Amino Nitrogen Content Research Articles

Maize plants have different strategies to protect their developing seeds against cadmium toxicity

This work aimed to quantify the concentration of soluble amino acids, nitrogen (N) and Cd in the developing seeds of maize plants that were grown in Cd-contaminated soil from seed sowing to the reproductive stages. The specific activities and feedback inhibition properties of lysine (Lys) metabolic enzymes were also determined in developing seeds. The potential maize yield was depressed by Cd exposure. Cadmium concentration in plant organs followed the decreasing order: roots > stems = leaves > developing seeds (37.04, 1.95, 1.46 and 0.22 mg kg−1 Cd, respectively). The relatively low Cd concentration in the remained developing seeds was a result from root- and ear-mediated reductions of the Cd translocation in plants. Plants under Cd exposure presented developing seeds with an increased N concentration (up to 7%) when compared to control plants. Furthermore, the level of soluble amino acids (particularly histidine, glycine, tyrosine, methionine, isoleucine and valine) was increased in the developing seeds of Cd-treated plants. In addition, changes in the feedback properties of dihydrodipicolinate synthase (DHDPS), an enzyme from lysine metabolism, were observed in developing seeds. In conclusion, the current study showed that maternal plant exposure to Cd can alter the concentration of soluble amino acids and the behavior of Lys metabolic enzymes in developing seeds. This study provided not only new information about the influence of the long-term Cd exposure on plants, but also data about protective plant strategies against Cd toxicity.

Effects of different strains and fermentation method on nattokinase activity, biogenic amines, and sensory characteristics of natto.

Nattokinase activity(NK), biogenic amine content and sensory properties of natto are of great significance to consumers, which are affected by strains and fermentation methods. In this study, changes in the pH, biogenic amine and free amino nitrogen (FAN) contents, NK and protease activities, and sensory characteristics of natto prepared using Bacillus subtilis GUTU09 combined with different strains (Lactobacillus, Bifidobacterium and Mucor) and fermentation methods were investigated. The combination of two strains showed the best fermentation performance among all samples. The NK and protease activity and FAN content in double-strain fermentation increased by 10.33FU/g, 88.78U/g, and 2.34g/kg, respectively, compared with those in single-strain fermentation. Sensory evaluation demonstrated that mixed fermentation primarily affected the sensory acceptance. This method also reduced the contents of various biogenic amines in natto compared with single-strain fermentation. Tyramine, cadaverine, spermine, and spermidine were significantly reduced, whereas histamine was slightly increased. The total biogenic amines decreased from 390.76mg/kg to a minimum of 16.16mg/kg. Some Mucor strains also reduced the contents of various biogenic amines. In the dual-bacteria fermentation of Mucor and GUTU09, co-fermentation has advantages over stage-fermentation, with higher NK and protease activity and higher sensory scores. Correlation analysis showed that the formation and accumulation of some biogenic amines in natto prepared using different microbial combinations were related to NK activity and pH. All these results showed that the quality of natto was improved by mixed fermentation and suitable fermentation methods, which laid a foundation for its potential industrial application.

The effects of magnetic nanoparticles combined with microwave or far infrared thawing on the freshness and safety of red seabream (Pagrus major) fillets

The effects of magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT) on the freshness and amines content of red seabream fillets were investigated. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FIRT), magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT). The quality of the fresh sample, the sample after thawing and thawed sample after being stored for 6 h were compared by measuring the freshness indexes such as the volatile amino nitrogen content, thiobarbituric acid content, pH value, total number of viable colonies, and the food safety evaluation indexes such as the formaldehyde, dimethylamine, trimethylamine and putrescine contents. The results showed that MNPFT and MNPMT can maintain better freshness than microwave and far-infrared thawing, and the increase in amines content was significantly inhibited.

Evaluation of Antiobesity Activity of Soybean Meal Products Fermented by Lactobacillus plantarum FPS 2520 and Bacillus subtilis N1 in Rats Fed with High-Fat Diet.

