Abstract:In order to explore the effect of tannase on the fermentation process and antioxidant activity of Phyllanthus emblica wine,Phyllanthus emblica was used as the raw material.After Phyllanthus emblica juice was treated with tannase(NF)or without such a treatment(CK),yeast was inoculated for fermentation to produce Phyllanthus emblica wine.Every 24 hours,the total sugar content,alcohol content and yeast quantity of Phyllanthus emblica wine were measured.The experimental data were fitted using Logistic model,Boltzmann model,SGompertz model and DoseResp model Meanwhile,the changes in total phenol content,total flavonoid content and antioxidant activity during the fermentation process were also determined.The results showed that the fitting correlation coefficients R2 of the selected models for the test data were all higher than 0.99,indicating that they could well describe the fermentation process of Phyllanthus emblica wine.At the end of fermentation,the alcohol contents were 13.37%vol for the CK group and 13.13%vol for the NF group.The addition of tannase had no significant effect on the fermentation of Phyllanthus emblica wine.After the Phyllanthus emblica wine was fermented for 12 days,the ABTS+free radical scavenging rate(75.59%),hydroxyl free radical scavenging rate(70.00%)and Fe3+reducing power(1.73)of the Phyllanthus emblica wine in NF group were all higher than those in the CK group,and the difference was extremely significant(P<0.01).The use of tannase had little impact on the fermentation process of Phyllanthus emblica wine,and could also reduce the tannin content while improving the quality of Phyllanthus emblica wine.This study provides a theoretical foundation for the application of tannase in fruit wine processing.

Abstract:Tremella polysaccharide(TP)and Dendrobium officinale polysaccharide(DOP)are natural polysaccharide-based hydrocolloids with considerable potential to enhance the performance of frozen dough and increase its nutritional value.To assess the effects of natural polysaccharides on frozen dough,the influence of TP-DOP polysaccharide mixtures on the stability of frozen dough was investigated systematically.The results showed that TP-DOP enhanced the thermal stability of the dough and delayed starch retrogradation.Dough with 1.2 wt.%TP-DOP addition exhibited the highest water absorption rate(67.80%),the longest formation time(8.42 min),and the shortest stability time(9.47 min),along with decrease in gluten strength and pasting viscosity.Moreover,0.8%TP-DOP significantly inhibited water migration,delayed the increase in freezable water content,and reduced moisture loss in the dough during frozen storage,effectively preventing the deterioration of the rheology and microstructure of the frozen dough(P<0.05).After 8 weeks of frozen storage,the dough with 0.8 wt.%TP-DOP exhibited a moisture loss rate of 8.06%and freezable water content of 37.28%.Bread made from this dough exhibited superior baking properties,including lower hardness(1 944.20 g)and higher specific volume(3.20 mL/g).These results indicate that TP-DOP can serve as a natural additive to enhance the stability of frozen dough during storage,with optimal improvements at 0.8 wt.%addition.This study provides a reference for the application of TP-DOP in high-quality food production and the development of complex frozen-dough processing methods.

Abstract:Food crops are at risk of mycotoxin contamination during production,storage,and transportation,raising food safety concerns.Traditional chemical methods for detecting mycotoxins are complex and time-consuming.In contrast,molecular vibrational spectroscopy simplifies detection and allows for the simultaneous analysis of multiple components,attracting significant attention.This study explores the principles and applications of molecular vibration spectroscopy and multispectral image data fusion for the rapid detection of mycotoxins in food crops,emphasizing the need for improved sensitivity,stability,and practicality.The proposed strategies focus on simplifying procedures,upgrading chemometrics,building databases,and developing portable devices to advance the application of molecular vibrational spectroscopy and multispectral image data fusion.

