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关键词： polymerization   2-[(2Z   E)-2-chloro-1-methylbut-2-en-1-yl]aniline   dopants of different nature   solubility   conductive polymer   sensors  

摘要： Highly soluble polyaniline was synthesized from a newly designed aniline derivative, namely 2-[2-chloro-1-methylbut-2-en-1-yl]aniline. The corresponding polyanilines, PClPA-HA, PClPA-SA, PClPA-NA and PClPA-PA, were characterized by means of H-1 NMR, C-13 NMR, high resolution mass spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy and SEM images. The elemental analysis and electrical conductivity of the polymers are also presented. It is shown that the molecular weight of the polymers obtained depends on the method of synthesis. Spectroscopic studies confirmed the emeraldine form of the polyaniline derivatives. In the work, the dependence of the current passing through resistive structures based on thin poly[2-(2-chloro-1-methylbut-2-en-1-yl)aniline] films on the relative humidity of air was studied. The results of the studies showed the prospects of using thin polymer films in the design of chemical sensors. (c) 2020 Society of Chemical Industry

关键词： Microencapsulation   Red mombin juice   Rotatable central composite design   Spray drying  

摘要： Optimal spray drying conditions were selected to microencapsulate red mombin juice and maximize carotenoid retention. Microencapsulation was optimized following a rotatable central composite design where inlet temperature, feed flow rate, and maltodextrin concentration were chosen as independent variables. The powder prepared under optimized conditions, whose reconstituted nectar was the most appreciated by sensory analysis, exhibited a high total phenolic content and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging capacity, and its physicochemical properties proved to be suitable for applications in the food industry.

关键词： Water absorption  

摘要： This study aimed to evaluate the changes throughout storage of pasta formulations enriched with basil, beet, cheese, chocolate, coffee, dried tomato, ginger, pepper, rosemary, socol, spinach, and wine in metallic and transparent packages. Pasta color, moisture content, water activity (a(w)), pH, total titratable acidity, cooking time, water absorption, and cooking loss were evaluated for 120 days. The packages used were efficient throughout storage in preserving moisture,a(w), pH, total titratable acidity, cooking time, and water absorption for all formulations. Cooking loss and kinetics of the total color difference (Delta E) of some pasta were significantly (p < .05) affected. Beet pasta was the only one that showed a significant difference in cooking loss (p < .05) and Delta E was not influenced by packaging and storage time. Spinach pasta presented the largest Delta Ebetween the two packaging types after 120 days. The metallic packaging was better at preservation of the pasta color throughout storage. Practical applications Adding ingredients in pasta formulations is a good alternative for the manufacture of products with attractive consumer features. Storage time and packaging are factors that can influence the quality of pasta, generating characteristics that may affect the product. Therefore, the study of these factors for different types of pasta provides relevant information for the food industries, since it is possible to identify the storage conditions that promote the lower change in quality. The results indicated that storage time and packaging are factors that influenced mainly the preservation of color characteristics of pasta containing added nontraditional ingredients. Metallic packaging can be considered an efficient alternative to reduce color change throughout the storage.

关键词： trachyandesibasalt   mineral composition   melting   magnetic properties  

摘要： We studied by physicochemical modeling (PCM) how the temperature and redox properties of the crystallization atmosphere affect the equilibrium compositions of product phases using trachyandesibasalt as an example. The chemical composition of rock-forming minerals and their influence on the properties of rocks are presented. The heating, melting, and crystallization features of trachyandesibasalt are considered taking into account external conditions and the mutual influence of the minerals present in the rock. Temperature-dependent magnetization is determined for various fractions of the studied rock. The fundamental possibility is shown, and recommendations are given, for choosing methods to modify the chemical and mineral composition of trachyandesibasalt.

关键词： biopolymers   1,3-beta-D-glucan   vibrational spectroscopy   X-ray photoelectron spectroscopy   AFM microscopy   biomaterials  

摘要： In order to determine the effect of different gelation temperatures (80 degrees C and 90 degrees C) on the structural arrangements in 1,3-beta-d-glucan (curdlan) matrices, spectroscopic and microscopic approaches were chosen. Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and Raman spectroscopy are well-established techniques that enable the identification of functional groups in organic molecules based on their vibration modes. X-ray photoelectron spectroscopy (XPS) is a quantitative analytical method utilized in the surface study, which provided information about the elemental and chemical composition with high surface sensitivity. Contact angle goniometer was applied to evaluate surface wettability and surface free energy of the matrices. In turn, the surface topography characterization was obtained with the use of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Described techniques may facilitate the optimization, modification, and design of manufacturing processes (such as the temperature of gelation in the case of the studied 1,3-beta-d-glucan) of the organic polysaccharide matrices so as to obtain biomaterials with desired characteristics and wide range of biomedical applications, e.g., entrapment of drugs or production of biomaterials for tissue regeneration. This study shows that the 1,3-beta-d-glucan polymer sample gelled at 80 degrees C has a distinctly different structure than the matrix gelled at 90 degrees C.

关键词： Differential scanning calorimetry   Thermogravimetric analysis   Pyrolysis   Lignocellulosic biomass  

摘要： This research paper is about the kinetics of drying and pyrolysis processes of lulo (Solanum quitoense Lam.) peel powder, which was studied using thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and mass spectrometry (MS). TG data was fitted using theoretical approximation according to the Newton model to obtain the kinetic parameters of drying, and the isoconversional methodology using Friedman's method for the pyrolysis process. The results of each thermogram showed a relation between each other. In all of them, three characteristic stages were identified related to drying, pyrolysis, and carbonaceous matter. At the same time, there was a decomposition of the lignocellulosic biomass and light volatiles in the pyrolysis process. In the thermograms, three characteristic stages were identified: the first stage is the dehydration which ended at 120 degrees C, the second is the pyrolysis which is between 120 and 450 degrees C, and from this temperature, the third stage, carbonization, begins. In the pyrolysis stage, five peaks corresponding to independent reactions were identified;activation energy (E-a) and the reaction mechanism (f(alpha)) of each peak were calculated by means of master curves. After comparing the theoretical and experimental master plots, it was observed that the reaction mechanism corresponds to the Avrami-Erofeev model. Thermal analyses indicate that lulo peel is a potential waste for the production of coal for power purposes. It could be contributing to improve the management of waste and at the same time it could be used as a power supply or for water treatments such as activated carbon.