Single strain or mixed strains of Lactobacillus plantarum FPS 2520 and Bacillus subtilis N1 were used to ferment soybean meal (SBM), and the antiobesity activity of the fermented SBM product was investigated in rats fed with high-fat diet (HFD). After fermentation, free amino nitrogen, total peptide, and isoflavone contents were markedly raised, and genistein and daidzein were the major isoflavones in the fermented SBM. After fed with HFD for 10 weeks, obese Sprague-Dawley rats were orally treated with various fermented products for 6 weeks. The body weight gains, as well as weights of abdominal fat and epididymis fat, of rats fed with fermented SBM products were significantly downregulated. The treatment with the mixed-strains fermented SBM product significantly decreased plasma levels of triglyceride (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol, but increased the level of high-density lipoprotein-cholesterol. Moreover, the levels of TG, TC, fatty acid synthase, and acetyl-CoA carboxylase (ACC) in liver were diminished, and the activities of hormone-sensitive lipase and lipoprotein lipase in adipose tissue were augmented. Taken together, these data demonstrated the antiobesity activity of fermented SBM products, among which the product fermented by the mixed strains being the most effective one. Therefore, these fermented SBM products are potential to be developed as functional foods or additives for treatment of obesity and prevention against obesity-induced complications.

Optimization of the Temperature and Time for the Autolysis and Enzymolysis of Perna Viridis Protein

To determine the optimal conditions for autolysis, the autolysis of mussel (Perna viridis) protein was studied. Using P. viridis meat as the raw material and the degree of hydrolysis as the index, the effects of hydrolysis temperature and hydrolysis time, were researched. Single-factor experiments of autolysis of P. viridis were conducted, taking the degree of hydrolysis as the index. Keeping the pH, time, and solid/liquid ratio unchanged, the temperature was controlled at 30, 40, 50, 60, and 70 °C to study the effects of temperature on the autolysis of P. viridis protein. When the enzymatic hydrolysis temperature was 30 °C, the degree of protein hydrolysis was very low. The results showed that: with increasing temperature up to 50 °C, the degree of hydrolysis increased, reaching a maximum of 15.84%. Keeping the pH, temperature, and solid/liquid ratio unchanged, hydrolysis times of 2, 3, 4, 5, and 6 h were tested to determine the effect of time on the autolysis of P. viridis protein. The results showed that: hydrolysis occurred between 2 and 5 h, when the degree of hydrolysis increased from 13.62% to 15.31%, exhibiting a marked change in the extent of hydrolysis. The continuous increase in hydrolysis could be explained by the fact that P. viridis increased the amino nitrogen content in the hydrolysate via enzymatic hydrolysis and microbial degradation of endogenous enzymes. Therefore, the optimum conditions obtained in these experiments were a temperature of 50 °C, time of 5 h.

Effects of glutinous rice protein components on the volatile substances and sensory properties of Chinese rice wine.

The content of protein components of glutinous rice significantly affects the quality of Chinese rice wine. Therefore, the effects of protein components on the quality of Chinese rice wine were investigated by adding the exogenous proteins glutelin and albumin individually or in combination RESULTS: Compared with the control, the samples with increased glutelin components exhibited improved formation of numerous alcohol esters with alcoholic and fruity representatives. The promotion rates of glutelin to total alcohols and total esters were 18% and 99%, respectively. The amount of 4-vinylguaiacol characterized by a spicy, smoky odor was reduced to 40%. Correlation analysis between chemical composition and sensory characteristics showed a significant positive correlation between umami and amino nitrogen (r = 0.935) and total amino acid content (r = 0.729). The bitterness of Chinese rice wine was related to the change of alcohol content (r = 0.689) and total soluble solid (r = 0.904). Sensory analysis revealed that the increase of the glutelin component of Chinese rice wine increased its alcoholic, fruity, and honey-like features, as well as its umami, acidity and bitterness. The increase also reduced the caramel-like, herb-like, and smoky sensory characteristics of Chinese rice wine and its Qu aroma and sweetness CONCLUSION: The protein content of glutinous rice significantly affects the quality of rice wine. The Glutelin has a significant relationship with fruity, honey, and umami flavors; the albumin has a significant relationship with medicinal, bitter, and astringent flavors. Therefore, reasonable adjustment of the glutelin content of glutinous rice can effectively improve the sensory quality of rice wine. © 2020 Society of Chemical Industry.

