Objective To systematically evaluate the differences in overall quality of rice from different regions in Liaoning Province. Methods Using 125 different rice varieties as research objects, the quality of rice from different regions in Liaoning Province was analyzed and comprehensively evaluated through physical and chemical testing methods, using correlation analysis (CA), principal component analysis (PCA), and hierarchical cluster analysis (HCA). Results The order of influence of different varieties and origins of rice on quality indicators was: Retention rate of germ grains>chalky grains rate>chalkiness>milled rice rate>brown rice rate>moisture> ash>protein>brown rice quality>fat>length-width ratio>fiber. Using stepwise regression analysis, the regression equation was obtained as follows: Brown rice rate=4.672×brown rice quality-0.104×chalky grains rate+0.141×chalkiness-0.860×length-width ratio-13.205. PCA extracted 4 principal components with a cumulative variance contribution rate of 80.046%, effectively elucidating all quality information characteristics. The results from HCA were consistent with those obtained from PCA, categorizing the 125 rice varieties into 3 major groups; through comprehensive assessment, the top 3 ranked varieties were identified as Yudao No.17 from Xiqing Village, Shiyuan Town, Dashiqiao City in Yingkou; Ichigo-hime from Zhangjia Village at Xinli Farm in Dawa County, Panjin; and Yanfeng No.47 from Gongxing Village in Tianshui Township, Panshan County, Panjin. Conclusion This study effectively highlights the differences in quality among various regional rices within Liaoning and provides a theoretical basis for breeding programs and product development related to rice germplasm.

Objective To investigate the induced expression level and enzymatic properties of recombinant bacterial laccase and to improve the degradation efficiency of sulfadiazine antibiotics by bacterial laccase. Methods In this study, the effects of induction temperature, induction time, and concentration of isopropyl β-D-thiogalactopyranoside (IPTG) on enzyme expression were investigated by one-way experiments. The enzymatic properties of recombinant bacterial laccase were also investigated by both pH and temperature. Results The degradation of sulfadiazine by recombinant bacterial laccase at 24 h was 50%. The optimal conditions for the expression of recombinant bacterial laccase in Escherichia coli BL21 (DE3) were as follows: Induction temperature of 16 ℃, induction time of 16 h, and IPTG concentration of 0.2 mmol/L. The optimal pH was 3, and the stability was best at pH 7, with the enzyme activity reaching 150% in 6 h. The optimal temperature was 80 ℃, and the thermal stability was best at 70 ℃, with the enzyme activity increasing to 120% in 1 h. The half-life was about 6 h. Conclusion This study provides an experimental basis for the application of bacterial laccase in the degradation of sulfadiazine antibiotics and lays down a theoretical basis for the future study of its potential application in the industry.

Objective To establish a method for the determination of chlorophyll a and chlorophyll b content in vegetables by convergence chromatography (CC). Methods The Soxhlet extraction method was used for efficient extraction of chlorophyll from vegetables and their products, followed by separation and detection using an ultra-performance convergence chromatography system coupled with a ultraviolet-visible detector. Results Through comparison of the stability of different solvents, petroleum ether was selected as the extraction solvent, and the extraction conditions were optimized. The method was validated with a limit of detection of 0.02 mg/kg, a limit of quantification of 0.06 mg/kg, a linear range of 0.06-800.00 mg/kg, a spike recovery rate of 99%-102%, and a relative standard deviation of 2.2%-14.0% for real samples. The reliability and accuracy of the method were confirmed through precision testing of real samples, including kale, fresh mustard greens, pickled mustard greens, dried pickled mustard greens, steamed dried pickled mustard greens, and boiled dried pickled mustard greens, as well as cross-validation with existing standard methods. Conclusion This study establishes a CC-based method for detecting chlorophyll a and chlorophyll b in vegetables, demonstrating high sensitivity, a wide linear range, good specificity, and precision. The method is not only suitable for laboratory research but also has practical application potential.

