Volume 42, Issue 8 (2026)
Fundamental Research
Effects and mechanisms of carrageenan-sodium caseinate interactions on oil-water interfacial properties
Huang Zequan, Cao Hongfang, He Jian, Wang Caiyun, and Zhao Qiangzhong
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80301
[Objective] To investigate the effects of κ-carrageenan concentration on its interaction with sodium caseinate and the oil-water interfacial properties of the composite system. [Methods] Sodium caseinate composite systems with different κ-carrageenan concentrations were prepared. Protein structure, surface hydrophobicity, endogenous fluorescence, zeta potential, particle size, interfacial adsorption behavior, and interfacial dilatational modulus were determined. [Results] After the addition of κ-carrageenan, the secondary structure of sodium caseinate changed markedly, and the proportion of ordered structures showed a trend of initially increasing and then decreasing. Surface hydrophobicity and endogenous fluorescence intensity exhibited a similar trend. When the addition level of κ-carrageenan was 0.15‰, the contents of α-helix and β-sheet increased from 13.07% and 50.97% to 14.30% and 55.48%, respectively (P<0.05); surface hydrophobicity decreased from 46 832 to 32 362, and fluorescence intensity decreased from 478 366 to 319 298. With increasing κ-carrageenan addition, the surface electronegativity of the composite system increased and the particle size gradually increased. The ζ-potential decreased from −25.53 mV to −30.05 mV, while the particle size increased from 227.20 nm to 252.80 nm. The adsorption process of the complexes at the oil-water interface gradually slowed, with Kdiff decreasing from 0.021 mN/(m·s1/2) to 0.014 mN/(m·s1/2). The interfacial dilatational modulus exhibited a trend of initially increasing and then decreasing, increasing from 6.224 mN/m to 8.463 mN/m at a κ-carrageenan addition level of 0.15‰. [Conclusion] Appropriate addition of κ-carrageenan promoted the formation of a relatively stable composite structure by sodium caseinate and improved its oil-water interfacial properties, with 0.15‰ identified as the optimal addition level.
5-Formyl- 3-methylene- 3,6-dihydropyridines formed in foods activate RAGE-dependent signaling cascades in RAW 264.7 cells
Wu Jiaqi, Ou Shiyi, Guo Hongyang, Huang Caihuan, Ou Juanying, and Zheng Jie
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80299
[Objective] 5-Formyl -3-methylene -3,6-dihydropyridine (FMDP) is a novel compound derived from the reaction of amino acids with formaldehyde (FA) and acrolein (ACR), and its content in biscuits has been reported to be more than 40 times higher than that of free acrolein and formaldehyde. Given the structural similarity to FDP -lysine, an advanced glycation end product (AGE) derived from acrolein, this study aims to evaluate the potential safety risk of FMDPs by assessing their ability to stimulate the receptor for advanced glycation end products (RAGE). [Methods] Three FMDP compounds, each possessing a 5-formyl -3-methylene -3,6-dihydropyridine core structure, are synthesized by reacting formaldehyde and acrolein with alanine, asparagine, and threonine, respectively. Following purification, RAW 264.7 macrophages are cultured with various concentrations of each FMDP compound. Cytotoxicity, RAGE expression, proteomic profiles, and the Keap 1-Nrf2 signaling pathway are subsequently evaluated. [Results] All three FMDP compounds exhibit significantly lower |cytotoxicity than acrolein and formaldehyde. However, FMDP treatment upregulates RAGE expression in RAW 264.7 cells relative to the control group, with threonine -derived FMDP showing the strongest stimulatory effect, increasing RAGE expression by 60% at an exposure concentration of 300 μg/mL. Proteomic analysis identifies 69, 59, and 111 differentially expressed proteins in response to alanine -, asparagine -, and threonine -derived FMDP, respectively. Gene Ontology (GO) enrichment analysis indicates that FMDPs increase the expression of proteins associated with oxidative stress. Western blotting assays reveal that FMDPs induce oxidative stress through activation of the Keap 1-Nrf2 signaling pathway, as evidenced by elevated Nrf 2 levels, enhanced dissociation of Keap 1 from Nrf 2, and increased expression of oxidoreductases, including NQO 1, HO-1, and GCLC. [Conclusion] The food -borne compounds FMDPs can stimulate RAGE and induce oxidative stress, highlighting the need for attention to their potential health risks.
Effects of material form on the modification of rice by heat-moisture treatment
Wang Haoyan, Feng Wei, Zheng Yubin, Wang Ren, and Huo Jian
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80035
[Objective] To investigate the effects of two material forms (rice flour and whole rice grains) on the modification performance of rice by heat-moisture treatment and physicochemical properties. [Methods] Early indica rice is used as raw material. Rice flour and whole rice grains are subjected to heat-moisture treatment (100 ℃, 2 h) under three moisture levels (21%, 24%, and 27%). Subsequently, the basic chemical composition, surface particle morphology, crystal structure characteristics, and farinograph processing properties of samples from the two groups are characterized. [Results] After heat-moisture treatment, the particle dispersibility of samples in both groups decreases significantly, accompanied by obvious aggregation and fusion. All the samples maintain the typical A-type crystal structure of rice starch, with a slight reduction in crystallinity, a shift of endothermic peak toward higher temperature, and a decline in enthalpy (ΔH). After treatment, the samples exhibit decreased peak viscosity, final viscosity, breakdown and setback values, delayed occurrence of peak time, and increased gelatinization temperatures. Meanwhile, the thermal stability and anti-retrogradation capacity of starch are improved. Moisture content exerts remarkable influences on surface particle morphology, damaged starch content, crystallinity, and thermodynamic characteristics of samples, whereas its effects on gelatinization properties and gel texture are weak. Material form significantly affects the modification performance of heat-moisture treatment. Compared with the rice flour group, the whole rice grain group exhibits increased amylose content, damaged starch content, characteristic particle size, gel hardness, chewiness, and resilience, as well as slightly declined starting temperature, peak temperature, ΔH, and breakdown value. [Conclusion] Material form significantly affects the modification performance of heat-moisture treatment on rice.