Abstract:To improve the oxidative stability and organoleptic flavor of docosahexaenoic acid(DHA),and enhance its application value in nutritional and health products,DHA algal oil was encapsulated in whey protein isolate(WPI)and pectin(PEC),gum arabic(GA),and octenyl succinic anhydride-modified starch(OSA)matrix using a complex coacervation method.The effects of different complexes on the physicochemical properties of emulsions,total oil and surface oil contents,storage stability,and apparent morphology of microcapsules with corresponding formulations were systematically examined.The results showed that the WPI-PEC complex significantly enhanced the emulsion stability of DHA algal oil,with an average particle size of 362 nm,D[3,2]of 312 nm,and D[4,3]of 391 nm.In addition,the LUMiSizer transmittance fingerprint curves exhibited only minor fluctuations in the transmittance.Furthermore,the spray-dried WPI-PEC microcapsules exhibited an oil loading capacity of approximately 50%,a low surface oil content of 2.59%,and a complete microstructure,as revealed by scanning electron microscopy.After storage at 40℃for 3 months,the peroxide value remained lower than 1 g/100 g,and the samples exhibited a high sensory score with a low fishy flavor.However,the addition of GA and OSA weakened the emulsification properties of WPI,resulting in emulsions with large particle sizes and lower stability,high surface oil content,incomplete microstructures,and poor storage stability of the microcapsule powder.In conclusion,the WPI-PEC complexes exhibited a synergistic effect that improved the stability and quality of DHA algal oil emulsions and microcapsules,thus laying a foundation for enhancing the application value of DHA algal oil.

Abstract:The advantages of endogenous enzymes and commercial enzymes were combined to obtain earthworm protein peptides with efficient pancreatic lipase inhibition activity using a two-step enzymatic hydrolysis method to hydrolyze earthworm protein.The pancreatic lipase inhibition rate was used as the evaluation index,and single-factor experiments and orthogonal experiments were used to optimize the second-step enzymatic hydrolysis process.In addition,the hydrolysates were purified using ultrafiltration and Sephadex G-15 gel chromatography,and peptide segments with high pancreatic lipase inhibitory activity were screened by combining LC-MS/MS,molecular docking,and other technologies with the PeptideRanker database.The results showed that the optimal preparation process for the second-step enzymatic hydrolysis involved a solid:liquid ratio of 1:2(50%,m/m),alkaline protease dosage of 6.0×104 U,temperature of 50℃,pH value of 9.5,and enzymatic hydrolysis time of 3 hours.Under these conditions,the pancreatic lipase inhibition activity reached 53.92%,the hydrolysis degree was 41.98%,and the soluble peptide yield reached 89.17%.A total of 10 peptide segments with high affinity,good biological activity,and non-toxicity were screened,namely GDAPPFFP,YPFDPGP,WGPDLP,FDFP,DDFFR,FLDF,SDDGFF,FDDF,SDDFF,and WDDFF.Small molecule peptides and amino acids are thought to be the primary substances causing the inhibitory effect of earthworm protein on pancreatic lipase.Overall,this study provides a new perspective for understanding the lipid-lowering activity of earthworm protein.It establishes a foundation for further research on the structure-activity relationship of earthworm protein functional peptides and the mechanisms of pancreatic lipase inhibition.

Abstract:To investigate the effects of sea cucumber phospholipids on depression-like behaviors induced by chronic unpredictable mild stress(CUMS)in zebrafish and associated mechanisms,Zebrafish were randomly divided into a control group,a stress group,a stress+low-dose(50 mg/kg)sea cucumber phospholipids intervention group,and a stress+high-dose(100 mg/kg)sea cucumber phospholipid intervention group.After the stress period,the novel tank and light-dark box behavioral tests were performed,the contents of interleukin(IL)-10,IL-6,indoleamine-2,3-dioxygenase(IDO),Tryptophan(TRP)and Kynurenine(KYN)were determined by enzyme linked immunosorbent assay(ELISA),whilst the level of 5-hydroxytryptamine(5-HT)was detected by high performance liquid chromatography(HPLC).Compared with the stress group,the depression degree of zebrafish in the low(50 mg/kg)and high dose(100 mg/kg)sea cucumber phospholipid groups was effectively reduced as shown in the new tank and the light-dark box behavior tests.Their contents of IL-10 in the brain increased by 12.05%and 15.26%(P<0.05 and P<0.01),contents of IL-6 decreased by 12.23%and 14.87%(P<0.01 and P<0.000 1),activities of IDO decreased by 14.12%and 22.20%(P<0.01 and P<0.000 1),and contents of TRP increased by 4.07%and 4.33%(P<0.05),contents of KYN decreased by 6.83%and 8.67%(P<0.05),ratios of KYN/TRP decreased by 9.43%and 11.32%(P<0.05),and contents of 5-HT increased by 28.57%(P<0.05)respectively.Therefore,depression can be ameliorated by sea cucumber phospholipids.The mechanisms include the amelioration ofinflammation and reduction of 5-HT synthesis caused by the activation of TRP-KYN pathway by IDO.This study provides new ideas for the development of antidepressant products by using sea cucumber phospholipids.

