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Physicochemical analysis, headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and high-throughput sequencing were used to investigate the potential relationship between the microecology of different flavor types of Daqu and their physicochemical indexes and characteristic flavor compounds. The results showed that the highest saccharification power and fermentation power were found in Fen-flavor Daqu, the highest esterification power and starch content in Luzhou-flavor Daqu, and the highest acidity were found in Maotai-flavor Daqu. In the three types of Daqu, the dominant bacterial genera were Saccharopolyspora, Weissella and Bacillus, and the dominant fungal genera were Saccharomycopsis, Aspergillus and Thermomyces. Correlation analysis showed that Bacillus was positively correlated with saccharification power, liquefaction power, fermentation power, ethyl caprate and phenyl ethanol. Thermomyces was positively correlated with ethyl caproate, isoamyl alcohol, ethyl lactate, acetic acid and ligustrazine.

This study compared the differences in the growth and metabolism of Clostridium celerecrescens JSJ-1, a strain able to produce caproic acid, and Clostridium tyrobutyricum D-1, a stain able to produce butyric acid, when cultured separately or co-cultured in different systems (solid medium, and liquid medium with or without use of dialysis bag). Furthermore, this study investigated the effect and mechanism of co-culture with C. tyrobutyricum on caproic acid metabolism in caproic acid-producing bacteria by culturing JSJ-1 alone in the presence of butyric acid or sodium butyrate at different concentrations. The results showed that when co-cultured on a composite solid medium containing glucose in anaerobic conditions at 34 ℃, D-1 grew better than JSJ-1, and could preferentially utilize glucose for growth. The generation time of caproic acid was three days earlier when D-1 and JSJ-1 were co-cultured in a liquid medium than when JSJ-1 was cultured alone under the same conditions, and the concentration of caproic acid was 9.93 and 9.79 g/L on the 12th day in the two cases, respectively. Glucose had a strong inhibitory effect on the production of caproic acid by JSJ-1, which could be relieved by preferential utilization of by D-1 upon co-culture. The co-culture in the liquid medium with and without use of dialysis bag were compared, revealing that whether there was direct contact between JSJ-1 and D-1 had no effect on the yield of caproic acid. By purely culturing JSJ-1 in the presence of butyric acid or sodium butyrate, it was found that butyric acid generated by D-1 at pH 6–6.5 could promote the synthesis of caproic acid by JSJ-1. During co-culture, the preferential utilization of glucose by D-1 could relieve the inhibitory effect of glucose on the production of caproic acid, and butyric acid produced by D-1 could promote the synthesis of caproic acid.

ObjectiveTo explore the association between dietary behavior and weight change in medical staff during the COVID-19 pandemic， and provide the scientific basis for their nutrition and health improvement.MethodsFrom May to July 2022， 1 487 doctors and nurses from 12 COVID-19 designated hospitals in Northeast China were randomly recruited to participate in the survey. After excluding invalid questionnaires， 1 352 valid questionnaires were obtained. Data were collected by self-compiled general questionnaire， eating behavior indexes and emotional eating scale， and analyzed by statistical methods such as analysis of variance （ANOVA） and linear regression model.ResultsAmong the medical staff of COVID-19 designated hospitals， there were 485 （35.9%） individuals with stable weight （±3%）； individuals with substantial weight loss （5%） were 8.2%（111/1 352）， 22.7%（307/1 352）， 23.6%（319/1 352） and 9.6%（130/1 352）， respectively. The results of ANOVA showed that there were significant differences of irregular diet， unbalanced nutrition， high oil diet， high salt diet， high carbohydrate diet， beverage intake， and emotional eating behaviors between different weight change groups （P0.05）. The results of multivariate linear regression indicated that irregular diet， high carbohydrate diet， beverage intake， emotional eating and income were risk factors of weight change （P

In this study, magnetic metal organic framework composites as capture probe and immunofunctionalized gold nanoparticles as signal probe were used to develop a rapid colorimetric method for the detection of Listeria monocytogenes. Under optimal conditions, the visual detection limit for L. monocytogenes was 1.2 × 103 CFU/mL. The results of ultraviolet spectroscopy showed a good linear relationship in the range of 1.2 × 101‒1.2 × 108 CFU/mL (Y = 0.519 ‒ 0.043X, R2 = 0.978), the detection limit was as low as 0.45 CFU/mL, and the intra-batch coefficient of variation of all concentration gradients was between 0.31% and 1.30%. The recoveries for spiked chicken breast were 91.1%‒108.7% with coefficient of variation less than 7.4%, and the result was consistent with that of the plate counting method. In conclusion, the proposed assay is rapid, accurate sensitive, and highly applicable to the detection of foodborne pathogens.

