New technical combination of seawater and ultrasound wave energy for excavation of highly plastic sticky clays in urban EPB tunneling

In urban tunneling with an earth pressure balance-tunnel boring machine (EPB-TBM), highly plastic clays or sticky clay containing fine-grained sediments makes tunneling conditions more difficult. The proper amount and consistency of the ground conditioning chemicals to be used for the excavation of these difficult or complex geological units are also controversial. Due to the lack of proper management and optimization of such chemical foaming agents in accordance with the excavation material and tunneling method, some environmental impacts may occur. However, environmental pollution and its effects, in other words, the ecological costs emerged as a result of exposure to these chemicals, can sometimes be ignored.

In this study, the use of seawater is proposed as a ground conditioning agent in EPB-TBM operations and the use in addition of ultrasound wave energy application on fine-grained and highly plastic sedimentary clays conditioned with seawater.

Preliminary analyses and evaluations of the new eco-technical combination indicate that the seawater can easily compete with existing sodium-based foaming agent (SLES) on a laboratory scale by providing the required dispersive effect, which can be enhanced with ultrasonic applications.

     

Effect of high pressure (HP) on the quality and shelf life of red mullet (Mullus surmelutus)

The effect of different temperature/time/pressure high hydrostatic pressure (HP) treatment on the quality and shelf life of red mullet were studied. Different high pressure treatments (at 3, 7, 15 and 25 °C, 5 to 10 min and 220, 250 and 330 MPa) were tested to establish the best processing conditions for the quality of red mullet. The effect of the process on the quality of the sample was examined by colour, Trimethylamine nitrogen (TMA-N) and Thiobarbituric acid number (TBA) analysis. Based on the results of the parameters, the best combinations of HP treatments were determined as 220 MPa/5 min/25 °C and 330 MPa/5 min/3 °C for red mullet. The effects of this combination treatment on sensory, chemical and microbiological properties of red mullet stored at 4 °C were studied. The results obtained from this study showed that the shelf life of untreated and HP treated stored at 4 °C, as determined by overall acceptability of sensory and microbiological data, are 12 days for untreated red mullet and 14 days for treated red mullet at 220 MPa for 5 min at 25 °C and 15 days for treated red mullet at 330 MPa for 5 min at 3 °C.Industrial relevanceFresh fish have short shelf life. HP treatment has shown to be an effective method to control pathogen and spoilage microorganisms in fish and fish products. However, high pressure treatment can promote colour and oxidation changes that could modify their sensory characteristics. The main objective of the first part of this study was to detect the best combination among the applied pressure (220, 250 and 330 MPa), temperature (3, 7, 15 and 25 °C) and time (5 and 10 min) combinations. The treatment ranges were chosen according to the unchanging colour, lower TBA value and TMA stability by HP and considering the economical aspects of HP processing. In the second part of the study, HP was applied on the selected samples and a shelf-life study was performed by measuring the changes in the quality parameters, of the samples throughout their storage. The storage conditions were set so as to achieve refrigeration handling (4 °C). Shelf-life estimation was performed according to the data obtained. HP (at 220 MPa for 5 min at 25 °C and at 330 MPa for 5 min at 3 °C) treatment is the most effective treatment for shelf-life extension as compared to non-treated red mullet.     

Quality characteristics of spent layer<Emphasis Type="Italic"> surimi</Emphasis> during frozen storage

The effects of different washing solutions and cryoprotectants on quality characteristics of spent layer surimi were studied during frozen storage at –18 °C. The highest (P<0.05) process yield was obtained with 0.5% sodium bicarbonate and 0.04 M sodium phosphate buffer solutions. While washing resulted in decreases (P<0.05) in protein, fat, cholesterol and ash contents, collagen and myofibrillar protein showed increases compared to the unwashed mince. A cryoprotectant mixture of 2% sucrose+2% sorbitol+0.3% sodium pyrophosphate resulted in higher water-holding capacity, except for surimi washed with 0.04 M sodium phosphate buffer solution, and lower cooking loss (P<0.05) than a cryoprotectant mixture of 4% sucrose+2.8% sorbitol. Increased lightness and decreased redness was observed as a result of washing with all solutions (P<0.05).     

