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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.

关键词： Reconstituted micellar casein   High hydrostatic pressure   Quality follow up  

摘要： The aim of this work was to evaluate the effect of high hydrostatic pressure (HHP) treatments (300 MPa, 450 MPa, and 600 MPa for a holding time of 5 min) on the physicochemical, microbiological and rheological properties of a reconstituted micellar casein concentrate (R-MCC) at two different concentrations (4 and 8% w/w). Quality changes after 7 days at 10 degrees C of treated products were compared to untreated ones. From a microbiological point of view, increased pressures led to a significant reduction of spoilage population. Besides, MCCs treated at either 450 or 600 MPa showed an increase of acidity. Color was also affected by HHP treatments with a loss of lightness and increase of blue/grey tonalities. Reduction of particle size was observed and an aggregation phenomenon was confirmed at 450 MPa and 600 MPa. These results suggest destabilization and disintegration of casein micelles. However, no changes were detected in rheological and multiple light scattering measurements.

关键词： g-ZnS@GO@CS ternary hybrid   green synthesis   optical properties   thermal stability   antibacterial activity  

摘要： In this study, green-ZnS nanoparticles (g-ZnS NPs) were synthesized via chemical precipitation using aqueous solutions of ZnCl(2)and Na2S at the presence of green tea solution. The ternary hybrid nanocomposite of green-ZnS@ Graphen oxide@Chitosan (g-ZnS@GO@CS) was also prepared throughin situchemical deposition of g-ZnS nanoparticles on GO@CS composite. The obtained nanostructures were characterized by FTIR, SEM, XRD, EDX, X-map, photoluminescence (PL), TGA, and UV-DRS analyses. Based on the results, the g-ZnS@GO@CS composite possessed cauliflower morphology in which ZnS NPs were homogeneously distributed on the composite matrix. Crystallographic investigations revealed the fcc phase of ZnS NPs. Moreover, the crystallite sizes of ZnS, g-ZnS, and g-ZnS@GO@CS samples were estimated as 28.8, 17.9, and 14.8 nm, respectively. Using UV-vis spectroscopy, the bandgap energy of g-ZnS@GO@CS composite, pure ZnS, and g-ZnS were determined 3.02, 3.37, and 4.42 eV, respectively;suggesting a significant reduction in the bandgap of the composite sample due to the synergic effect of GO@CS. Among various g-ZnS@GO@CS composites with different GO@CS contents (4, 8, and 12 wt%) the sample containing 4 wt% GO@CS exhibited the highest photoluminescence intensity. The g-ZnS@GO@CS nanocomposite displayed higher antibacterial activity (growth inhibition zone of 27.6 mm) on Gram-positiveStaphylococcus aureusbacteria compared to g-ZnS NPs (growth inhibition zone of 23.5 mm). No significant bioactivity was, however, observed against Gram-negative bacteria (Escherichia coli). According to the results, g-ZnS@GO@CS composite with reduced bandgap, enhanced PL intensity, and smaller ZnS NPs can offer better antibacterial activity as compared to pristine g-ZnS NPs.

关键词： Functional food   Response surface methodology   Overall acceptance   Cape gooseberry  

摘要： The aim of this research was to develop and characterize an innovative nectar formulation of Physalis peruviana fruits from the Argentinean Northern Andean region with optimized proportions of pulp and sucrose that maximizes the antioxidant activity and with good sensorial acceptance, using the response surface methodology as optimization strategy. Physicochemical characteristics (total soluble solids, titratable acidity and pH), antioxidant activity (measured as the free radical scavenging activity against DPPH center dot) and sensorial attributes (color, acidity, sweetness, texture, aroma and overall acceptance) were evaluated in a series of nectar formulations. A significant correlation between overall acceptance and antioxidant activity contributed to achieve the objective outlined. The mathematical modelling defined a nectar with 65% fruit juice and pulp and 8% sucrose;this nectar presented absence of indicator microorganisms (aerobic mesophilic microorganisms, molds and yeasts, Salmonella spp., total coliforms, and Staphylococcus aureus coagulase positive) despite having no added preservatives. beta-carotene and vitamin C contents (1.13 +/- 0.02 and 16.56 +/- 0.52 mg/100 mL respectively) and antioxidant activity towards DPPH center dot (EC50: 2.43 +/- 0.07 mg/mL), ABTS(center dot+) (3.48 +/- 0.07 mu mol Trolox/mL) and FRAP (10.16 +/- 0.10 mu mol Trolox/mL), make this nectar a functional food with potential for the food industry.