Study on preparation and emulsification properties of distillers dried grains with solubles arabinoxylan hydrolysate/soy protein isolate complex
Yu Shuo, Guo Qingbin, Zhao Shudi, Li Zhenjing, Jia Xing, and Kang Ji
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2024.80618
[Objective] To expand the application fields of distillers dried grains with solubles and improve its market value. [Methods] Arabinoxylan (AX) was extracted from distillers dried grains with solubles and modified to prepare AX with different molecular structures. AX was then reacted with soy protein isolate (SPI) via the Maillard reaction to prepare the AX-SPI covalent complex. The structure of the complex was characterized using circular dichroism spectroscopy, Fourier transform infrared spectroscopy, particle size, and zeta potential, and its emulsifying properties were studied. [Results] The AX-SPI covalent complex is formed by SPI and AX via the Maillard reaction, and differences in the polysaccharide molecular structure affect the extent of the Maillard reaction. As the relative molecular mass and chain length of the polysaccharide increase, the difficulty of its attachment to the protein peptide chain also increases. Compared with SPI, the protein solubility of the covalent complex increases by 16.29%, indicating that the solubility of the complex in the isoelectric point region is significantly improved. The average particle size (0.799 μm) of the emulsion stabilized by AX-SPI is small and evenly distributed, and the absolute value of the zeta potential is high (38.19 mV). [Conclusion] The AX-SPI covalent complex exhibits better emulsification and stability than SPI. Moreover, the emulsifying properties of the complex increase with the decrease in the relative molecular mass of the polysaccharide. When the relative molecular mass is similar, a shorter polysaccharide chain length results in better emulsifying properties.
Correlation between thermal characteristics and fat concomitants and flavor quality in the refining process of Camellia oleifera seed oil
Liu Zhaofan, Liu Jiabao, Li Hang, Huang Zonghai, He Xinyi, and Li Yun
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80638
[Objective] To investigate the correlation between thermal characteristics, fat concomitants, and flavor quality during the refining process of Camellia oleifera seed oil, and to provide a theoretical basis for precise regulation of the refining process. [Methods] Oil samples were collected during the refining process (crude oil, alkali refining, decolorization, deodorization, and winterization). The dynamic changes in physicochemical indexes, thermal characteristics, fat concomitants, fatty acid composition, and volatile flavor substances were systematically determined, and their correlations were analyzed. [Results] The refining process reduced the acid value of C. oleifera seed oil from 1.79 mg/g to 0.26 mg/g and the peroxide value from 0.205 g/100 g to 0.025 g/100 g, and shifted the main melting peak temperature to the right by 1.4 ℃, collectively confirming the enhancement of thermal stability. The refining process also resulted in the loss of functional components, with total loss rates of α-tocopherol, squalene, and polyphenols reaching 45.8%, 49.0%, and 76.3%, respectively, mainly occurring in the alkali refining and deodorization stages. The variation in fatty acid composition was less than 0.5%. Meanwhile, the refining process promoted the generation of aldehydes and pyrazines contributing to nutty flavor. Correlation heatmap analysis showed that the characteristic peak temperature determined by differential scanning calorimetry (DSC) was significantly negatively correlated with fat concomitant content, physicochemical indexes, and flavor compound abundance. [Conclusion] The refining process enhanced the thermal stability and flavor quality of C. oleifera seed oil, while also leading to the loss of fat concomitants.
Safety & Inspection
Effect of sodium butyrate on biofilm formation and virulence of Salmonella typhimurium
Yao Meng, Li Zhiheng, Wang Yan, Pan Wanlong, and Liu Peng
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80670
[Objective] To investigate the regulatory effects of sodium butyrate on biofilm formation by Salmonella typhimurium and clarify its effects on the expression of virulence-related genes and pathogenicity under in vivo conditions. [Methods] S. typhimurium was treated with 4 mg/mL and 8 mg/mL sodium butyrate, and the effects of sodium butyrate on biofilm formation, motility, metabolic activity, and quorum sensing of the strain were detected. The expression changes of virulence genes (hilA, invF, and sipA) in sodium butyrate-treated strains were analyzed by quantitative real-time PCR. A C57BL/6 mouse infection model was established using S. typhimurium pretreated with 8 mg/mL sodium butyrate, and the survival time of mice, bacterial loads in the liver and spleen, and pathological changes in these organs were analyzed. [Results] Sodium butyrate at concentrations of 4 mg/mL and 8 mg/mL reduced biofilm formation by the strain in 96-well plates (P<0.05), decreased the diameters of bacterial colonies formed on semi-solid medium by 43.68% and 63.73%, respectively, reduced metabolic activity by 6.85% and 34.00%, respectively, and decreased purple pigment production by quorum sensing indicator bacteria by 42.15% and 67.46%, respectively. Treatment with 8 mg/mL sodium butyrate increased the expression levels of the hilA, invF, and sipA genes by 1.6-, 2.7-, and 1.3-fold, respectively, shortened the survival time of mice, increased bacterial loads in the liver and spleen, and caused obvious pathological changes in these organs. [Conclusion] Sodium butyrate can weaken biofilm formation by S. typhimurium through regulating its motility, quorum sensing, and metabolic activity, but it may also promote changes in the virulence of S. typhimurium.