Enhanced antioxidant activity of okara through solid state fermentation of GRAS Fungi

Abstract The enhancement of antioxidant activity of fermented okara was investigated using fungal solid-state fermentation. The initial fungal concentration and water activity were found to influence the enhanced antioxidant capacity of fermented okara. Extracellular enzymes, especially proteases and carbohydrases might facilitate the hydrolysis of okara protein that yielded antioxidative amino acids and peptides, as well as the release of isoflavones-derived components. Fermentation of okara with R. oligosporus with 1.04×10-3 gDCW/gokara as initial concentration, water activity of 0.931 was found to yield the highest antioxidant strength. Whereas for A. Oryzae, 1.6×10-3 gDCW/gokara was optimum as the initial concentration with water activity of 0.913. With these optimum conditions, solid-state fermentation of okara could enhance the antioxidant activity up to 2.6- and 5.5-fold, respectively for R. oligosporus and A. oryzae. Besides having an enhanced antioxidant activity, the fermented okara also had higher protein content, amino nitrogen content, and protein digestibility.

Preparation of soy sauce by walnut meal fermentation: Composition, antioxidant properties, and angiotensin-converting enzyme inhibitory activities.

Remaining walnut meal after oil extraction still contains many nutrients. However, these by‐products have not been effectively used. In this study, walnut meal and Aspergillus oryzae (3.042) were used in combination to prepare a soy sauce‐like material with high amino nitrogen content (ANC). The optimal conditions for the preparation of walnut soy sauce (ratio of brine:koji of 1.7:1 for 6 days at 45°C) were determined using response surface experiments (RSE), which showed maximum ANC of 855 mg/100 ml. The results of amino acid analysis indicated that walnut soy sauce had a similar amino acid composition compared with three commercial soy sauces. It contained all the essential amino acids and had a high content of umami amino acids such as Glu and Asp, which may give it a stronger umami taste. Moreover, the crude walnut soy sauce was extracted sequentially using ethyl acetate, n‐butanol, acetone and water, and the total phenols, total flavonoids, reducing sugars, and the peptides of different solvent extracts were measured. Results showed that the total phenolic and flavonoid contents were highest in the ethyl acetate extracts. However, water residue had the highest levels of reducing sugars and peptides. In vitro, the water residue showed the highest antioxidant capacity and angiotensin‐converting enzyme (ACE) inhibitory activity, due to more reducing sugars and peptides. These results indicated that walnut soy sauce may have significant antioxidant and ACE inhibitory activity. The findings provide a scientific basis for developing a replacement for soy sauce and broaden the beneficial application of walnut meal.

Impact of beet quality on sugar manufacture Part 1. General considerations of the technological beet quality

Without doubt, the sugar content is the major quality parameter of sugar beets. The amount of sugar which can be crystallized as white sugar in processing is often predicted using empirical formula. These formulas are usually based on the potassium, sodium and amino-nitrogen content of the beets. The amount of sugar that cannot be crystallized (i.e. the sugar contained in molasses) is related to these internal quality parameters. However, from a process technology perspective other beet quality parameters play an important role too and may have a considerable impact on the efficiency of beet processing and thus production costs. The first part of this paper presents an overview of the technologically considered important external and internal beet quality parameters and how they affect processing.

System for the evaluation of malting quality of wheat varieties

A new system for the calculation of malting quality of wheat varieties was designed. The malting parameters affected by a variety more than by a year or a site were used in the system. These parameters include wort viscosity, soluble nitrogen content, free amino nitrogen content, diastatic power, final attenuation of wort, and extract of malt. The system was used to assess the malting quality in 38 wheat varieties. The point value of each parameter was calculated using the regression equations, and the total value of the malting quality of wheat was determined by the modified “superiority measure” method. The results of the assessment of the wheat malting quality showed considerable differences between the varieties. Several varieties exhibited a more pronounced tendency to accumulate nitrogenous substances in grain. Some varieties, even with a slightly higher content of nitrogenous substances, provided above average malt quality. The set included the varieties that exhibited the optimal content of nitrogenous substances in grain, yet they did not give malt of good quality. Spring wheat varieties Alondra, Anabel, and Seance achieved significantly above average malting quality. Dagmar, Evina, Sultan, Rumor, Sailor, and Brokat exhibited slightly above average malting quality. The proposed system for monitoring malting quality of wheat varieties can help find the varieties suitable for the production of quality wheat malt.