关键词： cosmeceuticals   lipid   liquid crystal   retinoids   spectrophotometry   viscosity  

摘要： Introduction Three original cosmetic formulations containing retinol as an active component with liquid crystal, lamellar, and lipid bases were prepared. The formulas contain different concentrations of retinol, that is, 0.5%, 0.3%, and 0.15%. Objectives The aim of the study was to evaluate a spectrophotometric method for assessing the quantity of retinol in the nine cosmetic products and to determine the viscosity of each formula. Materials and Methods The formulations were tested for stability;final product testing was preceded by sample weighing and pH measurement as well as exposure to the light source from xenon lamp that maps solar radiation in the range of 310-800 nm. Microbiological purity test was performed according to the PN-EN ISO 29621:2011 method and viscosity carried out using a cone-plate digital rheometer (DV-III Brookfield, version 3.0) on 0.5 cm(3) emulsion samples at 32 degrees C. The retinol content in preparations was assayed by UV spectrophotometry. Results Each of prepared cosmetic products with retinol storing in a room temperature occurred to be stable. The liquid crystal emulsion has the higher viscosity than lamellar and lipid emulsions. Although the retinol concentration in lipid serum was determined with high accuracy, the method has some limitations associated with differences between the lipid cosmetic base and the lamellar and liquid crystal sera. Nevertheless, the UV spectrophotometric method described herein is a simple and highly accurate approach for determining the retinol content in lipid cosmetics: Its coefficient of correlation was R-2 = 0.9982 with a relative standard deviation (n = 3) in the range of 0.5%-1.5%. Conclusion The presented UV spectrophotometric method represents an effective tool for fast and accurate determination of retinol content in lipid formulations. Probably, the method could be used in studies of other retinol-based preparations, for example, medications, and for determining the effective life of retino

关键词： Gaseous ozone   Buckwheat-wheat-gluten composite flour   Microbial and physicochemical properties   Shelf-life extension of fresh buckwheat noodle  

摘要： In recent years, the application of gaseous or aqueous ozone in the processing of flour and noodles has been reported. However, little information is available about buckwheat-based (buckwheat-wheat-gluten) composite flour treated with gaseous ozone and fresh noodles made from the flour. This study investigated the microbial count, and physicochemical properties of buckwheat-based composite flour treated with gaseous ozone at 2.4 g h(-1) for 0, 2.5, 7.5 and 15 min and the shelf-life of fresh buckwheat noodles made from ozone-treated buckwheat-based composite flour (OTBF). Gaseous ozone significantly (p < 0.05) reduced the microbial total plate count and increased the CIE L* value, water absorption, development time, and stability time of the OTBF. The peak viscosity, final viscosity, setback, swelling capacity and solubility of the flour were also enhanced by ozone treatment. Scanning electron microscopy showed that ozone treatment facilitated the formation of more clumps and exposure of starch granules in the composite flour. In addition, gaseous ozone treatment at 2.4 g h(-1) for 15 min significantly suppressed microbial growth and reduction of L* value, maintained the overall sensory acceptability during the whole storage period, and the shelf-life of fresh noodles prepared from ozone-treated flour was extended to 96 h.

关键词： polyaniline   catalysis   metal phthalocyanines   physical properties  

摘要： The polymerization of aniline in the presence of metal phthalocyanines was accomplished and the effect of the metal complexes on the physicochemical properties of polyaniline was examined based on UV-visible spectra, cyclic voltammograms, morphology and conductivity of the polymers. The formation of polyaniline in the presence of metal phthalocyanines led to an increase in polymer particle sizes and to a slightly higher conductivity of the samples, as compared to those of the initial polyaniline.