Effects of conventional and nonconventional drying on the stability of Bifidobacterium animalis subsp. lactis INL1

Freeze, spray, vacuum, microwave vacuum‐ and microwave freeze‐drying were applied to Bifidobacterium animalis subsp. lactis INL1. Freeze and microwave freeze‐drying showed the highest survival after drying. When a storage test (25 °C; oxygen) was performed, these cultures were the most sensitive ones at a_w = 0.23, but the addition of lactose improved their stability after 8 weeks. Flow cytometry was useful to assess viability after drying but not during storage. Our results show that dehydration technologies other than freeze‐drying might be suitable alternatives that deserve further investigation for the preservation of sensitive probiotic bacteria. Microwave drying rendered cultures of comparable characteristics to their conventional counterparts, requiring significantly shorter drying times.     

CD200 as a Potential New Player in Inflammation during Rotator Cuff Tendon Injury/Repair: An In Vitro Model

Rotator cuff tendon (RCT) disease results from multifactorial mechanisms, in which inflammation plays a key role. Pro-inflammatory cytokines and tendon stem cell/progenitor cells (TSPCs) have been shown to participate in the inflammatory response. However, the underlying molecular mechanism is still not clear. In this study, flow cytometry analyses of different subpopulations of RCT-derived TSPCs demonstrate that after three days of administration, TNFα alone or in combination with IFNγ significantly decreases the percentage of CD146+CD49d+ and CD146+CD49f+ but not CD146+CD109+ TSPCs populations. In parallel, the same pro-inflammatory cytokines upregulate the expression of CD200 in the CD146+ TSPCs population. Additionally, the TNFα/IFNγ combination modulates the protein expression of STAT1, STAT3, and MMP9, but not fibromodulin. At the gene level, IRF1, CAAT (CAAT/EBPbeta), and DOK2 but not NF-κb, TGRF2 (TGFBR2), and RAS-GAP are modulated. In conclusion, although our study has several important limitations, the results highlight a new potential role of CD200 in regulating inflammation during tendon injuries. In addition, the genes analyzed here might be new potential players in the inflammatory response of TSPCs.     

Monitoring the Simultaneous Implantation of Ti and Tb Cations to a Sacrificial Template and the Sol-Gel Synthesis of Tb-Doped TiO2 (Anatase) Hollow Spheres and Their Transition to Rutile Phase

Tb-doped TiO₂ (anatase) micro-hollow spheres (HSs) with nano-shells, in the range 0.00–3.00 at.% Tb, were successfully synthesized by a simultaneous chemical implantation route of both Ti and Tb cations from chlorides to a poly-styrene (PST)-co-poly-divinyl benzene (PDVB) sacrificial template, followed by controlled hydrolysis and polycondensation reactions. After water addition to the mixture of the precursors with the template, a decrease in the intensity and a shift to lower wavenumbers of the C=O absorption band in the IR spectra can indicate not only the anchoring of Ti and Tb ions to the carbonyl group of the template but also the hydrolysis of the implanted precursors. This latter process can involve a proton attack on the Ti–Cl, Tb–Cl and C=O bonds, the occupation of a vacant site by a water molecule, and then the dissociation of the dangling Ti–Cl, Tb–Cl ligands and C=O bonds. It gives rise to Ti_1−xTb_x[(OH)_4−uCl_v]@PST–PDVB and Ti_1−xTb_x[(OH)_4−y]@PST–PDVB complexes (x = 0.00, 0.0012, 0.0170 and 0.030). Finally, polycondensation of these species leads to Ti_1−xTb_xO_2−w′@PST–PDVB compounds. After subsequent thermal removal at 550 °C of the template, the IR bands of the core (template) totally vanished and new bands were observed in the 400–900 cm⁻¹ region which can be attributed to the metalloxane bondings (M–O, M’–O, M–O–M, M–O–M’ and/or M’–O–M’, being M and M’ = Ti and Tb, respectively, i.e., mainly vibration modes of anatase). Then, micron-sized HSs of TiO₂ and Tb-doped-TiO₂ (anatase) were obtained with nano-shells according to field emission gun scanning electron microscopy (FEG-SEM) and transmission electron microscopy (TEM) observations. Furthermore, X-ray photoelectron spectroscopy (XPS) measurements confirmed the presence of Tb⁴⁺ (38.5 and 41.2% for 1.70 and 3.00 at.% Tb, respectively) in addition to Tb³⁺ in the resulting HSs, with increasing Tb⁴⁺ content with both Tb doping and higher calcination temperatures. Then, these HSs can be considered as rare earth (RE) co-doped systems, at least for 1.70 and 3.00 at.% Tb contents being the transition to rutile phase favored by Tb doping for those compositions. Finally, diffusion of Tb from the inner parts to the surface of the HSs with the calcination treatments was also observed by XPS.     

