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Protein content in food is an important indicator of the nutritional value of food, and it is also related to food safety and many other issues, therefore it is significant to accurately determine the protein content for the valuation of food nutrition and safety. The main elements in food include carbon, nitrogen, hydrogen and sulphur, of which nitrogen mainly comes from protein. The average nitrogen content in protein is 16%, so the conversion factor for “nitrogen-to-protein” is 6.25. Therefore, the protein content in food can be obtained by measuring the nitrogen content of food combined with “nitrogen-to-protein” conversion factor. The traditional methods of protein detection are Kjeldahl method, spectrophotometry, and Dumas combustion. The Kjeldahl method is timeconsuming and consumes a large amount of reagents, which can cause environmental pollution. Spectrophotometry is susceptible to interference and the quantitative curve is not easy to draw. Dumas combustion is expensive in terms of consumables. In this paper, a platform of tube furnacequadrupole mass spectrometer was set up to analyze the protein content in food. Food samples were heated at high temperatures in a tube furnace and combusted in an oxygen-rich environment. After the gas products were ionized, they were directly introduced into a quadrupole mass analyzer for detection, which eliminated the need for processes such as oxidation-reduction, adsorption-desorption by using the selection ion scan function of the mass spectrometer. Five kinds of food samples with different protein contents were selected as research object. Each food sample was weighed at 1g. The food samples were fully combusted in tube furnace at high temperature (1 300 ℃). The gas products were infused through a drying and filtering tube to remove water and smoke, and then entered the EI ion source through a capillary for ionization. By electronic ionization, nitrogen element characteristic ions, N+, NO+, and NO2+ are generated. The peak intensity of the NO2+ ions were detected by the selection ion scan function of the quadrupole mass analyzer. A standard curve for nitrogen quantification is plotted to be y=115.64x+1 896.9 with the correlation coefficient (R²) of 0.999 92 and the relative standard deviation (RSD) of 2.1%-6.1%. The nitrogen content can be calculated by using the peak intensity of NO2+ ions according to the standard curve. The experimental platform of tube furnace-mass spectrometer provides a green, rapid, accurate, and low-cost detection method for quantitative analysis of protein content in food. [ABSTRACT FROM AUTHOR]

The study was to increase the biomass and protein content of Chlorella pyrenoidosa, the fermentation recipe and fermentation conditions were optimized. Using Design-Expert 12 Perfect software, Plackett-Burman screening was performed on 13 factors including complex carbon source, nitrogen source and vitamins, the significant effect factors were found to be complex carbon source (glucose + starch, the fermentation yield of Chlorella pyrenoidosa could be increased by adding them at a ratio of 2.5∶1.0), organic nitrogen source (urea), and VB12. The Box-Behnken experimental design was carried out using the above three significant effect factors, and the optimized process was obtained by response surface analysis, which were composite carbon source 7.4 g/L, urea 8.8 g/L and VB12 addition 0.4 g/L. The results of 250 mL and 1 000 mL triangle flask medium test and 50 L fermenter feeding process verification showed that the final three different levels of fermentation were higher than the control group, the algal density increased by 38.9%, 31.1% and 42.5%, and the protein concentration increased by 29.8%, 31.0% and 31.4%, respectively. Under the optimized feeding conditions, the OD680 nm of the 50 L fermentor of Chlorella pyrenoidosa was 0.929, the dry weight was 91.64 g/L, and the protein content was 43%. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Black soldier fly is a kind of saprophagous insect belonging to genus flathorn soldier fly, which is characterized with wide feeding range, strong reproductive ability and rich nutrients. As one of the high nutritional insect protein sources, black soldier fly can partially replace fish meal in fish feed, and exhibit a good application prospect in aquaculture. The paper reviews the biological characteristics and nutritional value of black soldier fly and its effects on growth performance, feed utilization efficiency, nutritional quality, intestinal morphology and immunity of aquatic animals, to provide reference for the application of black soldier fly products in aquaculture. [ABSTRACT FROM AUTHOR]

