The changes of microbial community structure and biomass of different layers of Daqu for the production of special-flavor Baijiu (Te-Daqu) and its correction with flavor compounds are not well understood. In this study, the absolute quantitative and relative quantitative amplification sequencing techniques were used to determine the microbial compositions as well as their changes of different layers of Te-Daqu. Moreover, microbial source tracking was used to analyze the origins of dominant bacteria and fungi. Headspace solid phase micro-extraction combined with gas chromatography-mass spectrometry was used to analyze the content of flavor compounds in different layers of Te-Daqu. The results showed that the total bacterial biomass in core of Te-Daqu was significantly lower than that of surface-layer and middle-layer, i.e, was 55% of that of surface-layer and 53% of that of middle-layer. Weissella, Lactobacillus, and Enterobacter were the dominant bacteria within the surface-layer. Thermoactinomyces was the specific bacteria of the core-layer, whereas Saccharopolyspora only dominated in the middle- and core-layer rather the surface-layer. Isatchenkia and Pichia were the main yeasts within the surface-layer, while Aspergillus was the dominant mold within the core-layer. The total contents of alcohols, aldehydes and ketones, pyrazines, ethers, and phenols in the core-layer were higher than that in the surface- and the middle-layers, while the total contents of esters in the surface-layer were higher than that in the core-layer. These results provided an essential reference to optimize the Te-Daqu making process and to improve the quality of Te-Daqu by using ecological fermentation technology.

6-α-glucosyltransferase has catalytic activities of exo-hydrolysis towards α-1,4-glucan and transglycosylation, and can produce the α-glucan which links α-1,6 glycosidic bonds on the nonreducing end through transglycosylation activity.Therefore, it can be used to produce cyclic alternating sugars and their branched derivatives, as well as cycloisomaltooligosaccharide, which can be used as new functional sugar.To expand the application of 6-α-glucosyltransferase in the food industry, the 6-α-glucosyltransferase from Bacillus globisporus N75 was expressed heterologously in the food safety strain Bacillus subtilis, and the expression level of recombinant protein increased by selecting the host strain and optimizing fermentation condition.These results indicated that the host WHS9 was more beneficial for the recombinant expression of 6-α-glucosyltransferase and the total soluble enzyme activity could achieve 2.11 U/mL at 20 ℃, including intracellular and extracellular.After adding 20 mmol/L trehalose, the total enzyme activity could reach 2.21 U/mL at 25 ℃ for 48 h.Then the fermentation period was optimized, and it was found that the highest enzyme activity could reach 3.14 U/mL at 36 h, which was 196 times higher than in WHS9 before optimization.This study firstly achieves recombinant expression of 6-α-glucosyltransferase in B.subtilis.

This study aimed to investigate the effects and mechanism of ultrasonic (US) combined with salicylic acid (SA) treatment on the postharvest black spot of jujube during storage. This paper used the US alone or combined with SA to treat jujube fruits, determined the incidence rate and natural decay rate, then screened the best treatment conditions, and further investigated its control mechanism in terms of its direct effect on pathogenic bacteria and induced disease resistance in jujube fruits. Results showed that the US alone or combined SA treatment significantly controlled the disease incidence of black spots and reduced the natural decay rate of jujube, and the combined treatment was significantly better than that alone (P<0.05). Furthermore, US combined with SA treatment significantly inhibited the mycelial growth of Alternaria alternata in vitro (P<0.05). US treatment not only reduced the attachment of A. alternata at the wound of the jujube but also caused microcracks to form on the surface of the jujube fruit skin, which facilitated the contact between SA and fruit and promoted the penetration of SA into the fruit. In addition, the combined treatment significantly increased the activity of peroxidase, polyphenol oxidase, phenylalanine deaminase, and 4-coumarate coenzyme A ligase (P<0.05), promoted the accumulation of total phenols, flavonoids, free phenols, and bound phenols (P<0.05), induced disease resistance, and improved the defense ability of jujube fruit against diseases, thus reducing fruit decay rate. In conclusion, the US combined with SA has good research potential and development prospects as a green and safe treatment for the control of postharvest black spot disease of jujube.

