Objective To explore the mixing ratio of different oil seeds in microwave-assisted blended cold pressing process, and develop polyunsaturated fatty acid balanced oil that meets the recommended dietary intake ratio. Methods The safflower seed and flaxseed were used as raw materials. The process parameters were optimized by single factor experiment (microwave treatment time, pressing temperature and moisture content of oil seed) and Box-Behnken response surface experiment. The oxidation characteristics of blended cold pressed oil were compared and analyzed. Results The mass ratio method determined that the blended mass ratio range was 1.8-2.4 (safflower seed:flaxseed, W_s:W_f). This method was simple and the results did not need to be verified, but it had the disadvantages of large demand for raw materials and low accuracy of boundary value. The mixing ratio range determined and verified by the fatty acid ratio method was 1.66-2.59 (W_s:W_f). This method had less raw material demand and high accuracy near the boundary value. However, due to the interaction of oil seeds, verification experiments needed to be carried out. Response surface methodology was used to optimize the process parameters of microwave-assisted blended cold pressing. The optimal extraction conditions were as follows: Microwave (800 W) treatment time 1.5 min, cold pressing temperature 64 °C, oil seed moisture content 6.7%, oil extraction rate 19.83%±0.21 %, which was 17.2% higher than that before optimization. The basic physical and chemical indexes of blended cold-pressed oil and traditional cold-pressed blend oil were compared and analyzed. The oil oxidation degree was lower under the condition of microwave-assisted blended cold-pressed process. Conclusion Microwave-assisted blended cold pressing oil has lower primary and secondary oxidation product indexes than traditional cold-pressed blended oil. The results can provide a theoretical basis for the preparation of polyunsaturated fatty acid equilibrium oil and the application of microwave-assisted blended cold pressing process in the field of grain and oil processing.

Objective To investigate the effects of light and air on the storage quality and volatile flavor compounds of rice bran. Methods Fresh and high temperature and pressure steam stabilized rice bran were used as raw materials to investigate the effects of light and air on the changes of acid value, peroxide value, γ-oryzanol content, chromaticity and other physicochemical indexes as well as volatile flavor compounds during storage. Results During the storage process, light and air exerted insignificant influences on the acid value and γ-oryzanol content of stabilized rice bran, and had limited effects on the chromaticity indices L^*, a^* and b^* values. However, they had a significant impact on the peroxide value. For the stabilized rice bran, the peroxide value could increase by up to 25 times in the presence of light and air. As the storage time extended, the types of volatile flavor substances in rice bran samples kept increasing. The treatments of avoiding light and vacuum could effectively prevent the generation of oxidation products such as aldehydes, ketones, and alcohols. In the presence of light and air, the concentrations of aldehydes and ketones in the stabilized rice bran increased by 6 times and 26 times. Conclusion The acid value of rice bran stabilized using high temperature and high pressure steam exhibits minimal changes when exposed to light and air during storage. However, the peroxide value and its oxidation products increases substantially, this indicates that avoiding light and vacuum treatment is the key to extending the shelf life of stabilized rice bran, providing a theoretical basis for its storage and industrial application.

