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Silver nanoparticles (AgNPs) are widely used in the field of biomedicine. However, the synthesis of AgNPs by traditional physical and chemical methods has problems such as pollution, product toxicity, and time-consuming. Therefore, it is extremely important to explore the preparation of AgNPs. Silver nanoparticles (AgNPs) of sweet corncob polysaccharide (SCP-AgNPs) were successfully synthesized by green method using sweet corncob polysaccharide (SCP) as raw material and the reaction conditions were optimized. The generated AgNPs were characterized by transmission electron microscopy (TEM), X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and their antioxidant and anti-diabetic abilities in vitro were investigated. The results showed that the optimum reaction conditions of SCP-AgNPs were as follows: The concentration of silver nitrate in the solution was 0.75×10−3 mol/L, the pH was 10.0, and the reaction time was 80 min. The prepared SCP-AgNPs were spherical with an average particle size of 13.5 nm. The structure showed a face-centered cubic crystal structure, and Ag was determined to be Ag0 state. The synthesized SCP-AgNPs had strong free radical scavenging effect in vitro. At the same time, SCP-AgNPs had a good inhibitory effect on the activity of α-glucosidase and α-amylase. SCP-AgNPs has a significant inhibitory effect on key enzymes of diabetes and has potential anti-diabetic activity. It is a nano-drug suitable for nano-biomedical applications and will be widely used in food processing, medicine and other fields in the future.

In order to solve the enzymatic browning phenomenon in the pulping unit of Lonicera caerulea fruits and improve its utilization value. The main phenolic substrates involved in the enzymatic browning reaction in the pulping process of Lonicera caerulea fruits and the inhibition ability were investigated, and the interactions between phenolic substrates and epicatechin on the reaction of polyphenol oxidase (PPO) were analyzed and its mechanism of enzymatic browning was also determined. The three most effective inhibitors were further selected by comparing the effects of ascorbic acid, L-cysteine, calcium chloride, EDTA-2Na, and citric acid additions on the browning inhibition rate. The results showed that epicatechin was the primary influencing factor involved in enzymatic browning in the pulping process of Lonicera caerulea fruits, and the quenching mechanism of epicatechin on PPO was static quenching. The response surface optimization test determined the optimal combination of composite inhibitors as 0.11% ascorbic acid, 0.11% L-cysteine, and 0.08% EDTA-2Na, and the browning inhibition rate of Lonicera caerulea fruits juice under this condition was 93.17%. It indicates that the above composite inhibitors can inhibit the enzymatic browning in the pulping process of Lonicera caerulea fruits.

The transition metal Ni is widely used because of its low price, fast electron transfer rate and high catalytic activity. The electrochemical performance of the sensor will be improved by combining metallic Ni with other materials through different preparation methods. This combination can be applied to glucose detection in the food industry, health care and other fields. This paper reviews the methods of constructing electrodes from metal Ni-based composites and the effects of metal Ni compounded with carbon materials, monometallics, metal oxides, and metal hydroxides on sensor performance for the construction of high-performance electrochemical sensors and the practical application of glucose detection.

To enhance the biological activity of sweet corn cob polysaccharide, a sweet corn cob polysaccharide chromium complex (SCP80-Cr) was prepared, characterized and its in vitro activity was also explored. The results showed that the optimal process conditions for the preparation were pH10.1, reaction temperature 74 ℃, polysaccharide concentration of 3 mg/mL, and the reaction time of 60 min. The weight percentage of Cr(III) in SCP80-Cr was 21.08% and the elemental percentage was 6.67%. The characterization revealed that SCP80-Cr contained almost no protein, nucleic acid or pigment, while Cr was conjugated with SCP80 in the form of Cr-O and Cr-OH and had strong molecular agglomeration properties. The molar percentage of the monosaccharide composition of SCP80-Cr was mannose: glucose: galactose: xylose: arabinose = 0.58: 89.50: 4.65: 1.33: 3.58. The results of in vitro hypoglycemia experiments showed that the IC50 of SCP80-Cr on α-amylase and α-glucosidase inhibitions were 4.70±0.38 mg/mL and 3.99±0.26 mg/mL, respectively. Moreover, the results of in vitro antioxidant experiments showed that SCP80-Cr scavenged DPPH radicals and hydroxyl radicals with IC50 of 4.80±0.34 mg/mL and 4.99±0.28 mg/mL, respectively, indicating that SCP80-Cr had better in vitro hypoglycemic and antioxidant activities compared with SCP80. The results of the study provided some references for the study of sweet corn cob polysaccharides in functional foods.