Short-chain fatty acid esters are important flavor substances of Baijiu.It is of great application value to explore esterifying enzymes that suitable for Baijiu fermentation system to improve the quality of Baijiu.In this paper, seven fungal cutinases were successfully expressed in Escherichia coli BL21 (DE3), and their ability to catalyze the synthesis of flavor esters in aqueous phase under single and mixed acid conditions was investigated.The results showed that the cutinase AFLACUT-2 had a strong ability to synthesize short-chain fatty acid esters under aqueous conditions, with the highest enzyme activity at 30 ℃ and pH 4.Further analysis of enzymatic properties showed that when the reaction temperature rose to 40 ℃, the catalytic activity of the enzyme for the synthesis of ethyl caproate remained unchanged, while the catalytic activity for the synthesis of ethyl butyrate significantly decreased.The optimal reaction time for the synthesis of ethyl caproate catalyzed by cutinase AFLACUT-2 was 18 h, which was 25% shorter than that for the catalytic synthesis of ethyl butyrate.In addition, an increase in the ratio of acid to alcohol was beneficial to esterification, but excessive acid could inhibit enzyme activity.Furthermore, AFLACUT-2 has a better tolerance to caproic acid than butyric acid.These results not only broaden the understanding of the mechanism of ester synthesis during Baijiu fermentation,but also provide a new strategy for the directional regulation of base liquor flavor by using fungal cutinases.

Baijiu, a traditional Chinese fermented food, presents a unique advantage due to its production through solid-state fermentation and distillation.The distinctive manufacturing procedure yields a profusion of microbial fermentation products within the beverage.However, as an alcoholic beverage, excessive consumption of Baijiu may lead to alcoholic liver disease.Akkermansia muciniphila, a specialized anaerobic Gram-negative bacterium, is one of the most abundant microorganisms in the mammalian gut.It is considered to be a new generation of probiotic bacteria as well as a key microorganism in the pathogenesis of ALD.The purpose of this study was to determine the change patterns in the quantity of A.muciniphila in the intestine with Baijiu intake and to compare the quantitative differences of A.muciniphila between mice fed by Baijiu and alcohol.To achieve the objectives, this study constructed the model of chronic gavage of Baijiu or alcohol in C57BL/6 J mice and established a method for absolute quantification of intestinal A.muciniphila by real-time fluorescence quantitative PCR. Results showed that both Baijiu and alcohol intake resulted in a decrease in the quantity of intestinal A.muciniphila in mice, and the quantity of A.muciniphila decreased with the duration of modeling.It was also found that the number of intestinal A.muciniphila was greater in mice in the Baijiu group compared with the alcohol group, suggesting that the bioactive components in Baijiu could protect against alcohol-induced decrease in the quantity of intestinal A.muciniphila.This study provides a foundation for A.muciniphila to ameliorate alcohol-induced damage and presents a theoretical basis for exploring the beneficial active substances in Baijiu and elucidating the functionality of the effective substances.

Hyaluronic acid has a variety of physiological functions such as moisturizing and lubrication, and has been widely applied in food, medicine and cosmetics. Nowadays, the production of hyaluronic acid mainly relies on the fermentation of S. zooepidemicus. While, unclear genomic background limits the modification of S. zooepidemicus as a chassis cell and the improvement of hyaluronic acid fermentation yield. First, the genome-wide and transcriptome data of S. zooepidemicus WSH-24 were sequenced and analyzed in this study, and it was found that the strain had efficient glycolytic pathway and lactic acid synthesis capabilities, as well as incomplete tricarboxylic acid cycle and the absence of multiple amino acid synthesis pathways. Combined with the analysis of growth curves, this strain was further determined to be deficient in four amino acids: Valine, glutamine, arginine and tryptophan. On top of that, the yield of hyaluronic acid reached (2.65±0.02) g/L by exogenous addition of corresponding amino acids. Subsequently, combined with transcriptome sequencing data, the transcription level of vitamin B₅, B₇ and B₁₂-related synthetic genes were determined to be low. To effectively improve the synthesis of hyaluronic acid, the yield of hyaluronic acid reached (2.46±0.07) g/L by exogenous addition of corresponding vitamins. Finally, by optimizing the media components, the fermentation concentration of hyaluronic acid increased to 5.63 g/L in a 3 L fermenter, and the production intensity was 0.31 g/(L·h) (33.33% higher than that before optimization). This study lays foundation for the further modification of S. zooepidemicus WSH-24, and provides support for hyaluronic acid on the increasing of yield.

