Flavor and quality characteristics of salted and desalted cod (Gadus morhua) produced by different salting methods

Flavor characterization and quality of salt-cured and desalted cod (Gadus morhua) products was studied using sensory analysis and gas chromatography techniques. The products were produced in Iceland using two different processing methods (filleting and splitting) and three different salting procedures, i.e., the old single-step kench salting or a multistep procedure, and presalting (injection and brine salting or only brine salting), which was followed by kench salting. The main difference observed was between fillets and split fish, where the split fish was darker and had stronger flavor characteristics. Comparison of different salting procedures showed that the use of presalting improved the appearance of the salted products, which can be described as increased lightness and reduced yellowness of the products. In the same products, the intensity of curing flavors was milder, as described by sensory analysis and key aroma compounds. Derivatives from lipid and protein degradation contribute to the characteristic flavor of the salted products.     

Relationship Between Soft Wheat Flour Physicochemical Composition and Cookie‐Making Performance

Nowadays in Argentina, cookies, crackers, and cakes are made of flour obtained from bread wheat with additives or enzymes that decrease the gluten strength but increase production costs. The present research work aims to study the relationship between flour physicochemical composition (particle size average [PSA], protein, damaged starch [DS], water soluble pentosans [WSP], total pentosans [TP], and gluten), alkaline water retention capacities behavior, solvent retention capacities profile (SRC) and cookie‐making performance in a set of 51 adapted soft wheat lines with diverse origin to identify better flour parameters for predicting cookie quality. Cookie factor (CF) values were 5.06–7.56. High and significant negative correlations between sucrose SRC (–0.68), water SRC (–0.65), carbonate SRC (–0.59), and CF were found, followed by lactic SRC that presented a low negative but significant correlation (r = –0.35). The flour components DS (r = –0.67), WSP (r = –0.49), and TP (r = –0.4) were negatively associated to CF. PSA showed a negative correlation with CF (r = –0.43). Protein and gluten were the flour components that affected cookie hardness, but no significant correlation were found with pentosan or DS content. A prediction equation for CF was developed. Sucrose SRC, PSA, and DS could be used to predict 68% of the variation in cookie diameter. The cluster analysis was conducted to assess differences in flour quality parameters among genotypes based on CF. Clusters 1 and 4 were typified by lower CF (5.70 and 5.23, respectively), higher DS, pentosan content, and SRC values. Cluster 2 with a relative good CF (6.47) and Cluster 3 with the best cookie quality, high CF (7.32) and low firmness, and the lowest DS, TP, WSP content, and sucrose SRC values.     

Nutritional response of seedling tomato plants under different lighting treatments

In order to describe the effect of complementary artificial light supply on the nutrient status of tomato seedlings, fluorescent lamps were compared to each other. Nitrogen (N), phosphorus (P), and potassium (K) concentrations were measured (mg g^?1 dry matter). Blue, red and far-red relationships were established. The N, P and K higher concentration and uptake have been found under high efficiency fluorescent lamps. Phosphorus uptake increasing was observed at high levels of irradiation. Potassium concentration is significantly higher under compact fluorescent lamps. The relationship between ratios and N, P and K extractions were used as indicators of limitation for plant. The ratio N/P and N/K present a low relation with N extraction. The ratio N/P presents a significant correlation with P extraction, also the ratios N/K and P/K with K extraction. Significant differences in constant of lineal equation have been found in P/K ratio and K extraction.     

Photocatalytic Removal of the Antibiotic Cefotaxime on TiO<Subscript>2</Subscript> and ZnO Suspensions Under Simulated Sunlight Radiation

This study presents the main results about the removal of the antibiotic cefotaxime (CTX) under simulated sunlight radiation using heterogeneous photocatalysis with titanium dioxide (TiO₂) and zinc oxide (ZnO) in aqueous solutions. The effects of pH and catalyst initial load on pollutant removal were assessed considering the response surface methodology and a central composite circumscribed experimental design, which allowed to determine the optimized conditions that lead to a higher substrate elimination. Experimental results indicated that evaluated parameters have a significant effect on antibiotic removal in both TiO₂ and ZnO suspensions. In addition, the role of photogenerated holes, hydroxyl, and superoxide anion radicals on CTX degradation was evaluated to clarify the reaction mechanism. Finally, analysis of the dissolved organic carbon content in solutions and the antibacterial activity of treated samples showed that photocatalytic treatments were able to reduce a considerable portion of the organic matter present in the systems and its antimicrobial activity.     

