ObjectiveUsing Dunaliella spp. powder as the raw material, to explore the effect of pH value, alkali dissolution temperature, alkali dissolution time, and solid-liquid ratio on Dunaliella spp protein extraction.MethodsThe optimal conditions are screened by single-factor experiments. Response surface experiments are designed by the Box-Behnken method to determine the optimal extraction process parameters for Dunaliella spp. protein with the Dunaliella spp. protein extraction rate as the indicator. Additionally, the group composition, secondary structure, amino acid composition, and functional properties of Dunaliella spp. protein are determined.ResultsThe optimal extraction process conditions for Dunaliella spp. protein is pH 10.54, alkali dissolution temperature 51 ℃, alkali dissolution time 2.1 h, and a solid-liquid ratio of 1:206 (g/mL). Under these conditions, the extraction rate of Dunaliella spp. protein is 52.98%. At 50 ℃, Dunaliella spp. protein exhibits the highest water and oil holding capacity. At a mass fraction of 0.6%, Dunaliella spp. protein exhibits the highest foaming property (40%), foam stability (62.5%), emulsifying property (62%), and emulsifying stability (66%). Structural analysis shows that the secondary structure of Dunaliella spp. protein is mainly β-sheet (26.79%), with essential amino acids accounting for 32.94%, and hydrophobic amino acids accounting for 39.52%.ConclusionThe optimized extraction process for Dunaliella spp. protein can significantly increase protein extraction rate.
ObjectiveTo investigate the effects of different extraction methods on the efficacy, chemical composition, and functional group characteristics of flavonoids in Lycium barbarum leaves.MethodsThis study comparatively analyzes the effects of three methods-ultrasound-assisted ethanol extraction (UAE), microwave-assisted ethanol extraction (MAE), and aqueous two-phase system (ATPS)-on the yield, composition, and in vitro antioxidant activity of flavonoids from L. barbarum leaves.ResultsUAE and MAE achieve the highest yield of flavonoids from dried L. barbarum leaves. The main components are rutin, quercetin, chlorogenic acid, and kaempferol. The antioxidant capacity of the flavonoid extract from dried L. barbarum leaves is significantly higher than that of fresh samples, and the UAE extract has the highest DPPH radical scavenging rate (84.31%) and the strongest ferrous ion-reducing ability (26.23%).ConclusionThe dissolution efficiency of flavonoids varies under different extraction methods, and there is a significantly positive correlation between the flavanol structure and antioxidant activity.
ObjectiveTo investigate the aroma changes of sauce-flavored Baijiu during different aging periods, and to provide a theoretical basis for Baijiu aroma analysis and modern processing technology research.MethodsElectronic nose, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS) were employed. Sauce-flavored Baijiu with different aging times (original liquor, 1-year aged, and 5-year aged) was used as the research objects. Combined with multivariate statistical methods, including principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), the differences in volatile flavor compounds of Baijiu with different aging times were analyzed.ResultsA total of 1 626 volatile compounds were detected in the three Baijiu samples. Based on the calculation of relative odor activity value (rOAV) and screening of compounds with rOAV≥1, 47 important volatile compounds were identified, including 1 amine, 6 alcohols, 2 aromatic hydrocarbons, 1 phenol, 1 halogenated hydrocarbon, 3 ethers, 10 aldehydes, 3 terpenoids, 5 ketones, 3 heterocyclic compounds, and 12 esters.ConclusionThe aroma characteristics of Baijiu with different aging times are similar, but clear differences also exist. With increasing aging time, the contents of higher alcohols, aldehydes, and esters-contributing to a rich and delicate flavor-increase, while pungent and irritating substances decrease. As a result, the aroma of Baijiu becomes more stable and mellow, with a more complex aroma profile.