Irradiation effects on chemical and functional qualities of ready-to-eat Saengshik, a cereal health food

Saengshik is an uncooked Korean meal comprising of more than thirty different ingredients of plant and animal origins. In Korea, to reduce the microbial loads in the product, electron-beam (EB) or gamma-ray (GR) irradiation at 5 kGy is permitted for its major cereal ingredients. But decontamination effects are not often satisfied. Considering the over-doses in commercial treatment, this study intended to investigate EB and GR irradiations up to 10 kGy on the physicochemical and functional qualities of prepackaged Saengshik. The reducing sugar and amino nitrogen were not significantly affected, whereas total chlorophylls, carotenoids, phenolics, and antioxidant activities were more sensitive to both types of irradiation. Total carotenoids and chlorophylls were reduced at high irradiation doses. In contrast, irradiation increased the free radical scavenging abilities that may be due to increase in total phenolic content (139.63–169.02 mg/100 g, EB; 139.63–168.56 mg/100 g, GR). Although there was slight decrease in the chlorophyll and carotenoid constituents of Saengshik, irradiation up to 10 kGy improved its antioxidant activity without affecting the reducing sugar and amino nitrogen. Dose escalation up to 10 kGy for the cereal product revealed stable reducing sugar and amino nitrogen contents with slight changes below 0.31% in total chlorophylls, carotenoids, phenolics, and antioxidant properties.

Биотехнологические аспекты получения функциональных ингредиентов на основе конверсии биомассы Saccharomyces cerevisiae 985-Т

An algorithm for the biocatalytic conversion of polymers of subcellular structures of Saccharomyces cerevisiae 985-T has been developed. It was shown that the action of enzymes on cell wall mannoproteins and (3-glucans led to deformation of their structure and the transfer of more than 50% of polysaccharides to a soluble state with the formation of 13.4% reducing carbohydrates, 1.8% amine nitrogen and 7.7% free amino acids (biological-1). Biological-2 had an increased content of total carbohydrates (32.2%) and fiber (10.5%). It was found that the combined action of the complex of proteinases and peptidases contributed to an increase in the degree of hydrolysis of subcellular structures, which was accompanied by a growth of the content of amino nitrogen by 2.7 times, free amino acids by 3.1 times, and low-molecular peptides (up to 500 Da) by 3.5 times (biological-3). The obtained biologicals were characterized by a high content of phosphorus and potassium. It was shown that the use of enzyme systems that catalyze the hydrolysis of intracellular polymers in yeast biomass allows us to obtain products with different biochemical and structural-fractional composition, which determines their properties. Saccharomyces cerevisiae, enzymes, structural-fractional composition, functional ingredients The work was carried out at the expense of the subsidy for the implementation of the State Task.

Effect of Thymus vulgaris Aqueous Extract on Chemical, Microbiological and Organoleptic Properties of Kariesh Cheese.

An aqueous extract of thyme was added to the Kareish cheese made of skimmed buffaloʼs milk at 0.5, 2.0 and 3.0 %. Cheese was chemically and microbiologically analyzed during storage.The obtained results indicated that the titratable acidity, ash and total solid and soluble nitrogen increased by increasing the added theme extract, and by the prolonging of the storage. Addition of different concentration of thyme, On the other hand, didn’t affect significantly the total nitrogen, total protein and Protein/DM.The amino nitrogen content significantly increased by increasing the added thyme and with the increasing the storage period. Fat and Fat/DM and Salt and Salt/DM of cheese contents significantly increased by proceeding the storage period.Cheese made with supplementing of with 1% thyme gained the highest total scores (99.4 ), while the lowest of 81.83 was attained for the control. after 15 days. Concerning the microbiological quality, the results indicated thahe Increasing the concentration of added thyme extract resulted in significant decrease in the overall bacterial count. while the increase in cheese storage period resulted in lower increase in the microbiological load, but the increase was lower than the control

Improvement of barley (Hordeum vulgare L.) germination by application of biochar leacheate in steeping solution to upgrade malt quality.

To investigate an improvement of barley germination by application of biochar leacheate in the steeping solution for upgrading malt quality. Barley germination was improved when biochar leacheate was used in the steeping water during the first steeping cycle. A clear decrease in the time to reach 50% of final germination percentage was detected due to an addition of biochar leacheate, but no significant difference was observed in the percent germination at the end of germination. Hydrolase activities including α-amylase, proteinase and β-glucanase in barley grains were maximally increased during the malting process when 10% biochar leacheate was added to the first steeping water. The wort yielding indexes including both glucose and maltose content and the free amino nitrogen content were significantly increased but the β-glucan content was significantly decreased at a level of p < 0.05 when 10% biochar leacheate was added to the steeping water. Biochar leacheate could be used as a stimulator in the steeping solution during the first steeping cycle to improve barley germination and so upgrade malt quality.

