Experimental Annealing of Zircon: Influence of Inclusions on Stability, Intracrystalline Melt Migration, Common Lead Leaching, and Permeability to Fluids

Zircon derived from crustal rocks can survive dissolution into hot basalts during magma hybridization and rock assimilation if it is shielded as an inclusion phase in early-formed phenocrysts or in minerals from non-disaggregated xenoliths. Under these conditions, zircon can be thermally shocked, triggering recrystallization of metamict domains and reaction with its hosted mineral inclusions. This work simulates this process by performing thermal annealing experiments on zircon grains with variable degrees of metamictization. These were embedded in cristobalite powder under a N₂ atmosphere at 1 bar and 1300 °C. The thermal annealing produces recrystallization of metamict domains, melting of multi-phase mineral inclusions, nanopore formation, and microcrack propagation by thermo-elastic stress. The porosity enhances intracrystalline melt mobility, leaching out trace-element and mineral impurities. Baddeleyite was formed at temperatures below the thermal decomposition of pure zircon by two mechanisms: (i) recrystallization of metamict domains assisted by silica migration from the reaction site and (ii) incongruent zircon dissolution into molten mineral inclusions with a high CaO/SiO₂ ratio. Highly metamict zircons with elevated common Pb and radiogenic Pb loss, which were impossible to date with SHRIMP, lost all their common Pb and some radiogenic Pb upon annealing, producing well-fitted discordias with a significant upper intercept age.

Anti-Inflammatory Properties, Bioaccessibility and Intestinal Absorption of Sea Fennel (Crithmum maritimum) Extract Encapsulated in Soy Phosphatidylcholine Liposomes

A sea fennel (Crithmum maritimum) aqueous extract was prepared and loaded into soybean phosphatidylcholine liposomes. Both the free extract (FE), and the empty (L) and loaded (L-FE) liposomes were shown to be non-cytotoxic to THP-1 and Caco-2 cells. The anti-inflammatory effect was tested on THP-1 cells differentiated into macrophages. FE showed anti-inflammatory activity, revealed by the induced secretion of IL-10 cytokines in macrophages that were subsequently stimulated with LPS. Also, a decrease in TNF-α production by L was observed, evidencing that liposomes reduced the pro-inflammatory mediators' secretion. The liposomes (L) showed protective anti-inflammatory activity and also were able to downregulate the inflammation. Furthermore, L-FE were also found to downregulate the inflammation response, as they were able to decrease TNF-α secretion in macrophages previously exposed to LPS. The simulated in vitro gastrointestinal digestion (GID) of FE diminished the chlorogenic acid content (the main polyphenolic compound of the extract) by 40%, while in L-FE, the amount of this phenolic compound increased with respect to the undigested liposomes. The amount of bioaccessible chlorogenic, however, was similar for FE and L-FE. The percentage of chlorogenic acid absorbed through a Caco-2 cell monolayer after 3 h of incubation, was significantly similar for the extract and the liposomes (~1.5%), without finding significant differences once the extract and liposomes were digested.

Yogurt Fortification by the Addition of Microencapsulated Stripped Weakfish (Cynoscion guatucupa) Protein Hydrolysate

The aim of the present work was to fortify yogurt by adding a stripped weakfish (Cynoscion guatucupa) protein hydrolysate obtained with the enzyme Protamex and microencapsulated by spray drying, using maltodextrin (MD) as wall material. The effects on the physicochemical properties, syneresis, texture, viscoelasticity, antioxidant and ACE inhibitory activities of yogurt after 1 and 7 days of storage were evaluated. In addition, microbiological and sensory analyses were performed. Four yogurt formulations were prepared: control yogurt (without additives, YC), yogurt with MD (2.1%, YMD), with the free hydrolysate (1.4%, YH) and the microencapsulated hydrolysate (3.5%, YHEn). Yogurts to which free and microencapsulated hydrolysates were added presented similar characteristics, such as a slight reduction in pH and increased acidity, with a greater tendency to present a yellow color compared with the control yogurt. Moreover, they showed less syneresis, the lowest value being that of YHEn, which also showed a slight increase in cohesiveness and greater rheological stability after one week of storage. All yogurts showed high counts of the microorganisms used as starters. The hydrolysate presence in both forms resulted in yogurts with antioxidant activity and potent ACE-inhibitory activity, which were maintained after 7 days of storage. The incorporation of the hydrolysate in the microencapsulated form presented greater advantages than the direct incorporation, since encapsulation masked the fishy flavor of the hydrolysate, resulting in stable and sensorily acceptable yogurts with antioxidant and ACE inhibitory activities.