Objective To optimize the process of preparing low methoxy pectin-lentinan gel beads by combining low methoxy pectin and lentinan with calcium lactate, and characterize the structure of gel beads prepared under the optimal process conditions. Methods The effects of calcium lactate concentration, curing time, and curing temperature on the hardness of gel beads were investigated through single factor experiment and response surface methodology, and the structure of gel beads was characterized by Fourier transform infrared spectroscopy, texture analysis, rheological analysis and scanning electron microscopy. Results The optimum preparation process of low methoxy pectin-lentinan gel beads was determined by response surface methodology as calcium lactate concentration of 6.2%, curing time of 44 min, and curing temperature of 48 ℃. Under these conditions, the hardness of the gel beads was 35.60 gf. Compared with low methoxy pectin gel beads, low methoxy pectin-lentinan gel beads produced stronger hydrogen bond interaction, and their elasticity, cohesion, and dynamic modulus were improved. Conclusion Lentinan can effectively improve the mechanical properties and texture properties of low methoxy pectin gel beads, and this study will provide a reference for the improvement of pectin gel bead systems.

Objective To establish a quantitative analysis of multi-components by single marker (QAMS) method for the simultaneous determination of 9 kinds of components in Andrographis paniculata. Method The relative calibration factors of andrographolide with forsythitin, oleanolic acid, caffeic acid, andrographolide, dehydrated andrographolide, andrographolide, deoxyandrographolide, dehydrated andrographolide half succinate and sodium bisulfite were established by ultra performance liquid chromatographolide-tandem mass spectrometry. The relative correction factor was used to calculate the content of each component, and the calculated results of QAMS method were compared with the measured values of external standard method. Results The relative correction factors showed good reproducibility, and there was no significant difference between the results obtained by the QAMS method and the external standard method. Conclusion The QAMS method is suitable for the simultaneous determination of 9 kinds of components in Andrographis paniculata, ensuring the reliability of quality.

Objective To establish a method for the simultaneous determination and risk assessment of multi-class pesticide residues in Cucumis sativus L. and Malus pumila Mill. using QuEChERS-liquid chromatography-tandem mass spectrometry. Methods Fruit and vegetable samples were homogenized using acetonitrile as extraction solvent, sodium chloride and anhydrous sodium acetate as salting-out agent, and the supernatant was taken and purified by primary secondary amines (PSA), graphitized carbon black (GCB) and anhydrous magnesium sulfate reagent, and 7 kinds of pesticides were analyzed in 11 min using an Agilent Poroshell 120 EC-C₁₈ column with gradient elution. The potential health risks associated with the consumption of Cucumis sativus L. and Malus pumila Mill. were assessed by calculating the estimated daily intake the estimated dietary intake (EDI) and hazard quotient (HQ). Results The 7 kinds of pesticides exhibited satisfactory linearity within the range of 5‒500 μg/L, with correlation coefficients more than 0.99. The limits of detection were 0.5‒1.0 μg/kg and the limits of quantification were 2.0‒4.0 μg/kg. The average recoveries ranged from 71.0% to 118.8% at three different spiked levels, with the relative standard deviations ranging from 3.1% to 12.7%. Concurrently, the HQ values of individual pesticides evaluated from the acceptable daily intake (ADI) were found to be less than 1, and their risks were within acceptable limits. Conclusion The method exhibits high accuracy, precision, and sensitivity, and is suitable for the simultaneous determination of multi-class pesticide residues in fruit and vegetable samples. Furthermore, the risk assessment results of this study demonstrated that the health risk to individuals from pesticide residues in Cucumis sativus L. and Malus pumila Mill. is within acceptable limits.

Objective To study the nutritional components of Weiying watermelon foranalyze and evaluate the nutritional quality of Weiying watermelon. Methods Namely “Meidu” watermelon from 2 main production areas of Weiying watermelon (S1 and S2) were used as experimental materials, and the same variety of watermelon from two other production areas (S3 and S4) as controls. The content of sugar, organic acid, amino acid, mineral, soluble solid, β-carotene, lycopene and vitamin C in the watermelons from the 4 production areas were detected and analyzed. Results The watermelon from different producing areas exhibited certain variations in quality characteristics. The sugar components in watermelon was mainly glucose and fructose, organic acids was mainly malic acid and lemon, free amino acids was mainly citrulline, and it also contains abundant mineral elements; the glucose content, sugar-acid ratio and sweetness-sourness ratio in S1 and S2 were higher than those in S3 and S4, while the total acid content was the opposite. In addition, the levels of the citrulline, β-carotene, lycopene and vitamin C in S1 and S2 were also higher than those in S3 and S4, respectively. The comprehensive performance of the nutritional quality of S1 and S2 were superior to that of S3 and S4 based on the principal component analysis. Conclusion Weiying watermelon has better flavor and texture, richer nutritional components, and superior nutritional quality.