Foliar application of urea to Tempranillo vines increased the amino acid concentration of the must

ABSTRACTThe aim of this study was to investigate the impact of fertilisation with foliar urea of Vitis vinifera var. Tempranillo on the concentration of amino acids in must and on their evolution during the final stage of grape ripening. Foliar urea fertilisation increased the concentration of amino nitrogen, ammonium nitrogen and yeast assimilable nitrogen (YAN) in Tempranillo must. In addition, fertilisation with foliar urea produced an increase in the concentration of many amino acids in the must. This increase was especially noticeable in the case of the most important amino acids for yeast metabolism throughout the alcoholic fermentation (arginine, glutamic acid, aspartic acid, histidine, serine and lysine). After comparing the results of this study with other ones, we may state that: in order to increase the amino acid concentration in must, it is important to apply the urea several times instead of making just one single application. Moreover, it is important to use a preparation of urea without biuret, which is a phytotoxic carbamyl urea formed as a condensation product arising from urea thermal decomposition.

Effect of pretreatment with paste and sauce extract made using Tenebrio molitor larvae on ethanol‐damaged HepG2 cells

AbstractIn this study, we made koji using protein‐rich Tenebrio molitor larvae (TML) inoculated with Aspergillus oryzae, and then used the koji to prepare a paste and a sauce. The TML koji showed the highest amino nitrogen, protease activity, and free amino acids content when it was fermented for 72 h after inoculation with 0.8% A. oryzae. The koji was aged in 20% saltwater for 50 days, and then the paste and sauce were separated. To evaluate the effect of TML paste and sauce on ethanol (EtOH)‐damaged hepatocytes, aspartate aminotransferase (AST) and alanine aminotransaminase (ALT) were measured in EtOH‐treated HepG2 cells after pretreatment with TML paste and sauce extract. As a result, we confirmed that TML paste and sauce extracts lowered the AST and ALT content in the medium, compared to soybean sauce and paste extracts. TML paste and sauce extract significantly reduced the expression of tumor necrosis factor (TNF)‐α and interleukin (IL)‐6, a biomarker of inflammation, and significantly increased the activity of the antioxidants superoxide dismutase (SOD) and reduced glutathione (GSH) in proportion to the amount of TML added to the paste and sauce. These results suggest that the intake of TML paste and sauce, a new type of fermented food made from insects, may provide effective protection to the liver against hepatocyte injury by EtOH via anti‐inflammatory and antioxidative effects.

Feasibility of synthesizing γ-[Glu](n≥1)-Gln using high solid concentrations and glutaminase from Bacillus amyloliquefaciens as the catalyst

Effects of using high solid concentrations on the synthesis of γ-[Glu](n≥1)-Gln catalyzed by glutaminase from Bacillus amyloliquefaciens were examined in this study. An increment in solid concentration from 10% to 50% (w/w) increased the extent of synthesis of γ-[Glu](n≥1)-Gln, based on the analyses of amino acid composition and amino nitrogen content. Size-exclusion high-performance liquid chromatography analysis revealed an increase in molecular mass of γ-[Glu](n≥1)-Gln resulting from the increase of solid concentration from 10% to 50% (w/w). UPLC-Q-TOF-MS/MS analysis showed that the enzymatic reaction mixtures post γ-glutamyl transpeptidation contained γ-Glu-Gln, γ-Glu-Glu-Gln, γ-Glu-Glu-Glu-Gln, γ-Glu-Glu-Glu-Glu-Gln and γ-Glu-Glu-Glu-Glu-Glu-Gln. The intensity of each γ-[Glu](n=1,2,3,4,5)-Gln produced at a solid concentration of 50% (w/w) was higher than that at 10% (w/w). These findings indicated the potential of such an energy- and water-efficient approach for synthesizing γ-[Glu](n≥1)-Gln at high solid concentrations.

Study on metabolites of Bacillus producing soy sauce-like aroma in Jiang-flavor Chinese spirits.

