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Current prospects of social–ecologically more sustainable agriculture and urban agriculture
(2025) von Cossel, Moritz; Díaz-Chavez, Rocío; Winkler, Bastian
Complementary effects of pollination and biocontrol services enable ecological intensification in macadamia orchards
(2024) Anders, Mina; Westphal, Catrin; Linden, Valerie M. G.; Weier, Sina; Taylor, Peter J.; Grass, Ingo
In many crops, both pollination and biocontrol determine crop yield, whereby the relative importance of the two ecosystem services can be moderated by the landscape context. However, additive and interactive effects of pollination and biocontrol in different landscape contexts are still poorly understood. We examined both ecosystem services in South African macadamia orchards. Combining observations and experiments, we disentangled their relative additive and interactive effects on crop production with variation in orchard design and landscape context (i.e., cover of natural habitat and altitude). Insect pollination increased the nut set on average by 280% (initial nut set) and 525% (final nut set), while biocontrol provided by bats and birds reduced the insect damage on average by 40%. Pollination services increased in orchards where macadamia tree rows were positioned perpendicular to orchard edges facing natural habitat. Biocontrol services decreased with elevation. Pest damage was reduced by higher cover of natural habitat at landscape scale but increased with elevation. Pollination and biocontrol are both important ecosystem services and complementary in providing high macadamia crop yield. Smart orchard design and the retention of natural habitat can simultaneously enhance both services. Conjoint management of ecosystem services can thus enable the ecological intensification of agricultural production.
Enrichment and structural assignment of geometric isomers of unsaturated furan fatty acids
(2023) Müller, Franziska; Conrad, Jürgen; Hammerschick, Tim; Vetter, Walter
Furan fatty acids (FuFAs) are valuable minor fatty acids, which are known for their excellent radical scavenging properties. Typically, the furan moiety is embedded in an otherwise saturated carboxyalkyl chain. Occasionally, these classic FuFAs are accompanied by low amounts of unsaturated furan fatty acids (uFuFAs), which additionally feature one double bond in conjugation with the furan moiety. A recent study produced evidence for the occurrence of two pairs of E -/ Z -uFuFA isomers structurally related to saturated uFuFAs. Here, we present a strategy that allowed such trace compounds to be enriched to a level suited for structure determination by NMR. Given the low amounts and the varied abundance ratio of the four uFuFA isomers, the isolation of individual compounds was not pursued. Instead, the entire isomer mixture was enriched to an amount and purity suitable for structure investigation with contemporary NMR methods. Specifically, lipid extracted from 150 g latex, the richest known source of FuFAs, was subsequently fractionated by countercurrent chromatography (CCC), silver ion, and silica gel column chromatography. Analysis of the resulting mixture of four uFuFAs isomers (2.4 mg in an abundance ratio of 56:23:11:9) by different NMR techniques including PSYCHE verified that the structures of the two most abundant isomers were E -9-(3-methyl-5-pentylfuran-2-yl)non-8-enoic acid and E -9-(3-methyl-5-pent-1-enylfuran-2-yl)nonanoic acid. Additionally, we introduced a computer-based method to generate an averaged chromatogram from freely selectable GC/MS runs of CCC fractions without the necessity of pooling aliquots. This method was found to be suitable to simplify subsequent enrichment steps.
Monitoring a coffee roasting process based on near‐infrared and raman spectroscopy coupled with chemometrics
(2025) Munyendo, Leah; Schuster, Katharina; Armbruster, Wolfgang; Babor, Majharulislam; Njoroge, Daniel; Zhang, Yanyan; von Wrochem, Almut; Schaum, Alexander; Hitzmann, Bernd
Roasting is a fundamental step in coffee processing, where complex reactions form chemical compounds related to the coffee flavor and its health‐beneficial effects. These reactions occur on various time scales depending on the roasting conditions. To monitor the process and ensure reproducibility, the study proposes simple and fast techniques based on spectroscopy. This work uses analytical tools based on near‐infrared (NIR) and Raman spectroscopy to monitor the coffee roasting process by predicting chemical changes in coffee beans during roasting. Green coffee beans of Robusta and Arabica species were roasted at 240°C for different roasting times. The spectra of the samples were taken using the spectrometers and modeled by the k‐nearest neighbor regression (KNR), partial least squares regression (PLSR), and multiple linear regression (MLR) to predict concentrations from the spectral data sets. For NIR spectra, all the models provided satisfactory results for the prediction of chlorogenic acid, trigonelline, and DPPH radical scavenging activity with low relative root mean square error of prediction (pRMSEP < 9.649%) and high coefficient of determination ( R 2 > 0.915). The predictions for ABTS radical scavenging activity were reasonably good. On the contrary, the models poorly predicted the caffeine and total phenolic content (TPC). Similarly, all the models based on the Raman spectra provided good prediction accuracies for monitoring the dynamics of chlorogenic acid, trigonelline, and DPPH radical scavenging activity (pRMSEP < 7.849% and R 2 > 0.944). The results for ABTS radical scavenging activity, caffeine, and TPC were similar to those of NIR spectra. These findings demonstrate the potential of Raman and NIR spectroscopy methods in tracking chemical changes in coffee during roasting. By doing so, it may be possible to control the quality of coffee in terms of its aroma, flavor, and roast level.
Assessing the combination efficiency of some unconventional feed resources with concentrates and Chloris gayana grass in mitigating ruminal methane production in vitro
(2024) Melesse, Aberra; Steingass, Herbert; Holstein, Julia; Titze, Natascha; Rodehutscord, Markus
In a preliminary in vitro study, leaves of Acacia nilotica, Prosopis juliflora, Cajanus cajan, Leucaena leucocephala and seed kernel of Mangifera indica were identified as potential candidates in mitigating ruminal methane (CH4) production. The objective of the current study was to investigate the combination efficiency of these unconventional feeds with concentrate mix (CM) or Chloris gayana grass in CH4 reduction. Two feed combinations in different proportions were incubated in vitro with buffered rumen fluid at Hohenheim Gas test. In combination 1, C. gayana and CM were included as basal substrates, while in combination 2, A. nilotica, P. juliflora, C. cajan, L. leucocephala or M. indica seed kernel were included as CH4 reducing supplements at different proportions. The CH4 reducing potentials of feed combinations were presented as the ratio of CH4 to net gas production and expressed as percentage (pCH4). The pCH4 for CM and C. gayana was 16.7% and 16.9%, respectively, while it ranged from 3.18% in A. nilotica to 13.1% in C. cajan. The pCH4 was reduced (p < 0.05) from 14.6% to 9.39% when A. nilotica was combined with CM. In combination of L. leucocephala or C. cajan with CM, the pCH4 (p < 0.05) was reduced from 16.5% and 16.6% with the lowest proportion to 15.1% and 15.2% with the highest inclusion rate respectively. The combination of C. gayana with L. leucocephala or C. cajan reduced (p < 0.05) the pCH4 from 16.3% and 16.4% to 15.1% and 14.9% respectively. The pCH4 was reduced (p < 0.05) from 13.4% to 7.60% when A. nilotica was combined with C. gayana. Estimated digestible organic matter (dOM) and metabolizable energy (ME) increased (p < 0.05) with increasing proportions of M. indica seed kernel with CM or C. gayana. In conclusion, the combination of the basal substrates with unconventional supplements resulted in CH4 reduction without affecting the dOM and ME at lower inclusion rates. Animal‐based experiments await to validate in vitro findings.