Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05‐8, KTU05‐9 and KTU05‐10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48‐h fermentation at solid‐state conditions and compared with that in samples after submerged fermentation and in the control nonfermented samples. The lupin variety, fermentation conditions and the Pediococcus strain were found to have the significant effect on the FAA profile and BA contents in fermented lupin; the interaction between analysed factors was F(5.989) = 1755.321 (P < 0.0001) and F(5.660) = 130.736 (P < 0.0001), respectively. A weak correlation was found between amino acid His and histamine (r = 0.3709; P = 0.0005) and between Phe and phenylethylamine (r = 0.3914, P = 0.0002) in lupin samples, but the significant correlations between amino acid Tyr and tyramine and between Lys and cadaverine were not found. By optimising the fermentation technology, it is possible to increase the nutritional value and functionality of lupin.     

3D printing hybrid organometallic polymer‐based biomaterials via laser two‐photon polymerization

Materials with microscale structures are gaining increasing interest due to their range of technical and medical applications. Additive manufacturing approaches to such objects via laser two‐photon polymerization, also known as multiphoton fabrication, enable the creation of new materials with diverse and tunable properties. Here, we investigate the properties of 3D structures composed of organometallic polymers incorporating aluminium, titanium, vanadium and zirconium. The organometallic polymer‐based materials were analysed using a variety of techniques including SEM, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy analysis and contact angle measurements and their biocompatibility was tested in vitro. Cell viability and mode of death were determined by 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay and acridine orange/ethidium bromide staining. Polymers incorporating Al, Ti and Zr supported cell adhesion and proliferation, and showed low toxicity in vitro, whereas the organometallic polymer incorporating V was shown to be cytotoxic. Inductively coupled plasma optical emission spectrometry suggested that leaching of the V from the organometallic polymer is the likely cause of this. The preparation of the organometallic polymers is straightforward and both simple 2D and complex 3D structures can be fabricated with ease. Resolution tests of the newly developed organometallic polymer incorporating Al show that suspended lines with widths down to 200 nm can be fabricated. We believe that the materials described in this work show promising properties for the development of objects with sub‐micron features for biomedical applications (e.g. biosensors, drug delivery devices, tissue scaffolds etc.). © 2019 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Fortification of dairy products with vitamin D3

The purpose of this study was to analyse emulsions for vitamin D₃ delivery in yoghurt and sour cream. Oil‐in‐water emulsions stabilised by whey proteins alone and by whey proteins plus carboxymethylcellulose were used. No change in vitamin D₃ added to the yoghurt and sour cream in the form of both emulsions was observed after storage at 7 days in light and 14 days in dark at 4 °C. The results of bioavailability tests, using rats, for vitamin D₃ from the fortified emulsions and yoghurt indicated that it is feasible to use stabilised emulsions as delivery systems of vitamin D₃ in fortified products.     

Benefits of β-xylanase for wheat biomass conversion to bioethanol

BACKGROUND: The efficiency of bioethanol production from wheat biomass is related to the quality of end products as well as to safety criteria of co‐products such as distiller's dried grains with solubles (DDGS). The inclusion of a new biocatalyst for non‐starch polysaccharide degradation in fermentation processes could be one of the solutions. The objective of this study was to evaluate the influence of β‐xylanases in combination with traditional amylolytic enzymes on the efficiency of bioethanol production and DON detoxification during fermentation of Fusarium‐contaminated wheat biomass with high concentration of deoxynivalenol (DON; 3.95 mg kg^?1). RESULTS: The results showed that the negative effect of Fusarium spp. on yield and quality of bioethanol could be eliminated by the application of Trichoderma reesei xylanase in combination with amylolytic enzymes. This technological solution allowed to increase the concentration of ethanol in the fermented wort by 35.3% and to improve the quality of bioethanol by decreasing the concentrations of methanol, methyl acetate, isoamyl and isobutyl alcohols. Mass balance calculations showed that DDGS was the main source of DON contamination, comprising 74% of toxin found in wheat biomass. By using new enzyme combination for wheat biomass saccharification, a higher level of detoxification (41%) of DON was achieved during the fermentation process. CONCLUSION: The addition of Trichoderma reesei xylanase played a positive role in bioethanol production from Fusarium‐contaminated wheat biomass, indicating that the yeast‐growing medium was enriched during the enzymatic treatment. Copyright © 2011 Society of Chemical Industry     