Sex Matters in the Association between Physical Activity and Fitness with Cognition

PURPOSE

The benefits from physical activity (PA) and cardiorespiratory fitness (CRF) on normal age-related cognitive decline might be sex dependent. Our aim was to explore the relationship between different types of PA, CRF, and cognition and to identify the mediating effects of CRF in the association between PA and cognition in women and men.

METHODS

We recruited 115 healthy adults 50-70 yr of age. We obtained demographic, cognitive, and PA status data based on the Projecte Moviment protocol. We calculated cognitive domains by grouping z-sample scores. We obtained self-reported total energy expenditure during the last month and grouped it into sportive PA (S-PA) and nonsportive PA (NS-PA). CRF was estimated using the Rockport 1-Mile Walk Test. We applied regression models and mediation analyses in a final sample of 104 individuals (65 women and 39 men).

RESULTS

In the total sample, CRF was positively associated with executive function, verbal memory, and attention-speed. S-PA was positively related to executive function and attention-speed, whereas NS-PA was unrelated to cognitive domains. Greater amounts of S-PA were associated with executive function and attention-speed for both women and men. Higher CRF was associated with executive function, memory, language, and attention-speed only in men. Mediation analyses showed that CRF was a significant mediator of the positive effects of S-PA on executive function and attention-speed in men but not in women.

CONCLUSIONS

Both women and men show cognitive benefits from greater S-PA, but not from NS-PA. However, there were sex differences in the mediating effects of CRF in this relationship, showing that CRF was mediating these benefits only in men.

Ciliated Carcinoma Associated With Human Papiloma Virus: Presentation As Cervical Metastasis Of Unknown Primary

Introduction/Objective

There is a significant increase in high-risk human papilloma virus (HPV) -related carcinomas of the head and neck. Half of them debut with metastases in cervical nodes, of expansive growth, usually cystic-necrotic. Most are oropharyngeal primaries. They are non-keratinizing squamous carcinomas with mild atypia, sometimes with exceptional characteristics, such as glandular differentiation and inclusion of ciliated cells

Methods

Clinical Case: 39-year-old male patient, operated two years ago, in another institution, for cervical metastasis from HPV-related Ciliated Carcinoma (HPV-RCC), 4.5 x 2 cm. No primary cancer was found in his study. Two months ago, a new 4.3 x 2.7 cm metastasis was resected, performing a right cervical dissection, with another 36 lymph nodes without tumor. Palatine tonsils, adenoids are removed and a biopsy of the oral mucosa is taken, and no malignancy was found. In our center, biopsies of the tongue and right glosso-tonsillar fold are taken, without objectify malignancy.

Results

The metastases had macroscopic cystic-necrotic appearance. Histology corresponded to nonkeratinizing squamous carcinoma with microcystic spaces and the presence of ciliated columnar cells. The immunohistochemical study gave strong and diffuse positivity for p16. The real-time multiple PCR study detected HPV genotype 16.