ObjectiveTo develop an intelligent method for non-destructive recognition of pork loin freshness based on computer vision technology, which is to be achieved by establishing a classification model for accurate, fast, and non-destructive detection of pork freshness in the cold chain industry.MethodsA classification detection model is proposed based on the YOLO v11 architecture. First, total volatile basic nitrogen (TVB-N) content and pH values are measured before the meat samples are divided into three categories: "fresh", "less fresh", and "spoiled". A dataset of 4 680 high-resolution images is constructed (generated from 1 247 original images enhanced through operations such as rotation, flipping, cropping, brightness adjustment, and blurring). Then, the dataset is divided into training, validation, and test sets in a 6∶2∶2 ratio. Utilizing a transfer learning strategy, the YOLO v11 model with pre-trained weights is initialized in the PyTorch framework and trained using the SGD optimizer (learning rate of 0.01). Finally, the model established is compared with six mainstream models: DenseNet161, EfficientNet_b2, MobileNet_v2, ResNet50, ShuffleNet_v2_x1, and ViT_base_patch16_224.ResultsThe YOLO v11 model achieves excellent performance, with an overall classification precision of 1.000, significantly outperforming the best baseline model, ViT_base_patch16_224. Additionally, the proposed model demonstrates significant advantages over other models in both F1 score and accuracy metrics.ConclusionIn this study, the YOLO v11 model is successfully applied to the non-destructive detection of pork loin freshness. With high-precision generalization capabilities, the proposed instance classification method achieves a detection rate of 1.000 for spoiled meat and ensures food safety. With an inference speed of 12 ms, this model is suitable for real-time non-destructive detection in production lines. Additionally, exhibiting a strong generalization ability, the model can evenly recognize multiple levels of freshness, with classification accuracy greater than 98% for each category.
ObjectiveThe variations in inorganic element content and the safety of heavy metals and harmful elements in Ranunculi ternati radix from different origins were investigated.MethodsThe quantitative analysis of 24 elements in the samples was performed by inductively coupled plasma mass spectrometry (ICP-MS). Health risk assessment was conducted using estimated daily intake (EDI), target hazard quotient (THQ), and carcinogenic risk (CR). Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used for origin identification analysis and differential element screening.ResultsAll 25 Ranunculi ternati radix samples from different origins contain abundant macronutrients (K, Na, Ca, and Mg) and micronutrients (Fe, Cu, Zn, Cr, Mn, Ni, V, Co, Mo, and Se) essential for the human body. The contents of heavy metals and harmful elements Pb, Cd, As, Hg, and Cu are 0.63~0.51, 0.05~0.11, 0.26~0.62, 0.01~0.10, and 32.96~167.25 mg/kg, respectively. Among them, the Cu content exceeds the limit for botanical drugs in the Chinese Pharmacopoeia (2020 edition). In terms of health risk assessment, the EDI analysis reveals that the estimated maximum daily intakes of Cr, Al, Ni, Pb, As, and Cu for adults and children from Ranunculi ternati radix in all or some origins exceed 10% of the provisional tolerable daily intake (PTDI), with some exceeding the PTDI value, indicating health risks. In the THQ analysis, the target hazard quotient values of Cr, Al, Cu, and As for adults and children from Ranunculi ternati radix in all or some origins exceed the standard THQ, indicating health hazard risks. In the CR analysis, the potential carcinogenic risk indices of Cd and As, as well as the total potential carcinogenic risk index of the three heavy metals Cd, As, and Pb, range from 1×10-6 to 1×10-4, indicating potential carcinogenic risks. The PCA identifies elements such as V, Al, Cs, Co, As, Fe, Mn, Tl, Cr, Pb, K, Ni, Sr, Cu, Ag, Cd, Hg, Zn, Ca, Na, Mo, Mg, and Se as the characteristic elements of Ranunculi ternati radix. The PLS-DA identifies four elements, including K, Mg, Fe, and Al, as effective traceability indicators for the origin of Ranunculi ternati radix.ConclusionThe established method can rapidly and accurately analyze the inorganic element contents in Ranunculi ternati radix. When Ranunculi ternati radix is ingested for a long term, attention should be paid to controlling the dosage and duration of administration to reduce the health risks caused by elements such as Cr, Al, As, Cu, Ni, Pb, and Cd.