ObjectiveTo investigate the implementation of the standards （formula foods and complementary foods for infants and young children）， the contents of glucose， galactose， fructose， lactose， sucrose and maltose in formula foods and complementary foods for infants aged 0-36 months， and provide data support for the management of food safety standards related to infant formula and infant complementary food in China.MethodsBased on the principle of random sampling， 83 formula food and complementary food for infants and young children， including infant formula foods， older infant formula foods， young children formula foods， cereal complementary foods and canned foods for infants and young children， were collected from the domestic market， the content of glucose， galactose， fructose， lactose， sucrose and maltose were determined by ion chromatography-pulse ampere method and the results were analyzed.ResultsThe median of total sugar content in formula foods for infants and young children was 433.43-476.99 g/kg； the proportion of lactose in all kinds of products was higher than 95%， and the content from high to low was infant formula， older infant formula and formula for young children. The detection rate of sugar in infant cereal supplementary food was 36.8%， the median content was 0-28.35 g/kg； the medians of lactose and sucrose were 84.30 and 70.17 g/kg； while the third quartile（Q3） of sucrose was 53.43 g/kg. There was no significant difference in the content of added sugar between domestic and imported formula foods（P>0.05）.ConclusionThe lactose content in formula foods for infants and young children sold in China is higher than that of other sugars. The content of total sugar in cereal supplementary food is low， but the content of sucrose in biscuit should be concerned. It is suggested that enterprises should strictly control added sugar， and government departments should continue to push the implementation of the sugar content regulation in the newly released national standards.

In order to explore the effects of different wood types with different chemical compositions and structures on the types and amounts of polycyclic aromatic hydrocarbons produced in traditional smoked meat products, the structural and pyrolysis characteristics of lignin in five kinds of wood commonly used in the production of traditional smoked and roasted meat products, pine, poplar, beech, jujube and apple wood, were investigated by infrared spectroscopy, Raman spectroscopy, thermogravimetry and thermogravimetry coupled with infrared spectroscopy. The results showed that there were differences in the contents of lignin, guaiacyl (G) and syringyl (S) in the five kinds of wood. The pyrolysis process involved three stages, mainly in the range of 200?500 ℃, but the mass loss rate, mass loss temperature, pyrolysis rate and pyrolysis temperature of lignin were different among different kinds of wood, indicating that there are significant differences in the thermal stability of lignin from different wood sources. Differences in lignin content, S/G structure content and side chain structure in smoked and roasted wood could lead to different thermal stability, and different pyrolysis characteristics could in turn affect the formation of harmful substances such as polycyclic aromatic hydrocarbons.

Objective: To develop selenium-enriched （Se-enriched） Moringa oleifera seed protein resources. Methods: Using Se-enriched Moringa oleifera seed protein powder as raw material, the enzymatic hydrolysis conditions of Se-enriched Moringa oleifera seed protein antihypertensive peptides from Se-enriched Moringa oleifera seed protein were obtained by single factor and response surface optimization, and the ACE inhibitory activity, Se content and stability of the optimal enzymatic hydrolysate were analyzed. Results: The optimal enzymatic hydrolysis conditions of Se-enriched Moringa oleifera were as follows: enzymatic hydrolysis time 3 h, temperature 34 ℃, pH 8, concentration of substrate 7%, enzyme to substrate ratio 0.3%. Under these conditions, the semi-inhibitory concentration of ACE of the peptides was 1.956 mg/mL. The Se content of the antihypertensive peptide was 1.394 mg/kg, which was 1.1 times that of the raw protein. Moreover, the antihypertensive peptides （5 mg/mL） had good thermal stability and acid-base stability, and could still maintain good ACE inhibitory activity after digestion by gastrointestinal enzyme system in vitro. Conclusion: The Se-enriched Moringa oleifera seed protein antihypertensive peptides obtained by response surface optimization showed strong ACE inhibitory activity and good stability.