Conclusion

We present an exceptional case of Ciliated Carcinoma Related to HPV, a recently described entity. These are nonkeratinizing squamous neoplasms, which include cystic spaces and ciliated columnar cells. Both components reveal HPV positivity, with p16 expression and high-risk viral typing. HPV-RCC should be considered in the differential diagnosis of well-differentiated squamous lesions of the oropharyngeal cavity and at the cervical level, with non-neoplastic cysts. Our patient will undergo radiotherapy protocol, for unknown primary

Cells, Materials, and Fabrication Processes for Cardiac Tissue Engineering

Cardiovascular disease is the number one killer worldwide, with myocardial infarction (MI) responsible for approximately 1 in 6 deaths. The lack of endogenous regenerative capacity, added to the deleterious remodelling programme set into motion by myocardial necrosis, turns MI into a progressively debilitating disease, which current pharmacological therapy cannot halt. The advent of Regenerative Therapies over 2 decades ago kick-started a whole new scientific field whose aim was to prevent or even reverse the pathological processes of MI. As a highly dynamic organ, the heart displays a tight association between 3D structure and function, with the non-cellular components, mainly the cardiac extracellular matrix (ECM), playing both fundamental active and passive roles. Tissue engineering aims to reproduce this tissue architecture and function in order to fabricate replicas able to mimic or even substitute damaged organs. Recent advances in cell reprogramming and refinement of methods for additive manufacturing have played a critical role in the development of clinically relevant engineered cardiovascular tissues. This review focuses on the generation of human cardiac tissues for therapy, paying special attention to human pluripotent stem cells and their derivatives. We provide a perspective on progress in regenerative medicine from the early stages of cell therapy to the present day, as well as an overview of cellular processes, materials and fabrication strategies currently under investigation. Finally, we summarise current clinical applications and reflect on the most urgent needs and gaps to be filled for efficient translation to the clinical arena.

Nitrite inhibition of microalgae induced by the competition between microalgae and nitrifying bacteria

Outdoor microalgae cultivation systems treating anaerobic membrane bioreactor (AnMBR) effluents usually present ammonium oxidising bacteria (AOB) competition with microalgae for ammonium uptake, which can cause nitrite accumulation. In literature, nitrite effects over microalgae have shown controversial results. The present study evaluates the nitrite inhibition role in a microalgae-nitrifying bacteria culture. For this purpose, pilot- and lab-scale assays were carried out. During the continuous outdoor operation of the membrane photobioreactor (MPBR) plant, biomass retention time (BRT) of 2 d favoured AOB activity, which caused nitrite accumulation. This nitrite was confirmed to inhibit microalgae performance. Specifically, continuous 5-d lab-scale assays showed a reduction in the nitrogen recovery efficiency by 32, 42 and 80% when nitrite concentration in the culture accounted for 5, 10 and 20 mg N·L^-1, respectively. On the contrary, short 30-min exposure to nitrite showed no significant differences in the photosynthetic activity of microalgae under nitrite concentrations of 0, 5, 10 and 20 mg N·L^-1. On the other hand, when the MPBR plant was operated at 2.5-d BRT, the nitrite concentration was reduced to negligible values due to increasing activity of microalgae and nitrite oxidising bacteria (NOB). This allowed obtaining maximum MPBR performance; i.e. nitrogen recovery rate (NRR) and biomass productivity of 19.7 ± 3.3 mg N·L^-1·d^-1 and 139 ± 35 mg VSS·L^-1·d^-1, respectively; while nitrification rate (NOxR) reached the lowest value (13.5 ± 3.4 mg N·L^-1·d^-1). Long BRT of 4.5 d favoured NOB growth, avoiding nitrite inhibition. However, it implied a decrease in microalgae growth and the accumulation of nitrate in the MPBR effluent. Hence, it seems that optimum BRT has to be within the range 2-4.5 d in order to favour microalgae growth with respect to AOB and NOB.

Social inequalities in health: duration of unemployment unevenly effects on the health of men and women

Background

Employment status is an important determinant of health inequalities. The aim of this article is to analyze the association between duration of unemployment and the presence of cardiovascular risk factors, self-perception of health and presence of depression and anxiety, assessing differences in the effects of unemployment by sex and age.

Methods

The sample was composed of 12 123 people (52.4% men), 18 to 74 years old (mean age= 43.5 years, SD = 10.4). Logistic regression analyses were used to study the influence of duration of unemployment on health (‘0 days’, ‘≤11 months’ and ‘≥12 months’). Sex, age, level of education, employment status and time spent unemployed, as well as tobacco and alcohol use and physical activity, were considered. Morbidity variables were hypertension, hypercholesterolemia, diabetes, obesity, depression and anxiety, and a subjective health assessment.