Abstract:To enhance the development and application of water-soluble Monascus yellow pigment,a high-salt permeation fermentation system was established.Resin adsorption was used to separate the water-soluble Monascus yellow pigment,and ultraviolet-visible(UV-VIS)spectroscopy and high-performance liquid chromatography(HPLC)were employed to investigate the stability characteristics of the pigment.The results showed that the yield of the water-soluble Monascus yellow pigment reached 55.47 AU under high salt fermentation.The macroporous resin X-5 was used to adsorb and separate the water-soluble Monascus yellow pigment,achieving recovery and desalination rates of 93.65%and 98.44%,respectively.Furthermore,after rotary evaporation and lyophilization,a stock solution containing 86.93%water-soluble Monascus yellow pigment was obtained.Stability tests revealed that the pigment fermented under high salt conditions was more suitable for storage in acidic environments.It demonstrated good stability after exposure to white light for 24 h or heating at 100℃for 1 h,with preservation rates of 86.21%and 80.85%,respectively.Among the four main components of the water-soluble Monascus yellow pigment,Y2 exhibited stronger alkali resistance than Y1,Y3,and Y4.However,the UV stability of Y2 was lower than that of the other three pigment components,and the thermal stability followed the order Y1>Y2>Y3>Y4.The water-soluble Monascus yellow pigment fermented under high-salt osmosis conditions demonstrated good stability,although the stability of the four pigment components varied.These results provide a theoretical basis for the fermentation of water-soluble Monascus yellow pigment under extreme conditions and ensure its stable application.

Abstract:Vacuum freeze-drying effectively preserves the quality of jujube fruit.However,freeze-dried products are prone to quality deterioration,such as color deterioration,during shelf life.To mitigate the quality deterioration of freeze-dried jujube slices during their shelf life,Muzao was selected as the test material and pretreated with various concentrations of citric acid(CA),L-cysteine(L-Cys),and D-sodium erythorbate(D-SE).The sensory and entropy weight TOPSIS methods were used to comprehensively assess and identify high-quality groups by tracking changes in quality indices during shelf life.The results showed that compared with the CK group,1.5%L-Cys and 1.0%CA were more effective in maintaining the quality of freeze-dried jujube slices.L-Cys pretreatment was better than CA pretreatment,with better maintained values of a*(-2.64)and b*(16.07),effective inhibition of PPO activity(6.45 U/g),and slow decrease of chlorophyll(1.39 mg/100 g),carotenoid(0.145 mg/100 g),and total phenol(417.28 mg/100 g)contents in freeze-dried jujube slices over 180 days of shelf life.In contrast,the 0.6%D-SE group demonstrated inferior performance in maintaining the quality of freeze-dried jujube slices during shelf life,with the a* value(-0.79)and PPO activity(14.90 U/g)significantly higher than those of the CK group.These findings suggest that 1.5%L-Cys pretreatment can effectively preserve the quality of freeze-dried jujube slices,delay quality deterioration during shelf life,and extend the shelf life to more than 210 days.These findings provide theoretical support for the high-value processing and utilization of jujube fruit,significantly contributing to the development of the jujube industry.

Abstract:Commercially available meal replacement powders have drawbacks such as high sugar content,low nutritional value,poor taste,and unsatisfactory reconstitution performance.To address these issues,a formulation using Chinese water chestnut(CWC),which can disperse in boiling water without agglomeration,was developed as the primary raw material.Dried CWC granules with a strong characteristic flavor,konjac gum,cream,and whey protein were added.A fuzzy mathematics evaluation model,which allows for a more objective and accurate evaluation,together with a response surface optimization method,was employed to develop a high-quality CWC-based meal replacement powder.The experimental results showed that the optimal formulation,based on quality ratio,was 64.87%instant CWC powder,7.16%dried CWC granules,2.82%konjac gum,1.66%plant creamer,and 23.49%whey protein.The resulting product achieved a total score of 95.87 points in the fuzzy mathematical sensory evaluation.Its main nutritional indicators and contents of vitamins,calcium,iron,and zinc are superior to the standard outlined in'T/CNSS 002-2019 Meal Replacement Foods.'In addition,the resistant starch content was high,which is beneficial to human health,and it exhibited excellent rheological,pasting,and cold gel TPA textural properties,as well as good solubility,water-holding capacity,and swelling capacity,all of which characterized it as a high-quality meal replacement.These results provide a theoretical basis for the development and industrialized production of instant CWC-based meal replacements.

