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关键词： Emulsions   Gum tragacanth   Irradiation   Rheology   Particle size   Stability  

摘要： The addition of gum tragacanth (GT) as an emulsifier in oil in water systems can reduce the interfacial tension and stabilize emulsions. The major goal of this study was to investigate the particle size distribution, stability and rheological properties of 10% w/w oil in water emulsion at different pH conditions (2.5, 4, and 5.4) as affected by the addition of 0.5% w/w of previously irradiated (0, 1.5, and 3 kGy) GT. Irradiation treatment affected the stability of emulsions by changing rheological properties and parameters describing particle size. The extent of these differences was dose-dependent. Results indicated that using 1.5 kGy irradiated GT was more effective in providing optimum values of particle size and maximum emulsion stability. The least consistency coefficient (0.38 Pa s) and the most unstable emulsion were achieved in samples with pH 2.5 and the irradiated dose of 3 kGy. There was an increasing trend in the flow behavior index with the increasing irradiation dosage. Emulsions were less stable at pH 2.5 than at higher pH levels (4.5 and 5.5).

关键词： Cellulases   enzymes   microfiltration   pectinase   rheology   yield  

摘要： Feijoa fruit (Acca Sellowiana) has a short postharvest period, thus, processing is usually an alternative. The objective of this work was to evaluate the efficiency of three different commercial enzyme preparations in the extraction of feijoa juice in the yield and quality parameters. The juices with Pectinex (R), Lallzyme (R) and Rohapect (R) were evaluated under three different concentrations (1, 5 and 10 U mL(-1)) before and after the pulping process. The samples were valued for total soluble solids, pH, reducing sugars, titratable acidity and colour. The juice that showed the most promise was evaluated for the microfiltration stage and rheological behaviour and particle size distribution were measured. The three treatments with Pectinex had an increase in juice yield in 43, 55 and 60%, while the samples with enzymes Lallzyme and Rohapect had no increase in yield compared to the control. All the tested enzymes had a positive impact on the colour of the juice, improving the colour parameters. The microfiltered juice had a behaviour index value of 1,091, indicating Newtonian behaviour. The fresh juice showed values below one (0.2178), indicating a non-Newtonian and typically pseudoplastic behaviour. Among three enzymes used, Pectinex (R) showed the better results for physical-chemical parameters for extraction of feijoa juice.

关键词： Corn oil   LJ potential modeling   Peanut oil   Ultrasonic velocity   Viscosity  

摘要： Oils are commonly used in cooking as a frying medium which has been constantly subjected to different levels of heating. In this work, we have considered the most commonly used oils namely peanut oil and corn oil. Quality analyses of corn and peanut oils were made by relating macroscopic properties (ultrasonic velocity, viscosity, and density) to microscopic parameters (intermolecular free length, adiabatic compressibility etc.,) by subjecting them to six cycles of heating (190 degrees C). Variation in the mentioned property indexes, the degree of degradation and reusability for the next heating cycle that could be used in the food industry and processing were monitored. Using Newton-Laplace and Wood's equation, the adiabatic compressibility, acoustic impedance, and intermolecular free length of the oil were estimated from the experimental data. Ultrasonic velocity was observed linearly as related to viscosity with the dependency factor (R-2 = 0.932). With the aid of experiential data, the physical thermodynamic parameters, particularly particle size, packing factor, chemical potential, and L-J potential were computed. A high correlation factor was observed by fitting ultrasonic velocity, viscosity, and density to Parthasarathy and Bakshi, and Rodenbush equations. In the study, ultrasonic velocity, a macroscopic parameter, could be decoded to determine the microscopic variations in oil subjected to different temperatures in an industrial application.

关键词： Physicochemical properties  

摘要： The objective of this work was to study how six sorghum genotypes affected the production of whole grain expanded snacks using extrusion cooking and to evaluate their physicochemical properties, sensory characteristics, and consumer acceptance. The chemical composition and antioxidant capacity of raw flours from whole grains were evaluated. Sectional expansion index, paste viscosity, and texture (hardness and crispness) analyses as well as acceptance tests and check-all-that-apply questions were conducted on the extrudates. White pericarp sorghum extrudates presented the highest sectional expansion and sensory acceptance, and were negatively correlated to total phenolic compounds and antioxidant capacity. Sorghums with tannins had the highest antioxidant capacity but the lowest values of sensory acceptance. The combination of different sorghum genotypes could be used to produce a final product with good antioxidant capacity and acceptability. Practical applications Sorghum is the fifth most produced cereals in the world largely used for animal feed but limited in direct human consumption. It is known that it has interesting agricultural characteristics such as drought and heat resistant and also contain expressive content of bioactives linked with health benefits. As an example, tannin sorghum has the greatest values of antioxidant activity when compared with other cereals, but it was demonstrated by our work that it has low sensory acceptance;on the other hand, nontannin sorghum showed higher acceptability. By understanding the technological aspects and sensory differences of sorghum genotypes processed by extrusion cooking allow the development of sorghum ready-to-eat blend products (tannin and nontannin sorghum) with the best of both antioxidant capacity and sensory acceptance. Our results could be used by the food industry to develop novel products with improved technological and sensory characteristics that could be introduced as functional healthy food options