Results

The results showed both unemployed men and women had worse outcome in health compared with their active counterparts. The risk of hypertension was presented in long-term unemployed men, which had 1.3 times more likely to suffer from hypertension. The risk of obesity was presented only in unemployed women, which had 1.5 times more risk of obesity, doubling the risk (OR= 2.2) among women under age 40. The unemployment had a protective effect against anxiety among younger women (OR = 0.53)

Conclusion

It has been observed a different influence of unemployment time on men and women’s health. The employment status should be considered in public health policy agendas with the purpose of reducing inequalities in health.

Encapsulation of antioxidant sea fennel (Crithmum maritimum) aqueous and ethanolic extracts in freeze-dried soy phosphatidylcholine liposomes

Soy phosphatidylcholine liposomes encapsulating increasing concentrations of two sea fennel extracts (aqueous and ethanolic) prepared by ultrasonication were freeze-dried, using glycerol as lyoprotectant. Particle properties, water dispersibility, colour, thermal properties and antioxidant capacity (radical scavenging capacity, ferric ion reducing power, Folin-reactive substances) of the liposomal preparations were determined. The freeze-drying process caused an overall increase in particle size and polydispersity index, while the zeta-potential became more electronegative. Both sea fennel extracts were rich in chlorogenic acid (42.61 and 58.48 mg/g for the aqueous and ethanolic extracts, respectively) and showed great antioxidant activity. Vitamin C was identified in the aqueous extract, whereas rutin and rosmarinic acid in the ethanolic one. The entrapment efficiency, determined in the liposomes prepared at the highest extract concentration, was 65.6% and 49.1% for the aqueous extract and the ethanolic extract, respectively. The liposomal antioxidant activity and total phenolic content followed a linear increasing tendency as a result of increasing the extract concentration, irrespective of the type of extract. Higher antioxidant activity was found in the liposomes loaded with the ethanolic extract, in a clear relationship to the greater amount of highly antioxidant phenolic compounds extracted, and also to their lower entrapment efficiency, which caused a greater amount of extract to remain outside the liposome. Both extracts were suitable for producing liposomes with antioxidant properties which could be dried and used to design functional foods.

Bioaccessibility and antimicrobial properties of a shrimp demineralization extract blended with chitosan as wrapping material in ready-to-eat raw salmon

A shrimp extract (SME) obtained from the mild-acid demineralization treatment of shrimp shells to produce chitosan was collected. It was mainly composed of fat (≈73%), protein (≈19%), and ash (≈9%) and contained considerable amounts of calcium (≈1.9 g/100 g), astaxanthin (≈30 mg/100 g) and unsaturated fatty acids (≈27% MUFA, ≈39% PUFA). The SME was used in combination with chitosan for wrapping raw salmon to produce a ready-to-eat product enriched in calcium. No significant changes in hardness were found, as compared to the unwrapped salmon. Estimated intakes of bioaccessible calcium increased significantly by 3.6-fold, whereas intake of bioaccessible fat was reduced by 15%. SFA were the main fatty acid group reduced (≈80%), whereas MUFA and PUFA were only reduced by ≈20% each. Total viable counts, pseudomonads, enterobacteria, and specific fish spoilers were reduced by 2-4 log CFU/g in wrapped sample during the chilled storage period (19 days).