Abstract:The cell wall protein PhiA is implicated in conidiogenesis in filamentous fungi and is closely associated with the development and formation of conidiophores.To preliminarily analyze the role of PePhiA in Penicillium expansum,PephiA was cloned and its cellular location was identified.Homologous recombination was then used to create ΔphiA,a PephiA gene deletion mutant,to explore the function of PePhiA in P.expansum.The results demonstrated that PePhiA encodes a protein of 182 amino acids with a signal peptide located in the cell wall,which is predominantly distributed in the mycelial membrane,conidiophore,and spores.The colony morphology of the mutant ΔphiA was green and circular with smooth edges,almost identical to that of the wild-type.Although the colony diameter and spore production were unaffected,the spore germination rate and bud tube length decreased by 22.73%and 13.26%,respectively,at 12 h.The pathogenicity and patulin yield of the mutant ΔphiA were not significantly different from those of the wild-type.Additionally,PephiA responded to both cell wall stress and osmotic stress,and its sensitivity to KCl,NaCl,CR,and SDS increased in sequence,resulting in increased inhibition of 14.47%,11.89%,11.36%,and 6.70%,respectively.These results suggest that PhiA is involved in the regulation of spore and mycelium formation in P.expansum and that PephiA is essential for maintaining cell wall integrity and responding to osmotic stress.This study provides a theoretical foundation for understanding the genetic network of asexual development associated with the biocontrol potential of P.expansum.

Abstract:To investigate the impact of storing shredded carrots and shredded lettuce treated with preservatives for different periods on the flavor of stir-fried fish-flavored shredded pork,A total of 126 volatile flavor compounds across 9 categories were identified in fish-flavored shredded pork with untreated or preservative-treated vegetables by full two-dimensional gas chromatography(GC×GC-MS)technology,including 17 alcohols,14 aldehydes,18 esters,8 ketones,2 phenols,6 acids,6 ethers,43 hydrocarbons and 12 nitrogen,sulfur and heterocycles.In the fish-flavored shredded pork samples,a total of 22 aroma-active compounds were identified,among which geraniol,n-hexanal,heptanal,and n-octanal were commonly detected in all samples.Isovaleraldehyde,α-terpinene and o-isopropylbenzene were only detected in the untreated group,whilst methyl-2,6-octadienal,E-2-octenal,ethyl decanoate,2-nonone,and trans-caryophyllene were specifically found in the preservative-treated groups.These phenomena might result from the abilities of chitosan to adsorb aldehydes,ketones,phenols,and esters,and such adsorption effects vary with the types of volatile compounds.Overall,the results indicate that preservative-treated side vegetables are more favorable for the formation of flavor substances in fish-flavored shredded pork,which provides theoretical support for the industrial production of fish-flavored shredded pork.

Abstract:In order to achieve rapid and non-destructive detection and classification of the freshness of mutton,in this work,a raw dataset of chilled mutton's freshness was first constructed through integrating multiple freshness indicators with hyperspectral data.A variety of preprocessing techniques were applied to establish a Support Vector Regression model,through which the optimal preprocessing method was determined.Subsequently,a feature selection process was initiated via Random Forest-based Recursive Feature Elimination and an autoencoder for band selection on the basis of the preprocessed datasets.A Light Gradient Boosting Machine(LightGBM)was subsequently built on the selected feature dataset to detect the freshness of chilled mutton.Given the limitations of traditional LightGBM in handling high-dimensional and sparse spectral data,particularly the low classification performance and lack of generalization capability,a multi-strategy optimization method based on the Hybrid Bat Algorithm and Nutcracker Optimization Algorithm was introduced to improve LightGBM.The improved LightGBM was compared with classification methods such as the original LightGBM,XGBoost,Support Vector Machine(SVM),and Random Forest(RF),followed by validation on datasets of different scales.The results demonstrated that the multi-strategy improved LightGBM achieved a freshness grade classification accuracy of 0.988 1,resulting in a 3.57%improvement compared with the unimproved version,with weighted precision,weighted recall,and weighted F1 scores reaching 0.988 6,0.988 2,and 0.988 3,respectively,all outperforming other classification methods.Furthermore,when detecting freshness grades across datasets of different scales,the model exhibited a consistent accuracy within the range of 0.984 0 to 0.989 0,indicating its good generalization capability and robustness.In summary,the effectiveness of the proposed improved LightGBM model has been validated in this work,providing a novel approach for rapid and non-destructive detection and classification of chilled mutton's freshness.

