查看更多>>摘要：Abstract Cadmium is widely found in nature and excessive cadmium content in Chinese herbal medicine has become a common phenomenonis.?For the human body, cadmium is a very harmful and toxic heavy metal, which will cause immeasurable harm to the liver and kidney. Panax notoginseng has been widely praised as a Chinese herbal medicine with many benefits to the human body. In order to avoid a series of safety problems caused by excessive cadmium content in Panax notoginseng, it is necessary to detect cadmium before it is used. Herein, a novel flueorescent aptasensor for the detection of cadmium in Panax notoginseng was developed by combining the carbon quantum dots NCDs prepared by one-step hydration of citric acid and ethylenediamine and the CD-4 aptamer. The aptamer-NCDs conjugation binds to the target cadmium, resulting in fluorescence quenching due to electrostatic interaction. Under certain conditions, the fluorescence intensity of cadmium decreases linearly with the increase of cadmium concentration and the LOD value of this method is 0.89?μg/L and LOQ value is 2.68?μg/L. After simple pretreatment of the actual sample of Panax notoginseng powder, this method was used to detect the cadmium. The accuracy and superiority of the proposed fluorescence aptasensor was verified by compared with ICP-MS method. This aptasensor with simple operation, high sensitivity, strong specificity provides a broad prospect for the detection of toxins in Chinese medicinal materials.
查看更多>>摘要：Abstract The objective of the present study was to develop and characterize a new biodegradable film based on pistachio green hull pectin (PGHP)/poly vinyl alcohol (PVA) incorporated with different ratios of curcumin. With increase of curcumin concentration from 10 to 50?mg g?1, tensile strength and water solubility of the films decreased significantly (p < 0.05). The surface of the films containing 50 (mg g?1) curcumin was morphologically uniform. The PGHP/PVA/curcumin films showed a clear antibacterial activity against Escherichia coli and Staphylococcus aurous (with inhibition zones of 6.3?±?0.3 and 4.7?±?0.3?mm, respectively). The developed films showed considerable color variations with the quality change of fish. A strong positive correlation was observed between total volatile base nitrogen contents of the fishes and a* values of the films over storage period (R2?=?0.971). Overall, pectin/PVA/curcumin films can be introduced as a promising packaging system for food industries’ objectives.
查看更多>>摘要：Abstract In this study, the antimicrobial activity of free cinnamaldehyde (CA) and nanoemulsion (NE)-CA was compared against S. aureus, E. coli, and C. perfringens in a sausage product. At first, the droplets size of the NE-CA was measured, which was about 146.1?nm. According to minimum inhibitory concentration, minimum bactericidal concentration, and agar disk diffusion test results, NE-CA was significantly more effective in inhibiting the growth of three tested bacteria than CA. In agar disc diffusion test, the halo diameter increased significantly with CA (or its NE) concentration (1.1 to 36.1?mm). In in situ experiment, the formulated sausages were inoculated with E. coli, C. perfringens, and S. aureus in average at?4?×?105?CFU/g and then were stored at 4?°C for 4?weeks. An increasing trend was observed for the microbial population in all samples over time. The control samples showed the highest bacterial counts (1?×?108?CFU/g), followed by 120?mg/kg nitrite treated samples (3.16?×?107?CFU/g). The lowest microbial population was observed in CA (600?mg/kg), NE (containing 600?mg/kg CA), CA (600?mg/kg)?+?Nitrite (60?mg/kg), and NE (containing 600?mg/kg CA)?+?Nitrite (60?mg/kg) sausages with no significant difference among them against each tested bacterium (~?8?×?106?CFU/g). A first-order reaction was detected for bacterial growth in all sausages. CA and its NE reduced 1 log cycle the population of examined bacteria after 4?weeks. Overall, the results showed that the use of NE-CA did not improve the antimicrobial effect of CA in the sausage product.
Katyal MehakSingh NarpinderTiwari PoojaKaler R. S. S....
