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关键词： Oxidation  

摘要： The effects of polysaccharide from chicory root on the sensory quality and storage quality of silver carp surimi balls were studied. First, chicory polysaccharides with nine gradient dosages (0%-8%) were added to surimi balls, and the optimal amount of chicory polysaccharides was determined to be 3% by sensory evaluation and fuzzy mathematical matrix. Then, the changes of drip loss, pH value, texture properties analysis (elasticity and hardness), total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and total plate count were measured. In addition, partial least squares regression (PLSR) was used to analyze the changes of fatty acid composition. The results showed that the addition of 3% chicory polysaccharide could reduce the drip loss and the pH fluctuation, maintain the better hardness and elasticity, decrease the oxidation of protein and lipids, as well as inhibit the reproduction of microorganisms. Practical applications Results from this study showed the potential of polysaccharide from chicory root adding in silver carp surimi balls to improve physicochemical properties of the surimi balls during storage. The optimal amount of chicory polysaccharides was determined to be 3% by sensory evaluation and fuzzy mathematical matrix. In addition, the addition of 3% of chicory polysaccharide could reduce the drip loss and the pH fluctuation, keep good structural properties, inhibit the oxidation of protein, lipids, and inhibit microbial reproduction during storage. It provides reference for the application of natural plant polysaccharides in easily oxidized surimi products.

关键词： Natural ingredient   Mortadella   Fat replacer   Descriptive analysis   Sensory profiling  

摘要： The potential of green banana biomass (GBB) as a natural ingredient and its impact as a fat replacer in chicken mortadella on sensory perception were investigated. The GBB was assessed for physicochemical characterization, antioxidant capacity and antimicrobial activity. Five chicken mortadella formulations were developed with fat replacement of 25, 50, 75 and 100% by GBB. Microbiological stability of the formulations was assessed, and the sensory profiling was evaluated by Preferred Attribute Elicitation (PAE). The dietary fiber, resistant starch, total phenolic compounds and antioxidant capacity in GBB were 3.99%, 4.16%, 518.39 mg GAE/100 g (GAE: Gallic acid equivalent) of dry sample, 5307.62 mu mol of trolox equivalent (TE)/100 g of dry sample and 3583.12 mu mol of trolox equivalent (TE)/100 g of dry sample, respectively. GBB contained potassium (1121 mg/100 g), phosphorus (183.6 mg/100 g), magnesium (77.4 mg/100 g), copper (0.53 mg/100 g) and iron (7.21 mg/100 g). The microbial counts in the formulations after 90 days of chill storage were within the safe limit. The results concluded that GBB showed desirable functional and technological proprieties to be used in chicken mortadella without affecting the characteristic flavor of these products. Besides, PAE proved to be a potential method to characterize chicken mortadella.

关键词： Additive   {LiBr    +    water} system   VLE   Density   Viscosity   COSMO-RS  

摘要： In recent years, many compounds have been proposed as additives to conventional working fluids to improve the performance of the absorption refrigeration system. The main aim of this research is to show the influence of ionic liquid based additives on thermodynamic and physicochemical properties of {LiBr + water} solutions. The following additives: 3-(1-methyl-morpholinium)propane-1-sulfonate, N,N-di(2-hydroxyethyl)-N,N-dimethylammonium bromide, and N,N,N-tri(2-hydroxy-ethyl)-N-methylammonium bromide have been added to aqueous lithium bromide solutions (IL to LiBr mass fraction, w(2) = 0.3). The physicochemical and thermodynamic properties of {LiBr (1) + additive (2) + water (3)} and {LiBr + water} systems including (vapor + liquid) phase equilibria (VLE), density (rho) and dynamic viscosity (eta) were determined over wide temperature and composition ranges. The conductor-like screening model for real solvents (COSMO-RS) was used for the VLE data prediction. For the density and dynamic viscosity correlations, empirical equations were applied. A comparison of experimental data for {LiBr + additive + water} with those for {LiBr + water} systems shows the influence of using the additives proposed in this work. The data presented are complementary to the current state of knowledge in this area and provide directions for future research.