Chemical characterization of wash water biomass from shrimp surimi processing and its application to develop functional edible films

The aim of this work was to recover and study the composition of the biomass obtained from the surimi processing industry, and to explore the feasibility of its valorization by developing functional edible films. A concentrate from wash water of minced shrimp muscle of low commercial value [shrimp concentrate (SC)] was obtained by alkaline solubilization and isoelectric precipitation, which had protein content of 61.8% and fat 23.6%. The protein fraction of low molecular weight (≤37 kDa), with maximum solubility at basic pH 9-11, and was rich in essential amino acids (296 essential amino acids/1000 residues), whereas the fat fraction showed a high degree of unsaturation (26.8% MUFA, 28.3% PUFA). SC, showed antioxidant activity measured by FRAP and ABTS assays and, was successfully incorporated into an agar film matrix (agar-to-protein ratio of 3:1). The films were translucent and brownish and maintained integrity upon immersion in water, but swelled considerably. Films were able to release protein and exert antioxidant activity in water and 95% ethanol (aqueous and fatty food simulants, respectively), the release being faster and greater in the former. In conclusion, the biomass obtained from shrimp mince/surimi processing was for developing edible films.

The JAK2 pathway is activated in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is the most rapidly progressive and fatal fibrotic disorder, with no curative therapies. The signal transducer and activator of transcription 3 (STAT3) protein is activated in lung fibroblasts and alveolar type II cells (ATII), thereby contributing to lung fibrosis in IPF. Although activation of Janus kinase 2 (JAK2) has been implicated in proliferative disorders, its role in IPF is unknown. The aim of this study was to analyze JAK2 activation in IPF, and to determine whether JAK2/STAT3 inhibition is a potential therapeutic strategy for this disease.

Methods and results

JAK2/p-JAK2 and STAT3/pSTAT3 expression was evaluated using quantitative real time-PCR, western blotting, and immunohistochemistry. Compared to human healthy lung tissue (n = 10) both proteins were upregulated in the lung tissue of IPF patients (n = 12). Stimulating primary ATII and lung fibroblasts with transforming growth factor beta 1 or interleukin (IL)-6/IL-13 activated JAK2 and STAT3, inducing epithelial to mesenchymal and fibroblast to myofibroblast transitions. Dual p-JAK2/p-STAT3 inhibition with JSI-124 or silencing of JAK2 and STAT3 genes suppressed ATII and the fibroblast to myofibroblast transition, with greater effects than the sum of those obtained using JAK2 or STAT3 inhibitors individually. Dual rather than single inhibition was also more effective for inhibiting fibroblast migration, preventing increases in fibroblast senescence and Bcl-2 expression, and ameliorating impaired autophagy. In rats administered JSI-124, a dual inhibitor of p-JAK2/p-STAT3, at a dose of 1 mg/kg/day, bleomycin-induced lung fibrosis was reduced and collagen deposition in the lung was inhibited, as were JAK2 and STAT3 activation and several markers of fibrosis, autophagy, senescence, and anti-apoptosis.

Conclusions

JAK2 and STAT3 are activated in IPF, and their dual inhibition may be an attractive strategy for treating this disease.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0728-9) contains supplementary material, which is available to authorized users.

Freeze-dried phosphatidylcholine liposomes encapsulating various antioxidant extracts from natural waste as functional ingredients in surimi gels

Three antioxidant extracts (collagen hydrolysate, pomegranate peel extract, shrimp lipid extract) were encapsulated in soy phosphatidylcholine liposomes with the addition of glycerol. The particle size of the fresh liposomes ranged from 75.7 to 81.0 nm and zeta potential from -64.6 to -88.2 mV. Freeze-drying increased particle size (199-283 nm), and slightly decreased zeta potential. The lyophilized liposomes were incorporated in squid surimi gels at 10.5% concentration. An alternative functional formulation was also prepared by adding 2% of non-encapsulated bioactive extract. The gels were characterized in terms of colour, texture and oxidative stability (TBARS) after processing and also after frozen storage. The incorporation of the freeze-dried liposomes caused a slight decrease in gel strength and contributed to maintaining the stability of the gels during long-term frozen storage. The antioxidant properties of the bioactive extracts, liposomes and in vitro digested surimi gels were determined.