There is a wide range of applications for β-1,4-endoglucanase in the detergent industry, which with good low temperature and alkaline tolerance is an important prerequisite for its industrial application. In this thesis, a novel β-1,4-endoglucanase gene EgDC from Deinococcus cellulosilyticus with low-temperature tolerance was obtained by gene mining. It was expressed in Escherichia coli, with most of it existed in the periplasmic space and a small portion secreted to the extracellular space. The enzymatic properties of EgDC enzyme were characterized, and it was found that the optimum temperature and pH of the enzyme were 40 °C and pH6.5, respectively. It could maintain more than 70% of its activity at 20 °C, while its half-life reached 83.43 min and 53.79 min at pH8.0 and pH9.0. The β-1,4-endoglucanase EgDC had good catalytic properties with specific enzyme activity and kcat/K_m values reaching (26.38±1.43) U/mg and (520.03±17.07) s^-1/mg, respectively, which is also highly tolerant to metal ions and surfactants. Thus, the new β-1,4-endoglucanase EgDC has good catalytic ability and is stable at low temperature, alkaline environment and in the presence of surfactant. Therefore, it has potential industrial applications.

A mixed strain of fermented Zha-chili was prepared using fresh chili and corn flour as raw materials, Lactiplantibacillus plantarum XZ3 and aroma-producing yeast Y50 as strains.The fuzzy sensory score of the Zha-chili was used as the response value, and the Box-Behnken center combination design experiment was conducted to optimize the mixed strain fermentation process of the zha-chili and determine the functional composition of the product. The optimal fermentation conditions for the mixed strain of fermented Zha-chili were as follows:the ratio of L. plantarum XZ3 to aroma-producing yeast Y50 was 1∶1, the amount of mixed strain was 2.5%, the amount of salt was 4%, and the fermentation time was 6 days.Under these optimized conditions, the organoleptic score of the Zha-chili was 8.45.Compared with natural fermented Zha-chili without inoculation and pure fermented Zha-chili using L. plantarum XZ3, it is found that the aroma of the optimized mixed fermentation Zha-chili was more prominent.Further determined of the functional components revealed that the content of polyphenol components in mixed fermented Zha-chili was the highest and the most types were detected, with their total acid content, capsaicin content, and total flavonoid content significantly higher than those in naturally fermented Zha-chili.In addition, the content of sweet amino acids increased and the proportion of bitter amino acids decreased in the mixed strain of fermented Zha-chili compared to the other two fermentation methods.This study provides a useful reference for the production of mixed strains of fermented Zha-chili.

Monensin is a kind of polyether antibiotic produced by Streptomyces cinnamonensis, which is widely used in fields including medicine and agriculture due to its environmentally friendly and efficient properties.However, the low oxygen condition commonly existing in the monensin production process strictly limited the monensin fermentation level.Based on the previous integrated expression of the monensin biosynthesis pathway specific regulatory genes monH and monRII, this study attempted to integrating Vitreoscilla hemoglobin gene vgb by heterologous expression to increase the monensin fermentation titer by improving the oxygen uptake capacity of strains.Results showed that the optimized conditions (40 mmol/L Ca²⁺, donor-recipient ratio 100∶1, antibiotics adding time 18 h) significantly improved the conjugation efficiency by 3 times.With successful integration of vgb with monH and monRII, two engineering strains, 2110-monH-vgb and 2110-monH-monRII-vgb were obtained.They produced 18.0% and 21.3% of the monensin higher than that without heterologous expression, respectively, under the extremly weak oxygen shake-flask condition.The biomass of 2110-monH-monRII-vgb in a 5 L bio-fermentor was slightly higher than that of the starting strain, but its monensin titer reached 13.4 kU/mL, which was 55.7% higher than that of the starting strain.In conclusion, by optimizing the conjugation efficiency of S.cinnamonensis and applying it to the genetic engineering of S.cinnamonensis in monensin fermentation, this study successfully obtained a vgb integrated strain by heterologous expression that effectively increased the monensin fermentation level, which would supply a substantial foundation for its subsequent industrial application.

Suansun (sour bamboo shoot) is a kind of traditional Chinese fermented vegetables from microbial fermentation of bamboo shoots, which is often used as ingredients for snail powder and Guilin rice noodles, and it's deeply favored by consumers because of its unique flavor. The core of Suansun production are composition and metabolism of microbial communities, meanwhile, the content and type of flavor substances determine the quality of Suansun. Flavor substances are mainly derived from the metabolism of microorganisms and they are closely related in the fermentation process. Therefore, this review concludes the composition and succession of microorganisms, analyzes the factors affecting the microbial succession, summarizes the flavor substances, and expounds the formation mechanism of flavor substances induced by microorganisms in Suansun, which is helpful to further understand the interaction between complex microbial communities and flavor substances in Suansun to provide a theoretical basis for the quality improvement and control of Suansun.