Abstract:To study the key aroma components of Torreya nuts before and after roasting,the headspace-solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GCMS)combined with the odor activity value(OAV)was used to analyze the compositions and contents of volatile substances as well as the key aroma components in three varieties,sesame Torreya nuts,scorpion Torreya nuts,millet Torreya nuts,before and after roasting.The results showed that 122 compounds were detected from the volatile components of the three different varieties of Torreya nuts before and after roasting,including 19 alkenes,30 esters,12 alcohols,23 aldehydes and ketones,13 pyrazinfurans,5 pyridine pyrroles,4 alkanes,4 ethers,5 acids,2 benzenes and 5 other compounds.The volatile components in the three kinds of raw Torreya nuts were alkenes,esters,alcohols and aldehydes.After roasting,the volatile components of the roasted Torreya nuts were mainly pyrazinofuran,aldehyde-ketone and pyridine-pyrrole.The OAV determinations indicated that sesame Torreya nuts had 11 key aroma components in total,with more aldehydes,ketones,and alkenes compounds;scorpion Torreya nuts had 17 key aroma components in total,with more alkenes and esters compounds;millet Torreya nuts had 10 key aroma components in total,with more pyrazinfurans and alkenes compounds.The types and contents of aroma components in the three types of Torreya nuts varied,with Sesame Torreya nuts having a prominent caramel aroma,scorpion Torreya nuts exhibiting a distinct fruity aroma,and millet Torreya nuts having a clear and fresh aroma.The findings of this study provide a scientific reference for the selection and comprehensive utilization of Torreya nuts.

Abstract:In order to clarify the effects of exogenously applied indoleacetic acid(IAA)on postharvest Shanghai pak choi,distilled water spraying was used as a control group in this study,the changes in chlorophyll content,chlorophyll metabolism-related gene expression and enzyme activities,IAA metabolic pathway-related gene expression,endogenous hormone content,and antioxidant-related gene expression and enzyme activities during the senescence process of postharvest pak choi were investigated.It was found that the colour quality of postharvest pak choi was effectively maintained and its leaf senescence was delayed by exogenous application of IAA at 2 mg/L,mainly by reducing the expression of chlorophyll metabolism-related genes(BrNYC1,BrNOL,BrPPH,BrPAO,BrSGR1,and BrSRG2)and enzyme activities(PPH,PAO,and MDcase)to delay the degradation of chlorophyll.Meanwhile,the expression of growth hormone signalling transduction pathway-related genes(BrARF2,BrARF7,BrARF19,BrGH3.5,BrGH3.12,and BrGH3.17)could be regulated by IAA to maintain the endogenous IAA content in postharvest pak choi.In addition,the IAA treatment could increase the expression of antioxidant metabolism-related genes(BrCAT,BrPOD,and BrSOD)to increase the activities of antioxidant enzymes,catalase(CAT),peroxidase(POD),and superoxide dismutase(SOD)and enhance the antioxidant properties of postharvest pak choi.In summary,an exogenous IAA treatment can effectively maintain the colour quality of pak choi and delay its leaf senescence.These findings of this study provide a basis for the development of postharvest technologies for Shanghai pak choi.