The experiment was to select an accurate and rapid method for determination of free gossypol in cotton products by phloroglucinol method and high performance liquid chromatography (HPLC) and the drying temperature, which could stabilize the free gossypol content in cottonseed meal, cottonseed hull and cottonseed protein. The content of gossypol in three kinds of cotton products was determined by phloroglucinol method and high performance liquid chromatography. The method of rapid and accurate detection of gossypol content was screened by comparing the recovery rate. The results showed that the content of standard free gossypol in gossypol, cottonseed meal and cottonseed shell determined by phloroglucinol method were significantly higher than those determined by HPLC (P<0.05). There was no significant difference in free gossypol content between untreated and 65 °C drying treatments (P>0.05). The content of free gossypol in gossypol without drying was significantly higher than that in gossypol without drying at 75, 85, 95 and 105 °C (P<0.05). There was no significant difference in the content of free gossypol in cottonseed meal and cottonseed shell between untreated and 65 and 75 °C treatments (P>0.05). The content of free gossypol in non-drying group was significantly higher than that in 85, 95 and 105 °C drying treatments (P<0.05). The experiment indicates that phloroglucinol method for the determination of free gossypol faster and more accurate. Different drying temperatures affect the content of free gossypol in cotton products. With the increase of drying temperature, the content of free gossypol decreases, and the content of free gossypol in cotton products dried at 65°C is stable. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Edulis Fungi is the property of Acta Edulis Fungi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problem that the accuracy and recall of the protein complexes identification algorithm based on ant colony and FCM clustering are not high and the running efficiency is low, this paper proposed a novel protein complex recognition algorithm named FAC-PC. Firstly, combing with the Pearson correlation coefficient and edge aggregation coefficient, the algorithm constructed the weighted protein network. Secondly, in order to overcome the defects of massive merger and filter, repeated pick-up and drop-down operations in ant colony clustering algorithm, it designed the EPS metric to select essential protein, and designed the PFC metric to traverse neighbors of essential proteins to obtain essential group proteins. Then it used the essential group protein to replace the seed node in the process of ant colony clustering, which resulted that the accuracy and time performance were improved . Furthermore, it proposed the SI metric to optimize the probability of pick-up and drop down operations of ant colony to obtain the number of clustering. Finally, according to the improved ant colony algorithm, it obtained the essential protein and the number of clustering to initialize the FCM algorithm, and designed the membership update strategy to optimize the membership update, at the same time, it proposed a new FCM objective function which took a balance between intra-clustering and inter-clustering variation, and finally identified th e protein complex by improved FCM algorithm. This paper used FAC-PC algorithm to identify protein complexes on DIP data. The experimental results show that FACPC algorithm has better performance on accuracy and recall, which is more reasonable to identify protein complexes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Excessive training or non-adaptive high-intensity exercise makes negative effect on the skeletal muscle, and causes changes in ultrastructure of muscle fibers, thus causing damage. Exercise-induced mechanical stimuli can regulate gene expression by physical connection between cytoskeleton and nuclear matrix. OBJECTIVE: To investigate the effects of different recovery time and recovery conditions on the protein content of skeletal muscle focal adhesion complex after one eccentric exercise. METHODS: The study was approved by the Experimental Animal Ethics Committee of Beijing Sport University, approval number: 2014011. Fifty-six male Sprague-Dawley rats aged 8 weeks were randomly divided into control group, normoxic recovery group and hypoxic recovery group. Normoxic recovery group was subjected to a bout high-intensity eccentric exercise and hypoxia treatment (12.7% O2) while hypoxic recovery group performed exercise intervention. Hypoxic recovery and normoxic recovery groups were divided into 24-, 48- and 72-hour groups according to different time points after exercise. The gastrocnemius muscle was taken at the corresponding time phase. The expression levels of integrin α7 and β1, p-FAK and p-paxillin protein were detected by western blot assay. RESULTS AND CONCLUSION: (1) Compared with the control group, the expression level of integrin α7 in the 24-hour normoxic recovery group was significantly increased (P < 0.05), and restored to the level of control group with time. The expression level of integrin α7 in the 72-hour hypoxic recovery group was higher than that in the control group (P < 0.01). (2) The expression level of integrin β1 in the normoxic recovery and hypoxic recovery groups was on a rise, and the expression level in the normoxic recovery group was higher than that in the hypoxic recovery group. The expression level in the 48- and 72-hour normoxic recovery groups was significantly higher than that in the control group (P < 0.05, P < 0.01). (3) The expression level of p-FAK in the normoxic recovery and hypoxic recovery groups was on a descent, and the expression level in the normoxic recovery group was higher than that in the hypoxic recovery group. The expression level in the 48- and 72-hour normoxic recovery groups was significantly lower than that in the control group (P < 0.05). (4) The expression level of p-paxillin in the normoxic recovery and hypoxic recovery groups was firstly decreased and then increased, and the expression level in each group except for 24-hour normoxic recovery group was significantly lower than that in the control group (P < 0.05). (5) In summary, a single bout eccentric exercise can affect the protein expression of skeletal muscle focal adhesion complex. Different recovery conditions have different effects on focal adhesion complex. Normal oxygen is beneficial to the recovery of integrin α7, while hypoxia is beneficial to integrin β1, p-FAK and p-paxillin. [ABSTRACT FROM AUTHOR]

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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)