During the production and storage of Huangjiu, the liquor often has off-flavor and sediment. Activated carbon is widely used in the post-treatment of liquor because of its strong adsorption capacity. In this experiment, Huangjiu was filtered by activated carbon, not only the off-flavor was removed, but also some undesirable secondary metabolites in Huangjiu were adsorbed, such as fusel alcohols, biogenic amines, purines, and ethyl carbamate. The results showed that the more active carbon was added, the more adsorption amount of the above substances, but the color and flavor loss more of the original Huangjiu. Under the optimum adsorption conditions: 10 g/L activated carbon, 35 ℃ and 9 h, the sensory evaluation score was 85(the initial score was 82). The acidity decreased by 27.96%, and amino acid nitrogen had little loss. Fusel alcohols decreased by 14.22%, biogenic amines decreased by 31.10%, purines decreased by 27.78% and ethyl carbamate decreased by 30.77% respectively, and esters retained. This study provides a convenient and effective method for the quality control of Huangjiu in the industrial production.

For large-scale production of papain using aqueous two-phase extraction (ATPE), high extractant concentrations and volume ratio are usually required to obtain high recovery, but this results in a decrease in the purity and concentration of the target. In this study, the aqueous two-phase system composed of polyethylene glycol (PEG) and sodium citrate (Na₃C₆H₅O₇) was transferred between multiple centrifuge tubes to simulate the multi-stage crosscurrent extraction and multi-stage countercurrent extraction processes commonly used in industry, and the theoretical number of stages of multi-stage countercurrent ATPE was obtained by McCabe Thiele diagram method with the indexes of partition coefficient and recovery of enzyme activity. The results showed that the recovery of papain activity using the three-stage countercurrent ATPE achieved 96.75% when the volume radio was 0.5 and the initial concentration of papain in the bottom phase of the feedstock was 0.20 mg/mL, while an optimized scheme for multi-stage countercurrent ATPE of papain was designed.

The in vitro antioxidant, anti-diabetic, and acetylcholinesterase inhibitory activities of polyphenol extracts from broken green tea under different drying treatments were investigated in this study. Two different drying processes, including steam drying combined with vacuum drying and vacuum-freeze drying, were used to dry the ethyl acetate extraction phase of broken green tea, the color values, scavenging abilities of DPPH free radicals, ABTS cationic radicals, and ·OH, FRAP antioxidant capacities, and the inhibitory activities against α-amylase, α-glucosidase, and acetylcholine esterase, as well as anti-glycosylation activities of two extracts, were comparatively evaluated. Results showed that the vacuum-freeze drying polyphenol extract from broken green tea (BGTE-FD) displayed a deeper yellow color and stronger scavenging abilities of DPPH free radicals, ABTS cationic radicals, and ·OH, and FRAP antioxidant capacities with the IC₅₀ values of 2.64 mg/L, 5.17 mg/L, 247.01 mg/L, and 27.73 mg/L, respectively, and meanwhile exhibited higher inhibitory activities against α-amylase, acetylcholine esterase, and α-glucosidase with the IC₅₀ values of 85.84 mg/L, 416.45 mg/L, and 4.38 mg/L, respectively, compared with the steam drying combined with vacuum drying polyphenol extract from broken green tea (BGTE-SVD). In addition, BGTE-FD showed stronger α-glucosidase inhibition than that of acarbose (IC₅₀=929.59 mg/L). Moreover, the inhibition rates of BGTE-FD and BGTE-SVD on advanced glycosylation end products were 65.28% and 63.66%, respectively, slightly lower than that of aminoguanidine (71.81%). Therefore, the polyphenol extracted from broken green tea by vacuum-freeze drying method has strong in vitro antioxidant and anti-diabetic activity and certain inhibitory activity against acetylcholinesterase, and the broken green tea can be used as a potential natural resource for the development of hypoglycemic and anti-dementia products.

