Pinto, Raquel O. M.do Nascimento, Renata B.Jermolovicius, Luiz AlbertoJurkiewicz, Cynthia...
7页
查看更多>>摘要：Thermal processing of coconut water is designed to ensure safety and stability and microwave may be used as an alternative process. This study evaluated the feasibility of microwave processing of acidified green coconut water (pH 4.30-4.50) concerning inactivation of Bacillus coagulans spores with specific power between 115 and 135 W/ mL. Four variables were evaluated (temperature, microwave power, amount, and composition of added acids) according to a central composite design with four replicates at the center point. After holding periods of 5, 10, 15 and 20 min, the reduction in spore population was determined. The only significant variable for spore inactivation was the temperature; consequently, the survival curves were described by Weibull model, which was adjusted in a single-step procedure that integrated the time-temperature profile of 112 experiments. The alpha value (time of the first decimal reduction) at reference temperature of 90 degrees C was 33.8 s and the z' value (temperature required for a 10-fold change in alpha) was 5.06 degrees C. The reduction in the population of B. coagulans spores and the kinetics parameters suggest that microwave may be used as a viable alternative for coconut water processing.
查看更多>>摘要：In this study, the laws of migration and distribution of thermal and water in different part of Chinese steamed buns (CSB) were studied during cooling process after steam cooking. Low field-nuclear magnetic resonance (LFNMR) and magnetic resonance imaging (MRI) were used to investigate the correlation among crust (skin of steamed bun) temperature, water migration, and textural properties of CSB. Results showed that the temperature of each layer of CSB was highly dependent on the cooling time. The major water existent status (more than 85%) was immobile and free, and the water redistribution was hugely affected by the retrogradation of starch and ingredients of fillings during cooling. What's more, the dynamic changes of hardness and adhesiveness were extremely significantly correlated with the content of different states of water in CSB during cooling (p < 0.01). The method to predict the water distribution and textural properties of CSB during cooling has been built, with temperature as reference. Our research helped to explain the reason for the changes of edible quality of CSB and provide theoretical basis and practical guidance to maintain and optimize the edible quality of CSB during cooling.
查看更多>>摘要：The application of alginate-based coatings in food preservation is limited owing to their poor antimicrobial, UVshielding, and water-barrier properties. For this concern, multifunctional alginate films were designed for the preservation of green capsicums through the incorporation of aloe vera (AV) and frankincense oil (FO). FTIR confirmed the successful incorporation of AV and FO while XRD showed a crystallinity reduction in the presence of FO. Significant improvements in thermal stability and mechanical properties were achieved in the presence of AV and FO. The addition of AV and FO made the films more bright, yellow and green meanwhile the film's transparency was not significantly influenced. A significant UV-shielding was detected upon increasing either AV or FO. Water vapor permeability was significantly reduced from 21.53 +/- 1.43 g mm/m2 day kPa for alginate to 8.18 +/- 0.24 g mm/m2 day kPa for the film containing AV at 67% and FO at 6%. Excellent inhibition activities against different bacteria and fungi were obtained for the films containing AV and FO. The prepared films exhibited excellent senescence retardation and resistance to the mass loss for green capsicums. Due to their enhanced UV-barrier, physical and microbial-inhibition properties, the prepared active films might be potentially used in food preservation.
查看更多>>摘要：In this study, the use of barberry fruit (Berberis crataegina DC.) extract was investigated as a natural red colorant in chewing gum, jelly, and marshmallow samples at different percentages (1%, 5%, and 10%). The color stability (Delta E) values were determined for all sample groups and it was observed that the barberry extract had higher color stability than beet juice concentrate, which was used in the control chewing gum samples as a natural red colorant. The water activity values were within the specified limits for all sample groups except the jelly samples and 10% colorant added chewing gum. The antioxidant and anti-radical properties of all the samples were significantly improved by the addition of the barberry extract. According to the results of the texture profile, the hardness values of all chewing gum and marshmallow samples decreased with the addition of barberry extract, and this decrease became even more important as the concentration increased.
查看更多>>摘要：Light-emitting diode (LED) technologies are economical and efficient devices that could be considered in poultry processing as disinfection strategies. This study evaluated the efficacy of a LED-based device to reduce the microbial load on chicken meat and investigated it's impact on selected quality parameters. Quality parameters including pH, texture and color after LED-UV exposure and during subsequent storage for 7 days at 4 degrees C were investigated. Diced chicken breast fillets were exposed to UV light wavelengths of 255, 280, 300 and 365 nm for 2, 4, 6, 8 and 10 min. A microbiological analysis was conducted on chicken samples to enumerate bacterial counts. Reductions between 1.17 and 1.67 log CFU/g for total viable counts of mesophilic, psychrophilic bacteria and total Enterobacteriaceae counts were observed, whereas, up to 2 log CFU/g was obtained for Pseudomonas and lactic acid bacteria groups after treatment with wavelengths of 280, 300 and 365 nm. Furthermore, color, texture and pH were not affected by exposure to UV light at 280 nm even following 7 days storage. Thus, LED-based technologies could be applied on poultry meat to reduce the levels of spoilage bacteria while maintaining quality attributes.
