Effect of Cereal α-Amylase/Trypsin Inhibitors on Developmental Characteristics and Abundance of Digestive Enzymes of Mealworm Larvae (Tenebrio molitor L.)

The objective of this work was to investigate the potential effect of cereal α-amylase/trypsin inhibitors (ATIs) on growth parameters and selective digestive enzymes of Tenebrio molitor L. larvae. The approach consisted of feeding the larvae with wheat, sorghum and rice meals containing different levels and composition of α-amylase/trypsin inhibitors. The developmental and biochemical characteristics of the larvae were assessed over feeding periods of 5 h, 5 days and 10 days, and the relative abundance of α-amylase and selected proteases in larvae were determined using liquid chromatography tandem mass spectrometry. Overall, weight gains ranged from 21% to 42% after five days of feeding. The larval death rate significantly increased in all groups after 10 days of feeding (p < 0.05), whereas the pupation rate was about 25% among larvae fed with rice (Oryza sativa L.) and Siyazan/Esperya wheat meals, and only 8% and 14% among those fed with Damougari and S35 sorghum meals. As determined using the Lowry method, the protein contents of the sodium phosphate extracts ranged from 7.80 ± 0.09 to 9.42 ± 0.19 mg/mL and those of the ammonium bicarbonate/urea reached 19.78 ± 0.16 to 37.47 ± 1.38 mg/mL. The total protein contents of the larvae according to the Kjeldahl method ranged from 44.0 and 49.9 g/100 g. The relative abundance of α-amylase, CLIP domain-containing serine protease, modular serine protease zymogen and C1 family cathepsin significantly decreased in the larvae, whereas dipeptidylpeptidase I and chymotrypsin increased within the first hours after feeding (p < 0.05). Trypsin content was found to be constant independently of time or feed material. Finally, based on the results we obtained, it was difficult to substantively draw conclusions on the likely effects of meal ATI composition on larval developmental characteristics, but their effects on the digestive enzyme expression remain relevant

Coffee by-products as sustainable novel foods: Report of the 2nd international electronic conference on foods—“future foods and food technologies for a sustainable world”

The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as fertilizer or animal feed. Modern, ecologically oriented society attaches great importance to sustainability and waste reduction, so it makes sense to not dispose of the by-products of coffee production but to bring them into the value chain, most prominently as foods for human nutrition. There is certainly huge potential for all of these products, especially on markets not currently accessible due to restrictions, such as the novel food regulation in the European Union. The by-products could help mitigate the socioeconomic burden of coffee farmers caused by globally low coffee prices and increasing challenges due to climate change. The purpose of the conference session summarized in this article was to bring together international experts on coffee by-products and share the current scientific knowledge on all plant parts, including leaf, cherry, parchment and silverskin, covering aspects from food chemistry and technology, nutrition, but also food safety and toxicology. The topic raised a huge interest from the audience and this article also contains a Q&A section with more than 20 answered questions

Coffee By-products as Sustainable Novel Foods: Report of The 2nd International Electronic Conference on Foods - "Future Foods and Food Technologies for a Sustainable World"

The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as fertilizer or animal feed. Modern, ecologically oriented society attaches great importance to sustainability and waste reduction, so it makes sense to not dispose of the by-products of coffee production but to bring them into the value chain, most prominently as foods for human nutrition. There is certainly huge potential for all of these products, especially on markets not currently accessible due to restrictions, such as the novel food regulation in the European Union. The by-products could help mitigate the socioeconomic burden of coffee farmers caused by globally low coffee prices and increasing challenges due to climate change. The purpose of the conference session summarized in this article was to bring together international experts on coffee by-products and share the current scientific knowledge on all plant parts, including leaf, cherry, parchment and silverskin, covering aspects from food chemistry and technology, nutrition, but also food safety and toxicology. The topic raised a huge interest from the audience and this article also contains a Q&amp;A section with more than 20 answered questions

The antibacterial activity of date syrup polyphenols against S. aureus and E. coli

Plant-derived products such as date syrup have demonstrated antibacterial activity and can inhibit bacteria through numerous different mechanisms, which may be attributed to bioactive compounds including plant-derived phenolic molecules. Date syrup is rich in polyphenols and this study hypothesized that date syrup polyphenols demonstrate inherent antimicrobial activity, which cause oxidative damage. This investigation revealed that date syrup has a high content of total polyphenols (605 mg/100g), and is rich in tannins (357 mg/100g), flavonoids (40.5 mg/100g) and flavanols (31.7 mg/100g) that are known potent antioxidants. Furthermore, date syrup, and polyphenols extracted from date syrup, the most abundant bioactive constituent of date syrup are bacteriostatic to both Gram positive and Gram negative Escherichia coli and Staphylococcus aureus respectively. It has further been shown that the extracted polyphenols independently suppress the growth of bacteria at minimum inhibitory concentration (MIC) of 30 mg/mL and 20 mg/mL for E. coli and S. aureus, and have observed that date syrup behaves as a prooxidant by generating hydrogen peroxide that mediates bacterial growth inhibition as a result of oxidative stress. At sub-lethal MIC concentrations date syrup demonstrated antioxidative activity by reducing hydrogen peroxide, and at lethal concentrations date syrup demonstrated prooxidant activity that inhibited the growth of E. coli and S. aureus. The high sugar content naturally present in date syrup did not significantly contribute to this effect. These findings highlight that date syrup’s antimicrobial activity is mediated through hydrogen peroxide generation in inducing oxidative stress in bacteria