Detection of egg components in food by microfluidic digital PCR
Li Ben, Zhuo Yiming, Qin Jijun, and Yang Lixia
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80797
[Objective] To establish a detection method for egg components in food using microfluidic digital polymerase chain reaction (PCR) technology. [Methods] Specific primers and fluorescent probes are designed based on the mitochondrial gene nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1). Then, the reaction system and amplification conditions are optimized, and specificity and sensitivity are evaluated before being applied to actual food detection. [Results] The established method can specifically detect egg components, while no cross-reactivity is observed with other common poultry egg components, such as duck and goose eggs. The optimal annealing temperature is 56 ℃, and the optimal concentrations of primers and probes are 800 nmol/L and 200 nmol/L, respectively. Under these conditions, the limit of detection (LOD) for microfluidic digital PCR is 5.30 copies/μL. Furthermore, the method is applied to detect 20 batches of food samples, yielding consistent results with the sample labels. [Conclusion] Characterized by anti-interference, high sensitivity, rapidity, and simplicity, the established microfluidic digital PCR method can be applied to detect trace egg components in food.
Simultaneous determination of eight sweeteners in glycyrrhizin by ultrahigh performance liquid chromatograph-tandem mass spectrometry
He Liang, Zhu Lingchao, Hu Ruilin, Zhang Tao, and Song Chunman
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80725
[Objective] To establish a method based on ultrahigh performance liquid chromatography-tandem mass spectrometry for rapid determination of eight sweeteners in glycyrrhizin. [Methods] The sample is ultrasonically extracted with 20 mL pure water for 30 min, passed through a 0.22 μm microporous filter membrane, separated through the Waters HSS T3 column, subjected to gradient elution with 0.2% (V/V) ammonia solution-methanol, and detected under the negative mode of electrospray ionization. [Results] The eight sweeteners showed a good linear relationship between peak area and concentration within the range of 0.1–20.0 μg/mL, with correlation coefficients greater than 0.99. The limits of quantification are within the range of 0.2–1.0 μg/g. The average recoveries of samples spiked are within the range of 85.8%–103.0%, and the relative standard deviations are in the range of 2.4%–4.6%. [Conclusion] This method is simple, rapid, and suitable for determination of the content of eight sweeteners in glycyrrhizin.
Rapid determination of 81 illegal weight loss additives in tablet candy by ultra-performance liquid chromatography-tandem mass spectrometry
Li Hongli, Su Min, Wu Yanlei, Zhang Mian, Wang Yuqi, Zhou Chunjie, and Tao Juan
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80809
[Objective] To establish a rapid detection method for 81 illegal weight loss additives in tablet candy using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). [Methods] Samples were ultrasonically extracted with 80% methanol-water (containing 0.1% formic acid), separated on a Waters ACQUITY UPLC HSS T3 column, and eluted with a gradient of methanol and 0.1% formic acid water solution. Detection was performed using multiple reaction monitoring (MRM) with simultaneous scanning in positive and negative electrospray ionization modes, and quantification was carried out using the external standard method. [Results] The 81 target analytes showed good linear relationships within their respective mass concentration ranges, with correlation coefficients greater than 0.990 0. The limits of quantification ranged from 0.01 to 0.40 mg/kg. The average recoveries ranged from 71.0% to 119.5%. The relative standard deviations for method precision and repeatability were all less than 13.5% (n = 6). [Conclusion] The method is simple, rapid, highly accurate, and shows good repeatability, and is suitable for the detection of illegal weight loss additives in tablet candy.
Origin identification of pineapples based on mineral element fingerprint analysis technology
Ke Jiancan, Chen Liyi, Dong Hai, Zheng Hongtao, and Chen Yabo
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80862
[Objective] To analyze the differences in mineral element contents among different pineapple samples and explore the feasibility of applying a discriminant model based on elemental fingerprint analysis to the identification of Shenwan pineapple, a geographical indication product. [Methods] Inductively coupled plasma mass spectrometry was employed to determine the contents of 28 mineral elements in 5 different pineapple samples. Combined with principal component analysis, partial least squares discriminant analysis, and Fisher discriminant analysis, the classification characteristic elements were identified. Discriminant models for pineapples from different producing areas and different bases within the same producing area were established and evaluated. [Results] The characteristic mineral elements (Ca, K, Mg, and Mn) for identifying pineapples from three different producing areas, namely Mangchong Village of Shenwan Town, Yugonglou Village of Xuwen Town, and Wuhe Village of Jiangchuan Town, are screened out. For pineapples from three different planting bases (Mangchong, Dapai, and Modao) in Shenwan Town, the characteristic mineral elements identified are Ca, K, Mg, Na, and B. The Fisher discriminant model established based on these characteristic mineral elements achieves an overall discrimination accuracy of 100% for pineapple samples from different producing areas and 95.9% for those from different bases. [Conclusion] The multivariate statistical analysis method based on mineral elements can effectively discriminate pineapple samples from different producing areas or different bases and can be applied to the traceability of pineapples.
Food Equipment & Intelligent Manufacturing
Structural optimization and material separation characteristics of an updraft rice mill based on CFD-DEM
Li Yuan, Zhou Long, Fan Jijun, Yu Nanhui, and Yang Yong
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80986
[Objective] To enhance the separation efficiency of rice bran and broken rice in an updraft rice mill by optimizing the air duct structure and operating parameters. [Methods] A combined approach of CFD-DEM coupled numerical simulation and experimental verification was adopted to investigate the material separation characteristics of the updraft rice mill under different structural and operating parameters. Key parameters, including air duct width, air velocity, baffle width, and baffle spacing, were optimized through single-factor experiments and response surface methodology. [Results] The addition of baffles at the lower suction inlet improved the pressure and flow velocity distributions within the air duct of the updraft rice mill, significantly increasing the upward suction rate of rice bran and reducing the settling rate of broken rice. The experimental and simulation results showed consistent trends. Response surface analysis showed that the optimal parameter combination was an air duct width of 39.2 mm, air velocity of 9.3 m/s, baffle width of 13.2 mm, and baffle spacing of 26.7 mm. Under the optimal conditions, numerical simulation verified that the upward suction rate of rice bran reached 96.2%, while the settling rate of broken rice reached 97.4%. [Conclusion] Through the coordinated design of flow field regulation and structural optimization, the common problem of insufficient particle separation efficiency in updraft rice mills can be effectively addressed.
