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关键词： Aflatoxins  

摘要： Hazelnut contaminated with aflatoxin (5, 10, 25, and 50 ppb) were treated ozone at three different doses and two exposure times (5, 10, and 20 ppm for 10 and 20 min) on aflatoxin degradation. The highest peroxide value was reached (12.89 meqO(2)/kg) 20 ppm/20 min, and the lowest was 5 ppm/20 min (3.20 meqO(2)/kg). The reductions of alpha-tocopherol were 15.38%-28.87%, when control 19.14%, and the highest reduction were ozone concentration had adverse effect on alpha-tocopherol (24.96% 20 ppm/10 min), 28.87% (20 ppm/20 min). Ozonation was not lead to significant changes in color (L*, a*, and b*) and textures. Decrease in aflatoxin B1(AFB(1)) contents was dependent on increasing ozone concentration, the highest degradation for AFB(1)(38.96%) and total aflatoxins(31.35%) were obtained with use of 20 ppm/20 min ozonation. At 5 mu g/kg contaminated group, the AFB(1) reduction rate was 19.88% for *** and 32.23% for 20 min. Ozonation, especially 5 ppm is innovative for reducing aflatoxin, while maintaining the quality. Practical applications The effect of different ozone treatments on the degradation of the aflatoxin (AFB(1)), which was produced by mold growth on hazelnuts' physicochemical characteristics, was determined. It is essential that ozonation with low concentration and short application time is needed to minimize the destruction to tocopherols and specific nutrition. The current research aimed to determine the lowest optimal dose of detoxification using different amounts of ozone and exposure time on the different amounts of AFB(1.)In addition, the effects of ozone applications on the physicochemical characteristics of nuts were also determined.

关键词： Taro starch   Octenyl succinic anhydride   Encapsulation   Spray drying   Spherical aggregates  

摘要： The objective of the work was to evaluate OSA-esterified taro starch as wall material to encapsulate avocado oil as lipophilic bioactive compounds, using spray drying for encapsulation. It was found that OSA-esterification decreased the amylose content (8.93-6.13%), %C (33.29-31.88%), and thermal properties of gelatinization (Tp: 86.1 to 80.7 degrees C, and Delta H: 8.4 to 7.9 J g(-1)). Besides, OSA-esterification did not modify the diffraction pattern (Type A). The OSA-starch granules did not show surface alterations, while showing a monomodal particle diameter distribution. However, the particle diameter increased from 2.8 to 3.3 um after modification. The emulsions of OSA-starch (350 and 400 mg starch. mL(-1) oil) showed greater stability against coalescence than those obtained with unmodified starch. Encapsulates with native and OSA-starches showed differences in diameter, shape and presence of pores. Likewise, the esterification reduces the diameter distribution in the microcapsules (15.1-13.1 mu m). The vegetable oil was located internally and superficially in the cavities and intraparticle area of the microcapsules. Encapsulation efficiency was increased by modification with OSA from 23.63 to 40.0% and the value of peroxides decreased during storage. The results demonstrated that malanga OSA-starch can be considered as wall material for protection of hydrophobic substance.

关键词： Quaternary ammonium surfactants   Dipeptide   Proline   Phenylalanine   Mixed surfactant system   Antibacterial activity   Ocular irritation   Cytotoxicity   Membrane permeability   Foaming ability  

摘要： Novel quaternary ammonium surfactants (QUATs) derived from phenylalaninyl-proline dipeptide with chain length C-12 and C-14 were synthesised as potential active ingredients to be used in body cleansing formulations. The physicochemical properties and biological activities of the QUATs were determined in both single and in mixed surfactant system with either the conventional anionic surfactant sodium dodecyl sulphate (SDS) or sodium N-dodecyl prolinate. The C-12 QUAT derivative showed antagonistic behaviour in both SDS and sodium N-dodecyl prolinate mixed surfactant system. Comparing the mixed system of the C-12 QUAT with SDS and sodium N-dodecyl prolinate, it was found that the latter displayed better antibacterial activity together with the lower ocular irritation. The C-12 QUAT-sodium N-dodecyl prolinate mixture were non cytotoxic at a concentration corresponding to its MIC value, showing that the mixture was selective towards bacterial cells rather than mammalian cell lines. Diffusion measurements showed that the sodium N-dodecyl prolinate surfactant consisted of 26 molecules per micelle in water but only 3 molecules per micelle in DMSO/water (1:1). On the other hand, C-12 QUAT did not form a micelle in DMSO/Water. Membrane permeability studies of the C-12 QUAT and sodium N-dodecyl prolinate showed that these surfactants are capable to penetrate into deeper skin layers to exert their antibacterial and cleansing action and hence can be used as a promising candidate as active ingredients in body wash formulations.