In this study, low-fat set yogurt was prepared with egg white protein as a quality improver. The influences of the ratio of whey protein to egg white protein, total protein content and sucrose content on the pH, firmness, rheological properties, water state and sensory quality of set yogurt was investigated. The increase of egg white protein ratio increased the pH, firmness, storage modulus and apparent viscosity and water-holding capacity of yogurt. The yogurt with a total protein content of 2.5% failed to set, while the yogurt can set well when the total protein content of yogurt achieved 3.5% and 4.5%. The addition of sucrose improved the sensory quality of yogurt, it turned out that yogurt with a sucrose content of 6% had the highest sensory score. Correlation analysis showed that the texture of yogurt was positively correlated with storage modulus, firmness and pH, and negatively correlated with water-holding capacity. These results suggest that the egg white protein is effective to improve the quality of low-fat set yogurt.

Sea cucumber is a traditional health food in China, with high health and nutritional value.Sea cucumber polysaccharide is one of the important active ingredients of sea cucumber.It has biological activities such as immune regulation, anti-tumor, anti-coagulation, anti-inflammatory, hypoglycemic, hypolipidemic, and antioxidant, and has great development value and the application potential in the field of food and medical treatment.Different varieties of sea cucumber, extraction, and purification methods of polysaccharides will lead to certain differences in yield, chemical composition, chemical structure, and biological activity of sea cucumber polysaccharides.The methods of extraction, separation, purification, content determination, chemical composition analysis, and biological activities of sea cucumber polysaccharides at home and abroad in recent years were reviewed, providing a theoretical basis for further research, development, and application of sea cucumber polysaccharides.

To evaluate the effect of Ganoderma lucidum spore oil (GLSO) on alleviating physical fatigue in mice and explore its potential mechanism.144 SPF-grade male KM mice were randomly divided into four groups:solvent control group, low-dose GLSO group, medium-dose GLSO group, and high-dose GLSO group, 36 mice in each group, administered orally for 30 days.Mice were divided into four batches, which were used for measuring weight-bearing swimming time (I), liver glycogen levels (II), blood lactic acid levels (IV), serum urea nitrogen levels, muscle glycogen levels, and other indicators (including gastrocnemius HE staining, PAS staining, and TUNEL staining) (III), respectively.Results showed that compared with the solvent control group, the weight-bearing swimming time of the mice in medium-dose GLSO group significantly prolonged (P<0.01);the serum urea nitrogen levels of mice in all dose groups of GLSO significantly reduced (P<0.01);the levels of liver glycogen and muscle glycogen in all groups showed no significant difference (P>0.05);the area under the curve of blood lactic acid of mice in all dose groups of GLSO significantly reduced (P<0.01).HE staining results showed no obvious pathological changes in each group.PAS staining results showed that the positive area of muscle glycogen in the high-dose GLSO group significantly increased (P<0.05).TUNEL staining results showed that the positive rate of apoptotic cells in the low-dose GLSO group significantly reduced (P<0.05).Thus, GLSO can relieve physical fatigue, and its mechanism may be related to reducing glycogen consumption and the apoptosis of gastrocnemius muscle cells.

In order to optimize the quality of Monascus cheese and shorten the ripening time, this experiment applied the screened excellent Monascus strains to cheese making.Firstly, the optimal mixing ratio of Monascus BC20 and ZX99 was determined to be 1∶1.Then, the optimal ripening process parameters were obtained by single factor test and response surface optimization, and the physicochemical, texture and antioxidant properties were studied.The results showed that under the optimal mixing ratio, when the relative humidity was 55.3%, the first stage ripening time was 8.9 d, and the ripening temperature was 30.2 ℃, the formed Monascus cheese had the best sensory quality and better proteolytic indexes.In the ripening process, the moisture content decreased, and the pH first decreased and then increased.In chromaticity index, L^* value decreased, a^* and b^* value increased;The pigment content of Monascus increased gradually.The hardness and chewability increased first and then decreased, the cohesiveness decreased first and then increased, and the overall viscosity decreased.The Monascus cheese had better antioxidant activity than the control cheese without Monascus.In conclusion, the optimization of ripening conditions can improve the sensory quality and shorten the ripening time of cheese, and it is confirmed that the addition of Monascus can effectively improve the antioxidant activity of cheese.