Optimization of roller tooth parameters for roller mill based on Rocky DEM
Liu Yifan, Zhang Chao, and Guo Xing
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80821
[Objective] To investigate the effects of the surface technical parameters of the toothed roller in a 1B roller mill on the wheat grinding process and to optimize these surface technical parameters. [Methods] The grinding process of the toothed roller was simulated using Rocky DEM software. Tooth angle, sharpness angle, tooth tip width, and inclination were selected as variables to analyze their effects on wheat scraping rate and wear loss. Single-factor experiments and orthogonal experiments combined with matrix analysis were comprehensively applied to systematically evaluate the experimental results. [Results] The optimal combination of surface technical parameters for the 1B toothed roller, which resulted in minimum wear loss while maintaining a relatively high scraping rate, was a tooth angle of 110°, sharpness angle of 40°, tooth tip width of 0.4 mm, and inclination of 3%. The degree of influence of the surface technical parameters of the toothed roller on scraping rate and wear loss, in descending order, was inclination, sharpness angle, tooth angle, and tooth tip width. [Conclusion] Through multi-index orthogonal experimental matrix analysis and evaluation, the optimization of the surface technical parameters of the toothed roller was completed and a regression equation was constructed, effectively improving the grinding performance of the roller mill while reducing the wear loss of the toothed roller.
Storage Transportation & Preservation
Preparation process , antioxidant activity , and fruit preservation application of Polygonatum sibiricum polysaccharides with low relative molecular mass
Hu Chengzhi, Ma Yanli, Shen Qingshan, Li Mengna, Li Mi, and Fei Peng
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80398
[Objective] To compare the effects of four pretreatment methods—hot pressing (HP), steam explosion (SE), ultrasound (US), and solid-state fermentation (SF)—on the structural characteristics and antioxidant activities of Polygonatum sibiricum polysaccharides (PSP), and to explore the potential application of PSP in fruit preservation. [Methods] Ten PSP samples are prepared. The yield, relative molecular mass, functional groups, thermal stability, surface morphology, and DPPH·, ABTS·, and OH· free radical scavenging abilities of the samples are determined. The PSP sample with low relative molecular mass obtained by SE treatment is loaded with Zn2+ to prepare a sprayable hydrogel, which is then applied in the preservation of “Shatangju” mandarins. [Results] The yields of PSP from SE and US treatments are the highest (~10%), and are higher than those from HP and SF treatments (P<0.05). The PSP samples from SE and US treatments have low relative molecular mass (32.92×103 to 49.15×103), which is significantly lower than that of samples from HP and SF treatments. All the ten samples show similar functional groups and thermal stability, while they differ in surface morphology. In the concentration range of 0.5 to 4.0 mg/mL, all the samples exhibit concentration-dependent scavenging rates against DPPH·, ABTS·, and OH· free radicals. The antioxidant activity of PSP from SE treatment is higher than that from the other treatments (P<0.05). The Zn2+-loaded sprayable hydrogel prepared from SE-derived PSP with low relative molecular mass effectively reduces the weight loss rate of “Shatangju” mandarins during storage, slows down the decline in fruit firmness and the progression of mildew, and exhibits good antifungal effects, with Zn2+ being the key component responsible for the antifungal activity. [Conclusion] SE treatment offers significant advantages in obtaining PSP with low relative molecular mass, improving the yield and antioxidant activity, and showing application potential in fruit preservation.
Inhibitory effect of TBHQ on the deterioration of leisure dried tofu
Chen Durun, Huang Zhanrui, Hu Lianhua, Chen Hao, and Zhao Dan
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80777
[Objective] To address key industrial challenges of leisure dried tofu subjected to mild sterilization, namely shortened shelf life (30~90 d) and susceptibility to photoenzyme -induced oxidative deterioration, this study aimed to elucidate the mechanisms by which tert -butylhydroquinone (TBHQ ) inhibits quality deterioration in leisure dried tofu induced by photoenzyme initiators. [Methods] Leisure dried tofu was prepared using marinade treated with TBHQ and photoenzyme initiators (chlorophyll and azodiisobutyronitrile ). During a 90 d storage period, dynamic changes in nutritional components, characteristic oxidation indices, textural properties, intermolecular forces, and microstructure of the dried tofu were systematically monitored.［Results］ During the early storage stage (0~60 d), TBHQ significantly delayed the oxidative loss of protein (18.21 g/100 g) and fat (12.54 g/100 g), inhibited the increase in peroxide value (0.16 g/100 g), acid value (0.98 mg/g ), and thiobarbituric acid reactive substances (TBARS,1.58 mg/kg ), and maintained L* and b* values close to those of the blank group. TBHQ stabilized disulfide bond interactions (1.96~2.48) and hydrogen bonding (0.16~0.25), while maintaining hardness and elasticity at 9.25~11.03 N and 0.85~0.91, respectively. During the late storage stage (75~90 d),TBHQ continued to inhibit the loss rates of protein and fat, resulting in fewer and smaller pores in the tofu gel network compared with the initiator group. [Conclusion] TBHQ exhibited a long -lasting and stable inhibitory effect on quality deterioration in dried tofu during 90 d of storage and can be considered a |preferred antioxidant for dried tofu with extended storage periods.