Objective To develop a colorimetric analysis method based on nanozymes, rapidly evaluate the total antioxidant capacity of wild edible mushrooms (Auricularia cornea, Flammulina filiformis, and Pleurotus ostreatus) in Yangzhou. Methods Nano silver modified manganous oxide (Mn/Ag NPs) nanozyme was prepared by the hydrothermal method, and its microstructure was confirmed by various characterization methods. The total antioxidant capacity of 3 kinds of wild edible mushrooms were extracted using different solvents, and their total antioxidant capacity were evaluated by the colorimetric analysis method based on Mn/Ag NPs nanozyme. In addition, the evaluation results were verified using the commercial 2,2’-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) kit. Results The colorimetric analysis method based on Mn/Ag NPs nanozyme achieved the rapid evaluation of the total antioxidant capacity of wild edible mushrooms in Yangzhou. Total antioxidant activity was Pleurotus ostreatus>Flammulina filiformis>Auricularia cornea. Extraction efficiency of solvent was ultrapure water>mixed solvent>ethanol>ethyl acetate. Conclusion The colorimetric analysis method based on Mn/Ag NPs nanozyme can rapidly evaluate the total antioxidant capacity of wild edible mushrooms in Yangzhou.

Cyperue esculentust L. oil was a kind of high-quality edible oil rich in monounsaturated fatty acids, protein and other nutrients. This paper reviewed the main extraction technologies of Cyperue esculentust L. oil (supercritical CO₂ extraction, subcritical butane extraction, pressing, leaching, aqueous enzymatic extraction, aqueous extraction, ultrasonic-assisted extraction and microwave-assisted extraction) in recent years. By summarizing and analyzing the characteristics of different extraction technologies in practical operation and their effects on the basic physical and chemical properties, fatty acids, sterols, vitamin E and volatile compounds of Cyperue esculentust L. oil, it was suggested that the development of Cyperue esculentust L. oil in the future could focus on 3 aspects: Optimizing the key machinery and equipment of traditional oil extraction technologies (pressing, aqueous extration and leaching) to improve the quality of oil and reducing the production cost of new oil extraction technologies (aqueous enzymatic extraction, supercritical CO₂ extraction, ultrasonic-assisted extraction, subcritical butane extraction and microwave-assisted extraction) to increase the popularization feasibility, strengthening the cultivation of new varieties of Cyperue esculentust L. oil with high oleic acid and increasing the research and development of its functions, so as to be beneficial to the industrialization of Cyperue esculentust L. oil.

Tricholoma matsutake is a high-quality edible wild fungi in China, rich in a variety of nutritional constituents. Research shows that Tricholoma matsutake contains Tricholoma matsutake polysaccharides, Tricholoma matsutake proteins, Tricholoma matsutake polyphenols, sugar alcohols and other nutrients, high nutritional value, delicious taste, with the promotion of intestinal peristalsis, antioxidant, activation of the immune system, anticancer, antihypertension, antidiabetic and other efficacy, is known as “King of Fungi”. The principal production regions of Tricholoma matsutake in China is divided into the southwest region, such as Sichuan Province, Yunnan Province and other places, as well as the northeastern region, such as Heilongjiang Province, Jilin Province. Due to the different genetic backgrounds and growth environments of different production areas, the types and content of nutrients contained in Tricholoma matsutake are also different. Tapping into the nutritional quality characteristics of local Tricholoma matsutake is the basis for developing local specialty Tricholoma matsutake industry and creating regional brands. This paper systematically summarized and compared the main nutritional characteristics of the Tricholoma matsutake produced in the main producing regions of China. In general, the total fat content of the matsutake mushrooms in the producing regions was lower and the protein content was higher, among which the amino acid and crude fiber contents were higher in the southwestern producing region, while the northeastern producing region had lower fat content and higher average protein content. This review will provide new ideas and theoretical basis for the development of specialty food and health food of Tricholoma matsutake in each production area in China.