13页
查看更多>>摘要：Abstract The physicochemical, pasting, dynamic rheology and muffin making properties of air classified fractions obtained from original wheat flour (OWF) and after stone grinding the OWF were evaluated and compared. Fractions from stone ground flour (SGF) showed higher proportions of fine particles and protein content but lower ash content than their counterpart fractions from OWF. The stone grinding showed significant impact on lactic acid solvent retention capacity (SRC) and water SRC. Fractions from SGF showed significantly lower breakdown and setback viscosity and higher pasting temperature than their counterpart fraction from OWF. Muffins made from different SGF fractions were lighter in color (lower L′, a′ and b′ values) and softer in texture than those from fractions obtained from OWF. The study demonstrated that fractionation of OWF and SGF can be employed to produce fractions with varied composition and baking potential.
查看更多>>摘要：Abstract The purpose of this study was to explore the effects of different drying methods included hot air (HD), vacuum (VD) and freezing drying (FD) on the chemical composition, structural characteristics, antioxidant activities and glucose consumption of HepG2 cells in vitro of coconut water polysaccharides (CWPs). Results showed that drying methods had significant effects on the contents of neutral sugars and total phenols, the size and distribution of molecular weight, biological activities in vitro of CWPs. All CWPs composed of six monosaccharides including rhamnose, arabinose, galactose, glucose, xylose and galacturonic acid were small molecule acidic heteropolysaccharide containing pyranoid ring structure and a-glycosidic linkages. And the CWP-HD, CWP-VD and CWP-FD would not decompose when the temperature was lower than 183.76?°C, 182.75?°C and 176.48?°C. Furthermore, CWP-HD had the best DPPH (IC50 value of 0.21?±?0.001?mg/mL) and ABTS radical scavenging ability (IC50 value of 5.44?±?0.05?mg/mL), while CWP-FD had the best hydroxyl radical scavenging ability (IC50 value of 20.80?±?0.002?mg/mL) and promoting effect on glucose consumption of HepG2 cells. These could provide support for the high-value development and utilization of coconut water.
查看更多>>摘要：Abstract To produce cooked rice that can be stored under a chilled condition, the effect of maltotriose syrup on the retrogradation of gelatinized rice starch and cooked rice was investigated using dynamic mechanical thermal analysis, rheometer, differential scanning calorimetry, and sensory analysis. The storage modulus (G’) of gelatinized rice starch increased considerably after chilled storage at 5?°C for up to 72?h. The time course of the G’ corresponded to that of the re-gelatinization enthalpy of retrograded starch. The G’ decreased with increasing maltotriose syrup content, but there was no significant difference in the G’ between samples with 20% and 30% maltotriose syrup. According to the results, cooked rice samples with (additive samples) and without (non-additive samples) 20% maltotriose syrup were prepared with preset water contents of 60% and 65%. After chilled storage at 5?°C for 24?h, the G’ and hardness (force generated by 50% compressive strain) of the additive samples were much lower than those of the non-additive samples. In addition, the G’ and hardness decreased with increasing water content. The G’ of the additive sample with a preset water content of 65% was lower than that (G’ = 26.9?kPa) of the tolerance limit determined by the sensory analysis. However, the additive samples showed substantial browning. The pH of the samples was adjusted to diminish the browning. The color parameter (b*) did not differ significantly between the additive sample at pH 5.5 and the non-additive sample at pH 7.0.
查看更多>>摘要：Abstract This study investigated the effect of ultrasound assisted irradiation on the carotenoids and lipids extraction from the Chlorella vulgaris and Porphyridium purpureum microalgae in the presence of three solvents with various polarities (water, ethanol, and hexane) allowed in the food industry. The optimization of the ultrasound assisted extraction operational parameters (solvent composition, solvent to sample ratio, power) was realized using Response Surface Methodology based on a face-centered composite design (FCCD). The results of this study showed that the increased solvent polarity led to the maximum extraction yield of 6435.60?μg/g in total carotenoid content. Regarding the distribution of carotenoid between the aqueous ethanolic phase and hexane, the highest yield of 5762.08?μg/g carotenoid was obtained in hexane phase. Regarding the lipid content, the yield increased with the increase of ethanol concentration reaching a maxim value of 29.07?mg/g. Also, it was observed that, when single solvents were used for carotenoid extraction, the yields were much lower compared with mixtures solvents. For example, when hexane was tested the yield was of 226.87?μg/g carotenoid, meanwhile for absolute ethanol the yield was of 2027.72?μg/g The optimal parameters determined was applied for the extraction of carotenoids from Porphyridium purpureum microalgae. The results indicate a total carotenoid content of 947.25?μg/g and 21.59?mg/g lipids. The analysis of fatty acid profile of both microalgae biomass in ethanolic and hexane phase indicated the selective accumulation of saturated and polyunsaturated fatty acids in hexane and respectively in ethanolic phase.