Effects of Vermicompost and Vermiwash on Plant,Phenolic Content,and Anti-oxidant Activity of Mexican Pepperleaf (Piper auritum Kunth) Cultivated in Phosphate Rock Potting Media

The aim of this investigation was to determine the effect of vermicompost, vermiwash, and phosphate rock on plant, total phenols, flavonoids, and anti-oxidant activity in Piper auritum Kunth leaves. P. auritum plants were obtained from cuttings and were planted according to the Box-Behnken experimental design with three repetitions at the central point. The factors and levels were vermicompost (10, 20, and 30 g plant^?1), vermiwash (5, 10, and 15 mL plant^?1), and phosphate rock (1, 2, and 3 g plant^?1). Plant growth parameters (plant height, stem diameter, leaves number) and chlorophyll content were measured 1 month after treatment applications. Total phenols, total flavonoids, and 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity was measured after 4 months. Vermicompost, vermiwash, and phosphate rock had no statistically significant effect on plant growth. Plant height, stem diameter, leaves number, chlorophyll, innermost number, fresh weight stem, fresh weight leaves, fresh weight root, dry weight stem, dry weight leaves, and dry weight root were not different among treatments. Total phenolic compounds were statistically affected for both vermiwash and phosphoric rock (p < 0.05) and the anti-oxidant activity decreased by vermicompost addition. The application of 15 mL plant^?1 vermiwash, 1 g phosphate rock, and 20 g vermicompost plant^?1 increased the total phenol content.     

Aggregate stability in range sandy loam soils Relationships with runoff and erosion

The spatial variability of soil aggregate stability and its relationship to runoff and soil erosion were examined in a catena of soils and vegetation in a semiarid environment at the Rambla Honda field site (Tabernas, Almería, SE Spain) to evaluate the validity of structural stability as a soil erosion indicator in sandy loam range soils. The influence of soil properties and topography on the variability of aggregate stability was also examined. Methods include: 1) aggregate stability assessment at 12 sites (3 repetitions per site) on the hillslope by two methods: a) aggregate size distribution by dry sieving b) water drop test; 2) soil organic carbon content; 3) particle size distribution determination; 4) terrain attributes derived from a digital elevation model (1-m resolution); 5) monitoring runoff and erosion for nearly 3 years in eight (10 × 2 m) plots distributed over the hillslope. Results: 41% of the average soil mass is formed by > 2-mm aggregates. However, wet aggregate stability is poor, with a mean (of a total of 1440 aggregates) of only 26 drop impacts necessary to break up a wet aggregate (pF = 1). Significant relationships were found in the number of water drops required for aggregate breakdown and runoff and erosion rates. However, no significant relationships between the mean weight diameter of aggregates under dry conditions and runoff or erosion rates were observed. The relationships of aggregates with other soil properties, hillslope position and proximity to plants are also analysed. The most significant correlation found was between the number of drop impacts and soil organic matter content. The stability of topsoil aggregates seems to be a valuable indicator of field-assessed runoff and inter-rill erosion of sandy loam range soils under semiarid conditions.     

Silvopastoral systems improve carbon stocks at livestock ranches in Tabasco,Mexico

Silvopastoral systems have great potential for storing carbon because of carbon assimilation in tree woody biomass, carbon input through litterfall and below-ground carbon turnover. In this study, we quantified and compared the carbon stocks at livestock ranches in Tabasco, Mexico, containing either scattered trees in grazing pastures (STP) or grass monocultures. Sampling plots were randomly established at each ranch where the above- and below-ground carbon stocks, carbon input from litterfall, grass production and arboreal biomass growth were measured. We found that silvopastoral systems stored an average of 257.45 Mg ha⁻¹ of soil organic carbon (SOC) compared to 119.17 Mg SOC ha⁻¹ at grass monoculture ranches (to 30 cm depth); silvopastoral systems also stored 44.64 Mg C ha⁻¹ in wood biomass; and, grass monocultures had greater cumulative grass biomass production. Overall, it is concluded that livestock ranches in Tabasco, Mexico, with scattered trees in grazing pastures stored 58.8% more carbon than those grass monocultures, with carbon stocks of 327.01 Mg C ha⁻¹and 134.47 Mg C ha⁻¹, respectively. The results are useful for land management decision making for sustainable livestock systems framed in the Sustainable Development Goals (SDGs).     

A review of extracellular virulence product of Vibrio species important in diseases of cultivated shrimp

Shrimp aquaculture is an important industry that experiences significant losses from Vibrio species, especially at the larval and juvenile stages. Proteinaceous virulence factors, including alkaline proteases, metalloproteases, cysteine proteases and alkaline serine proteases, have been identified as important elements in Vibrio pathogenesis. This review summarizes current knowledge regarding the principal pathogenic Vibrio species in shrimp, with emphasis on relevant exotoxins and their modes of action, principal characteristics and molecular database. This pathogenic factors and their relation with other molecules produced by microorganisms may be help to understand the virulence mechanisms present in Vibrio strain.