关键词： Wine   Ultrasounds   Frequency   Colour   Phenolic compounds  

摘要： This study presents the application of high-power ultrasounds (US) to crushed grapes using winery-scale equipment and studies, for the first time at this scale, how the frequency of the ultrasounds affects the extraction of phenolic compounds from grapes and the chromatic and physico-chemical characteristics of the finished wines, in an attempt to optimize the maceration process. The results showed how US modified the physical characteristics of the grape skin, facilitating phenolic extraction and improving the wine chromatic characteristics but only produced slight differences in the physico-chemical characteristics of the finished wines. The two different frequencies applied led to some differences in the wine phenolic composition, especially higher tannin extraction at 20 kHz whereas anthocyanin extraction was favoured at 28 kHz. Wines made with sonicated grapes and 72 h of skin maceration time were chromatically very similar to control wines with four more days of skin contact, indicating that this technological process may increase the working capacity of the winery by allowing a reduction of more than 50% in the maceration time.

关键词： extraction   pectin   pasting   response surface methodology   starch   sugar beet pulp   viscosity  

摘要： The objective of this study was to characterize the properties of pectin extracted from sugar beet pulp using subcritical water (SWE) as compared to conventional extraction (CE). The research involved advanced modeling using response surface methodology and optimization of operational parameters. The optimal conditions for maximum yield of pectin for SWE and CE methods were determined by the central composite design. The optimum conditions of CE were the temperature of 90 degrees C, time of 240 min, pH of 1, and pectin recovery yield of 20.8%. The optimal SWE conditions were liquid-to-solid (L/S) ratio of 30% (v/w) at temperature of 130 degrees C for 20 min, which resulted in a comparable yield of 20.7%. The effect of obtained pectins on viscoamylograph pasting and DSC thermal parameters of corn starch was evaluated. The contents of galacturonic acid, degree of methylation, acetylation, and ferulic acid content were higher in the pectin extracted by SWE, while the molecular weight was lower. Similar chemical groups were characterized by FTIR in both SWE and CE pectins. Color attributes of both pectins were similar. Solutions of pectins at lower concentrations displayed nearly Newtonian behavior. The addition of both pectins to corn starch decreased pasting and DSC gelatinization parameters, but increased Delta H. The results offered a promising scalable approach to convert the beet waste to pectin as a value-added product using SWE with improved pectin properties.

关键词： Aniline  

摘要： A new polymer, poly-2-(1-methylbut-2-en-1-yl)aniline, is synthesized using doping and oxidizing agents. The influence of its preparation conditions on the physicochemical properties of materials is considered. The morphology of polymers is investigated by scanning electron microscopy, their solubility and IR and UV spectral characteristics are studied, and the photoluminescent properties are revealed. It is shown that the properties of the polymer depend on the nature of the doping agent. It is found that the use of FeCl3 as an oxidizing agent makes it possible to obtain the material in the doped form and with the highest luminescence intensity. The synthesized polymers are tested as an active material in moisture sensors.

关键词： Single crystals  

摘要： The organic nonlinear optical (NLO) single crystal of 4-aminopyridinium 4-nitrophenolate 4-nitrophenol (4AP4NP) single crystal was grown by the solution method at room temperature. The unit cell parameters of the grown 4AP4NP single crystal were confirmed by single-crystal X-ray diffraction (SXRD) measurement. The various (hkl) planes of the grown crystal and their average lattice strain were analyzed by powder X-ray diffraction (PXRD). The crystalline perfection of the 4AP4NP single crystal was analyzed by high-resolution X-ray diffraction (HRXRD) measurement. The optical quality of 4AP4NP single crystal and its cut-off energy were analyzed by UV-Vis-NIR. The photoluminescence (PL) study reveals that the grown crystal has high-intense green emission at 500 nm. The thermal stability of the grown crystal was analyzed by TG/DTA. The mechanical stability was analyzed by Vickers microhardness measurement. The dislocation density of 4AP4NP crystal has been investigated by etching studies. Laser-induced damage threshold (LDT) of the 4AP4NP crystal was analyzed by Q-switched Nd:YAG laser of wavelength 532 nm. The optical homogeneity of 4AP4NP was determined by the birefringence interferometry technique. The dielectric measurement has been carried on the grown crystal. The electronic polarizability (alpha*) of the grown crystal was determined by various theoretical calculations. The second-harmonic generation (SHG) and third-order nonlinear optical properties of the grown 4AP4NP crystal were analyzed by Kurtz-Perry powder and Z-scan technique, respectively.