Protective effect of Spirulina platensis enriched in phenolic compounds against hepatotoxicity induced by CCl4

Phenolic compounds make up the major secondary metabolites with high pharmaceutical potential. Microalgae were reported to contain low amounts of phenolic compounds. The present study aimed to investigate the hepatoprotective potential of biomass of Spirulina platensis enriched in phenolic compounds. The protective effects of the biomass of S. platensis with low amounts of phenolics (SP1) and with high amounts of phenolics (SP2) against CCl₄-induced acute hepatotoxicity were evaluated in rats. The increased levels of ALT, AST and MDA along with decreased activities of SOD and CAT were significantly (p < 0.01) ameliorated by SP2. Histological examinations revealed that SP2 was more potent than SP1 in protecting the liver from toxic injury of CCl₄ and preserving the hepatocyte ultrastructure. The lesions including necrosis, lymphocyte infiltration, ballooning degeneration and hepatocyte injury as irregular lamellar organisation, dilations in endoplasmic reticulums and the presence of great number of cytoplasmic vacuolization were healed by SP2.     

Gutted and Un-Gutted Sea Bass (Dicentrarchus Labrax) Stored in Ice: Influence on Fish Quality and Shelf-Life

The sensory characteristics, chemical freshness indicator contents, and microbial counts (total aerobe, psychrotrophic bacteria, H₂S-producing bacteria, and Pseudomonas spp.) of whole un-gutted and gutted sea bass stored in ice were compared. Results of this study indicated that the acceptability quality of whole and gutted sea bass as determined by sensorial data is 11 days, respectively. No significant differences (p > 0.05) were found in the level of sensory score between whole and gutted sea bass samples. Total volatile basic nitrogen (TVB-N) values showed no significant increase for whole and gutted sea bass during storage. Trimethylamin (TMA-N) values of whole and gutted sea bass increased very slowly, reaching final values of 3.94 and, 3.38 mg/100g, respectively (day 13). Development of initial decomposition (after 7 days) occurred when bacterial counts were > 4 log CFU/g. Microbial counts showed a significant increase for whole and gutted sea bass during storage. Significant differences (p < 0.05) were found in the microbial counts between whole and gutted sea bass samples. This difference, may be attributed either to gutting procedures, which most probably were the cause of cross-contamination of fish or to the significantly higher fish flesh surface area exposed to environmental microbial contamination in the case of gutted fish.     

Copper contents in grapes and wines from a Mediterranean organic vineyard

This work was conducted in an organic vineyard in Bari (South-Eastern Italy) to evaluate copper concentrations in grapes and wines of four local and international varieties (Chardonnay, Primitivo, Uva di Troia and Negroamaro) and to relate these contents to total and available copper concentrations in soil. Approximately 7.4 kg/ha of copper were used in the trial year. Soil copper availability was higher in the 0–20 cm (10.3%) than in the 20–40 cm layer (4.7%). No copper phytotoxicity was observed on leaves. Copper residues on berries and in wines resulted below the maximum residue levels (MRLs). Concentrations in berries increased with applications number and varied according to the variety. Copper content in the white wine (Chardonnay) was higher with respect to red ones (Primitivo, Uva di Troia and Negroamaro). Results provided evidence that in the natural conditions typical of a Mediterranean environment, characterised by calcareous soils and a dry climate, the use of copper formulations in vineyards according to European legislation guidelines should not raise any concern with regards to human health.     