关键词： Carrots   Carotenoids   Co-crystals   Encapsulation   Antioxidants  

摘要： Natural pigment carotenoids specifically beta-carotene present in carrots is very sensitive to heat and light. The present work studied the co-crystallization as a process to increase the stability of the carotenoids extracted from carrots. Carotenoids encapsulated co-crystals were evaluated for their encapsulation efficiency, antioxidant activity, thermal behavior, physicochemical, and structural properties. Co-crystallization of the carotenoids with sucrose showed an encapsulation efficiency of 77.58% and an antioxidant activity of 68% towards DPPH free radicals. DSC thermogram confirmed the thermal stability of carotenoids encapsulated co-crystals by indicating the endothermic peaks at 190 degrees C. XRD pattern and FTIR spectra revealed that the crystal nature of sucrose and functional groups remained the same even after co-crystallization. SEM results revealed the irregular cavities in well-defined cubic crystals of sucrose which suggested the better entrapment of carotenoids into sucrose. Hence, co-crystallization significantly improved the overall stability of the carotenoids, and these co-crystals can be used as a natural colorant, sweetener, and antioxidant.

关键词： Modified-atmosphere packaging   Vacuum packaging   Shelf-life   Commercial categories   Montanera  

摘要： The physico-chemical characteristics and sensory attributes of Iberian sliced dry-cured loin from three commercial categories according to the current Spanish Iberian Quality Standard (Black, Red;purebred Iberian and Iberian x Duroc-crossed (50%) pigs, respectively, reared outdoor with the final fattening phase based on acorns and grass;Montanera, and White;Iberian x Duroc crossed (50%) pigs reared indoors and fed on commercial fodder) and packaged using different systems (vacuum and modified-atmosphere packaging, MAP) were evaluated at various stages throughout their long-term storage (12 months). The slices from the Black and Red categories yielded higher antioxidants, monounsaturated and polyunsaturated fatty acids and higher lipid oxidation at the end of storage time (from t8 to t12). alpha-tocopherol was better preserved in the case of the slices kept in MAP although, after 8 months of storage, lipid oxidation was seen to increase in the latter (Delta t12-t0 MAP = 0.4) compared to the vacuum packaged product. Regarding sensory evaluation, the marbling and texture attributes were affected by commercial category, whereas the influence was insignificant by type of packaging and storage time.

关键词： N-alkylpyridine trifluoroacetate ionic   liquids   Density   Surface tension   Molar surface Gibbs energy   Polarity  

摘要： Series of N-alkylpyridine trifluoroacetate ionic liquids [CnPy][TFA] (n = 2-6) were designed and synthesized by the neutralization method and characterized by H-1 NMR and DSC. The density, surface tension, and refractive index of [CnPy][TFA] (n = 2-6) with different mass fraction of water were measured by standard addition method (SAM) at (293.15-343.15) K and the respective properties for the anhydrous [CnPy] [TFA] (n = 2-6) were calculated on the basis experimental data. The molecular volume V-m, the standard entropy S-0(298), the crystal energy U-POT, the surface entropy S-a, the surface energy E-a of ionic liquid [CnPy] [TFA] (n = 2-6) were calculated. The enthalpy of vaporization at 298.15 K were estimated according to the Kabo's and Rebelo's empirical equation, and the traditional Ebtvos equations were modified based on the calculated molar surface Gibbs energy, and its coefficients have clear physical meaning. The thermal expansion was estimated by the classical interstitial theory. At the same time, the classical interstitial theory has been improved and the molar surface Gibbs energy of interstice was proposed. In addition, surface tension could be estimated by the molar surface Gibbs energy, and the estimated values were highly correlated with the experimental ones. Finally, the concept of solubility parameter was introduced, which can be used to estimate the polarity of ionic liquids and it was consistent with our experience. (C) 2020 Elsevier Ltd.

关键词： Biochar   Functionalization   Ultrasound   Heavy metals availability   Soil enzyme activities  

摘要： Poor physicochemical characteristics and high heavy metals content are main limitations of applying sludge-based biochars in remediation studies. The present study attempts to combine two practical approaches of ultrasound pre-treatment with low-time and low-frequency and chemical functionalization using citric acid. The aims of this study are enhancement physicochemical characteristics and environmental applicability of sludge-derived biochar. The characteristics of obtained ultrasound-treated functionalized biochar (UFB), sludge-derived biochar (SDB) and sewage sludge (SS) were evaluated. Then, the effects of these additives on soil heavy metals availability, soil enzyme activities and soil physicochemical characteristics were investigated during a 2-month stabilization process. The results indicated that ultrasound pre-treatment and functionalization considerably increased pore volume, surface area, and surface functional groups of the biochar, but significantly decreased total heavy metals concentration and metals ecological risk index (Er). The results of soil amending showed that application of UFB decreased Pb, Zn and Cd availability in soil by 85.3, 82.9 and 30.6%, respectively. In all cases, except for Cd, the Pb and Zn availability decreased by UFB was two times greater than the availability decreased by SDB and SS. Compared to SDB, the UFB potentially enhanced the positive effect of additive on soil enzyme activities. The obtained results revealed that the feasible, uncomplicated physical and chemical techniques can be used as a valuable approach for enhancing the environmental applicability of sludge-derived biochar and management of the excessively produced sewage sludge in the world. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Polysaccharides  