关键词： Tyramine   Bioactive amines   Goat milk   Cow milk   Lactobacillus acidophilus  

摘要： Bioactive amines (BAs) represent a considerable toxicological risk in fermented dairy products because they provide the ideal environment for their formation. Thus, secondary control measures to prevent or reduce BAs formation in dairy products are urgently needed. However, additional scientific knowledge about the factors affecting BAs production and the interaction among them is currently necessary to achieve this goal. In this context, Partial Least Square with Variable Importance in Projection (PLS-VIP) analysis followed by cross-validation was applied to variables to investigate their interactive effect on BAs accumulation in cow's and goat's fermented milk during refrigerated storage. Streptococcus thermophilus and Lactobacillus acidophilus LA-5 increased tyramine and total BAs content in both cow's (CFM) and goat's (GFM) fermented milks. In CFM, Maillard reaction involving galactose and increased post acidification interacted to enhance accumulation of BAs (R-2 = 0.895, P = 1.11 x 10(-5));whereas for GFM, losses of consistency coefficient and viscosity were essential for BAs accumulation (R-2 = 0.919;P = 2.72 x 10(-6)). These findings show that by preventing Maillard reaction and delaying post acidification in CFM, as well as by controlling viscosity in GFM, there can be mitigation of BAs formation during storage.

关键词： Strawberry flavour   Spray drying   Freeze drying   Encapsulation   Mixture design   Wall material  

摘要： This study was aimed to enhance the encapsulation stability of natural strawberry flavour using spray and freeze drying processes. Optimum spray drying conditions in terms of the wall materials (maltodextrin, soluble fibre, modified starch, beta-cyclodextrin and arabic gum) and the inlet air temperature (130-190 degrees C) were determined using the response surface methodology where dependent parameters were minimum aroma release, maximum aroma recovery, drying yield and solubility. Partide morphology, particle size, bulk and tapped density analyses were also determined. The optimum conditions were found as;air inlet temperature: 190 degrees C, maltodextrin: 1530%, modified starch: 1.83% and arabic gum: 12.87%. Optimum process yield and solubility of the In imencapsulation were determined as 85.17 and 98.19%. respectively. Spray dried miancapsules were generally spherical, smooth and homogeneous while those obtained by freeze-drying were heterogeneous and spongy. Partide size of the spray dried samples (D-90 value: 22.91 mu m) was much lower than the freeze dried samples (D-90 value: 326.83 mu m). (C) 2020 Elsevier B.V. All rights reserved.

关键词： Phytoplankton pigments   Eastern Arabian Sea   Winter convection   CHEMTAX  

摘要： The paper describes the community composition of phytoplankton in the eastern Arabian Sea (EAS) during winter monsoon (WM, January-February 2018), encompassing the entire eastern part of the Arabian Sea basin (similar to 6-22 degrees N and 77-67 degrees E) with high-resolution sampling (7 transects, 56 sites), from coastal to offshore regions. The phytoplankton pigment concentrations estimated by high-performance liquid chromatography were interpreted using 'CHEMTAX' (Mackey et al., 1996) to determine relative abundance and contribution of phytoplankton functional groups at the class level. A distinct spatial heterogeneity was observed in the distribution of phytoplankton groups in the coastal and offshore regions of the northern as well as southern part of the EAS. The basin-scale column integrated chlorophyll a (Chl a) concentration in the upper 100 m was higher (16-118 mg m(-2)) in the northeastern Arabian Sea (NEAS) as against 9-79 mg m(-2) in the southeastern Arabian Sea (SEAS). The chromatographic analysis revealed the dominance of diatoms in the coastal waters of the EAS basin. A closer evaluation of the hydrodynamics and nutrient chemistry of the offshore regions revealed that entrainment of subhalocline nutrients into the sunlit water column through convective mixing supported the dominant cyanobacterial population in the NEAS. In the warm oligotrophic waters of the SEAS, the substantially high NH4+ concentration indicates that the dominant prochlorophytes were sustained by the regenerated production. The dominance of large phytoplankton like diatoms indicates a herbivorous control in the food chain in coastal waters of the EAS. Offshore waters are characterised by large proportions of pico-nano plankton along with considerable micro phytoplankton, which suggests a mixotrophic ecosystem. The statistical analysis showed that the silicate (Si/N ratio) concentration played a major role in controlling the diatom abundance in the coastal areas of the north (sout