Detection of apple freshness during storage based on Zigbee network and PLS-DA
Huang Haiyang, Qu Liqiu, and Ma Yunlong
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.60067
[Objective] To address the long detection cycles, complex operation, and destructive sampling in apple freshness detection, a rapid and non-destructive detection method based on Zigbee wireless sensor network and partial least squares-discriminant analysis (PLS-DA) is proposed. [Methods] With Red Fuji apples as the research object, a gas sensor array acquisition system based on the Zigbee protocol is designed to monitor the concentration changes of four characteristic gases (ethanol, ethylene, oxygen, and carbon dioxide) during apple storage in real time. Least squares filtering is employed to preprocess the raw data, and the stable value, mean value, and maximum value are extracted as freshness feature parameters. A PLS-DA model is constructed to achieve rapid discrimination of apple freshness levels (fresh, sub-fresh, and rotten). [Results] Under indoor storage conditions of 20 ℃ and 50% relative humidity, the four gas sensors exhibit obvious response characteristics to apple volatile gases, with significant differences in gas concentrations among different freshness levels. The first three latent variables of the PLS-DA model cumulatively explain 92.47% of variance, with samples from the training set and prediction set forming clear clusters by category. The overall recognition accuracy of the model for 36 samples in the prediction set reaches 94.44%, with recognition accuracy of 100.00%, 91.67%, and 91.67% for fresh, sub-fresh, and rotten samples, respectively. [Conclusion] This method enables rapid and non-destructive detection of apple freshness.
Effects of different pretreatment methods on moisture variation and pore structure of apple slices during microwave freeze-drying
Qu Zhanping, Zhang Xiaoyan, Zhang Jinglin, and Gu Yujuan
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80802
[Objective] To investigate the effects of pretreatment methods on moisture variation and pore structure of apple slices during microwave freeze-drying. [Methods] Apple slices pretreated with four methods (ultrasound, blanching, freeze-thawing, and osmotic dehydration) are subjected to microwave freeze-drying. The effects of different pretreatments on drying characteristics, moisture migration, and microscopic pore structure of the samples are comparatively analyzed. [Results] All four pretreatment methods increase the effective moisture diffusion coefficient and reduce drying time by 11.1% to 44.4%, with osmotic dehydration requiring the shortest drying time. Low-field nuclear magnetic resonance (NMR) analysis indicates that the pretreatments accelerate free water removal, consequently enhancing internal moisture migration. Pore structure analysis reveals that the pretreatments improve the internal structure of the samples and increase porosity, thereby accelerating the drying process. Specifically, osmotic dehydration leads to smaller pore sizes, while ultrasound and freeze-thawing treatments result in similar porosity with relatively larger pore sizes. In contrast, blanching yields the highest porosity. [Conclusion] The four pretreatment methods improve the internal pore structure of the samples and promote moisture migration during microwave freeze-drying, thus enhancing drying efficiency.
Nutrition & Activities
Overexpression of LiaX enhances stress tolerance in Lacticaseibacillus paracasei L9
Liu Ting, Ma Xiayin, Yan Ningning, Chen Shihao, and Bai Jingfu
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.81085
[Objective] To investigate the protective role of the surface protein LiaX in Lacticaseibacillus paracasei L9 against external stresses, such as bile salts, antibiotics, and the gastrointestinal environment. [Methods] A LiaX-overexpressing strain was constructed and the protein was purified. Spent media assays, in vitro simulated digestion, and exogenous protein supplementation experiments were comprehensively employed to evaluate the effect of LiaX on the survival rate of the strain under digestive, bile salt, and antibiotic stresses. [Results] The LiaX-overexpressing strain LPL9psip0968 his was successfully constructed, and the LiaX protein was isolated and purified. Spent media assays and exogenous addition of purified LiaX protein showed that the lysate of the LiaX-overexpressing strain exerted a significant protective effect on the bacteria under various stress conditions. In vitro simulated digestion experiments showed that LiaX significantly improved the survival rate of the strain during simulated gastric and intestinal digestion. [Conclusion] LiaX protein significantly enhances the stress resistance of the strain.
Preparation of Agaricus bisporus chitosan nanoliposomes and their in vitro hypoglycemic effects
Chen Yanzhi, Zhang Jiawen, Zhang Molan, and You Lijun
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80330
[Objective] To address the limited oral utilization of metformin hydrochloride (MET) and the insufficient delivery efficiency of conventional liposomes, MET-loaded nanoliposomes modified with Agaricus bisporus chitosan (ACS) (ACS-modified liposomes, A-M-L) were developed, and their physicochemical properties, storage stability, cytocompatibility, and effects on glucose consumption by HepG2 cells were evaluated. [Methods] ACS was used as a substitute for crustacean chitosan to prepare MET-loaded nanoliposomes using the thin-film dispersion-ultrasonication method. The structural characteristics and microscopic morphology were observed by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM), and particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency, storage stability, cytotoxicity, and glucose consumption were determined. [Results] ACS modification improved the physicochemical properties of the liposomes. The 0.5% ACS-modified group exhibited a particle size of approximately 159.45 nm, a low PDI of 0.10, and an initial encapsulation efficiency of 87.46%. Microscopic characterization indicated the successful encapsulation of the drug. After storage at 4 ℃ for 21 days, the particle size increased by only 1.8%, while the encapsulation efficiency remained at 83.1%, indicating good stability under the storage conditions used in this study. In vitro experiments demonstrated that the 1.0% ACS-modified group promoted glucose consumption by HepG2 cells and enhanced glucose metabolism, with glucose consumption reaching 4.9 mmol/L, higher than that in the MET drug group (3.5 mmol/L) and the unmodified liposome group (2.3 mmol/L). In addition, ACS modification effectively attenuated the cytotoxicity of the free drug. [Conclusion] ACS-modified MET-loaded nanoliposomes can improve the dispersibility, encapsulation efficiency, and storage stability of liposomes and increase glucose consumption by HepG2 cells in vitro.