To solve the problems of sour taste, seasonality, and storage difficulties of Lonicera edulis, fermented Lonicera edulis juice was produced by yeast. Its fermentation conditions were optimized by single-factor and orthogonal experiments, and the gas chromatography-mass spectrometry (GC-MS) was used to study the changes of aroma components of Lonicera edulis juice during fermentation under optimal conditions. The results showed that the optimal fermentation conditions for Lonicera edulis juice were fermentation temperature of 18 ℃, fermentation time of 8 d, yeast addition of 1%, under which the sensory score was 93.10±2.73 in fermented juice. A total of 62 aroma substances were detected during the fermentation of the juice under the optimal conditions, and four principal components were obtained by principal component analysis. The cumulative contribution of the first three components was 88.64%, and ethyl decanoate, ethyl acetate, ethyl 9-decenoate, ethyl caproate, heptanic acid and isoamyl alcohol were the main aroma components of juice during fermentation processing. The Lonicera edulis juice with rich flavor substances and pleasant taste could be gained with this method. The results of this study could provide the technological support for produce of Lonicera edulis fermented juice.

In order to rapidly detect sulfamethoxazole (SMZ) residues in honey, zinc oxide (ZnO) prepared by hydrothermal method and manganese dioxide (MnO2) prepared by co-precipitation method were compounded on glassy carbon electrode (GCE) to construct MnO2/ZnO/GCE electrochemical sensor for the detection of SMZ. The morphology and structure of the composites were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Differential pulse voltammetry (DPV) was used to explore the ratio and modification amount of the composite material to optimize the construction conditions of the sensor. DPV and cyclic voltammetry (CV) were used to investigate the detection conditions such as buffer solution pH and scanning rate. The results showed that when the mass ratio of m(ZnO):m(MnO2) was 1:0.6, the addition amount of MnO2/ZnO composite was 1.7×10−3 mg/mm2, the pH was 8 and the scanning rate was 30 mV/s, the sensor had a good detection effect on SMZ. In the range of 0.3~100 μmol/L, the peak current of SMZ had a good linear relationship with the concentration, the linear equation was Ip=0.0843c+4.5168 (R2=0.9916), the limit of detection was 0.39 μmol/L and the limit of quantification was 1.30 μmol/L. The sensor was applied to the determination of honey sample, with a recovery of 95.5%~102.6% and a relative standard deviation (RSD) of 0.68%~2.55%. It shows that the sensor can realize the accurate detection of SMZ content. It has certain application value for the detection of SMZ residues in honey samples.

Carotenoids are widely distributed food components in nature and have various biological activities, which have received much attention from scholars. The article reviewed the research progress of carotenoids in terms of their biological functions, the effects of food ingredients on carotenoid absorption and utilization, and the improvement of their biological utilization. The carotenoids specifically regulate the functions of related genes and proteins, which in turn have various biological activities. The article summarized the functional properties of carotenoids from a mechanistic perspective. After that, the effect of food component interactions on carotenoid bioavailability was organized. And three methods to improve the bioavailability of carotenoids are summarized (nano-drug delivery system technology, isomerization treatment technology, and food processing methods). The article would provide some theoretical references for the development of functional carotenoid products.

