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Application of derivative ratio spectrophotometry for determination of β-carotene and astaxanthin from Phaffia rhodozyma extract

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Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2005年第6期6卷 514-522页

作者：倪辉何国庆阮晖陈启和陈锋 department of food science and nutrition Zhejiang University Hangzhou 310029 China department of food science and human nutrition Clemson University Clemson South Carolina 29634 USA

A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer’s law and that the additivity when the concentrations of β-carotene and astaxanthin and their mixture were within the range of 0 to 5 μg/ml, 0 to 6 μg/ml, and 0 to 6 μg/ml, respectively. When the wavelength interval (?λ) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining β-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 μg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for β-carotene within 0?6.0 μg/ml and for astaxanthin within 0?5.0 μg/ml with their corresponding regressive equations in: y=?0.0082x?0.0002 and y=0.0146x?0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was suc- cessfully applied to simultaneous determination of β-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture.

关键词： Derivative ratio spectrum β-carotene Astaxanthin Spectrophotometry

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Comparative molecular docking studies of lupeol and lupenone isolated from Pueraria lobata that inhibits BACE1: Probable remedies for Alzheimer's disease

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Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1117-1122页

作者： Prashamsa Koirala Su Hui Seong Hyun Ah Jung Jae Sue Choi department of food and Life science Pukyong National University department of food science and human nutrition Chonbuk National University

Objective: To discover lead lupane triterpenoid's potential isolated from Pueraria lobata roots against b-site amyloid precursor protein cleaving enzyme 1(BACE1), which serve as a rate limiting step in amyloid beta(Aβ) production altering the course of Alzheimer's disease. In addition, enzyme kinetics study and molecular docking were conducted to establish the inhibition type and structure activity ***: A systematic study of 70% ethanolic P. lobata root extract was employed to identify its BACE1 inhibitory potential. Further, BACE1 inhibitory potential of two lupane terpenoids, yielded from ethanolic extract, was assessed. In order to determine their inhibition mode, Lineweaver–Burk plots and Michaelis–Menten model for BACE1 was performed. Auto Dock 4.2 program in addition determined the molecular interaction of BACE1 with isolated ***: Considering the inhibitory potential of 70% ethanolic extract of P. lobata against BACE1(IC_(50)= 80.35 mg/mL), lupeol and lupenone were subsequently isolated and exhibited notable or moderate BACE1 inhibitory activity with IC_(50) values of 5.12 and 62.98 mmol/L, respectively, as compared to the positive control quercetin(IC_(50)= 21.28 mmol/L). The enzyme kinetics study enabled us to identify both compounds as competitive inhibitors, where lupeol displayed a very potent inhibition against BACE1 with low inhibition constant(Ki) value of 1.43 mmol/L, signifying greater binding *** order to understand the binding mechanism and structure–activity relationship of two triterpene-based BACE1 inhibitors, we employed computer aided docking studies which evidently revealed that hydroxyl group of lupeol formed two hydrogen bonds with the ASP32(catalytic aspartic residue) and SER35 residues of BACE1 with the binding energy of(-8.2 kcal/mol), while the ketone group of lupenone did not form any hydrogen bonds with BACE1 giving evidence for less binding affinity. These results in turn have predicted the dep

关键词： Pueraria lobata BACE1 Lupeol Lupenone Molecular docking Kinetics

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Lipids and Fatty Acid Composition of Dried Edible Red and Black Ants

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Agricultural sciences in China 2010年第7期9卷 1072-1077页

作者： Oranut Sihamala Subhachai Bhulaidok department of food science and nutrition Zhejiang University

Total lipid contents,lipid classes and fatty acid compositions of hot-air dried edible black ants（Polyrhachis vicina Roger） from Wenzhou and Guizhou,China,and edible red ant（Oecophylla smaragdina Fabricius） from Thailand were *** major lipid components were triacylglycerol（43.4-79.4% of total lipid）,followed by phospholipids（6.1-21.5%）,diacylglycerol（6.1-18.1%） and cholesterol ester（4.9-13.5%） while free fatty acids（1.8-2.9%） and sterol（0.5-0.8%） were the minor *** acid（C18：1） was the most predominant fatty acid,accounting for 3 407.8,9 098.8 and 3 790.1 mg 100 g-1 in Wenzhou and Guizhou black ants,and Thai red ant,*** by palmitic acid（C16：0）,922.9,2 523.3 and 1 511.8 mg 100 g-1;linoleic acid（C18：2n-6）,133.7,305.2 and 506.4 mg 100 g-1;α-linolenic acid（C18：3n-3）,35.1,138.0 and 52.5 mg 100 g-1;eicosapentaenoic acid（C20：5n-3） was 19.1,15.0 and 20.0 mg 100 g-1 in Wenzhou and Guizhou black ants,and Thai red ant,*** acid（C22：5n-3） was only found in black ants,7.0 and 7.3 mg 100 g-1 for Wenzhou and Guizhou ants,*** edible black and red ants were shown to be a good source of unsaturated fatty acid.