Objective To construct a quality evaluation system for the main-sold pork in Shanghai and analyze the appearance, texture, nutrition, and flavor indicators of different pig breeds. Methods A total of 95 samples of the longissimus dorsi muscles were collected from 7 boar breeds, including Pudong White pigs. Fifty-five parameters were detected. Correlation analysis and radar charts were used to determine the core indicators for quality evaluation. Results In terms of appearance quality, different pig breeds showed differences in indicators such as pH and moisture content. Shawutou pigs, Pudong White pigs and Shanghai White pigs had slightly lower water content, while Shawutou pigs had a high drip loss rate. Topigs had slightly higher intramuscular fat content. Correlation analysis showed that the water content was negatively correlated with 24-hour drip loss. Regarding texture, Fengjing pigs had high shear force, Topigs had high hardness. Correlation analysis showed that the shear force was negatively correlated with hardness and positively correlated with elasticity. In terms of nutritional quality, it showed that the protein content in Shanghai local pig breeds was higher than that in common Duroc-Landrace-Yorkshire pigs. Three-way crossbred pigs and Shanghai White pigs had slightly lower fat content. The proportion of essential amino acids was the lowest in three-way crossbred pigs. In terms of flavor quality, the total amount of umami amino acids in each pig breed was similar. Shanghai White pigs had a high content of cytidine monophosphate, three-way crossbred pigs and Fengjing pigs had a high content of uridine monophosphate, Topigs had a low content of multiple flavor-related nucleotides, and Shawutou pigs had a high content of adenosine monophosphate. Correlation analysis showed that aspartic acid was positively correlated with the total amount of umami amino acids. Conclusion A quality evaluation system for Shanghai pork can be constructed around 13 core indicators, including water content, conductivity, shear force, hardness, resilience, protein, fat, magnesium, potassium, selenium content, adenosine monophosphate, inosine monophosphate, and aspartic acid. In the future, relevant factors need to be comprehensively considered to construct a comprehensive evaluation model.

Objective To evaluate of the effects of drying methods on the quality of Astragalus membranaceus based on technique for order preference by similarity to an ideal solution analysis. Methods In this study, 6 kinds of drying methods including hot air drying (HAD), heat pump drying (HPD), carbon fiber far infrared combined heat pump drying (CFFCHPD), medium short wave infrared drying (MSWID), vacuum pulsating drying (VPD), and vacuum freeze-drying (FD) were conducted to drying experiments. The effect of the drying time, unit energy consumption, color, sensory quality and effective components of Astragalus membranaceus were evaluated by technique for order preference by similarity to an ideal solution (TOPSIS). Results The results showed that CFFCHPD had the shortest drying time and lowest energy consumption for Astragalus membranaceus, with (0.15±0.00) h and (3.41±0.03) (kW·h)/kg, respectively. The L^* of the dried sample was the highest, which could have a positive effect on maintaining the color of Astragalus membranaceus, while other treatments showed varying degrees of browning. The VPD had the highest sensory score, but there was not significant difference with other treatments. CFFCHPD had a better taste, making its freshness, sweetness and richness at a high level. At the same time, retaining the nutritional components such as astragalosides, polysaccharides and calycosin-7-glucoside in Astragalus membranaceus could achieve better quality. Correlation analysis showed that the L^* was negatively correlated with the content of astragalosides and positively correlated with the content of polysaccharides. The a^* was positively correlated with the content of astragalosides, and the content of astragalosides and polysaccharides could be indirectly judged by color. Conclusion The comprehensive ranking of CFFCHPD ranked first, indicating that CFFCHPD is a promising combined drying technology suitable for drying traditional Chinese medicinal materials. This research result provides certain data support for efficient and high-quality drying of Astragalus membranaceus.

Objective To predict and control the fermentation process of Agrobacterium sp. A02 strain to produce curdlan, establish a time-varying model to simulate bacterial growth and obtain the kinetic changes of curdlan production and sucrose consumption. Methods The viable bacteria count, sucrose content and curdlan content during the batch fermentation process of Agrobacterium sp. A02 were measured, and the experimental values were fitted using Logistic equation, Luedeking-Piret equation and Luedeking-Piret-Like equation, respectively. Results The fitting results indicated that the 3 kinds of models were applicable to the growth kinetics of bacterial cells, the generation kinetics of pectin, and the consumption kinetics of sucrose. The R² were above 0.99, and the significance level was extremely significant. The errors between the fitted and experimental values were less than 10%, indicating a good fit. Conclusion The established bacterial growth kinetics model, sucrose consumption kinetics model and curdlan production kinetics model can predict and describe the dynamic metabolic changes of Agrobacterium sp. A02 during the fermentation process, providing theoretical support for describing the fermentation kinetics characteristics and industrial production of curdlan.