ObjectiveTo establish a method for the determination of five fluorescent whitening agents (FWAs) in prepared dishes using gel permeation chromatography combined with high-performance liquid chromatography (GPC-HPLC).MethodsThe prepared dish samples were homogenized, ultrasonically extracted with acetonitrile, purified and reconstituted by GPC, then filtered before being analyzed by HPLC. The separation was performed on a Waters Symnetry Shield PR-C18 column (4.6 mm×250 mm, 5.0 µm) using acetonitrile and water as the mobile phase with gradient elution.ResultsThe five FWAs in the prepared dishes showed good linearity within the range of 2~500 µg/L, with correlation coefficients greater than 0.999. The limits of detection (LODs) ranged from 0.016 to 0.233 µg/kg, and the limits of quantification (LOQs) ranged from 0.05 to 0.78 µg/kg. At three spiked levels (low, medium, and high), the recoveries for the five FWAs were between 75.3% and 97.1%, with relative standard deviations (RSDs) ranging from 0.3% to 5.0%.ConclusionThe developed method is accurate, reliable, and highly sensitive, making it suitable for the determination of FWAs in prepared dishes.
ObjectiveTo investigate the dynamic changes in the major non-volatile chemical components during the processing of Jianghua Kucha 21-3 Gongfu black tea.MethodsFresh one-bud-two-leaf autumn tea leaves of Jianghua Kucha 21-3 were used as raw materials. Samples at different processing stages were obtained by liquid nitrogen pre-freezing and freeze-drying. The mass fractions of water extract, tea polyphenols, catechins, theaflavins (TFs), thearubigins (TRs), theabrownins (TBs), caffeine, theanine, free amino acids, and soluble sugars were determined. Additionally, sensory evaluation was conducted on Gongfu black tea processed with different fermentation durations.ResultsDuring processing, the mass fraction of water extract in Jianghua Kucha 21-3 Gongfu black tea gradually decreased, reaching (39.19±0.30) g/100 g after drying. The mass fractions of tea polyphenols, catechins, and theanine also decreased progressively, with rapid declines occurring during rolling and the early stage of fermentation. In contrast, the mass fractions of TFs and TRs increased sharply during rolling and early fermentation, reaching maximum values at 2 h and 6 h of fermentation, respectively, at (1.35±0.02) g/100 g and (7.22±0.54) g/100 g. The mass fraction of free amino acids reached its maximum at 3 h of fermentation and then gradually decreased, while the mass fraction of caffeine remained relatively stable throughout the processing. Sensory evaluation revealed that fermentation duration had little effect on the appearance of Gongfu black tea but significantly influenced its internal quality. When fermented for 3~4 h, Jianghua Kucha 21-3 Gongfu black tea exhibited a mellow and brisk taste with a bright red liquor, indicating superior quality.ConclusionThe optimal fermentation time for Jianghua Kucha 21-3 Gongfu black tea should be controlled at 3~4 h.
ObjectiveTo develop a shrimp freshness indicator film with good amine responsiveness and stability for the rapid and non-destructive detection of shrimp quality changes.MethodsUsing sodium carboxymethyl cellulose and starch as film-forming substrates, indicator films were prepared with grape seed proanthocyanidins, curcumin, and their mixtures as indicators. The responses of the three indicator films to aqueous solution pH and trimethylamine were compared. The detection sensitivity and storage stability of the mixed indicator film were further evaluated. The indicator film was then applied to monitor the freshness of Litopenaeus vannamei, and the correlation and kinetics between total volatile basic nitrogen (TVB-N) values of shrimp and the color difference (ΔE) of the indicator film were analyzed.ResultsThe mixed indicator film exhibited high sensitivity to trimethylamine and good storage stability at different temperatures. Under storage conditions of 4, 25, and 37 ℃, the TVB-N value of shrimp was positively correlated with the ΔE value of the indicator film, with correlation coefficients all greater than 0.98. According to the Arrhenius equation, the activation energies for changes in shrimp TVB-N and the ΔE of the indicator film were 52.78 and 50.61 kJ/mol, respectively, showing good agreement.ConclusionThe color change of the indicator film can maintain a similar variation trend with the TVB-N value of shrimp at different temperatures, thereby indicating shrimp quality and demonstrating good application prospects.