Preparation , structural characterization , and in vitro hypoglycemic activities of acetylated Elaeagnus moorcroftii Wall . polysaccharides
Xue Xue, Tang Hui, Liao Bingwu, Chen Lu, Zhao Wenbin, Wang Xinbing, Sun Yan, and Wei Youhong
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80766
[Objective] To explore the preparation conditions, structural information, and in vitro hypoglycemic activities of acetylated Elaeagnus moorcroftii Wall. polysaccharides of Kashgar (A-EMP-K). [Methods] EMP-K is extracted by the water extraction and alcohol precipitation method, and modified by the acetic anhydride method. Then, A-EMP-K preparation conditions are optimized using Box–Behnken response surface methodology. Furthermore, structural characterization and in vitro hypoglycemic activity assays of A-EMP-K are performed. [Results] The optimal preparation conditions are a reaction time of 3 h, a reaction temperature of 61 ℃, and an acetic anhydride addition volume of 9.3 mL. Under these conditions, A-EMP-K exhibits a degree of substitution at 0.326. The A-EMP-K is a heteropolysaccharide consisting of galactose, arabinose, galacturonic acid, and other constituents. The absorption peaks of infrared spectra at 1 731 cm-1 and 1 257 cm-1 confirm the successful introduction of acetyl groups. Scanning electron microscope (SEM) results reveal a distinct porous structure and a relatively smooth surface. The particle size and zeta potential results indicate a relatively stable solvent system. With acarbose as the positive control, the inhibition rate of the A-EMP-K is (63.80±4.58)% against α-glucosidase, and is (81.18±2.48)% against α-amylase. [Conclusion] EMP-K and A-EMP-K exhibit potent performance in hypoglycemic activities.
Purification , characterization , and hypoglycemic activity of peanut coat polyphenols
Zhou Wenda, Yin Yunhui, and Fu Jingxuan
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80837
[Objective] To optimize the purification process of peanut skin polyphenols (PSPs), improve purification efficiency, and investigate their in vitro hypoglycemic activity. [Methods] Three types of PSPs (red, white, and purple) were extracted by ultrasound-assisted ethanol extraction. Seven macroporous resins were used for static adsorption and desorption of PSPs, and the resin with the best performance was selected for single-factor experiments. The components of the purified PSPs were analyzed by UPLC-ESI-QTOF-MS/MS. Using acarbose as a positive control, the inhibitory activity and inhibition types of PSPs against α-amylase and α-glucosidase were investigated. [Results] Purple peanut skins exhibited the highest contents of total phenols, total flavonoids, and anthocyanins. NKA-9 resin showed the best adsorption and desorption performance for PSPs. The optimized purification conditions were as follows: PSP concentration of 2.5 mg/mL, solution pH of 5, eluent concentration of 70%, sample loading flow rate of 2 BV/h, and elution flow rate of 1 BV/h. Under these conditions, the purity of PSPs reached 77.42%, representing a 2.27-fold increase. A total of 19 phenolic compounds, including procyanidins B1, B2, B4, gallic acid, and kaempferol, were identified in the purified PSPs. The half-inhibitory concentrations (IC50) of PSPs against α-amylase and α-glucosidase were 96.33 and 7.01 μg/mL, respectively, and both exhibited mixed-type inhibition. [Conclusion] Purified PSPs exhibit excellent in vitro hypoglycemic activity and have potential for development and utilization as functional ingredients in hypoglycemic foods.
Effects of total flavonoids from perilla leaves on anti-fatigue capacity in adolescent athletes
Liu Baofeng and Liang Xiao
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.60150
[Objective] To clarify the improvement effects of total flavonoids from perilla leaves on the anti-fatigue capacity of adolescent athletes and to compare the effects of different purification methods and liquid-to-solid ratios on their efficacy. [Methods] Total flavonoids from perilla leaves were extracted using microwave-assisted extraction, and two purification methods were employed for total flavonoid purification. Male adolescent track and field athletes aged 16 years with comparable physical fitness were selected to participate in a trial involving total flavonoid intake. Exhaustion time, maximum oxygen uptake, and serum lactate, serum urea nitrogen, and creatine kinase levels were measured in the male adolescent track and field athletes before and after total flavonoid intake. [Results] Total flavonoids from perilla leaves significantly prolonged the exhaustion time and increased maximum oxygen uptake in adolescent athletes, while effectively reducing post-exercise serum lactate, serum urea nitrogen, and creatine kinase levels. The chromatographic separation method for total flavonoid purification effectively retained the anti-fatigue active components in total flavonoids from perilla leaves. [Conclusion] Total flavonoids from perilla leaves help improve the anti-fatigue capacity and exercise recovery efficiency of adolescent athletes.
