Zoekresultaten

Control of anthracnose (Colletotrichum gloeosporioides) growth in “Hass” avocado fruit using sachets filled with oregano oil-starch-capsules.

Active antifungal packaging is a technological solution for reducing the postharvest losses of fruits and vegetables associated with phytopathogens. Anthracnose (Colletotrichum gloeosporioides) is the principal fungus that causes post-harvest avocado fruit decay. In this study, antifungal sachets filled with oregano oil-starch capsules were prepared, and their active effects were demonstrated on Hass avocado fruits. Oregano oil (31 % of carvacrol) was encapsulated with corn starch by spray drying. Tyvek sachets (4 × 4 cm) filled with 80 (T1) and 160 mg (T2) of oregano oil-starch capsules (99.35 ± 1.86 mg g − 1) were fabricated. The antifungal effects of the sachets were tested in vitro and in vivo using a humidity chamber (90–95 % relative humidity (RH)) on fruits inoculated with anthracnose. The results showed that T1 and T2 inhibited 75.21 ± 2.81 and 100 % in vitro growth of anthracnose at 25 °C for 12 days. Furthermore, Hass avocado fruits stored in a humidity chamber at 25 °C for 6 days showed that only T2 significantly (p < 0.05) reduced the area of lesion produced by artificial inoculation of Hass avocado fruits with anthracnose. On average, the lesion area in the Hass avocado fruits treated with T2 was 13.94 % smaller than that in the control fruit.

Synthesis of α- and β-D-glucopyranuronate 1-phosphate and α-D-glucopyranuronate 1-fluoride: intermediates in the synthesis of D-glucuronic acid from starch

The title uronates were prepared by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) catalysed sodium hypochlorite oxidation of α- and β-D-glucopyranosylphosphate (α-/β-Glc-1-P) and α-D-glucopyranosyl fluoride (α-Glc-1-F). Quantitative recovery of the TEMPO catalyst was achieved by azeotropic distillation of a small part of the reaction mixture. Also, a heterogeneous catalyst system was prepared by immobilisation of 4-oxo-tetramethyl-1-piperidinyloxy (OTEMPO) on amino-functionalized silica. The protected uronates were hydrolysed to yield D-glucuronate. Since α- and β-Glc-1-P and α-Glc-1-F can be obtained from starch in one step, D-glucuronic acid is now available from starch in a convenient three-step sequence.

Sustained changes in body composition during 6 months follow-up after combined lifestyle intervention in older adults with obesity and type 2 diabetes

An ecosystem services analysis of oil palm and alternative land use systems on peat in Malaysia

In this article, we assess the potential of alternative land use systems using non-drainage peatland species which could eventually phase out or partly replace oil palm plantations on undrainable peatlands. We have used the ecosystem services approach to analyse what scenarios using drainage-free peatland species could be suitable alternatives for oil palm cultivation on peat and how these scenarios compare to oil palm plantations in terms of selected ecosystem services. Our results indicate that alternative paludiculture systems will provide more direct and indirect ecosystem services than oil palm plantations on peat. We also found that stakeholders were aware of issues with growing oil palm on peat, and that there was a general intention for sustainable use of peatlands amongst several groups of stakeholders. Replacing oil palm with alternative systems such as paludiculture in Malaysia is not yet realistic. The most important impediments are a lack of knowledge on potential of non-drainage peatland species and its associated value chains, as well as the technical difficulty for smallholders to implement such a system. We recommend starting experimental plantings with paludiculture systems to further test species performance, life cycle analysis, growth, intercropping limitations and possibilities, yields and improvements in the value chain.

The Northern Netherlands

The Northern Netherlands is an unique environment for sustainably-minded (bio)chemical businesses due to the regional availability of renewable feedstock, energy and existing infrastructure as well as the proximity to excellent knowledge centers and upscaling facilities. Within the last decades, several developments unravelled in the biobased circular transition. Exploring how these developments were initiated, the article means to show the opportunities that this region has to offer today. It also makes a strong argument for the economic potential arising from the creative combination of available feedstocks in an innovative ecosystem providing necessary frame-work conditions and fostering close intersectoral collaboration.

The design of a novel, environmentally improved cotton pre-treatment proces

The scope of this thesis of Gerrit Bouwhuis, lecturer at Saxion Research Centre for Design and Technology in Enschede is the development of a new industrial applicable pre-treatment process for cotton based on catalysis. The pre-treatment generally consists of desizing, scouring and bleaching. These processes can be continuous or batch wise. Advances in the science of biocatalytic pre-treatment of cotton and catalytic bleaching formed the scientific basis for this work. The work of Agrawal on enzymes for bio-scouring and of Topalovic on catalytic bleaching led to the conclusion that reduced reaction temperatures for the pre-treatment processes of cotton are possible. A second reason for the present work is a persistent and strong pressure on the industry to implement ‘more sustainable’ and environmental friendlier processes. It was clear that for the industrial implementation of the newly developed process it would be necessary to ‘translate’ the academic knowledge based on the catalysts, into a process at conditions that are applicable in textile industry. Previous experiences learned that the transition from academic knowledge into industrial applicable processes often failed. This is caused by lack of experience of university researchers with industrial product and process development as well as a lack of awareness of industrial developers of academic research. This is especially evident for the so-called Small and Medium Enterprises (SME’s). To overcome this gap a first step was to organize collaboration between academic institutes and industries. The basis for the collaboration was the prospect of this work for benefits for all parties involved. A rational approach has been adopted by first gathering knowledge about the properties and morphology of cotton and the know how on the conventional pre-treatment process. To be able to understand the conventional processes it was necessary not only to explore the chemical and physical aspects but also to evaluate the process conditions and equipment that are used. This information has been the basis for the present lab research on combined bio-catalytic desizing and scouring as well as catalytic bleaching. For the measurement of the performance of the treatments and the process steps, the performance indicators have been evaluated and selected. Here the choice has been made to use industrially known and accepted performance indicators. For the new bio-catalytic pre-treatment an enzyme cocktail, consisting of amylase, cutinase and pectinase has been developed. The process conditions in the enzyme cocktail tests have been explored reflecting different pre-treatment equipment as they are used in practice and for their different operation conditions. The exploration showed that combined bio-catalytic desizing and scouring seemed attractive for industrial application, with major reduction of the reaction and the rinsing temperatures, leading to several advantages. The performance of this treatment, when compared with the existing industrial treatment showed that the quality of the treated fabric was comparable or better than the present industrial standard, while concentrations enzymes in the cocktail have not yet been fully optimized. To explore the application of a manganese catalyst in the bleaching step of the pre-treatment process the fabrics were treated with the enzyme cocktail prior to the bleaching. It has been decided not to use conventional pre-treatment processes because in that case the combined desizing and scouring step would not be integrated in the newly developed process. To explore catalytic bleaching it has been tried to mimic the existing industrial processes where possible. The use of the catalyst at 100°C, as occurs in a conventional steamer, leads to decomposition of the catalyst and thus no bleach activation occurs. This led to the conclusion that catalytic bleaching is not possible in present steamers nor at low temperatur