Effect of chemical composition and sonication procedure on properties of food-grade soy lecithin liposomes with added glycerol

The effect of two-step and five-step acetone washing of soybean lecithin (SL) on compositional properties of partially purified phosphatidylcholines (PW2 and PW5) was studied. Trace amounts of protein were detected in SL, PW2 and PW5, with a predominance of glutamic acid and aspartic acid. Increasing the number of acetone washing steps significantly reduced the total content of γ-, δ- and α-tocopherol. Similar reductions (≈90%) of neutral lipids were found in both PW2 and PW5, but the removal of free fatty acids was higher in PW5 than in PW2 (78% vs. 71%). Linoleic acid was the main constituent in both the neutral lipids and the phospholipid fractions of SL, PW2 and PW5, accounting for around 53-59% of total fatty acids; however, a considerable amount of it was removed by increasing the number of washing steps. All phospholipid classes were mostly concentrated in the first two-step washing of lecithin. Further washing increased the concentration of phosphatidylcholine (PC) in PW5, as compared to PW2. Glycerol-containing liposomes from PW2 and PW5 were produced using two different-intensity sonication procedures (method A: 120W, 5min; method B: 30W, 2min) using a probe-type sonicator (100mL volume suspension). Liposomes of soy lecithin and liposomes of PW5 without glycerol were also obtained by using strong sonication (method A). The liposomal dispersion with the highest purification and the stronger sonication was clearly distinguished from the others, both in particle size and in zeta potential. DSC results showed noticeable interference of glycerol in the membrane structure, but minimal changes in particle size and surface charge.

Computer keyboard interaction as an indicator of early Parkinson's disease

Parkinson’s disease (PD) is a slowly progressing neurodegenerative disease with early manifestation of motor signs. Objective measurements of motor signs are of vital importance for diagnosing, monitoring and developing disease modifying therapies, particularly for the early stages of the disease when putative neuroprotective treatments could stop neurodegeneration. Current medical practice has limited tools to routinely monitor PD motor signs with enough frequency and without undue burden for patients and the healthcare system. In this paper, we present data indicating that the routine interaction with computer keyboards can be used to detect motor signs in the early stages of PD. We explore a solution that measures the key hold times (the time required to press and release a key) during the normal use of a computer without any change in hardware and converts it to a PD motor index. This is achieved by the automatic discovery of patterns in the time series of key hold times using an ensemble regression algorithm. This new approach discriminated early PD groups from controls with an AUC = 0.81 (n = 42/43; mean age = 59.0/60.1; women = 43%/60%;PD/controls). The performance was comparable or better than two other quantitative motor performance tests used clinically: alternating finger tapping (AUC = 0.75) and single key tapping (AUC = 0.61).

Gelificación de serrín de merluza (Merluccius australis) / Gelling of hake (Merluccius australis) sawdust

Fish 'sawdust' is powdered muscle produced by sawing blocks of frozen fish. It is an underuti lized material with very poor functional properties, and is difficult to use in reconstituted prod ucts without the addition of ingredients to enhance these properties. In order to enhance the gel-forming capacity of sawdust from hake muscle (Merluccius australis), different ingredients were added: (1) a formula (designated ACC formula) composed of starch, i-carrageenan and dried egg white (at a proportion of 5, 5 and 3% respectively of the dough), (2) surimi from the same species as sawdust, and (3) sodium ascorbate (100-1500 ppm). The results suggest that fish sawdust with either ACC formula or a high proportion of surimi could be used to produce gels (folding test score 5) highly suitable for restructuring fish products, with good water holding ability (more than 93%) but poor gel strength (13 N·mm). If the proportion of surimi exceeded 75% (with respect to total muscle) and the formula contained sodium ascorbate (750 ppm), gel strength was much greater (more than 40 N·mm).

Chemical and functional properties of sardine (Sardina pilchardus W.) dark and light muscle proteins during frozen storage. Effect of washing on mince quality / Propiedades químicas y funcionales de las proteínas del músculo oscuro y claro de sardina (Sardina pilchardus w.) durante el almacenamiento en congelación. Efecto del lavado en la calidad del músculo picado

This paper examines the effects of eight months of frozen storage on the protein conformation and functionality of whole, light and dark sardine muscles, and washed mince. The variation in protein surface hydrophobicity and Ca-ATPase activity was different in dark muscle from that in whole muscle over the storage period. The dark muscle lacked gel forming capacity because of its higher fat content and a greater presence of low molecular weight proteins, and it also became insoluble faster than the light muscle. The Ca-ATPase activity of the actomyosin extracted from the dark muscle was higher than in light or whole muscle during the first three months. Washing the minced muscle induced conformational changes in the myosin molecule which, together with the added cryoprotectants, contributed to greater functional stability of the washed mince at least during the first three month's storage, at which stage gels were somewhat softer and more elastic than with unwashed mince.