ObjectiveThis study aims to establish an analytical method for detecting the migration levels of 4-methyl-1-pentene and 1-decene monomers from food contact materials into four food simulants, including 4% acetic acid, 10% ethanol, 20% ethanol, and 50% ethanol.MethodsChromatographic columns of different polarities and specifications are compared to select the optimal column. The headspace equilibrium temperature and equilibrium time are optimized using peak area as the evaluation index. Methodological validation is performed by conducting recovery experiments at low, medium, and high spiking levels using the soaking solutions of the negative sample of the four food simulants as the matrix, and the recoveries and relative standard deviations of the migration levels of target analytes are determined and calculated.ResultsThe optimal experimental conditions are as follows: HP-5 capillary chromatographic column (30 m×0.25 mm, 1 μm), headspace equilibrium temperature of 80 ℃, equilibrium time of 40 min, detection by flame ionization detector (FID), quantification by the external standard method. Both target compounds exhibit good linearity in the concentration range of 0.01~0.1 mg/L, with correlation coefficients all greater than 0.995. The limits of detection (LOD, S/N=3) range from 0.000 1 to 0.002 mg/kg, and the limits of quantification (LOQ, S/N=10) range from 0.000 3 to 0.006 mg/kg. The spiked average recoveries range from 81.0% to 109%, with relative standard deviations (RSD, n=6) of 1.3%~9.8%.ConclusionThis method is convenient and sensitive, with satisfactory accuracy and precision. It is suitable for the determination of 4-methyl-1-pentene and 1-decene monomer migration levels in plastic materials for food contact.
ObjectiveTo investigate the regulatory effects of a composite preservation technology combining slow-release plant essential oil (SPEO) with electron beam irradiation on the storage quality and physiological metabolism of Shanghai sand pears (Pyrus pyrifolia Nakai).MethodsThe fruits of Shanghai sand pear variety 'Cuiguan' are used as test materials. The experiment is conducted with four groups: control, 0.5 kGy electron beam irradiation, SPEO, and 0.5 kGy electron beam irradiation+SPEO. During storage, quality parameters including fruit firmness, weight loss rate, total soluble solids (TSS) content, titratable acid content, and vitamin C (VC) content, as well as physiological metabolism indicators such as respiratory rate and polyphenol oxidase (PPO) activity, are measured to evaluate preservation performance.ResultsCompared with the control group, all treatments effectively delay fruit quality deterioration. The 0.5 kGy electron beam irradiation+SPEO treatment demonstrates the best performance in maintaining fruit firmness and achieves the lowest weight loss rate after 70 days of storage, which is significantly lower than that of the control. This combined treatment delays the decline in TSS content while maintaining higher titratable acid content and VC content, significantly outperforming other treatments. Furthermore, the 0.5 kGy electron beam irradiation+SPEO treatment delays and reduces the respiratory peak and significantly inhibits the peak PPO activity, effectively delaying fruit senescence and browning.ConclusionThe combination of 0.5 kGy electron beam irradiation and SPEO exhibits a significant synergistic effect, effectively delaying pear browning and senescence and achieving optimal comprehensive preservation performance.