Thermoanalytical characterization and catalytic conversion of de-oiled micro algae and jatropha seed cake

The thermal decomposition of the by-products of the biodiesel process was studied by thermoanalytical methods. De-oiled algae cake and jatropha seed de-oiled cake were pyrolyzed and the catalytic effects of silica supported iron catalysts (Fe/FSM-16 and Fe/SBA-15) and magnetite (Fe3O4) were tested. The evolution profiles of the decomposition products as well as the thermal stability of the samples were determined by thermogravimetry/mass spectrometry (TG/MS). The formation of the volatile products was monitored by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The composition and the amounts of the gaseous products changed significantly in the presence of the silica supported iron catalysts: the yield of hydrogen and carbon monoxide considerably increased above the decomposition temperature of 400 °C. Both silica supported iron catalysts had important effects on the yield of the products originating from carbohydrates and lignins. The formation of anhydrosugars and phenolic compounds was hindered, while the evolution of aromatic and aliphatic hydrocarbons was enhanced. Fe/FSM-16 proved to be more efficient than Fe/SBA-15 and Fe3O4 catalysts. The thermal decomposition of the protein content of the samples resulted in the formation of 2,5 diketopiperazines and smaller molecules (e.g., ammonia). The silica supported iron catalysts had a special effect: their presence promoted the reaction of fatty acid esters and ammonia resulting in the formation of alkyl nitriles during the thermal decomposition

Soluble polysaccharides reduce binding and inhibitory activity of tea polyphenols against porcine pancreatic α-amylase

The effects of three soluble polysaccharides on the inhibitory activity of tea polyphenols against porcine pancreatic α-amylase (PPA) were studied through PPA inhibition, half inhibition concentration (IC50), inhibition kinetics and fluorescence quenching. The results show that citrus pectin, wheat arabinoxylan and oat β-glucan could each increase the IC50 values and competitive inhibition constants (Kic), and decrease the fluorescence quenching constants (KFQ) of tea polyphenols interacting with PPA. The data show a competitive interaction equilibrium among polysaccharides, polyphenols and PPA. For individual polyphenols, there were negative linear correlations between both the values of 1/Kic and KFQ and that of IC50 with and without polysaccharides, indicating that the decreased inhibitory activity of polyphenols induced by the polysaccharides was caused by the reduced binding of polyphenols with PPA. Additionally, the slopes of the linear relationship between IC50 and Kic and that between KFQ and 1/Kic remained stable with and without polysaccharides, suggesting that these constants may be combined to characterize the effects of soluble polysaccharides on the PPA inhibition by polyphenols

Probing the Interstellar Medium in Early type galaxies with ISO observations

Four IRAS-detected early type galaxies were observed with ISO. With the exception of the 15 micron image of NGC1052, the mid-IR emission from NGC1052, NGC1155, NGC5866 and NGC6958 at 4.5, 7 and 15 microns show extended emission. Mid-IR emission from NGC1052, NGC1155, and NGC6958 follows a de Vaucouleurs profile. The ratio of 15/7 micron flux decreases with radius in these galaxies, approaching the values empirically observed for purely stellar systems. In NGC5866, the 7 and 15 micron emission is concentrated in the edge-on dust lane. All the galaxies are detected in the [CII] line, and the S0s NGC1155 and NGC5866 are detected in the [OI] line as well. The ISO-LWS observations of the [CII] line are more sensitive measures of cool, neutral ISM than HI and CO by about a factor of 10-100. Three of four early type galaxies, namely NGC1052, NGC6958 and NGC5866, have low ratio FIR/Blue and show a lower [CII]/FIR, which is due to a softer radiation field from old stellar populations. The low [CII]/CO ratio in NGC5866 ([CII]/CO(1-0) < 570) confirms this scenario. We estimate the UV radiation expected from the old stellar populations in these galaxies and compare it to that needed to heat the gas to account for the cooling observed [CII] and [OI] lines. In three out of four galaxies, NGC1052, NGC5866 and NGC6958, the predicted UV radiation falls short by a factor of 2-3. In view of the observed intrinsic scatter in the "UV-upturn" in elliptical galaxies and its great sensitivity to age and metallicity effects, this is not significant. However, the much larger difference (about a factor of 20) between the UV radiation from old stars and that needed to produce the FIR lines for NGC 1155 is strong evidence for the presence of young stars, in NGC1155.Comment: To appear in the Astrophysical Journal. Figure 1 appears as a separate jpg figur

Instructive conductive 3D silk foam-based bone tissue scaffolds enable electrical stimulation of stem cells for enhanced osteogenic differentiation

Stimuli-responsive materials enabling the behaviour of the cells that reside within them to be controlled are vital for the development of instructive tissue scaffolds for tissue engineering. Herein we describe the preparation of conductive silk foam-based bone tissue scaffolds that enable the electrical stimulation of human mesenchymal stem cells to enhance their differentiation towards osteogenic outcomes