关键词： Chlorine  

摘要： Chlorinated water treatment has been extensively used to manage postharvest decontamination of fruits for decades. It has been well established that chlorine may produce undesirable by-products that have a potential carcinogenic impact on human health and toxic waste on the environment. Electrolyzed water is an eco-friendly technique that has been regarded as an effective method for decontaminating microbes on fruit surfaces. However, the impact of alkaline electrolyzed water (AEW) on the physical and biochemical quality attributes of nectarine fruit during postharvest storage is not fully understood. Therefore, this study investigated the effects of AEW treatment (200 mg/L, pH, 6.7), sodium hypochlorite, and nontreated (control) on the storability, quality attribute, and decay incidence of fresh nectarine stored at -0.5celcius and 95% RH for 31 days. Results obtained indicated that the AEW treatment effectively maintains firmness, reduced weight loss, and maintains high total soluble solid content with a slight decline in titratable acidity for nectarines. Furthermore, the AEW suppresses the decrease of color qualities of the peel L*, a*, b*, reduced the incidence of browning (h degrees) and surface decay compared with chlorine-treated and control fruit. Novelty impact statement Alkaline electrolyzed water (AEW) and its efficacy to minimize decay and maintain physicochemical quality of nectarine fruit compared with chlorinated water treatment were investigated. Treatment with AEW (200 mg/L, 10 min) effectively preserves the freshness of the nectarine fruit by reducing surface decay compared with the chlorine-treated and control fruit. The outcome of this study provides guiding tools for stone fruit pack-houses and other industry role players on the potential of EW as an alternative to chlorine treatments.

关键词： Lactobacillus plantarum   Mango nectar   Prebiotics   Probiotics   Stevia   Synbiotic  

摘要： Probiotic functional foods are an emerging trend in consumer demand. This study aimed to investigate probiotic viability as well as physico-chemical and sensory characteristics of synbiotic sucrose-free mango nectar during 45-days storage time. Mango nectar samples were prepared by incorporating L. plantarum as a probiotic, inulin (0, 4, and 8%) as a prebiotic texturizer, and stevia (0, 2, and 4%) as a natural low-calorie sweetener. The results showed that the addition of inulin and stevia up to 4% improved the viability of L. plantarum bacteria during 45-day storage. The pH and TSS values of nectar samples were significantly (P < 0.05) decreased during storage time, while the viscosity values of the samples were increased. The addition of stevia and inulin improved the L* and b* color values of nectar samples, while a* value of the samples decreased. Finally, the mango nectar sample containing 4% stevia and 4% inulin was selected as optimum formulation because of the higher viability of probiotic bacteria, and acceptable physico-chemical and organoleptic properties.

关键词： Solvated radii   Butylammonium ion   Preferential solvation   Acetonitrile   Dimethylsulfoxide  

摘要： The present study reports a physico-chemical characterization of the solutions of n-butylammonium perchlorate (C4H9NH3ClO4) (BAP) in acetonitrile-dimethylsulfoxide (AN-DMSO) binary mixtures. One objective is to optimize the extraction of components from waste propellants, BAP acting as a model compound. Combining the conductometric and viscometric approaches, quantitative analysis of molecular interactions is reported for solutions of BAP in AN-DMSO binary mixtures containing 0, 20, 40, 60, 80 and 100 mol% DMSO at different temperatures. Analysis of the conductance data to obtain limiting molar conductivities was done using the Onsager equation and the viscosity data were analysed using the Jones-Dole equation. From viscosity data, A and B-coefficients, B/V-phi values and the temperature derivative of B-coefficients, (dB/dT) are calculated. Using the appropriate division of limiting molar conductivity and B-coefficients of tetra-n-butylammonium tetraphenylborate (Bu4NBPh4) as a 'reference' electrolyte, the limiting ionic conductivities (lambda(o)(+/-)) and B-+/--coefficients for individual ions have been estimated. The conductivity data is further utilized for obtaining different transport properties such as Walden product, solvated radii (r(s)), solvation numbers (n(s)), diffusion coefficients (D-+/-) and ionic mobility (mu(i)) of the ions. The influence of the solvent composition on the solvation of ions was discussed in terms of the composition dependence of solvated radii, Walden product, solvation numbers and viscosity B-+/--coefficients. In the light of all these parameters, the existence of ion-ion and ion-solvent interations in the investigated system has been identified. Eyring transition state theory has also been used to calculate various activation parameters of viscous flow. Results show preferential solvation of butylammonium (C4H9NH3+) ions by DMSO in the AN rich region and by AN in the DMSO rich region of the solvent mixtures at all the temperatures