ObjectiveTo establish a method for authenticity identification of camellia seed oil.MethodsThe fatty acid composition of camellia seed oil and six common vegetable oils are determined by gas chromatography. Principal component analysis (PCA) is employed to explore the distribution patterns of fatty acids among the vegetable oils and to screen for potentially adulterated oils. Partial least squares discriminant analysis (PLS-DA) is applied to establish a model between fatty acid profiles and actual adulterated oils. Finally, multiple stepwise linear regression analysis is used to establish quantitative analysis models for adulteration in camellia seed oil.ResultsAmong the six common vegetable oils, olive oil and peanut oil exhibit fatty acid compositions most similar to that of camellia seed oil, and are therefore selected as potential adulterants. The PLS-DA model could discriminate adulterated oils with adulteration levels no lower than 5%, and identify characteristic fatty acids for olive oil adulteration (palmitic acid, behenic acid, linoleic acid, palmitoleic acid and stearic acid) and for peanut oil adulteration (oleic acid, linoleic acid and palmitic acid). The quantitative models established by stepwise linear regression for olive oil and peanut oil adulteration in camellia seed oil achieve correlation coefficients (R2) greater than 0.9 for both models. The limits of detection (sensitivities) for the two models are 5% and 2%, respectively, and the method repeatabilities range from 0.7% to 6.0% and from 0.8% to 3.3%, respectively. The errors between predicted and actual values range from -1.93% to 2.08% and from -0.79% to 0.15%, respectively.ConclusionThis comprehensive technical strategy, encompassing screening, qualitative discrimination, and quantitative analysis, provides a complete solution for the authenticity assessment of camellia seed oil.
In view of the prevailing issues of severe homogenization and insufficient cultural distinctiveness in current agricultural food packaging, this study puts forward an innovative approach to promote the upgrade of agricultural food packaging from functional consumption to cultural consumption through intangible cultural heritage (ICH) narrative design. In terms of methodology, the value of ICH narrative in food packaging is first analyzed, followed by the proposal of a design pathway encompassing three aspects: ICH content selection and story construction, narrative graphic and layout design, and material and process selection, with interactive experience being strengthened by integrating technologies such as the Internet of Things (IoT) and augmented reality (AR). In terms of application outcomes, case studies including Shaoxing rice, Luhe souvenirs, Xigui tea, Wuyutai tea, Zhuxianzhen dried tofu, and Jingyang Fu brick tea demonstrate that ICH narrative endows agricultural food products with distinctive cultural features and evokes emotional resonance, while technological means can further broaden the scope of narration. It can be concluded that ICH narrative imparts a non-replicable cultural core to agricultural food packaging, thereby facilitating the transition from functional consumption to cultural consumption. In practice, it is essential to respect community subjectivity, balance tradition and innovation, and conduct prudent cultural and ethical assessments of sensitive content.
ObjectiveThis study aims to investigate the effects of three extraction methods-alkaline extraction, enzymatic extraction, and acid extraction-on the properties of corn fiber gum (CFG)-pea protein composite gels.MethodsCFG was extracted from corn bran using the three methods. The gel strength, water-holding capacity, rheological properties, and microstructure of the CFG-pea protein composite gels are evaluated.ResultsThe CFG extracted by enzymatic extraction increases the gel strength of pea protein gels from (27.20±2.45) g to (65.80±2.67) g, and the water-holding capacity from (40.60±3.40)% to (75.80±5.10)%. Additionally, it forms a more compact and ordered network structure with pea protein, demonstrating superior viscoelasticity. In contrast, the CFG extracted by alkaline and acid extraction contributes less to the composite gel properties compared with that extracted by enzymatic extraction.ConclusionThe CFG-pea protein composite gel prepared with enzymatically extracted CFG exhibits the best overall performance.
ObjectiveTo further understand the influence of the heat transfer process on the quality of self-heating foods and improve the heating rate of existing self-heating rice products.MethodsA combination of virtual simulation and experimental methods was used to analyze the actual temperature variations during the heating process of self-heating rice and the effects of heat transfer on rice texture. A three-dimensional heat transfer model of self-heating rice was established using COMSOL software to investigate the heat transfer process, and the packaging design of self-heating rice was optimized with the objective of maximizing the heating rate.ResultsAfter reheating and cooling at 20 ℃ for 90 min, differences in textural properties were observed among different layers of self-heating rice. The rice in the middle layer showed higher chewiness and better overall texture, whereas the springiness, cohesiveness, and chewiness of the bottom layer rice were significantly reduced. The established three-dimensional heat transfer model accurately described the temperature changes during the heating process of self-heating rice. In addition, for self-heating rice with the same volume, optimization of packaging dimensions and length-to-width parameter combinations (with a length of 133.49 mm and a width of 120 mm) shortened the heating time by 387 s; The use of a bowl-shaped package (with a top diameter of 273 mm and a bottom diameter of 200 mm) shortened the heating time by 194 s; And the application of a novel aluminum foil-bottom packaging material shortened the heating time by 251 s. Compared with the original commercial packaging, all these optimization strategies significantly improved the heating performance of self-heating rice.ConclusionThe combination of virtual simulation and experimental methods used in this study can intuitively describe the heat transfer performance of self-heating rice, and optimization of self-heating rice packaging can effectively improve the heat transfer rate.