In order to prepare mimetic enzyme with hydrogen peroxide catalytic activity, CeO2 was used as the research object in this paper, and nano-sized CeO2 particles with peroxidase activity were prepared by hydrothermal method. The effect of preparation conditions of hydrothermal synthesis on catalytic performance of nano-sized CeO2 for hydrogen peroxide was studied by the color reaction of Tetramethylbenzidine (TMB), including solid-liquid ratio, reaction temperature and reaction time. A nano-sized CeO2 with the best catalytic activity was selected. Its structure was characterized and its steady-state kinetics of catalytic reaction was studied. The results showed that when the ratio of solid to liquid was 1:60 g/mL, the reaction temperature was 80 ℃ and the reaction time was 8 h, the absorbance value was the largest, which was 0.501, and the catalytic performance of nano-sized CeO2 prepared by hydrothermal method was the best. The nano-sized CeO2 crystals synthesized possessed fluorite structure. The catalytic reaction was in good agreement with the Michaelis-Menten equation, and the Km value for H2O2 was 0.021 mmol/L. The results demonstrated that CeO2 synthesized under simple reaction conditions in excellent purity showed high performance catalysts for H2O2.

Honey is rich in many nutrients. It is used in the food processing industry not only as a sweetener for the production of beverages, candies and other foods, but also for pickling fruits and vegetables. However, there is a problem of inappropriate use of antibiotics in the prevention and treatment of infectious diseases of bees during beekeeping process. Antibiotics remain in honey because most antibiotics are difficult to be metabolized by bees. If the honey containing antibiotics is eaten by consumers for a long time, consumers' health will be affected. Therefore, the detection of antibiotic residues in honey contributes to assess the potential health risks. The current status of antibiotic residues in honey is reviewed in the paper. And the detection methods of antibiotic residues in honey are summarized. Chromatography has the advantages of rapid and sensitive detection. But there are problems of expensive equipment and high detection costs. The sensor method and the immunoassay are cheap and easy to operate. The electrochemical sensor method has good prospects for development because of its rapid response and high sensitivity. Besides, the development of detection methods of antibiotic residues in honey is prospected. This paper is expected to provide theoretical reference for the research and application of detection methods of antibiotic residues in honey.

In this study, the extraction process of fennel essential oil was optimized by response surface methodology. Fennel essential oil was used as oil phase, Tween 80+40 as surfactant and glycerol as cosurfactant to prepare fennel essential oil microemulsion system. The structure, particle size, total reducing power and storage property of fennel essential oil microemulsion were investigated by rheology, particle size analyzer and reduction reaction. The results showed that the yield of essential oil of fennel was as high as 15.99%±0.10% when the ratio of material to liquid was 1:8.40 g/mL, the extraction time was 4.09 h, the particle size was 80 mesh, and the extraction temperature 80 ℃. The diameter of fennel essential oil microemulsion was 30.92±0.13 nm, and when the moisture content was higher than 60%, it was a stable O/W microemulsion. The emulsification of fennel essential oil significantly improved the total reducing power of fennel essential oil. According to the principle of chemical reaction kinetics, the Arrhenius equation was established as k=2518.85·e−35583.09/RT. The model predicted that the fennel essential oil microemulsion could store 1899.18, 932.03, 492.94 and 271.51 h at 20, 35, 50 and 65 ℃, the maximum relative error was 8.73%, and the error was small, which could accurately predict the shelf life of the microemulsion.

CBD-NLC was prepared by film ultrasonic method with soybean phospholipid and cholesterol as solid esters. The effects of mass ratio of phospholipid to cholesterol, mass concentration of CBD broad-spectrum oil, pH value of buffer solution, rotary evaporation temperature and ultrasonic time on the encapsulation efficiency of CBD-NLC were analyzed by single factor experiment, The four factors which have great influence on the preparation of CBD-NLC were optimized by response surface test. The results showed that the optimum preparation conditions were as follows: the mass ratio of phospholipid to cholesterol was 3.4:1, the mass concentration of CBD broad-spectrum oil was 9.5%, the pH of buffer solution was 7.3, the rotary evaporation temperature was 39.1 ℃, and the ultrasonic time was 30 min. The results showed that the encapsulation efficiency of CBD-NLC was (91.3%±0.37%), the particle size was (94.0±0.4) nm, the PDI was (0.213±0.017), the zeta potential was (−45.0±0.8) mV. The color of CBD-NLC suspension is light yellow, with good dispersion uniformity and stability, which lays a foundation for the further development and application of CBD broad-spectrum oil.