关键词： Chitosan  

摘要： Chitin and chitosan (CHS) are extensively explored due to their remarkable biomedical applications. In the present study, chitin has been extracted from fish scales employing chemical process and further converted to the more valuable CHS. The obtained chitin and CHS are analyzed for their physicochemical properties. FTIR spectra verify the pattern of β-chitin. The thermal analysis advocates the effectiveness of the process to obtain considerable yields of stable chitin and CHS. Approximately 0.26 g of CHS is obtained using 1 g of fish scales. Hence, fish scales can be explored as a potential source for production of chitin and CHS that could further be exploited for biomedical or agricultural applications. © 2021 Wiley-VCH GmbH.

关键词： Mesoporous bioactive glass   Ultrasmall nanoparticles   Ultrasonic-assisted sol-gel synthesis   Ce-3(+)/Ce4+ ions   Catalase-mimic   Antioxidant  

摘要： The multifunctional biological properties of Ce ions including antioxidant, anti-inflammatory, antibacterial and anti-cancer effects are very encouraging for development of Ce-containing biomaterials with therapeutic properties. Herein, novel Ce3+/Ce4+ ions containing mesopomus bioactive glass ultrasmall nanoparticles (Ce-BGn) were prepared by a facile one-pot ultrasound-assisted sol-gel method. Interestingly, Ce2O3 incorporation exerted a significant influence on the particle size and textural properties of mesoporous BGn (SiO2 - CaO binary glass system). Ce-BGn exhibited ultrasmall nanoparticle size (< 30 nm), mesopomus texture (pore size up to 2.82 nm and pore volume up to 0.191 cm(3)/g) and large specific surface area ca. 132.9 m(2)/g. Notably, in situ formation of CeO2 nanospheres (3-6 nm) was detected at the surface and in the amorphous glass matrix of mesoporous Ce-BGn. Importantly, X-ray photoelectron spectroscopy (XPS) revealed the presence of 72.57 % Ce3+ and 27.43 % Ce4+ at the surface of mesoporous Ce-BGn with Ce3+/Ce4+ ratio = 2.66. Furthermore, mesopomus Ce-BGn exhibited high catalase-mimic activity and showed sustained release of Ce (2.5-32 ppm), Ca (85-327 ppm) and Si (54-200 ppm) ions within 4 weeks along with excellent bone-like hydroxyapatite formation. Finally, the in vitro biological behavior of mesoporous Ce-BGn in cell cultures of human skin fibroblasts (HSF) revealed that mesoporous Ce-BGn (with concentrations up to 300 mu g/mL) possess good cyto-biocompatibility. Taken together, novel ultrasmall mesoporous Ce-BGn showed remarkable catalase-mimic activity via surface containing Ce3+/Ce4+ ions which can scavenge ROS (Ce3+ <-> Ce4+) and decompose H2O2 molecules into H2O and O-2. In addition to that, Ce-BGn demonstrated sustained release of bioactive ions (Ce, Ca and Si), excellent bone-like hydroxy-apatite formation and good cyto-biocompatibility.

关键词： Snack   Gluten free   Corn flour   Flaxseed flour   Yerba mate  

摘要： Flaxseed (Linum usitatissimum L.) and yerba mate (Ilex paraguariensis) are particularly interesting as functional ingredients due to their high content of essential omega 3-fatty acids and antioxidant properties, respectively. The objective of this work was to formulate a corn snack enriched with flaxseed flour and yerba mate extract and evaluate its physicochemical and sensory properties. Flaxseed flour, added at three levels 1, 3 and 5%, increased the water activity, moisture content and cohesiveness, and decreased the hardness and plastic deformation of the samples. The flour also changed the superficial colour and made the microstructure more compact. On the contrary, yerba mate extract (1 and 3%) decreased the water activity, moisture content and cohesiveness, counteracting the effect of flaxseed flour. Yerba mate increased the plastic deformation and the antioxidant activity of the snacks. The colour was not modified and the microstructure was more fragmented in the presence of yerba mate. Sensory evaluation suggested that flaxseed flour and yerba mate affected the flavour but did not modify the colour and crunchiness of the product.