Abstract:Cyclophosphamide(CTX),a broad-spectrum anticancer drug,kills cancer cells but also induces immunocompromise.The ameliorative effects of Acaudina leucoprocta peptides(ALPs)on CTX-induced immunocompromise in mice were investigated.Sixty male ICR mice were randomly divided into the normal group,model group(CTX),ALPS-L group(CTX+50 mg/kg ALPs),ALPS-M group(CTX+100 mg/kg ALPs),and ALPS-H group(CTX+200 mg/kg ALPs).An immunocompromised mouse model was established by administering CTX intraperitoneally for 5 days,followed by ALP administration for 19 days,after which the changes in immune indices and morphological changes of immune organs were detected.The results showed that the body weight of the high-dose ALP group increased to 36.10 g,which was only 0.37 g higher than that of the model group.The thymus and spleen indices were significantly increased(P<0.01),and the spleen morphology tended toward normal.The synthesis of nitric oxide(NO)in peritoneal macrophages,the level of serum hemolysin,and the activity of natural killer(NK)cells significantly increased(P<0.01).In addition,ALPs significantly increased the levels of cytokines and immunoglobulins in the serum of mice(P<0.01),and the levels of interleukin-1β(IL-1β)in the medium and high dose groups increased by 1.60 and 1.62 times,respectively.In conclusion,ALPs effectively ameliorated CTX-induced immunocompromise in mice and may serve as a natural source of immune enhancers.

Abstract:The effect of starch removal treatment on the molecular weight,monosaccharide composition,functional groups,and in vitro immune activity of Dioscorea opposita Thunb.polysaccharides(DOP)was investigated.Polysaccharides were extracted using aqueous alcoholic precipitation.Specifically,the aqueous extract was directly precipitated with alcohol to obtain Dioscorea opposita Thunb.starch-containing polysaccharides(WDRP)and treated with α-amylase followed by alcoholic precipitation to obtain Dioscorea opposita Thunb.non-starch polysaccharides(CDRP).Chromatography and spectroscopy were combined to compare the structural information of the polysaccharides before and after starch removal.The molecular of WDRP has one more 1 590 kDa weight peak for starch than CDRP.In addition,while WDRP and CDRP had the same monosaccharides,there were notable differences in the molar percentages of specific monosaccharides.The molar percentage of glucose in WDRP was 20.93%lower than that in CDRP,while the percentage of other monosaccharides was greater than in CDRP.A cell assay revealed that the cell viability in the WDRP group reached 188.50%,while that in the CDRP group was 166.69%.Additionally,the phagocytosis rate was significantly higher in the WDRP group than in the CDRP group.Further analysis revealed that WDRP and CDRP play an immunomodulatory role by activating the p38 MAPK/NF-κB pathway to regulate the secretion of NO,TNF-α,IL-6,and IL-1β.In addition,the p38 MAPK and NF-κB protein expression levels were higher in WDRP than in CDRP,suggesting that WDRP exhibits stronger in vitro immunoactivity than CDRP.The findings indicated that the removal of starch from yams leads to varying structures of polysaccharides,which in turn result in differences in their activities.This suggested that amylase may disrupt the deconstruction of non-starch polysaccharides,thereby reducing their activity.These findings provide a reference for subsequent studies on the isolation and purification of DOP.

Abstract:In order to explore the quality changing trend and predict the shelf life of preserved pears stored at different temperatures,the changes of color,hardness and sensory score during storage at 25,35,45 or 55℃were analyzed.Meanwhile,the key indexes were fitted using kinetic equations,anda shelf-life prediction model was established by combining the Arrhenius equation.Moreover,the reasons for the deterioration of key indexes were explored according to the changes of 5-hydroxymethylfurfural(5-HMF)content during storage.The results showed that with the prolongation of storage time,the quality of preserved pears gradually decreased,mainly reflected in the changes in color,with a faster decline at a higher temperature.The L* values of preserved pears decreased from 43.57 to 43.51,39.09,38.24 and 31.29,respectively,after beingstored at 25,35,45 and 55℃for 60 days.Pearson correlation analysis revealed that the key index associated with the deterioration of preserved pear quality was L*value,and the degree of fitting with the first-order kinetic equation was the highest.Based on this,a shelf life prediction model with the L* value as the key index is established using Arrhenius equation,in which the activation energy(Ea)of L* value was 71.590 kJ/mol,the pre-index factor k0 was-1.34×109 kJ/mol,and the relative error of the model was less than 6%.In addition,it was found that the content of 5-HMF in preserved pears gradually increased during storage.These data showed that L* value was the key index of quality deterioration of preserved pears during storage,and the shelf-life prediction model established based on it was relatively reliable,and the main reason for the gradual decline of L* value was the occurrence of the Maillard reaction.The results of this study provide some reference for exploring the quality deterioration pattern of preserved pears during storage and determining their shelf life,and offer preliminary guidance for delaying their quality deterioration.