Extension of shelf life of chilled hake (Merluccius capensis) by high pressure/Prolongación de la vida útil de merluza (Merluccius capensis) sometida a altas presiones conservada en refrigeración

Vacuum packed hake muscle subjected to 400 MPa (three 5-min cycles) at 7 °C proved to be more stable at chilled temperatures (2-3 °C), and sensorially acceptable, until 43 days of storage in comparison with the nine days for the non-pressurized hake. The lot pressurized at 400 MPa had the appearance of cooked muscle. The microbial load was initially reduced by two log units by pressurization at 400 MPa. Trimethylamine nitrogen (TMA-N) values were also very low. Pressurization had no effect on dimethylamine nitrogen (DMA-N) production. The lot pressurized at 400 MPa showed slower increase in drip loss from day 15 of storage. In the lot subjected to 200 MPa (three 5-min cycles) at 7 °C, which retained the appearance of raw fish, microorganisms were one log unit lower than in the non-pressurized sample and TMA-N was lower. In conclusion, the chilled shelf life was prolonged by about one week in the lot pressurized at 200 MPa and about two weeks in the lot pressurized at 400 MPa.

Influencia de la subespecie, estacionalidad y procedimientos de estabilización en la aptitud gelificante del músculo de sardina (Sardina pilchardus) congelado/Influence of subspecies, season and stabilization procedures in gel-forming ability of frozen minced muscle of sardine (Sardina pilchardus)

This paper examines the gel-forming ability of minced muscle of sardine - caught from the Bay of Biscay and the Mediterranean at different seasons - kept in frozen storage for 150 days. The influence of atmospheric and vacuum packaging on the gel-forming capacity of minced muscle, and the addition of tocopherol as antyoxidant were also studied. From the outset of frozen storage, Mediterranean sardine muscle exhibited greater gel strength than that from the Bay of Biscay. Sardines from the Bay of Biscay caught in November produced the best gels from any area. Generally, when frozen muscle was vacuum-packed, rancidity was less and gel strength improved. Activity of tocopherol does not seem sufficiently clear. In nearly all cases, gel strength was greater the longer the muscle was kept in frozen storage, although in Bay of Biscay sardine muscle there was progressive myofibrillar protein aggregation throughout the storage.

Partial protease activity characterization of squid (Todaropsis eblanae) mantle / Caracterización parcial de la actividad proteolítica del manto de pota (Todaropsis eblanae)

Proteolytic activity in mantle of Todaropsis eblanae was maximum at 40 and 65 °C. Several peaks of activity were detected over the pH range studied (1.5-9.5), indicating the presence of acidic, neutral and alkaline proteases, depending on the temperature. The substantial enzymic inhibition at acidic pH by the inhibitor trans-epoxysuccinyl-L-leucylamine-4-guanidine butane (E-64) revealed the pre dominance of lysosomal cysteine proteases (cathepsins) which showed higher activity at 65 °C than at 40 °C. At 65 °C and pH 5.5 metallo-proteases were also detected by the inhibition with phenanthroline. Serine protease activity predominated at neutral pH (higher at 40 °C than at 65 °C), and cysteine proteases were detected at alkaline pH. There was evidence of cathepsin B and L activity at 65 °C and to a lesser degree at 40 °C.

Maternal plasma antioxidant status in the first trimester of pregnancy and development of obstetric complications

INTRODUCTION

Oxidative stress is present in pregnancy complications. However, it is unknown if early maternal antioxidant status could influence later development of complications. The use of assisted reproduction techniques (ART) is rising due to the delay of first pregnancy and there is scarce information on its influence on oxidative balance.