ObjectiveTo enhance the accuracy of detecting fruit surface defects caused by minor mechanical friction during transportation.MethodsA surface defect detection model for fused images of fruits based on improved ResNet18 is proposed. To address the challenge of multi-scale feature extraction, the model incorporates a MELA module designed to capture image details more comprehensively. Additionally, an energy function-based regularization loss function is introduced to collaboratively optimize the training process alongside the cross-entropy loss function. Furthermore, a transfer learning strategy is employed to mitigate overfitting.ResultsExperimental results demonstrated that the improved model exhibits exceptional performance in fruit surface defect detection tasks, achieving the accuracy, precision, recall, and F1 score as high as 99.53%, 99.60%, 99.58%, and 99.58%, respectively.ConclusionThe surface defect detection model for fused images of fruits based on improved ResNet18 significantly enhances the detection accuracy and is suitable for surface defect detection in fused images of fruits.
ObjectiveTo investigate the effects of ventilation conditions and Daqu stacking methods in the fermentation room on the humidity levels at various points within the room.MethodsA three-dimensional unsteady gas-solid coupling model of a small-scale fermentation room is established. Then, the humidity field variation patterns in the room are analyzed using the height of the humidifying air supply outlet (H), the interlayer spacing of fermentation racks (h), and the gap between fermentation piles (δ) as variables. Additionally, multi-objective optimization is performed based on response surface methodology (RSM) and the non-dominated sorting genetic algorithm II (NSGA-II).ResultsH, h, and δ all significantly affect the humidity field, with h exerting the highest influence weight. Parameter optimization yields the Pareto optimal front: H=492 mm, h=167 mm, and δ=140 mm. Compared with the original model, the humidity regulation rate is increased by 31.9%, and the humidity uniformity index is improved by 11.82% after optimization.ConclusionThe collaborative optimization of the fermentation room layout parameters H, h, and δ can effectively improve the regulation of the solid-state fermentation environment, significantly enhancing both the humidity regulation rate and uniformity.
ObjectiveTo comprehensively reveal the flavor and quality characteristics, and differences of Morchella esculenta under different cultivation methods, and systematically evaluate their volatile aroma components.MethodsQualitative and quantitative analyses are conducted on volatile aroma components in M. esculenta cultivated in greenhouses, under forests, and in caves in the vicinity of FAST by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) techniques. The contribution of different components to the overall flavor is assessed by the relative odor activity value (ROAV) method. Based on this, principal component analysis and cluster analysis are conducted, achieving a comprehensive evaluation of the flavor characteristics of M. esculenta.ResultsThe GC-MS analysis results show that 1 201 volatile substances are detected in M. esculenta under the three cultivation methods, mainly including acid, alcohol, aldehyde, amine, aromatics, ester, ether, halogenated hydrocarbons, heterocyclic compounds, hydrocarbons, ketone, nitrogen compounds, phenol, sulfur compounds, and terpenoids. Among them, the relative content of heterocyclic compounds is the highest, ranging from 11.042% to 28.365%, followed by ester and aldehyde. Due to different cultivation methods, the relative content of various volatile components varies, with significant differences between most of them (P<0.05). The analysis results of the ROAV method show that the main volatile aroma components in M. esculenta under three cultivation methods are α,α,4-trimethyl-3-cyclohexene-1-methylthiol, dihydro-2-methyl-3(2H)-furanone, 5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone, and 1-nonen-3-one. Different cultivation methods result in variations in the volatile aroma components in various M. esculenta. The comprehensive evaluation results of principal component analysis and cluster analysis indicate that the cave cultivation method leads to the highest comprehensive score on the aroma quality of M. esculenta and the best aroma quality.ConclusionThere are numerous types of volatile compounds in M. esculenta cultivated in greenhouses, under forests, and in caves in the vicinity of FAST, with significant differences in relative content. The main volatile aroma components vary with the cultivation method. Additionally, the best aroma quality is found in M. esculenta cultivated in caves.