Jiang‐flavor Chinese spirits are one of the four basic liquor types in China. It has thousands of years of history in China and is widely enjoyed because of its unique flavor and broad application. Although Jiang‐flavor Chinese spirits have a unique soy sauce flavor, the associated key compounds and production mechanism remain unknown. To investigate this process, soy sauce flavor‐producing strains were obtained, and their metabolites were evaluated. Using wheat as the fermentation medium, we observed changes in total acid, amino nitrogen, and reducing sugar in three strains of Bacillus cerberus with high yield of tetramethylpyrazine during the fermentation process. The results showed that total acid and amino nitrogen contents increased and reducing sugars decreased in a time‐dependent manner. Additionally, detection of volatile compounds via solid‐phase microextraction and gas chromatography–mass spectrometry that total pyrazine content reached 43.175%, 50.461%, and 45.955% in wheat fermentation medium fermented by strains Q1, Q2, and Q5, respectively, suggesting that this important flavor compound might be related to the flavor of soy sauce. Moreover, we found that fermentation time was an important factor in soy sauce flavor, as volatile compounds were detected at different times by the three strains, with pyrazines not detected before 48 hr and peaking at 50.461% after 144 hr. These results indicated that strain Q2 exhibited optimal fermenting performance and might be useful for fermentation of Jiang‐flavor Chinese spirits.

Production of Isomalto-Oligosaccharides from Available Economic Starchy Materials

ABSTRACT:Isomalto-oligosaccharides have a great potential to improve the physiochemical quality of many foods as anti-fading agent for food pigments, as prebiotic, food antioxidant and as a sweetener. Solid-state fermentation (SSF) has been applied in the production of many fermented foods (Couto and Sanroman, 2006). Various fungi have been used in order to produce amylolytic enzymes for starch degradation. Many fungal amylolytic enzymes are used to advantage in prebiotic oligosaccharide production. Isomaltooligosaccharides which are known as prebiotic branched-oligosaccharides have been synthesized from starchy grains (Kuriki et al, 1993; Pan and Lee, 2005). The effects of agricultural substrate and fungal strain were studied to maximize the isomalto- oligosaccharides yield. The production of Isomalto-oligosaccharides by fungal fermentation using available economic starchy materials as wheat, white corn, and starch was investigated. This study was designed to investigate the potential use of economic crops of Egypt to produce prebiotic isomalto-oligosaccharides using the process of solid state fungal fermentation. Solid state fermentation with Aspergillus Oryzae EMCC 126 was studied to increase the isomalto-oligosaccharides yield. Results show that the fermentation of wheat with A. Oryzae produced the highest concentrations of total reducing sugar (460.8 mg/g) and free amino nitrogen (20.3 mg/g) with the highest levels of amylolytic activity (87.0 U/g), α-amylase (32.5 U/g) and α-glucosidase (1.2 U/g) compared with that produced from fermentation of white corn or starch. The appropriate fermentation time for 5 days, the fermented wheat slurry was experimented on further in mashing for syrup production. The obtained wheat syrup contained the highest amounts of isomaltose, panose, and isomaltotriose, which were detected by very small amounts in the syrup of corn and starch.

High-throughput sequencing approach to characterize dynamic changes of the fungal and bacterial communities during the production of sufu, a traditional Chinese fermented soybean food

Red sufu is a traditional food produced by the fermentation of soybean. In this study, sufu samples were periodically collected during the whole fermentation to investigate the dynamic changes of fungal and bacterial communities using high-throughput sequencing technology. The overall process can be divided into pre- and post-fermentation. During post-fermentation, the pH value showed a gradual decrease over time while the amino nitrogen content increased. Trichosporon, Actinomucor and Cryptococcus were the main genera in pre-fermentation while Monascus and Aspergillus were dominant in post-fermentation. This huge shift in fungal composition was caused by process procedure of pouring dressing mixture. However, the bacterial composition was not greatly changed after pouring dressing mixture, the Acinetobacter and Enterobacter were the predominant genera throughout the whole process. Furthermore, Bacillus species were first detected after adding dressing mixture, but declined abruptly to a very low level (0.07%) by the end of the fermentation. Our work demonstrates the dynamic changes of physicochemical properties and microbial composition in every fermentation stage, the knowledge of which could potentially serve as a foundation for improving the safety and quality of sufu in the future.