OBJECTIVE

To assess the possible relationship between maternal plasma antioxidant status in first trimester of gestation with later development of pregnancy complications, evaluating the influence of ART and nutrition.

METHODS

Plasma from 98 healthy pregnant women was obtained at week 10, nutrition questionnaires filled and women were followed until delivery. We evaluated biomarkers of oxidative damage (carbonyls, malondialdehyde-MDA), antioxidants (thiols, reduced glutathione, phenolic compounds, catalase and superoxide dismutase activities) by spectrophotometry/fluorimetry and melatonin (ELISA). Antioxidant status score (Antiox-S) was calculated as the computation of antioxidants. Diet-antioxidants relationship was evaluated through multiple correspondence analysis.

RESULTS

Melatonin and carbonyls exhibited a negative correlation. No difference in oxidative damage was found between groups, but Antiox-S was significantly lower in women who developed complications. No differences in oxidative damage or Antiox-S were found between ART and no-ART pregnancies. High consumption of foods of vegetable origin cluster with high plasma levels of phenolic compounds and with high Antiox-S.

CONCLUSIONS

In early normal gestation, low plasma antioxidant status, assessed through a global score, associates with later development of pregnancy complications. Larger population studies could help to determine the value of Antiox-S as predictive tool and the relevance of nutrition on maternal antioxidant status.

Behavior of Octopus Muscle (Octopus vulgaris) under a Process of Pressure-Time-Temperature Combinations

Octopus muscle ( Octopus vulgaris) of different sex was treated for various different simultaneous combinations of pressure (0.1 or 450 MPa), time (15 or 30 min) and temperature (7, 40, 75 or 100 °C). The sex of specimens was not a significant factor. High pressure was effective in reducing the microbial load and the intense autolytic activity in the octopus muscle. Pressurization time was found to be a significant factor for hardness, but neither hardness nor the exudates were reduced by pressurizing at 450 MPa. Progressive raising of the temperature increased the drip loss, while hardness was reduced only at high temperatures. Increasing temperature produced ultrastructural changes relating to softening, but nevertheless, the ultrastructural changes observed after pressurization did not correspond with modifications in shear strength.

Incorporation of liposomes containing squid tunic ACE-inhibitory peptides into fish gelatin

BACKGROUND

Hydrolysates from collagen of jumbo squid (Dosidicus gigas) tunics have shown excellent angiotensin I-converting enzyme (ACE)-inhibitory activity. However, peptides directly included in food systems may suffer a decrease in activity, which could be minimized by loading them into nanoliposomes.

RESULTS

A fraction of peptides with molecular weights <1 kDa obtained from hydrolyzed squid tunics, with reasonably high ACE-inhibitory activity (half-maximal inhibitory concentration IC50 = 0.096 g L(-1)), was encapsulated in phosphatidylcholine nanoliposomes. The peptide concentration affected the encapsulation efficiency and the stability of the resulting liposomes, which remained with a high zeta potential value (-54.3 mV) for at least 1 week at the most suitable peptide concentration. The optimal peptide concentration was established as 1.75 g L(-1). Liposomes obtained with this peptide concentration showed an encapsulation efficiency of 53%, a zeta potential of -59 mV, an average diameter of 70.3 nm and proved to be stable in the pH range 3-7 at 4 °C.

CONCLUSION

Liposomes containing ACE-inhibitory peptides were incorporated in fish gelatin without detriment to the rheological properties and thermal stability of the resulting cold-induced gel. The ACE-inhibitory activity of the peptide fraction, which was not affected by the encapsulation process, conferred the bioactive potential to the nanoliposome-containing gelatin gel.

Enhancement of ACE and prolyl oligopeptidase inhibitory potency of protein hydrolysates from sardine and tuna by-products by simulated gastrointestinal digestion

This work was focused on the study of the bioactive potential of three fish protein hydrolysates, prepared from industrial sardine and tuna by-products.