millimetres around the burrow walls. It was shown that C accumulation in burrows can be fast with C sequestration rates of about 22 g C m^?2 yr^?1 in the burrow linings, but accumulated C in the burrows may be mineralised fast with turnover times of only 3–5 years. Carbon stocks in earthworm burrows strongly depended on the earthworm activity which maintains continuous C input into the burrows. The enhanced extracellular enzyme activity of fresh casts was not persistent, but was 47% lower in inhabited burrows and 62% lower in abandoned burrows. Enzyme activities followed the C concentrations in the burrows and were not further suppressed due to earthworms. Radiocarbon concentrations and stable isotopes in the burrow linings showed an exponential gradient with the youngest and less degraded organic matter in the innermost part of the burrow wall. Carbon accumulation by anecic earthworm is restricted to distinct burrows with less influence to the surrounding soil. Contrary to the initial hypothesis, that organic C is stabilised due to earthworms, relaxation time experiments with nuclear magnetic resonance spectroscopy (NMR) did not reveal any enhanced adsorption of C on iron oxides with C stabilising effect. Our results suggest that earthworm activity does not substantially increase subsoil C stocks but burrows serve as fast ways for fresh C transport into deep soil horizons.