ObjectiveAiming at the industrial bottleneck that the industrial peeling of small yellow ginger cannot balance high peel removal rate and low flesh damage rate due to its irregular shape, dense branches, thin and tender peel, a piece of peeling equipment based on three-dimensional turbulent flexible friction is developed.MethodsSmall yellow ginger is taken as the test material. With peel removal rate and flesh retention rate as evaluation indicators, single-factor and L9(34) orthogonal experiments are carried out to optimize three key parameters: processing time, material-water ratio, and stirring speed. Origin is used for data statistics and analysis.ResultsThe influences of factors follow the trend of processing time>stirring speed>material-water ratio. The optimal parameters are determined as follows: processing for 6 min, a material-water ratio of 1∶2, and a stirring speed of 35 r/min. Under the above conditions, the peel removal rate, the flesh retention rate, and the processing capacity reach 98.12%, 95.86%, and 2.11 t/h, respectively. Compared with brush mechanical peeling and chemical alkali peeling, the proposed equipment and supporting process present the advantages of high peeling efficiency, low flesh damage, no chemical residue, and favorable environmental performance.ConclusionThe coordination of equipment innovation and process optimization can realize efficient and low-damage industrial peeling of small yellow ginger and provide references and technical support for the green processing of irregular fruits and vegetables with thin peels.
Vegetable pickling is a time-honored food preservation and processing method, in which salt (primarily sodium chloride) plays an irreplaceable and core role. This paper systematically reviews the multidimensional effects of curing salt on vegetable quality. It comprehensively covers preservation mechanisms, textural transformations, the formation and conversion of flavor compounds, color stability, and nutritional value changes. Specifically, this article analyzes the decisive role of salt concentration gradients in final product characteristics. Furthermore, it examines the challenges posed by the low salinity, including microbial safety risks, textural deterioration, and flavor imbalances, while proposing corresponding strategies
ObjectiveTo establish a rapid detection method for viable Salmonella based on specific phage infection and recombinase polymerase amplification (RPA) in response to the key challenge that traditional molecular biological detection methods have difficulty in conveniently distinguishing between viable and non-viable foodborne pathogens.MethodsTaking advantage of the characteristic that O-1 phage only proliferates in viable bacteria, the phage is added to the enriched sample. After further incubation, total DNA is extracted. Fluorescent RPA is used to determine whether the phage has significantly proliferated, so as to judge the presence of viable Salmonella in the original sample.ResultsAfter optimization, the optimal detection conditions are as follows: 100 μL of O-1 phage with a concentration of 3×105 PFU/mL is added, and the infection and proliferation time is 3 hours. The detection limit of the method for phage DNA is 0.07 fg/μL, and that for viable Salmonella is 1.58×102 CFU/mL. The intra-generic inclusivity of the method is 100% when testing 37 Salmonella strains of different serotypes, and the inter-generic specificity is 100% when testing 17 non-Salmonella strains.ConclusionThe method utilizes the characteristic that phages only rapidly proliferate in viable host bacteria, enabling highly sensitive and specific detection of viable Salmonella within 4 hours without a PCR thermal cycler. The method is suitable for on-site rapid screening and identification of viable Salmonella in food production and circulation processes, providing a new approach for the on-site detection of viable Salmonella in food.