Objective To investigate the main active components of different monthly Tetrastigma hemsleyanum Diels et Gilg (TDG) from Zhoushan City and establish the map of different monthly TDG. Methods The quality of different monthly TDG was evaluated by combining fingerprint similarity evaluation cluster analysis (CA), principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). An InterSustainSwift C₁₈ chromatographic column (4.6 mm×250 mm, 5 μm) was used, with acetonitrile-0.1 formic acid aqueous solution as the mobile phase, gradient elution, flow rate of 0.8 mL/min, detection wavelength of 20 nm, column temperature of 30 ℃, and injection volume of 10 μL. Results The fingerprint similarity evaluation results of 12 batches of different monthly TDG showed that the similarity of different monthly TDG samples varied greatly; the 13 common were identified, and 3 common peaks were recognized; CA, PCA, and OPLS-DA analysis could all classify the 12 batches of different monthly TDG into 3 categories; and 2 differential quality markers, gallic acid and quercetin, were screened out by analyzing the variable importance in projection (VIP) values under OPLS-DA. Conclusion The high performance liquid chromatography (HPLC) fingerprint and multi-component content determination method established in this study is stable and reliable, and can provide a reference for quality control of Zhoushan TDG.

Objective To investigate and analyze the contamination of polycyclic aromatic hydrocarbon (PAHs) in 4 kinds of medicinal and edible substances, Aucklandiae radix, Citrus reticulatae pericarpium, Polygonati rhizoma, Fritillaria cirrhose bulbus in Chongqing, and assess human exposure risk from PAHs residues through ingestion of 4 kinds of substances. Methods A total of 160 samples were collected from 10 districts/counties in Chongqing. The residues of 16 kinds of PAHs were determined using gas chromatography-mass spectrometry. The contamination levels were evaluated based on the maximum residue limits of benzo[a]pyrene and PAH4 (sum of benzo[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene) set by the European Commission for “food supplements containing botanicals and their preparations” and “dried herbs”. The pollution characteristics of PAHs in the 4 kinds of substances were analyzed, and the sources were identified using isomer ratio analysis. Health risk assessment was conducted using the increased lifetime cancer risk (ILCR) model recommended by the US Environmental Protection Agency (USEPA). Results PAHs were detected in all Aucklandiae radix, Citrus reticulatae pericarpium, Polygonati rhizoma, Fritillaria cirrhose bulbus. The detection rate of the highly carcinogenic benzo[a]pyrene was 24%, with an exceedance rate of 1.25%, while the exceedance rate for PAH4 was 1.9%. Citrus reticulata peel exhibited the highest benzo[a]pyrene detection rate (83%), and its maximum PAH4 content reached 151.66 μg/kg, exceeding the MRL by more than threefold. PAHs in all 4 kinds of substances were predominantly low-molecular-weight 2-3 ring compounds. The ILCR values of cancer risk caused by taking 4 kinds of substances in different populations were 1.46×10^-7-7.26×10^-7, 1.21×10^-6-6.04×10^-6, 1.89×10^-7-9.38×10^-7, 6.96×10^-8-3.46×10^-7, respectively. Conclusion The 4 kinds of dual-purpose substances are contaminated with PAHs at varying levels, primarily due to biomass or coal combustion. The health risks from oral intake of Aucklandiae radix, Polygonati rhizoma, Fritillaria cirrhose bulbu are low and within acceptable limits. However, Citrus reticulatae pericarpium poses a potential health risk due to PAHs exposure, warranting further attention.

