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Lactic acid bacteria (LAB) plays an important role in the production of sourdough, and has a significant impact on its flavor and other qualities. In order to select LAB starter culture for specialty sourdough and develop differentiated sour dough bread, this study evaluated the glucose metabolism capacity, organic acid production capacity and flavor characteristics of LAB strains isolated from different kinds of traditional fermented foods, and their effects on the flavor of sourdough and bread were also verified. The results showed that there were 6 LAB strains with strong glucose metabolism and acid production performance, and excellent flavor characteristics. The volatile flavor substances produced by these strains were mainly composed of alcohols, esters, ketones, aldehydes, acids, and other compounds. Among them, two Lactobacillus plantarum strains might be the main contributors of special flavors such as sourness, fruitiness and rice wine flavor to sourdough bread. These obtained strains provide resources for the development of sourdough starter culture with characteristic aroma components, and have potential for industrial application.

In order to study the quality change of coffee malt premixed powder with the extension of storage period, the coffee malt premixed powder was stored at the environment where the temperature is 25 ℃ and 35 ℃, respectively, and the relative humidity is 50% respectively. Its moisture, fatty acid value and falling value were monitored during the whole storage period. The volatile compounds were separated and identified by solid phase microextraction accompanying gas chromatography-mass spectrometry during the whole storage period. The results demonstrated that with the extension of storage period, the overall moisture content shows a falling trend, while the fatty acid value and falling value show an overall rising trend. The higher the storage temperature, the more significant the change is 41 kinds of main volatile compounds of coffee malt ready mixed powder were identified. It mainly includes 13 kinds of aldehydes, 15 kinds of heterocycles, 7 kinds of esters, 4 kinds of alcohols and 2 kinds of ketones. Among them, the relative concentration of aldehydes (n-hexanal, nonanal, trans-2-nonenal) showed an increasing trend with the extension of storage period.

ObjectiveThis study analysed blood donation deferral trends, reasons and demographic/lifestyle characteristics among students in Huzhou City. The aim was to understand the health status of students and reduce the deferral rate.MethodsData on blood donation deferral among students in Huzhou City from 2018 to 2022 were collected and analysed. Deferral trends and main reasons were investigated. Using demographic and lifestyle data from 2,619 cases in 2022, a risk prediction model for deferral was constructed.ResultsThe deferral rate among students in Huzhou City from 2018 to 2022 was 12.60% (p = 0.000, 95%CI: 12.14–13.06%), showing a significant increasing trend. Temporary deferral was the main reason, with alanine aminotransferase (ALT), blood pressure (BP) and haemoglobin (Hb) as the main deferral factors. ALT had a deferral rate of 5.23% (4.92–5.53%), BP 3.30% (3.06–3.55%), and Hb 2.92% (2.68–3.15%). Demographic and lifestyle characteristics in 2022 showed no significant differences between education level, household registration and deferral rate (p > 0.05). However, age, sex, blood donation history, sleep quality, diet and mental state had variable effects on ALT, BP, and Hb deferrals (p

Yeast plays an important role in fermented cereal products, especially fermented flour products, affecting the texture, aroma, appearance and nutrition of the products. In order to select grain microbial starter and improve the quality of fermented flour products, yeasts were isolated from traditional old flour and natural flour collected from different provinces and cities in China. Yeast identification was carried out by combining morphology and 26S rDNA sequence alignment. High-sugar-resistant, heat-resistant and high-quality yeasts were screened out to verify their application characteristics in steamed bread, toast bread and frozen dough. The results showed that 65 strains of yeasts were isolated, all of which were Saccharomyces cerevisiae, and 9 strains with strong fermentation ability were screened out, among which 5 strains could improve the specific volume, texture and taste of steamed bread, and the other 4 strains were resistant to high sugar and heat, which could improve the texture and flavor of toast bread. Besides, one strain had strong frost resistance, which could prolong the vitality period of frozen dough. The discovered strain is expected to be developed into a high-quality starter for fermented grain products, improve the performance of different kinds of fermented flour products, provide differentiated products for consumers, and promote the innovative development of grain processing industry.

In order to study the dynamic law of the quality change in low temperature yogurts,yogurts were stored at temperatures of 4 ℃,15 ℃,25 ℃ and 30 ℃ respectively,and the changes in protein level,fat level,acidity level,particle size,color,texture and total number of colonies were observed.The regression equation analysis shows that the changes of a* redness value (at 15℃,25℃ and 30 ℃),total color difference ΔE,colony number (at 4 ℃,15 ℃ and 25 ℃),softness and consistency (at 15 ℃ and 25 ℃)match the Zero-order kinetic model,while the changes of titratable acidity and b* yellowness value match the First-order kinetic model.The established shelf-life prediction model equation provides insights in the adjustment of storage and transportation conditions of low-temperature milk products,as well as quality monitoring during the storage period.

In this paper, the nutritional composition, active ingredients, and digestibility of malt roots were measured and analyzed and compared with those of wheat bran.The results showed that the content of protein(34.3%) and dietary fiber (39.4%) in malt roots are higher than those in wheat bran.The content of essential amino acids (8.37 g/100 g) is twice than that of wheat bran (4.03 g/100 g).The content of lysine, threonine and valine are relatively high in malt roots.Additionally, malt roots not only contain vitamin E (3.14 mg/100g),but also have a higher content of vitamin B2, B6 and B12, folic acid, and vitamin C than those in wheat bran(0.6 mg/100 g, 0.46 mg/100 g, 0.11 μg/100 g, 0.17 mg/100 g, 4.35 mg/100 g, respectively).Furthermore, the malt roots are rich in sodium, potassium, calcium, zinc, copper, phosphorus, iron, and magnesium.It also contains a high content of total polyphenols (1.09%) and a small amount of polysaccharides.At the same time, the regulatory status, application status and application prospect were analyzed from the feed, food and cosmetics fields, which provided a basis for the high-value utilization of malt root by-products.

Two new sesquiterpene aryl esters, armimelleolides A and B (1 and 2), and four known ones, were isolated from the EtOAc extract of Armillaria gallica 012 m by column chromatography on silica gel, reversed-phase C18 silica gel and semi-preparative HPLC. Their structures were elucidated on the basis of spectroscopic methods, including extensive 1 D NMR, 2 D NMR and MS. All these compounds showed potential antitumor activities against at least one of the human cancer cell lines (A549, HCT-116, M231 and W256), with IC50 ranging from 2.57 to 19.94 μM. [ABSTRACT FROM AUTHOR]