Towards 3D Bioprinted Spinal Cord Organoids

Three-dimensional (3D) cultures, so-called organoids, have emerged as an attractive tool for disease modeling and therapeutic innovations. Here, we aim to determine if boundary cap neural crest stem cells (BC) can survive and differentiate in gelatin-based 3D bioprinted bioink scaffolds in order to establish an enabling technology for the fabrication of spinal cord organoids on a chip. BC previously demonstrated the ability to support survival and differentiation of co-implanted or co-cultured cells and supported motor neuron survival in excitotoxically challenged spinal cord slice cultures. We tested different combinations of bioink and cross-linked material, analyzed the survival of BC on the surface and inside the scaffolds, and then tested if human iPSC-derived neural cells (motor neuron precursors and astrocytes) can be printed with the same protocol, which was developed for BC. We showed that this protocol is applicable for human cells. Neural differentiation was more prominent in the peripheral compared to central parts of the printed construct, presumably because of easier access to differentiation-promoting factors in the medium. These findings show that the gelatin-based and enzymatically cross-linked hydrogel is a suitable bioink for building a multicellular, bioprinted spinal cord organoid, but that further measures are still required to achieve uniform neural differentiation.     

A comparative study on the structural and functional properties of water-soluble and alkali-soluble dietary fibres from rice bran after hot-water,ultrasound, hydrolysis by cellulase,and combined pre-treatments

The aim of the study was to estimate the optimum method to obtain water-soluble (WS-DF) and alkali-soluble (AS-DF) dietary fibres fibres from defatted rice bran (DRB) to develop functional components for food. The different pre-treatments of DRB, such as ultrasound (US) treatment, hydrolysis by cellulase (HC) and combined treatment (HC-US), were compared with hot-water (HWT) treatment on yields, and structural, physicochemical, and functional properties of WS-DF and AS-DF. Results showed that amounts of WS-DF (5.54–9.03 g/100 g) and AS-DF (7.22–9.58 g/100 g), and total dietary fibre (TDF) (42.21–45.44 g/100 g) obtained from the DRB after US, HC and HC-US treatments were significantly higher than that after HWT (6.36, 5.65 and 31.92 g/100 g, respectively). The FT-IR indicated that the effect of applied treatments on the changes of the chemical structure of polysaccharides was stronger for the WS-DF than that for the AS-DF. Scanning electron microscopy (SEM) showed that the surfaces of US-treated DFs particles were much more fractured than those after the HWT and HC. The combined HC-US treatment at 50°C for 30 min significantly enhanced the purity (85–91%) and homogeneity of RB DFs structure resulting in increased water-holding, swelling and glucose adsorption capacities compared to conventional processes maintaining acceptable bioactivity. Our study showed that conventional hot water extraction could be replaced with the ultrasonication technology as an effective tool for the modification of rice bran DFs’ structure and functional properties.     

Nutritional and quality aspects of wheat sourdough bread using L. luteus and L. angustifolius flours fermented by Pedioccocus acidilactici

Lupine has the potential to be a new domestic source of vegetable protein due to its comparable quality to the commonly used soy proteins. However, the bioprocessing that take place in the production of wheat bread with non‐conventional flours could play an important role. The wholemeal Lupinus angustifolius and Lupinus luteus flours were fermented by bacteriocin‐producing strain of Pediococcus acidilactici. The effect of lupine flour supplementation on wheat bread quality, sensory and safety criteria was studied. The lupine additives significantly decreased the quality of bread. The fermented L. luteus flour (10% of flour basis) had a slightly higher positive effect on the specific volume and crumb porosity (5.4%) and lowering of crumb hardness (9.5%) than those of L. angustifolius. In contrary, consumers rated higher for bread with L. angustifolius sourdough, which contributed to a stronger taste score. The levels of tyramine, histamine and putrescine (32.6–215.8, 20.8–96.7 and 33.7–195.2 mg kg^?1, respectively) do not present a health risk for consumers due to their relatively low levels in lupine fermented products. Bioprocessing used for wheat bread production with lupine flour additives could improve the nutritional profile of bread without increasing the risk of biogenic amine formation.     

Synthesis of the hole-transporting molecular glasses possessing pendant 3,6-dibromocarbazolyl moieties

Synthesis and properties of the well-defined 3,6-dibromocarbazolyl-containing molecular glasses are reported. They were prepared by the nucleophilic opening of the oxirane ring of 1,3-di(3,6-dibromocarbazol-9-yl)-2-propanol glycidyl ether with aniline, 4-fluoro-, 4-bromoanilines, 2,5-dimercapto-1,3,4-thiadiazole or glycidyl ether of 1,3-di(carbazol-9-yl)-2-propanol with 4,4′-thiobisbenzenethiol and 1,9-nonanedithiol followed by bromination. The obtained materials were examined by various techniques including differential scanning calorimetry, NMR, MS, UV, PL spectrometry. The electrophotographic parameters of the molecular glasses doped with difluoroboron-1,3-bis(4-metoxyphenyl)-1,3-propanedionate have been studied. The electrochemical properties and ionization potentials, measured by electron photoemission method in air, were investigated.