Objective To determine the content of 8 kinds of heavy metals, copper (Cu), lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), zinc (Zn), nickel (Ni), and chromium (Cr) in Astragalus membranaceus and soil samples, and conduct the risk assessment. Methods Thirty-five batches of samples were collected in 5 provinces, namely Inner Mongolia, Shanxi, Gansu, Ningxia and Shaanxi, for the determination of 8 kinds of heavy metals in the soils of Astragalus and Astragalus origin using inductively coupled plasma mass spectrometry. The health risks of Astragalus membranaceus in different intake groups were evaluated by calculating 3 kinds of different risk assessment models, namely, the estimated daily intake, the carcinogenic risk, and the target hazard quotient. Results The recoveries were in the range of 99.1%-108.8% with the relative standard deviations in the range of 0.445%-5.720%, which indicated that the accuracy and precision of the method were good. The average heavy metal content of the 35 batches of Astragalus membranaceus was Zn>Cu>Cr>Ni>Pb>As>Cd and Hg, and no exceedance of heavy metals complied with the limit standards for heavy metals in Chinese herbal medicines in the 2020 edition of Pharmacopoeia of the People’s Republic of China. The results of the 3 kinds of risk assessments showed that the health risk of heavy metal content of Astragalus membranaceus for different groups of people was within the acceptable range. Conclusion The contamination of heavy metals in Astragalus membranaceus is widespread, and the development of the Astragalus membranaceus industry is still potentially risky. In order to ensure the medicinal safety of Astragalus membranaceus, the prevention and control of heavy metals in Astragalus membranaceus shall be carried out in the future from the planting source of Astragalus membranaceus, the processing method, and other aspects of Astragalus membranaceus.

Objective To prepare sodium alginate-egg gel beads using sodium alginate and egg as carriers through calcium lactate complexation, optimize their preparation process, and conduct texture analysis. Methods The sodium alginate-egg gel beads were prepared using the cross-linking method, and based on single-factor experimental design, the effects of calcium lactate concentration, curing time, and curing temperature on the hardness of the gel beads were explored. Results Under single-factor conditions, the preparation process of the gel beads was optimized using response surface methodology. The optimal preparation conditions were: 6% calcium lactate concentration, 27 minutes of curing time, and a curing temperature of 39 ℃. Under these conditions, the prepared gel beads had the following properties: Cohesiveness of 0.6457, recovery of 0.6627, hardness of 9.9983 gf, elasticity of 1.0000, chewiness of 3.5975 gf, and water content of 84.56%. Conclusion This study prepares alginate-egg gel beads with good recovery and elasticity, and determines the optimal process for the preparation of the product. This provides theoretical support and reference for expanding the application prospects of sodium alginate-egg gel beads in the fields of biomedicine and material science.

Objective To explore the differences in volatile aromatic substances of Marselan wine from the eastern foot of Helan Mountain production area during the aging periods of 0, 3 and 6 months. Methods Comprehensive two-dimensional gas chromatography-time of flight mass spectrometer (GC×GC-TOF MS) was used to detect the volatile aromatic substances in the wine. Key differential volatile substances were screened according to the variable importance in projection (VIP) value and orthogonal partial least squares-discriminant analysis (OPLS-DA). Results The types of volatile aromatic substances during the wine aging period mainly included alcohols, esters, acids, phenols, etc. A total of 1286 kinds of substances were detected in the 3 aging periods. The relatively high contents of volatile aromatic substances were alcohols, esters and hydrocarbons. With the increase of the aging period, the content of esters increased from 16.9% to 27.9%, and the content of hydrocarbons increased from 13.6% to 21.5%, both showing a significant upward trend. However, the content of alcohols decreased from 53.8% to 30.3%, showing a downward trend. Taking VIP≥1.22 and P<0.01 as the indicators, a total of 21 kinds of volatile aromatic substances with important contributions to the wine in different aging periods were determined, which were 2,6,6-trimethylcyclohexadiene-1-methanol, 2-propyl-1-heptanol, heptanal, 4-tert-butylbenzyl alcohol, (S)-1-phenylethanol, diethyl methylsuccinate, isoamyl propionate, acetal, methoxyacetaldehyde, 3-chloro-1-butene, 1,8-cyclopentadeca- 1,3-diyne, β-ionone, linalool, linalyl formate, 2-furanmethanol, rose oxide, hexahydro-1,3,5-trinitro-1,3,5-triazine, 4-ethyl-5- hydroxy-3,5-dimethylfuran-2(5H)-one, 2(5H)-furanone,4,5,5-trimethyl-3-(3-methyl-2-methylidenebutyl), N-methylhexylamine, and dimethyl disulfide. Conclusion This study, by analyzing the volatile aromatic substances in Marselan wine during different aging periods, provides a theoretical basis for the control of the flavor quality during the wineaging period.