The Chinese government has announced the goal of carbon peak and carbon neutrality, demonstrating China's responsibility as a major country to actively respond to climate change and promote sustainable development of the world. In recent years, state-owned grain storage enterprises have vigorously promoted energy saving, carbon reduction, and efficient development in upgrading grain storage facilities and equipment, innovating grain storage technology and, strengthening standardized storage management. Combined with the current situation of the development of state-owned grain storage enterprises, the concept of "carbon neutral grain" was proposed firstly in the paper. Under the goal of carbon neutrality, state-owned grain storage enterprises should do a good job of “subtraction” of low carbon operation as well as actively utilize “addition” of green energy such as photovoltaic power generation, taking the lead to realize their own low carbon development and lead the industry as an example.

ObjectiveTo understand the sugar-sweetened beverages consumption, free sugar intake and its energy proportion among urban residents aged 3 and above in China.MethodsAccording to stratified multistage cluster random sampling, this study selected the consumption of sugar-sweetened beverages of 13 083 people aged 3 and above in 18 provinces in China by three nonconsecutive 24 h dietary recalls. The data of sugar content in sugar-sweetened beverages was obtained from the special monitoring carried out by China National Center for Food Safety Risk Assessment. The simple distribution model was used to calculate individual free sugar intake and its energy proportion ratio of sugar-sweetened beverages per day.ResultsThe consumption rate of sugar-sweetened beverages of urban residents aged 3 years and above in China was 11.35% (1 485/13 083), with that of men (12.14%, 768/6 326) was slightly higher than that of women (10.61%, 717/6 757). The consumption rate of sugar-sweetened beverages was highest in the 13-17 age group (27.20%, 139/511) and lowest in the group of over 60 (3.29%, 62/1 884). The average consumption of sugar-sweetened beverages in general population and consumers were 18.49 g/d and 162.89 g/d, respectively. The median consumption of sugar-sweetened beverages were and 130.00 g/d, respectively. The average consumption of sugar-sweetened beverages was the highest in 13-17 years old group (54.84 g/d in general population and 201.61 g/d in consumers, respectively) and lowest in the group of over 60 (3.88 g/d in general population and 117.77 g/d in consumers, respectively). The average free sugar intake via sugar-sweetened beverages in general population and consumers were 1.44 g/d and 12.71 g/d, respectively. The median free sugar intake were 0 and 10.08 g/d, respectively. The P95 value intake of free sugar was highest in 13-17 years old group (25.71 g/d in general population and 40.73 g/d in consumers, respectively) and followed by the group of 18-29 years old group (19.24 g/d in general population and 39.01 g/d in consumers, respectively). The average energy proportion ratio of sugar-sweetened beverages in general population and consumers were 0.35%TE and 3.06%TE, respectively. The median energy proportion ratio of sugar-sweetened beverages were 0 and 2.37%TE, respectively. The P95 value of energy proportion ratio of sugar-sweetened beverages was the highest in 13-17 years old group (6.04%TE in general population and 9.31%TE in consumers, respectively) and lowest in the group of over 60 (0 in general population and 4.05%TE in consumers, respectively).ConclusionThe consumption, free sugar intake and free sugar energy proportion ratio via sugar-sweetened beverages among Chinese urban residents aged 3 and above were at low level. However, the P95 value of the energy proportion ratio of sugar-sweetened beverages was close to 10% in children and teenage consumers. With the promotion of the National Nutrition Program, education related to nutrition should be taken into account to guide the industry and targeted people to reduce sugar scientifically.

ObjectiveTo analyze the product information, food label and nutrients composition characteristics of approved foods for special medical purposes (FSMP).MethodsThe product and label information of approved FSMP products were collected from China's State Administration for Market Regulation by March 5, 2021, and the classification, ingredients characteristics and nutrients content of each product as well as the comparison with standard requirements were analyzed.ResultsThere are 58 approved FSMP products in China at present.Most labeled nutrient contents were slightly higher than the minimum and lower than the middle line of content requirements of national standard. More than 50% of the products added choline, inositol, taurine and L-carnitine, and 72.2% of complete-nutrition formula added dietary fiber.ConclusionThe approved FSMP products had basically covered all categories in China. Nevertheless, the specific complete-nutrition food and incomplete-nutrition food were inadequate which were urgent in need of research and development. The nutrients content of FSMP products were within the ideal range of GB standard.