‘Cuixiang’ kiwifruit are usually hard when purchased and need to be stored to soften before they can be eaten.However, kiwifruit are respiratory leaps that are prone to concentrated ripening, and the uncontrollable evolution of kiwifruit fruit quality during home storage can lead to a poor consumer experience and a reduced desire to buy.In this paper, the evolution of fruit quality of ‘Cuixiang’ kiwifruit under home storage conditions was systematically analyzed based on the dimensions of physicochemical characteristics, organoleptic quality, and aroma characteristics.In terms of physicochemical characteristics, titratable acid content and hardness of kiwifruit decreased significantly during home storage, while the content of total soluble solids, sugar-acid ratio, and weight loss tended to increase significantly.Based on the correlation of the above indexes, hardness was chosen to establish a zero-level kinetic shelf-life prediction model, and the model had good accuracy and reliability.Meanwhile, the artificial sensory evaluation showed that, except for the appearance score, which continued to decrease during the storage period, the scores of other sensory indexes, such as color, aroma, taste, texture, etc., increased significantly and peaked on the 11th day.Therefore, the total artificial sensory scores of ‘Cuixiang’ kiwifruit were the highest on the 11th day of home storage, which was the most suitable for consumption at this time.Gas chromatography-mass spectrometry was used to evaluate the aroma profile of kiwifruit, and a total of 513 volatile organic compounds were detected, with ester concentrations accounting for the highest percentage of kiwifruit samples at different stages of home storage, and terpenes showing the highest percentage of species.On the 1st day and the 7th day, the volatiles were more abundant and the aroma was more complex, with the highest content of aldehydes and a prominent herbaceous note.On the 11th day, the proportion of esters in the total volatiles was significantly higher than that on the 1st day and the 7th day, and the fruity and sweet flavors were more intense.

To explore the processing suitability of different pomegranate varieties and provide reference for the development of powerful industries in Xinjiang, this paper examined the main quality indicators and aroma components of eight varieties of pomegranate from Shaanxi and two varieties of pomegranate from Xinjiang after juice making, and conducted principal component analysis (PCA) and heat map cluster analysis were used to compare the respective advantages of different varieties.Results showed that there were significant differences in the main quality indexes among different varieties.The total sugar content of Qianzihong was the highest, 176.8 g/L, the total acid content of Sainingmeng was the highest, 24.03 g/L, the juice extraction rate and hundred-aril weight of Lintongxing were the highest, 50.6% and 64.78 g, respectively, and the total phenol and total anthocyanin of Heizuan were the highest, 1.13 g/L and 50.46 g/L, respectively.PCA showed that Xinjiang varieties had similar characteristics and were clearly distinguished from Shaanxi varieties, with Black Diamond being distinguished from other Shaanxi varieties due to its high total phenol and total anthocyanin content.The aroma characteristics of 10 pomegranates were analyzed by GC-MS. A total of 33 aroma substances were detected, mainly alcohols and aldehydes, including 11 characteristic aroma substances.Through principal component analysis and heat map cluster analysis, it was found that the aroma components of Qianzihong and Sainingmeng were similar, and the aroma characteristics of Jingpitian and Heizuan were different from those of other varieties.The research results will help to better reveal the quality characteristics of different varieties of pomegranates, and provide a theoretical basis for the selection of pomegranate juice processing varieties.

Seven kinds of Lactobacillus strains were selected for solid-state fermentation, determined the best fermentation strain based on the yield of Polygonatum sibiricum polysaccharide as the evaluation index.The process of solid-state fermentation P. sibiricum was optimized through single factor test and response surface analysis.The monosaccharide composition, morphology characteristics, thermogravimetric characteristics, and antioxidant activity in vitro of solid-state fermentation P. sibiricum polysaccharide (SF-PSP) and unfermented P. sibiricum polysaccharide (PSP) under the same conditions were analyzed.The results showed that Lactobacillus parasitum ATCC 334 was the best fermentation strain.The optimal preparation process conditions for SF-PSP were as follows:Liquid to material ratio of 0.98∶1 (mL∶g), inoculation rat of 4.80%, and fermentation time of 51.30 h.Under this condition, the yield of the SF-PSP was (11.14±0.89)%.The SF-PSP was mainly composed of mannose, galacturonic acid, galactose and glucose.Compared with PSP, the contents of rhamnose, galacturonic acid and galactose increased by 4 times.The results of scanning electron microscope indicated that the structure of SF-PSP was looser and had more dense pores than PSP.The results of thermogravimetric analysis showed that the weight loss temperature nodes of the two crude polysaccharides were different, the water retention ability of SF-PSP was better than that of PSP.The results of antioxidant activity in vitro showed that DPPH radical scavenging rate, ABTS cationic radical scavenging rate, ferrous ion chelating ability, and total antioxidant activity of SF-PSP were significantly higher than those of PSP(P<0.05).In summary, the use of SF-PSP can significantly improve the yield and antioxidant activity of PSP.