Abstract:Xiaoqinggan(XQG),the immature fruit of Citrus reticulata'Chachi,'is a raw material used for preparing citrus Pu'er tea.During storage,a substance known as"white frost"often forms on the surface.However,its composition,safety,and formation mechanism remain unknown.Therefore,the microscopic morphology,surface composition,mycotoxin content,and microbial diversity of normal,white-frosted,and moldy XQG were analyzed.Scanning electron microscopy indicated that the"white frost"on the surface of XQG comprised blocky and needle-like crystals.UPLC/Q-TOF analysis revealed that the main components of the surface wash solution from white-frosted XQG were polymethoxyflavones.According to quantitative analysis,the nobiletin content in the surface wash solution of white-frosted XQG was 9.15 times and 14.94 times higher than that of normal and moldy XQG,respectively,whereas the tangeretin content was 26.87 times and 78.65 times higher,respectively.The diversity analysis of fungi and bacterial communities on the surface of the XQG showed that Ogataea,Penicillium,and Alternaria increased significantly in the moldy XQG.In contrast,the microbiota levels on the white-frosted XQG surface were similar to those in the normal group.Mycotoxin analysis showed that only moldy XQG contained 430 μg/kg of zearalenone.This indicated that"white frost"on the surface of XQG is formed by the precipitation of polymethoxyflavones,with nobiletin and tangeretin being the main components.Additionally,white-frosted XQG are harmless to humans.The results provide a theoretical basis for establishing product standards and product quality control in XQG.

Abstract:Globally,more than 1.6 billion tons of fruit and vegetable waste are generated annually,resulting in significant resource wastage and environmental pollution.Additionally,this waste contributes to greenhouse gas emissions,which exacerbate global climate issues and contradict the principles of a circular economy and sustainable development.To address this challenge,it is imperative to recycle fruit and vegetable waste with high polysaccharide content,which has significant nutritional and medicinal value.Ultrasound-assisted extraction of polysaccharides from fruit and vegetable waste has emerged as an effective method for recycling and maximizing waste value.This study examined the current status of fruit and vegetable waste resources,the mechanisms and influencing factors,and the application of ultrasound-assisted extraction for polysaccharides from such waste.Furthermore,the beneficial effects of ultrasound on the structure and activity of fruit and vegetable polysaccharides were also investigated.By focusing on the utilization of fruit and vegetable waste,this study supports the efficient use of bioactive substances and the circular economy,providing a theoretical basis for ultrasound-assisted extraction to promote the fruit and vegetable waste utilization industry and sustainable development,ultimately facilitating the sustainable and comprehensive use of fruit and vegetable waste resources and mitigating the global climate crisis.

Abstract:To develop a process for drying Parapenaeopsis hardwickii shrimp,their quality changes during storage were investigated.Based on single-factor experiments,a Box-Behnken multiple regression model was constructed using the response surface method to optimize the shrimp drying process.The effects of salt concentration,blanching time,drying temperature,and drying time on the sensory characteristics of dried shrimp were analyzed.Additionally,the appearance,color,pH,texture,TVB-N content,and total bacterial count of dried shrimp were measured during storage at 25℃and 37℃.Pearson's correlation analysis was applied to evaluate the correlations between storage indicators.The results showed that the optimal drying process for P.hardwickii was as follows:3%salt addition,blanching for 3 min,drying temperature of 57℃,and drying time of 14 h.During storage at 25℃and 37℃,the sensory quality of the dried shrimp gradually declined over time.The pH value initially decreased and then increased,whereas the whiteness,hardness,chewiness,and gumminess levels exhibited a downward trend.The TVB-N content and total bacterial count showed significant upward trends(P<0.05).The study revealed that storage at 37℃accelerated the deterioration of dried shrimp quality and promoted the growth and reproduction of spoilage microorganisms,protein degradation,and lipid oxidation.Pearson correlation analysis suggested that the discoloration and texture deterioration of dried shrimp might be associated with protein degradation and lipid oxidation during storage.These findings provide theoretical guidance for the deep processing of P.hardwickii.