Development & Application
Effects of re-frying processes on the quality and volatile flavor compounds of pre-fried coated tofu
Nie Jingwen, Chen Hao, Zhao Dan, Zhou Xiaohu, Yang Dajun, and Zhao Liangzhong
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80359
[Objective] To investigate the effects of deep frying process (DFP), microwave process (MP), and air frying process (AFP) on the quality and aroma characteristics of pre-fried coated tofu. [Methods] The optimal re-frying conditions are selected using slurry exudation rate, moisture content, color difference, and sensory evaluation as indicators. Subsequently, the re-frying method most suitable for consumers is comprehensively determined based on texture properties, oil content, malondialdehyde content, electronic nose analysis, and volatile compound composition. [Results] Under the three re-frying methods, the coated tofu exhibits an increase-then-decrease trend in slurry exudation rate and sensory evaluation, accompanied by a continuous decline in moisture content and a gradual shift to yellow color. The optimal conditions for each re-frying process are: 170 ℃ for 30 s in oil (the DFP group), 350 W for 60 s (the MP group), and 170 ℃ for 180 s (the AFP group). Under these optimal conditions, coated tofu in the AFP group exhibits a crispy and golden crust along with a tender and smooth slurry texture. It exhibits hardness and springiness values of 2.47 N and 0.96 mm, respectively, indicating superior overall texture quality compared to the other re-frying processes. Meanwhile, it shows a relatively low fat content of 31.34 g/100 g. Flavor analysis indicates that the AFP group effectively restores the flavor profile of oil re-frying. Furthermore, among the 45 identified volatile compounds, air-fried samples demonstrate high concentrations of alcohols and esters, imparting characteristic oiliness and fruity aromas. [Conclusion] Air frying offers significant advantages in reducing oil content and improving edible quality.
Effects of different extraction methods on the chemical composition and antioxidant activity of Guangfoshou essential oil
Wang Youdi, Chen Wentao, Yan Bin, Xu Shuling, Lyu Yiting, Yang Yuyan, Xu Juanjuan, and Ou Xiaohua
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80678
[Objective] To comparatively evaluate the effects of three extraction methods, i.e., steam distillation (SD), enzyme-assisted steam distillation (EHSD), and ultrasound-assisted steam distillation (UASD), on the extraction efficiency, chemical composition, and bioactivity of Citrus medica L. var. sarcodactylis (Guangfoshou) essential oil. [Methods] Guangfoshou essential oil was extracted using SD, EHSD, and UASD. The chemical constituents of the essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). Cluster heatmap analysis was employed to compare differences in essential oil composition obtained by the three extraction methods. Antioxidant activity was assessed based on total antioxidant capacity, DPPH radical scavenging activity, and hydroxyl radical scavenging activity. [Results] The yields of Guangfoshou essential oil obtained by the three methods, in descending order, were UASD (1.750%) > EHSD (1.252%) > SD (1.250%). A total of 38 components were identified by GC-MS, mainly olefinic compounds, among which 18 were common to all three methods. Among the common components, D-limonene (45%~47%) and γ-terpinene (28%~30%) exhibited the highest relative contents. The differential components included six compounds: β-pinene, α-pinene, D-limonene, tert-butyl peroxycyclopentanecarboxylate, geranylacetone, and (Z)-citral. KEGG pathway enrichment analysis of these differential components showed that the top 20 pathways ranked by P-value were mostly closely related to oxidative stress. Antioxidant results indicated that, within the tested concentration range, the total antioxidant capacity of essential oils obtained by the three methods decreased in the order UASD > SD > EHSD. The DPPH radical scavenging activity followed the order UASD (IC50 = 31.15 mg/mL) > EHSD (IC50 = 32.82 mg/mL) > SD (IC50 = 34.74 mg/mL), while hydroxyl radical scavenging activity followed the order UASD (IC50 = 3.82 mg/mL) > SD (IC50 = 9.14 mg/mL) > EHSD (IC50 = 9.43 mg/mL). [Conclusion] UASD can be considered the optimal method for the extraction of Guangfoshou essential oil.
Effects of shaping methods on water extract and chemical composition of Xinyang Maojian
Chen Yi, Zhang Hanxue, Sun Mufang, Guo Guiyi, and Yang Jie
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80519
[Objective] To explore the effects of shaping methods on the quality of Xinyang Maojian. [Methods] Fresh leaves (one bud and one leaf) from the Xinyang group tea cultivar are used as raw materials. Tea samples are prepared with four different processing techniques. Analysis was conducted based on sensory evaluation, water extract content under multiple infusions and after 30 minutes of brewing, and the physical and chemical components of the first infusion of tea. [Results] The content of water extract in the first infusion and after 30 minutes of brewing is in the order of frying > rolling = kneading > carding. The comprehensive sensory evaluation scores show that both taste and aroma are higher in samples processed by carding and kneading than in those by rolling and frying. The content of soluble sugars, amino acids, and total catechins is in the descending order of frying > rolling > kneading > carding. The content of flavonoids and caffeine is in the descending order of carding > frying > rolling > kneading. The polyphenol content is in the descending order of kneading > frying > carding > rolling. The content of chlorophyll a, chlorophyll b, and total chlorophyll, from highest to lowest, is frying > carding > kneading > rolling. Principal component analysis score plots show significant differences in Xinyang Maojian obtained from the four different shaping techniques. [Conclusion] The first infusion of tea with different shaping techniques has different chemical composition change patterns. The kneading shaped tea sample has the best appearance, while the carding shaped tea sample has the best tea infusion color and taste. The aroma of kneading and carding shaped tea samples is tied for first place. The kneading shaped tea sample achieves the highest comprehensive sensory quality score.