关键词： Polyrhachis vicina Roger Oecophylla smaragdina Fabricius edible black ant edible red ant polyunsaturated fatty acid (PUFA)

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Quantitative Structure-activity Relationship Studies on the Antioxidant Activity and Gap Junctional Communication of Carotenoids

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Chinese Journal of Structural Chemistry 2010年第9期29卷 1362-1372页

作者：孙玉敬吴丹刘东红陈健初沈妍叶兴乾 department of food science and nutrition School of Biosystems Engineering and Food ScienceZhejiang University

The antioxidant and gap junctional communication（GJC） activities of carotenoids are known to be the two main anticancer *** structure-activity relationship（QSAR） models of the two activities were developed using stepwise regression and multilayer perceptron neural network based on the calculated descriptors of quantum *** results showed that the significant molecular descriptor related to the antioxidant activity of carotenoids was the HOMO-LUMO energy gap（EHL） and the molecular descriptor related to the GJC was the lowest unoccupied molecular orbital energy（ELUMO）.The two models of antioxidant activity both showed good predictive power,but the predictive power of the neural network QSAR model of antioxidant activity was *** addition,the two GJC models have similar,moderate predictive *** possible mechanisms of antioxidant activity and GJC of carotenoids were discussed.

关键词： carotenoids antioxidant activity gap junctional communication multilayer perceptron neural network quantitative structure-activity relationship

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Edible insects as a means to address global malnutrition and food insecurity issues

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food Quality and Safety 2018年第1期2卷 17-26页

作者： Jaynie Tao Yao Olive Li department of human nutrition and food science California State Polytechnic UniversityPomonaCaliforniaUSA

Although unconventional in the USA,entomophagy,or the practice of consuming insects,can provide a nutritious relief to many malnourished people in developing *** insects are part of numerous traditional diets found in over 113 countries,including those in Asia,Africa,and South ***,there are 2 billion people consuming over 2000 recorded edible *** of these worldwide insects contain amounts of protein,fat,vitamins,and minerals comparable to commonly eaten *** the popularity of crickets in both developing and developed countries and the nutrient density of locusts,these insects were of particular *** flour,made from a major food crop around the world,was used as an effective vehicle to deliver these insect *** use of inexpensive single-screw cold-forming extrusion technology,due to its capability of high production rate yet low capital and operating costs,was employed in making insect-fortified *** feasibility of incorporating edible insect flours from cricket and locust in an extruded rice product has been demonstrated to be successful with acceptable shelf stability and sensory ***,the insect rice products developed were energy dense(high fat content)and as an excellent source of *** also contained considerable amounts of dietary fibre and *** evaluations involving 120 untrained panelists-suggested cricket formulations were well accepted compared with locust *** is a positive outlook on the overall acceptance of entomphagy even in developed *** a staple food providing 20%of the world’s dietary energy and consumed by over 1 billion people,rice is an ideal vehicle to deliver nutrients carried by edible *** incorporation of insect flours in processed foods such as extruded rice products can greatly promote the consumer acceptance by disguising the‘yuck’factor associated with intact insects.

关键词： edible insect food security malnutrition consumer acceptance extruded rice.

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Optimization of conditions for supercritical fluid extraction of flavonoids from hops (Humulus lupulus L.)

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Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2005年第10期6卷 999-1004页

作者：何国庆熊皓平陈启和阮晖王肇悦 TRAORé Lonseny department of food science and nutrition Zhejiang University Hangzhou 310029 China department of food science and nutrition University of Conakry PB 1147 Guinea

Waste hops are good sources of flavonoids. Extraction of flavonoids from waste hops (SC-CO2 extracted hops) using supercritical fluids technology was investigated. Various temperatures, pressures and concentrations of ethanol (modifier) and the ratio (w/w) of solvent to material were tested in this study. The results of single factor and orthogonal experiments showed that at 50 °C, 25 MPa, the ratio of solvent to material (50%), ethanol concentration (80%) resulted in maximum extraction yield fla- vonoids (7.8 mg/g). HPLC-MS analysis of the extracts indicated that flavonoids obtained were xanthohumol, the principal prenylflavonoid in hops.

关键词： Carbon dioxide Carbon disulfide Ethanol food processing Medicine Optimization Pressure Solvents Temperature

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Batch and fed-batch production of butyric acid by Clostridium butyricum ZJUCB

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Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2005年第11期6卷 1076-1080页

作者：何国庆孔青陈启和阮晖 department of food science and nutrition Zhejiang University

The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, different cultivation pH values ranging from 6.0 to 7.5 were evaluated in 5-L bioreactor. In controlled pH batch fermentation, the optimum pH for cell growth and butyric acid production was 6.5 with a cell yield of 3.65 g/L and butyric acid yield of 12.25 g/L. Based on these results, this study then compared batch and fed-batch fermentation of butyric acid production at pH 6.5. Maximum value (16.74 g/L) of butyric acid concentration was obtained in fed-batch fermentation compared to 12.25 g/L in batch fermentation. It was concluded that culti- vation under fed-batch fermentation mode could enhance butyric acid production significantly (P<0.01) by C. butyricum ZJUCB.