Adsorption of dark compounds with bentonites in apple juice

The adsorption equilibrium of dark-coloured compounds from apple juice has been investigated as a function of several variables including activation conditions of bentonite (heat and acid treatments), clay concentrations (2×10⁻³-8×10⁻³ kg clay/dm³ apple juice) and temperature (range of 296-336 K). The adsorption efficiency with acid-activated bentonite was greater than that with heat-activated and native bentonite, depending on surface properties; specific surface areas were 95.31, 71.95 and 71.76 m²/g, respectively.Absorbance data at 420 nm were fitted reasonably well with the Langmuir and Freundlich isotherms. The parameters K, Q₀, K_fr and n were determined for different temperatures. Thermodynamic parameters such as Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) change of adsorption were determined as about −3.125, 9.43 and 0.039 kJ mol⁻¹ K⁻¹, respectively, for acid-activated bentonite. These parameters were also determined for native and heat-activated bentonites. It was shown that the adsorption process was endothermic, spontaneous and controlled by physical mechanism. The adsorption and desorption rate constants (k_a and k_d) were obtained separately by applying a geometric approach to the first-order Langmuir model. k_a varied from 5.717×10⁻⁴ to 20.667×10⁻³ s⁻¹ and k_d from 1.425×10⁻⁴ to 7.473×10⁻³ s⁻¹. The results showed that acid-activated bentonite is more suitable for the adsorption of dark compounds from apple juice.     

Extraction of sesame seed oil using supercritical CO2 and mathematical modeling

In this work, extraction of sesame oil from sesame seeds using supercritical CO₂ was carried out. The effect of operating parameters such as pressure, temperature, and supercritical CO₂ flow rate and particle size on extraction yield were investigated. An increase in the pressure and the supercritical CO₂ flow rate improved the extraction yield and also shortened the extraction time. The extraction yield increased as the particle size decreased depending on decreasing intraparticle diffusion resistance. The maximum extraction yield obtained was about 85% (relative to Soxhlet extraction by hexane) at 50 °C, 350 bar, 2 mL CO₂/min, 300–600 μm of particle size. Some extraction curves were modeled with two mathematical approaches as shrinking core model and broken and intact core model. The evaluation of model parameters showed that shrinking core model, however, is better than broken and intact cell model.     

The Effect of Thyme and Garlic Oil on the Preservation of Vacuum-Packaged Hot Smoked Rainbow Trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)

Quality and shelf life of filleted hot smoked rainbow trout packaged in vacuum packaging (untreated) and with thyme oil (TO), and garlic oil (GO)-treated, after vacuum-packaged (VP) conditions stored at 2 °C, were investigated by measurement of microbiological, sensory and physicochemical analyses. Acceptability scores for appearance, odour, taste and texture of untreated and treated smoked trout decreased with storage time. The limit of sensory acceptance was reached after 5 weeks for the untreated samples, after 7 weeks for with thyme oil-treated samples (TO + VP) and after 6 weeks for with garlic oil-treated (GO + VP) samples. Total viable count evaluated that thyme oil- and garlic oil-treated vacuum-packaged samples had good results up to 7 weeks compared with 5 weeks in control vacuum packs. Psychrotrophic counts for untreated and treated samples exceeded 6 log cfu/g after 5 and 6 weeks of cold storage, respectively. Treated samples presented the lowest lactic acid bacteria counts. Total volatile basic nitrogen and trimethylamine nitrogen values gave acceptable results for up to 5 weeks for the untreated samples, 7 weeks for thyme- and garlic oil-treated samples. Treated with thyme oil samples presented the lowest thiobarbituric acid index values. The results obtained from this study showed that the shelf life of hot smoked rainbow trout stored in cold storage (2 °C), as determined by overall acceptability of all data, is 5 weeks for vacuum-packaged samples and 7 weeks for thyme- and garlic oil-treated vacuum-packaged smoked fish.     

Seasonal Micro- and Macro-Mineral Profile and Proximate Composition of Oyster (Ostrea edulis) Analyzed by ICP-MS

Oysters (Ostrea edulis) were investigated for micro–macro-mineral content and proximate composition throughout the year. Mercury, lead and aluminium were found to be below the legislative limits, while zinc was over throughout the year. Cadmium and copper were over legislative limits in winter. While the highest Na, Mg and Ca values were found in autumn, the highest K and P contents were found in spring. Ranges of moisture, protein, fat and ash contents were 71.06–80.65, 6.85–10.30, 1.47–5.51 and 3.42–9.45 g/100 g, respectively. While the highest protein, fat, ash values were found in spring, the highest moisture contents were found in autumn.