Crepidium sect. Crepidium (Orchidaceae, Malaxidinae)—Chemical and Morphological Study of Flower Structures in the Context of Pollination Processes

Crepidium is a large genus of mainly pantropical orchids. The lips of its flowers are upwardly directed and do not serve as landing platforms for pollinators. This role is assumed by the dorsal sepal and/or gynostemium. Information about the pollination and floral morphology of this genus is scarce. To date, no papers have been published on these topics. Field observations have revealed that the flowers are visited by small flies, midges, fruit flies, other small dipterans, ants, spiders, and mites. Preliminary observations revealed at least two forms of small liquid droplets secreted on the lip surface of Crepidium species: simple secretions from epidermal cells, and cell sap released upon the rupturing of raphide-producing cells. Further research revealed that this was the first time liquid secretion was recorded in this genus. Floral secretions were subjected to sequential organic solvent extraction and gas chromatography–mass spectrometry (GC–MS). Floral parts were investigated by means of scanning (SEM) and transmission electron microscopy (TEM), and histochemical tests. The presence of liquid droplets on the lip of Crepidium, the presence of a food reward, and the sequence of raphide development are reported here for the first time.

Essential oils as natural additives in dry-fermented sausages

The usage of food additives is one of the key methods for inhibiting microorganisms’ growth and delaying oxidative changes in dry-fermented sausages (DFS). However, they have numerous negative health effects, so the novel meat industry is oriented towards different natural alternatives while focusing on plant extracts, including essential oils (EOs). EOs are interesting since they are generally recognized as safe (marked as GRAS) and have a broad acceptance from the consumers. Their activity depends on numerous parameters including the method of extraction, concentrations and possible synergistic effects of their bioactive compounds. Various conventional (hydrodistillation and organic solvent extraction) and novel (microwave-assisted, ultrasound-assisted and supercritical fluid extraction) extraction techniques are being applied for EO recovery, and optimization of these process is an essential step towards cost-effective production of high-quality extracts. Generally, it can be concluded that EOs are added into DFS to delay or prevent lipid oxidation, retard microorganisms’ growth, improve colour stability and extend the shelf-life.

Aliphatic extractive effects on acetic acid catalysis of typical agricultural residues to xylo-oligosaccharide and enzymatic hydrolyzability of cellulose

Background Xylo-oligosaccharide is the spotlight of functional sugar that improves the economic benefits of lignocellulose biorefinery. Acetic acid acidolysis technology provides a promising application for xylo-oligosaccharide commercial production, but it is restricted by the aliphatic (wax-like) compounds, which cover the outer and inner surfaces of plants. Results We removed aliphatic compounds by extraction with two organic solvents. The benzene–ethanol extraction increased the yield of acidolyzed xylo-oligosaccharides of corncob, sugarcane bagasse, wheat straw, and poplar sawdust by 14.79, 21.05, 16.68, and 7.26% while ethanol extraction increased it by 11.88, 17.43, 1.26, and 13.64%, respectively. Conclusion The single ethanol extraction was safer, more environmentally friendly, and more cost-effective than benzene–ethanol solvent. In short, organic solvent extraction provided a promising auxiliary method for the selective acidolysis of herbaceous xylan to xylo-oligosaccharides, while it had minimal impact on woody poplar.

Knoevenagel condensation reaction catalysed by agro-waste extract as a greener solvent catalyst

This paper present a novel Knoevenagel reaction protocol for the condensation of aromatic/heteroaromatic aldehydes with malononitrile to give α, β–unsaturated benzylidene derivatives. The main focus of this work is to reveal the usability of agro-waste extracts as a catalyst in the Knoevenagel condensation. The present protocol proceeds efficiently for various substituted aromatic and heterocyclic aldehydes in the Knoevenagel reactions. In addition, the present method describes direct isolation of the formed products without using organic solvent extraction gave good yields product.

β-Carotene extraction from Dunaliella salina by supercritical CO2

This paper reports the results of supercritical carbon dioxide (scCO2) extraction of β-carotene from Dunaliella salina as potential alternative to conventional organic solvent extraction. In pilot-scale scCO2 experiments, the pressure, temperature, and co-solvent concentration were varied. The supercritical extraction at 500 bar, 70 °C, and 10 wt% ethanol as co-solvent yielded in the highly efficient pigment recovery of over 90%. Techno-economic assessment demonstrated higher energy consumption for the scCO2 extraction that was compensated by lower solvent costs. Thus, comparable pigment production costs to the reference extraction with n-hexane were estimated for the scCO2 process. Due to the green solvent properties of scCO2 and ethanol, this approach is highly promising for extraction of algal biomass in industrial scale.

Biocatalytic Transformation of 5-Hydroxymethylfurfural into 2,5-di(hydroxymethyl)furan by a Newly Isolated Fusarium striatum Strain

The compound 2,5-di(hydroxymethyl)furan (DHMF) is a high-value chemical block that can be synthesized from 5-hydroxymethylfurfural (HMF), a platform chemical that results from the dehydration of biomass-derived carbohydrates. In this work, the HMF biotransformation capability of different Fusarium species was evaluated, and F. striatum was selected to produce DHMF. The effects of the inoculum size, glucose concentration and pH of the media over DHMF production were evaluated by a 23 factorial design. A substrate feeding approach was found suitable to overcome the toxicity effect of HMF towards the cells when added at high concentrations (>75 mM). The process was successfully scaled-up at bioreactor scale (1.3 L working volume) with excellent DHMF production yields (95%) and selectivity (98%). DHMF was purified from the reaction media with high recovery and purity by organic solvent extraction with ethyl acetate.

Biocatalytic Transformation of 5-Hydroxymethylfurfural into 2,5-Di(hydroxymethyl)furan by a Newly Isolated Fusarium striatum Strain

2,5-Di(hydroxymethyl)furan (DHMF) is a high-value chemical block than can be synthesized from 5-hydroxymethylfurfural (HMF), a platform chemical that results from the dehydration of biomass-derived carbohydrates. In this work, the HMF biotransformation capability of different Fusarium species was evaluated and F. striatum was selected to produce DHMF. The effects of the inoculum size, glucose concentration and pH of the media over DHMF production were evalu-ated by a 23 factorial design. A substrate feeding approach was found suitable to overcome the toxicity effect of HMF towards the cells when added at high concentrations (>75 mM). The pro-cess was successfully scaled-up at bioreactor scale (1.3 L) with excellent DHMF production yields (95%) and selectivities (98%). DHMF was purified from the reaction media with high recovery and purity by organic solvent extraction with ethyl acetate.