关键词： Clostridium butyricum Batch fermentation Fed-batch fermentation pH Butyric acid production Acetic acid

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Effective extraction of elastase from Bacillus sp. fermentation broth using aqueous two-phase system

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Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2005年第11期6卷 1087-1094页

作者：徐莹何国庆李景军 department of food science and nutrition Zhejiang University School of food science and Technology Southern Yangtze University

This paper presents the evaluation of an aqueous two-phase system （ATPS） for extracting elastase produced by Bacillus sp. EL31410. The elastase and cell partition behavior in polyethylene glycol （PEG）/salt systems was investigated. The suitable system for elastase extraction was PEG/KHEPO4-KEHPO4, in which elastase is mainly partitioned into the PEG-rich phase, while the cells remained in the other phase. The influence of defined system parameters （e.g. PEG molecular mass, pH, NaCl addition） on the partitioning behavior of elastase is described. The concentration of phase forming components, PEG and KHEPO4-KEHPO4, was optimized for elastase recovery by means of response surface methodology, and it was found that they greatly influenced extraction recovery. The optimal ATPS was 23.1% （w/w） PEG 2000 and 11.7% （w/w） KHEPO4-KEHPO4. The predicted recovery was about 89.5%, so this process is suggested to be a rapid and convenient method for elastase extraction.

关键词： Elastase Aqueous two-phase system (ATPS) Bioseparation Purification Optimization Response surface methodology (RSM)

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Social-ecological correlates of fundamental movement skills in young children

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Journal of Sport and Health science 2019年第2期8卷 122-129页

作者： Nan Zeng Susan L.Johnson Richard E.Boles Laura L.Bellows department of food science and human nutrition Colorado State University department of Pediatrics University of Colorado Anschutz Medical Campus

Purpose: To identify the social-ecological correlates associated with fundamental movement skills at the child, family, and environment levels in young ***: Preschool children from 4 Colorado Head Start/preschool centers were recruited from 2010 to 2012. Two hundred twenty-eight children(128 girls; age = 56.08 § 4.09 months; body mass index(BMI) z-score = 0.53 § 1.12(mean § SD); 42.1% Hispanic/Latino) and 159 families were included in the final analysis. Children's perceived competence and fundamental movement skills were assessed via the Pictorial Scale of Perceived Competence and Social Acceptance and the Bruininks-Oseretsky Test of Motor Proficiency, 2 nd edition. Data on the number of children in the family, parent age, BMI, education, employment status, family income, perception of child coordination, and home physical activity environment were collected via a questionnaire. Linear regressions adjusted for child BMI, age, sex, and school site were performed at each ***: Child perceived cognitive competence was positively associated with locomotor skills(p = 0.04; adjusted R2= 0.035) and object-control skills(p = 0.003; adjusted R2= 0.083) at the child level. Parent education, BMI, and perception of child coordination were positively associated with locomotor skills and explained 8.8% of variance, but only parent education was significant(p = 0.04) at the family level. In addition, physical environment was positively associated with locomotor skills(p = 0.02) and explained 5.5% of variance at the environment ***: Social-ecological correlates associated with young children's fundamental movement skills are multidimensional and differ according to skill category at the child, family, and environment levels.

关键词： Activity environment Fundamental movement skills Parent education Perceived cognitive competence Preschool children

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Strategies to modulate the intestinal microbiota and their effects on nutrient utilization, performance, and health of poultry

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Journal of Animal science and Biotechnology 2019年第3期10卷 529-539页

作者： Sudhir Yadav Rajesh Jha department of human nutrition Food and Animal Sciences College of Tropical Agriculture and Human Resources University of Hawaii at Manoa

Poultry is widely produced and consumed meat *** demand is expected to continue increasing to meet the animal protein requirement for ever-increasing human ***,the challenge that poultry scientists and industry face are to produce sufficient amount of poultry meat in the most efficient *** the past,using antibiotics to promote the growth of poultry and manage gut microbiota was a ***,due to concerns over potential fatalistic impacts on food animals and indirectly to humans,their use as feed additives are banned or regulated in several *** this changed context,several alternative strategies have been proposed with some success that mimics the functions of antibiotics as growth promoters and modulate gut microbiota for their beneficial *** include the use of probiotics,prebiotics,organic acids,and exogenous enzyme,among *** microbiota and their metabolic products improve nutrient digestion,absorption,metabolism,and overall health and growth performance of *** paper reviews the available information on the effect of feed additives used to modulate intestinal microbiota of poultry and their effects on overall health and growth *** these functions and interactions will help to develop new dietary and managerial strategies that will ultimately lead to enhanced feed utilization and improved growth performance of *** review will help future researchers and industry to identify alternative feed ingredients having properties like prebiotics,probiotics,organic acids,and exogenous enzymes.

关键词： Enzymes Microbiota Organic acids Poultry Prebiotics Probiotics

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