查看更多>>摘要：Abstract This study was aimed to investigate the cryoprotective effects of collagen peptides (10?g/kg; Collagen A, about 4500 Da; Verisol, 2000–3000 Da) on myofibrillar protein (MP) from silver carp surimi and the effects of collagen peptides on the characteristics of surimi gels during frozen storage (? 18?°C, 3–30 days) in comparison with that of a commercial cryoprotectant (40?g/kg sorbitol and 40?g/kg sucrose), sericin peptides (10?g/kg, about 3500 Da) and the control group (without cryoprotectant). The results indicated that Verisol, a collagen peptide with low molecular weight, was the optimal cryoprotective agent for the frozen storage of silver carp surimi. After 30 days of frozen storage, the MP from frozen surimi with Verisol contained 6.0–33.5% less carbonyls (26.8?±?0.3 μmol/g), and 0.6–99.6% more free sulfhydryl (84.0?±?0.4 μmol/g), as well as exhibited 17.6–47.1% greater Ca2+-ATPase activity (0.23?±?0.02 μmol Pi/mgprot/hour) and 5.8–58.2% more extractable salt-soluble proteins (45.3?±?1.0%) in comparison with that of the other four treatments. In addition, the water holding capacity (94.2?±?2.2%), gel strength (314.8?±?8.0?g·mm) and whiteness (79.1?±?1.3) of the surimi gels with Verisol were also significantly better (p?<?0.05) than that of the other treatments.
查看更多>>摘要：Abstract This study demonstrates the electrochemical behaviour of caffeine on an acid activated carbon nanofiber (CNF) modified glassy carbon electrode (GCE) using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) techniques. Characterization of the bare and CNF modified GCE was performed using a [Fe(CN)6]?3/?4 redox probe and caffeine in 0.1?M H2SO4. The fabrication of the electrochemical sensor was achieved simply by drop-coating the surface of GCE with CNF solution. The pristine and acid activated CNFs was characterized by electron microscopy, FTIR, Raman spectroscopy and X-ray diffraction spectroscopy. The presence CNF modifier increased the rate of electrochemical reaction, favoured the electro-oxidation of caffeine at 1.35?V in comparison to oxidation at the bare which occurred at 1.44?V, and caused a 2.35-fold current increase for caffeine at CNF modified GCE. SWV was performed in a concentration range from 25 to 450 μM and the sensor obtained a limit of detection of 17.40 μM. The proposed method was successfully validated by UV–Vis spectroscopy. This sensor lends itself to the detection of caffeine in pharmaceutical, food and beverage samples.
Soleimanipour AlirezaAzadbakht MohsenRezaei Asl Abbas
11页
查看更多>>摘要：Abstract Robust and readily accessible identification systems for agricultural products have received increasing attention in inspection processes. The conventional visual inspection methods rely on human experts and could not be automated efficiently. This paper presents the application of the state-of-the-art Convolutional Neural Network (CNN) model to identify the top 4 most popular Iranian pistachio cultivars, including ‘Fandoghi’, ‘Kaleh-Ghouchi’, ‘Ahmad-Aghaei’, and ‘Akbari’. An image dataset was collected by acquiring pistachio samples images in the bulk mode under the condition of placing perpendicular to the camera with a fixed distance and natural lightening. The feature extraction block of EfficientNet-B3 was combined with a custom classification block. The proposed model was fine-tuned using the pistachio image dataset and adjusted to identify the various cultivars. The pistachio identification system was implemented using Python programming and the Keras API with TensorFlow Machine Learning framework. The results show that the classification accuracy of the best model evaluated on a hold-out test dataset is 98.00%. On the other hand, the proposed CNN model using EfficientNet-B3 presents average precision, recall, and F1-score values of 96.73%, 96.70%, and 96.67%, respectively. These results confirmed that the implementation of these methods as a mobile application and/or on an automated processing line could be a useful and effective approach to develop fast and robust food processing and inspection systems.
NSTL
Springer Nature