查看更多>>摘要：Ginseng (Panax ginseng), a tonic and functional food in Asia and among the ten top-selling herbal remedies worldwide, is often sulfur-fumigated (SF) during post-harvest handling. In this study, a practical protocol was developed using ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) and multivariate statistical analysis to identify characteristic SF markers, dissect chemical transformation mechanism, and control the quality of SF ginseng. The result showed that sulfur fumigation significantly altered the holistic chemical profile of ginseng by triggering chemical transformation of certain original components, 14 ginsenosides and its metabolites together with 2 potential sulfur-contained ginsenoside sulfates were screened out to be the most characteristic markers for distinguishing non-fumigated (NF) and SF ginseng. Moreover, the transformation mechanism of the sulfates of ginsenoside Rg1, Rh1 and 24(R)-pseudoginsenoside Rt5 was inferred, and which showed that in addition to hydrolysis, esterification and dehydration reaction occurred in the process of sulfur fumigation. This study shows that the comprehensive evaluation protocol-based chemical profiles and discriminated markers can be applied to quality evaluation of NF and SF ginseng and other edible or medical materials.
查看更多>>摘要：In this study, kinetic and mechanism of autocatalytic esterification of citronellol using microwave technique was investigated. Effects of acyl donor type, reaction temperature, molar ratio of citronellol to acetic anhydride, and microwave power level on reaction conversion, yield, and selectivity were investigated. Also, autocatalytic esterification of citronellol using microwave technique was compared to those of chemical and enzymatic esterification. By increasing microwave temperature from 313 to 333 K, the reaction conversion was increased from 53.39% to 94.84%. Also, by increasing the citronellol:acetic anhydride molar ratio from 1:1.5 to 1:4.5, the reaction conversion was increased from 78.88% to 94.84%. Chemical and enzymatic catalysts had no significant effect on improving the reaction conversion when acetic anhydride was used as acyl donor. Based on the modeling studies, it can be concluded that the reaction obeys second-order kinetic model. Microwave technique decreased the activation energy by 2.46% compared to magnetic stirrer technique. In microwave technique, frequency factor and entropy were 4.55- and 1.12-folds higher than those of magnetic stirrer technique, respectively. In conclusion, autocatalytic synthesis of citronellyl acetate using microwave radiation is a simple, low-cost, and safe technique which can be propose to apply instead of conventional chemical and enzymatic methods.
Ceccanti, CostanzaFinimundy, Tiane C.Heleno, Sandrina A.Pires, Tania C. S. P....
8页
查看更多>>摘要：Recent studies have dealt about the phenolic compounds and the nutraceutical properties of Sanguisorba minor Scop and about the possibility of their domestication to standardise the plant production. However, it is also known that the storage conditions can affect the bioactive compounds present in plants. Thus, wild (W) and domesticated (F1, F2, F3) S. minor samples were exposed to different drying methods (oven-drying at 60 degrees C until constant weight named OD or freeze-drying until constant weight named FD) and studied for their content in phenolic compounds, antioxidant, antimicrobial, cytotoxic and anti-inflammatory properties. In general, OD samples showed the highest nutraceutical properties and the highest content in phenolic compounds. The most abundant phenolic compounds in both drying methods were kaempferol-3-O-glucoside and caffeoyl ester, with some differences between wild and domesticated samples. Wild samples showed higher antimicrobial and cytotoxic activity than domesticated ones, except for the OD F3 and FD F2 samples that reported cytotoxicity against HeLa cells. This study provides important information to choose the most adequate methodology to retain phenolic compounds and nutraceutical properties of S. minor species. Further researches are necessary to standardise the domestication of the studied wild species and verify the highest efficiency of the OD method.
查看更多>>摘要：Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) were extracted from purple turnip (Brassica rapa L.). IDF was modified with alkaline hydrogen peroxide (AHP) or enzymatic hydrolysis (EH) to obtain modified IDF (A-IDF and E-IDF) and modified SDF (A-SDF and E-SDF). The composition and physicochemical properties of the samples were investigated using FT-IR, XRD, SEM, and DSC. Both modification methods improved the hydration properties, microrheological properties, and in vitro cholesterol adsorption capacities (CACs) of the samples. Specifically, AHP greatly improved the water retention capacity (WRC), water swelling property (WSC) and oil holding capacity (OHC) of the IDF. The effects of EH on the yield, WRC, OHC and CAC of the SDF were more significant than those of EH on IDF properties. Principal component analysis (PCA), clustering heatmap and correlation heatmap revealed that a significant negative correlation was found between OHC, CAC and particle size, and pectin content presented a positive correlation with crystallinity. In summary, EH was considered to be the ideal modification method to enhance the functional characteristics of dietary fiber from purple turnip, and E-SDF showed better application potential than A-SDF.
查看更多>>摘要：Candida zemplinina, Candida californica, Hanseniaspora uvarum, and Hanseniaspora osmophila were screened from spontaneous fermentations of Vidal blanc icewine. These non-Saccharomyces yeasts and commercial Saccharomyces cerevisiae were used in mixed inoculated fermentations, and pure S. cerevisiae fermentation was used as the control. The aim is to investigate the effects of these non-Saccharomyces yeasts on the aroma complexity of icewine, which is of great significance for the application of these non-Saccharomyces yeasts in icewine production. Compared with the icewine fermented with pure S. cerevisiae, the icewines fermented using mixed C. zemplinina contained higher glycerol, ethyl esters and beta-damascenone contents, while icewines fermented using mixed C. californica had more acetate esters and terpenes. Icewines fermented using mixed H. uvarum contained higher ethanol and ethyl acetate contents, and icewines fermented using mixed H. osmophila had lower ethanol and higher phenethyl acetate contents, than icewine fermented with pure S. cerevisiae. Therefore, mixed fermentations of different non-Saccharomyces yeasts contributed different aroma characteristics to icewines. To the best of our knowledge, this study is the first to investigate the application of C. californica and volatile aroma compounds in icewines.
NSTL
Elsevier