摘要： The effect inulin on the survival of Lactobacillus plantarum 1.0320 in cheese and the physicochemical and sensory features of the cheeses were evaluated. Addition of Lb. plantarum and inulin generated no alterations in the physicochemical characteristics of cheese. Inulin promoted Lb. plantarum growth, and counts were maintained at 8.03 log cfu g(-1), significantly higher (P < 0.05) than that in cheese produced with Lb. plantarum alone at 24 weeks (7.31 log cfu g(-1)). Presence of high levels of Lb. plantarum promoted secondary proteolysis and formation of amino acids, which resulted in favourable sensory qualities in cheese produced with Lb. plantarum and inulin. Interestingly, cheese containing inulin had similar mouthfeel and textual characteristics to full-fat cheese. Lb. plantarum from cheese produced with inulin exhibited satisfactory resistance to simulated gastrointestinal tract conditions. Therefore, incorporation of the Lb. plantarum and inulin is a strategy for improvement of low-fat cheese quality and healthy properties. (c) 2020 Elsevier Ltd. All rights reserved.

关键词： Propolis   Bacterial cell surface   Antimicrobial activity   Electrophoretic mobility   Hydrophobicity   Membrane integrity  

摘要： In the present study, an effort has been made to understand the interaction mode of propolis, a natural substance produced by honey bees, with gram-positive and gram-negative bacterial cells by measuring alterations in cell surface physico-chemical properties following the incubation of the cells with different sub-inhibitory concentrations of this antimicrobial agent. Electrophoretic mobility and surface hydrophobicity measurements revealed for the first time that propolis induced substantial changes in the volumetric charge density, electrophoretic softness and degree of hydrophobicity characterizing the outermost surface layer of cells. These changes, which appear to be dose-dependent, seem to be consistent with the increasing accumulation and penetration of the propolis antimicrobial components through the cells extracellular layer. Moreover, electron microscopy observation and the determination of the cell constituents' release demonstrated that propolis at sub-bactericidal concentrations already provoked (at least localized) cell wall damage and/or perturbations. These findings thus suggest that the initial mechanism of action of propolis is most likely structural, resulting from sufficient interaction between the different propolis components and bacterial cell wall structures.

关键词： Poly(butylene adipate-co-terephthalate)   Surfactant modification   Mechanical properties   Biodegradation in simulated soil  

摘要： This work aimed to prepare surfactant modified-PBAT (poly(butylene adipate-co-terephthalate)) sheets with superior properties to increase the PBAT applicability and be a possible solution for plastic disposal environmental problems. Three different surfactant contents (0, 1, 5, and 10 wt%) were investigated, and their effects on PBAT chemical structure, mechanical and morphological properties, wettability, and water absorption were investigated. Modified-PBAT samples showed high hydrogen bond coefficients (0.57) than the pristine PBAT (0.54), indicating an excellent electrostatic interaction between both components and the formation of a rigid hydrogen-bonded network, as confirmed by mechanical tests, where the elastic modulus values for PBAT and PBAT+10% surfactant were 44 and 60 MPa. SEM images and roughness measurements showed changes in PBAT morphology after surfactant addition, improving the roughness and wettability by the voids and polar groups presence, altering the water absorption (WA) behavior. The higher water affinity resulted in high water absorption for PBAT-10%S (17%) compared to the pristine PBAT (2%), which improves hydrolysis tendency, which is the initial step to biodegradation. Biodegradation results indicated that the roughness and WA behavior influenced the biodegradation rate, facilitating hydrolysis and microbial attack, and accelerating modified samples weight loss. Our results suggested developing a material with superior mechanical properties, mainly for PBAT-10%S, that can be applied in several applications, such as packaging and furniture. After discharge, it is not an environmental problem, being a biodegradable material with a green character. (C) 2020 Elsevier Ltd. All rights reserved.