Identification of mechanically separated meat in meat products: a simplified analytical approach by ion chromatography with conductivity detection

Due to food safety concerns, the European Food Safety Authority asked for novel approaches for identifying mechanically separated meat (MSM) in meat products. In this work, a novel and simplified approach for MSM identification in meat products is presented. This approach is based on the calcium and magnesium determination by suppressed cation-exchange chromatography coupled to conductivity detection, after sample mineralisation. One hundred samples of meat products were analysed. The difference between calcium and magnesium concentration (MSM_index) was identified as the most significant parameter useful for discriminating the presence of MSM in the product. The approach was also validated by analysing simulated meat samples containing increasing percentages of MSM. Meat samples with MSM_index higher than 390 mg kg⁻¹ can be classified as MSM products, even if the MSM was obtained at high or low pressure. The protocol is applicable for MSM identification in meat products with MSM percentage higher than 25%.     

Sulfites in meat: Occurrence,activity, toxicity,regulation, and detection. A comprehensive review

Sulfites are a class of chemical compounds, SO₂ releasers, widely used as additives in food industry, due to their antimicrobial, color stabilizing, antibrowning, and antioxidant properties. As the results of these pleiotropic functions they can be added to a broad range of products including dried fruits and vegetables, seafood, juices, alcoholic and nonalcoholic beverage, and in few meat products. Sulfites ingestion has been correlated with several adverse and toxic reactions, such as hypersensitivity, allergic diseases, vitamin deficiency, and may lead to dysbiotic events of gut and oral microbiota. In many countries, these additives are closely regulated and in meat products the legislation restricts their usage. Several studies have been conducted to investigate the sulfites contents in meat and meat products, and many of them have revealed that some meat preparations represent one of the main sources of SO₂ exposure, especially in adults and young people. This review discusses properties, technological functions, regulation, and health implications of sulfites in meat‐based foods, and lays a special emphasis on the chemical mechanisms involved in their interactions with organic and inorganic meat components.     

Potential of Amaranthus cruentus BRS Alegria in the production of flour,starch and protein concentrate: chemical,thermal and rheological characterization

BACKGROUND: Amaranth is a little‐known culture in Brazilian agriculture. Amaranthus cruentus BRS Alegria was the first cultivar recommended by Embrapa for the soil of the Brazilian scrubland. In order to evaluate the potential of this species in the production of flour, starch and protein concentrates, the latter products were obtained from A. cruentus BRS Alegria seeds, characterized and compared with the products obtained from the A. caudatus species cultivated in its soil of origin. RESULTS: The seeds of A. cruentus BRS Alegria furnished high‐purity starch and flour with significant content of starch, proteins, and lipids. The starch and flour of this species presented higher gelatinization temperatures and formed stronger gels upon cooling compared with those obtained from the A. caudatus species. This is due to their greater amylose content and a difference in the composition of the more important fatty acids, such as stearic, oleic and linoleic acids, which indicates that they have greater heat stability. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis and differential scanning calorimetry revealed the presence of albumins, globulins, glutelins and prolamins in the protein concentrate, which was obtained as a byproduct of starch production. CONCLUSION: Amaranthus cruentus BRS Alegria has potential application in the production of flour, starch and protein concentrates, with interesting characteristics for use as food ingredients. Copyright © 2010 Society of Chemical Industry     

Extraordinary Control of Terahertz Beam Reflectance in Graphene Electro-absorption Modulators

We demonstrate a graphene-based electro-absorption modulator achieving extraordinary control of terahertz reflectance. By concentrating the electric field intensity in an active layer of graphene, an extraordinary modulation depth of 64% is achieved while simultaneously exhibiting low insertion loss (～2 dB), which is remarkable since the active region of the device is atomically thin. This modulator performance, among the best reported to date, indicates the enormous potential of graphene for terahertz reconfigurable optoelectronic devices.     

Comparative study on the properties of flour and starch films of plantain bananas (Musa paradisiaca)

Biodegradable films were prepared by using the flour and starch isolated from plantain bananas of the variety “Terra” (Musa paradisiaca). Since the non-starchy fraction present in the banana flour represents 29.4% (on dry basis) of its composition, we considered it would be interesting to compare the properties of the film elaborated from this natural blend with that of the film produced from the banana starch only. Both films were characterized on the basis of their mechanical, barrier, optical, structural, and thermal properties. The banana flour film was less mechanically resistant but more flexible than the banana starch film. Despite the differences in the microstructure of the flour and starch films, the former was slightly soluble in water, and its water vapor permeability was similar to that of the starch film. Regarding the optical properties, the flour film was yellowish, which can be attributed to its protein content and the presence of phenolic compounds. The starch film, on the other hand, was lighter and less opaque. The FTIR spectra revealed the presence of the amide I group related to proteins only in the case of the flour film. Both plantain banana films displayed a C-type X-ray pattern and one glass transition temperature each, which was higher for the starch film (46.4 °C) as compared to the flour film (30.2 °C). The presence of other components (protein, lipids, and fiber) in the flour film had important effects on its properties. In general, the banana flour and starch are very promising materials for the formulation of coatings and films.