关键词： Chinese steamed buns   sago starch   sensory evaluation   slowly digestible starch   starch modification  

摘要： Effects of dual pullulanase-debranching (PD) and temperature-cycling (TC) treatments on the physicochemical properties and in vitro digestibility of sago starch as well as its potential application in Chinese steamed buns (Mantou) is investigated. Sago starch is debranched using PD (30 pullulanase unit per g) for 0, 2, 4, 8, 16, and 24 h before subjecting to TC (4/30 degrees C, for 24 h each) for 3 cycles. The modified sago starch (MSS) obtained at the optimum conditions is used to replace wheat flour at 20%, 30%, and 40% for production of Mantou. All the MSS samples exhibit B-type crystalline pattern and have lower relative crystallinity than the native starch. The PD results in an increase in the relative crystallinity of the MSS. The 8 h PD followed by TC storage are the optimum conditions for producing MSS with the highest slowly digestible starch (10.76%) and the lowest rapidly digestible starch (81.61%) contents. The physical, textural, and sensorial properties of Mantou decreases with increasing substitution level of the MSS due to a reduction of gluten network and a detrimental effect of retrograded starch. However, the Mantou containing 20% MSS substitution is found to be acceptable based on the sensory evaluation.

关键词： Whey protein   Physicochemical   Composition   Protein profile   Ingredient  

摘要： The objective of this study was to complete a comprehensive evaluation of the nutritional composition, physicochemical properties and protein profile of three different whey protein concentrate ingredients enriched in alpha-lactalbumin (LAC). The LAC ingredients studied were manufactured using different enrichment approaches, namely membrane filtration (LAC-M), selective precipitation (LAC-P) and ion exchange (LAC-IE), and were compared to benchmark whey protein concentrate (WPC) and skim milk powder (SMP) ingredients with unaltered protein profile. The LAC ingredients had heterogeneous chemical composition and protein profile, which depended on the enrichment approach used. Protein profile of LAC ingredients was dominant in alpha-lactalbumin and therefore higher in tryptophan when compared to the benchmark ingredients. Unlike LAC-M and LAC-IE, LAC-P had a very complex protein profile. The new information provided by this study for these novel added-value whey protein ingredients will support the development of next-generation dairy-based formulated nutritional products.

关键词： Melipona   Thermal treatment   Composition   Phenolic  

摘要： Different storage conditions (22 and 40 degrees C for 90 days) were used in thermally processed stingless bee honey (90 degrees C), seeking to evaluate their effect on the physicochemical properties (moisture, acidity, 5-hydroxymethylfurfural, and diastase activity) and bioactive (antioxidant potential and individual phenolic compounds). In addition, a commercial honey sample was also stored at 4 degrees C for 365 days and evaluated for 5-hydroxymethylfurfural, and bioactive properties. The results of the physicochemical properties showed that at the end of storage, honeys had little changes when compared the start of storage (after thermal treatment), but differed from fresh honey. Only honeys stored at 40 degrees C showed quantifiable levels of 5-HMF. As for bioactive properties, honeys showed antioxidant potential after storage under all tested conditions (22, 40, and 4 degrees C). Other phenolic compounds, which were not present in the fresh honey, were identified after heat treatment. This profile remained after storage in all conditions tested. However, storage at 40 degrees C caused the greatest reductions in most tested compounds, while at 4 degrees C their amount was preserved. Thus, it can be concluded that storage at 40 degrees C is not recommended, and temperatures lower may assist in maintaining the characteristics of thermally processed stingless bee honeys.

关键词： Bioactivities   Drying   Glycoprotein   Hydrolysate   Viscosity  

摘要： Previous studies indicated that enzymatic hydrolysis of edible bird's nest (EBN) glycoproteins to glycopeptides resulted in higher bioactivities than raw EBN. However, a drying process is necessary to remove water after hydrolysis to increase the shelf-life and broaden its application. The current work was carried out to study the properties of EBN hydrolysates as affected by different drying methods: oven-drying (EBNod), spray-drying (EBNsd) and freeze-drying (EBNfd). The dried EBN hydrolysate yields were in the order of EBNfd > EBNod > EBNsd. Both EBNfd and EBNsd were relatively stable against microbial and biochemical changes as the water activity was below 0.60. Low lightness (L*), high yellowness (b*) and colour intensity (C) were obtained from EBNod, suggesting that the oven-drying had a negative effect on the colour appearance. EBNsd has a high soluble protein content (15.14 +/- 0.56g/100g) and low viscosity (1.65 +/- 0.17 mPa s), indicating high solubility when incorporated into food products as a functional ingredient. Besides, EBNfd exhibited a high degree of hydrolysis (45.09 +/- 2.09%), essential amino acid content (42.62 +/- 0.23g/100g), antioxidant activities [DPPH (60.80 +/- 0.67%);FRAP (11.99 +/- 0.29 mg TE/g)] and antihypertensive (75.76 +/- 1.08%) activities. The FTIR spectrum showed that the powders exhibited similar functional groups. Freeze-drying of EBN with low-temperature exposure is preferable because it exhibits minimal effects on the properties of EBN hydrolysate.