Extrusion pretreatment improves the protein digestibility of black soybean meal and its effects on the final quality and antioxidant activity of soy sauce
Cheng Xiaoyuan, Ma Chengye, and Li Hongjun
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.60061
[Objective] To investigate the regulatory mechanisms of extrusion pretreatment on the protein digestibility of black soybean meal and systematically evaluate its effects on soy sauce quality and antioxidant activity. [Methods] A mixture of black soybean meal and flour was pretreated using extrusion technology for soy sauce brewing. Extrusion temperature, screw speed, flour addition, and moisture content were selected as the main process parameters to investigate their effects on protein digestibility. Under the optimal extrusion conditions, the raw materials were prepared and further subjected to simulated low-salt solid-state soy sauce fermentation. Amino nitrogen, total nitrogen, reducing sugar, pH, total acid, ammonium salt, soluble salt-free solids, and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl [DPPH] radical-scavenging rate and total phenolic content) were measured to evaluate the effects of extrusion modification on soy sauce quality and antioxidant activity. [Results] The optimal extrusion parameters were an extrusion temperature of 100.0 ℃, screw speed of 205 r/min, flour addition of 15.5%, and moisture content of 17.8%. Under these conditions, the protein digestibility of the extrudate reached 85.25%, representing a 49.23% increase compared with that of unextruded black soybean meal. Compared with the unextruded group, the amino nitrogen and total nitrogen contents of soy sauce in the extrusion pretreatment group increased by 50.8% and 44.9%, respectively, while the reducing sugar content increased by 36.2%. Meanwhile, antioxidant activity was significantly improved, with the DPPH radical-scavenging rate increasing from 42.6% to 60.3% and the total phenolic content increasing by approximately 42.2%. [Conclusion] Extrusion pretreatment can significantly enhance protein digestibility and, through the synergistic effects of moderate denaturation and starch gelatinization, improve the enzymatic hydrolysis efficiency and generation of flavor precursors in soy sauce fermentation substrates, while enhancing the antioxidant function of the product.
Effects of frost mulberry leaf powder on properties of dough and quality of bread
Zhang Erfang, Feng Yan, and Zhang Yixin
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80794
[Objective] To explore the effects of frost mulberry leaf powder (FMLP) on the processing characteristics of dough and the quality and storage properties of bread. [Methods] FMLP is blended with wheat flour, and the rheological properties of the dough are analyzed by a rheometer. Bread quality is evaluated in terms of texture, color, specific volume, and sensory attributes. The TOPSIS method is adopted for comprehensive evaluation, and variations in moisture and hardness of bread during storage are compared. [Results] The addition of FMLP increases the G', G", and tanδ of the dough, enhances the hardness and chewiness of the bread, while reducing the specific volume of the bread. The comprehensive score of the bread reaches a maximum of 0.757 at 5% FMLP. At this ratio, the bread exhibits moderate hardness, fine texture, a bright color, as well as the highest elasticity and chewiness. Compared with the control group (without FMLP) under the same storage conditions, the bread with FMLP demonstrates a decrease in staling rate, while the moisture loss rates within 7 days are similar. [Conclusion] The addition of a proper amount of FMLP improves the rheological properties of the dough and the quality of bread, while also helping retard bread staling.
Advances
Research progress in extraction of food functional ingredients with subcritical dimethyl ether
Wan Xiaofu, Pan Le, and Li Muchun
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80743
With the growing demand for high-quality natural product extracts, dimethyl ether as a new green solvent operating under subcritical conditions has exhibited notable benefits for the extraction of lipids, carotenoids, and long-chain polyunsaturated fatty acids, attributable to its distinctive physicochemical characteristics. This paper reviews the progress in the application of dimethyl ether in natural product extraction, focusing on its advantages in treating biomass with high moisture content, improving extraction efficiency, and reducing energy consumption and environmental load, with a view to providing reference for the application of subcritical dimethyl ether in extraction.
Functional components and food application progress of almond by-products
Xie Jingyi, Wang Wanqing, Wang Xinyi, Yuan Chunle, Li Yuna, and Hua Wei
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80858
As the global almond industry expands rapidly, large quantities of by-products are generated during processing (such as green hulls, shells, and skins), which are rich in functional constituents including polyphenols, flavonoids, dietary fibers, and volatile aroma compounds. This review summarizes the compositional characteristics and extraction technologies of these by-products, while elucidating their potential applications in food and biomaterials, with a specific focus on their antioxidant properties, bioactivities, and structural features. Furthermore, in light of recent research advances, the review further discusses poor stability, low bioavailability, challenges in processing compatibility, and other problems, proposing enhancement strategies such as nano-delivery, structural modification, and combined utilization.
Research progress of 3D printing technology in food texture design
Ou Suiling and Xie Zihong
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2025.80723
Food texture is a key factor influencing consumer acceptance. With the growing demand for personalized and health-oriented diets, the technical bottlenecks of traditional food processing methods have gradually become apparent in texture control and diversified texture presentation. Owing to its flexible and personalized characteristics, 3D printing offers a novel approach for food texture design. This paper reviews the textures that can be personalized and optimized by 3D printing through material modulation, structural modeling, and equipment optimization. Furthermore, this paper analyzes the challenges faced by this technology, including cooking adaptability, food safety assurance, and consumer acceptance, proposing corresponding solutions.
Packaging & Design
Aesthetic restraint and blank space : design translation of Yuezhou Kiln patterns in yellow tea packaging
Zhou Wenyu and Wan Changlin
Date posted: 9-20-2026
DOI: https://doi.org/10.13652/j.spjx.1003.5788.2026.80606
To explore a new path for traditional ceramic culture to empower local food packaging, this paper takes Yueyang yellow tea as the target carrier and investigates the application strategy of Yuezhou Kiln patterns in modern packaging design. The article analyzes the aesthetic characteristics of aesthetic restraint and blank space in the decorative crafts of Yuezhou Kiln, along with their deep compatibility with contemporary minimalist design philosophy, and proposes design principles such as cultural continuity, functional priority, and freehand-style translation. By deconstructing and reorganizing kiln patterns and reconfiguring colors and materials, this study constructs a packaging visual system with regional distinctiveness, aiming to provide practical references for the dynamic inheritance of intangible cultural heritage and the brand differentiation upgrade of local specialties.
