scholarly journals Evaluation of Yogurt Quality during Storage by Fluorescence Spectroscopy

2019 ◽  
Vol 9 (1) ◽  
pp. 131
Author(s):  
Haifeng Sun ◽  
Ling Wang ◽  
Hao Zhang ◽  
Ang Wu ◽  
Juanhua Zhu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Fluorescence Spectra ◽  
Ph Value ◽  
Average Rate ◽  
Ambient Air ◽  
Rate Of Change ◽  
Fluorescence Signal ◽  
Good Linear ◽  
Good Linear Relationship

The physico-chemical parameters including pH and viscosity, and the fluorescence signal induced by fluorescent compounds presenting in yogurts such as riboflavin and porphyrin were measured during one week’s storage at room temperature when five brands of yogurt samples were exposed to ambient air. The fluorescence spectra of yogurt showed four evident emission peaks, 525 nm, 633 nm, 661 nm, and 672 nm. To quantitatively investigate the quality of yogurt during deteriorating, a calculating method of the average rate of change (ARC) was proposed to study the relative change of fluorescence intensity in the spectral range of 600 to 750 nm associated with porphyrin and chlorin compounds. During the storage, the time evolution of two ARC, pH value, and viscosity were regular. Moreover, the ARC showed a good linear relationship with pH value and viscosity of yogurt. Further, multiple linear regression (MLR) models using two ARC as independent variables were developed to verify the dependence of fluorescence signal with pH value and viscosity, which showed a good linear relationship with an R-square of more than 85% for each class of yogurt. The results demonstrate that fluorescence spectra have a great potential to predict the quality of yogurt.

Determination of Chitosan Oligosaccharide Content by Acetylacetone Spectrophotometry Method

2012 ◽  
Vol 503-504 ◽  
pp. 543-547 ◽  
Author(s):  
Ze Ping Xu ◽  
Chuan Lun Yang ◽  
Xin Qing Zhang ◽  
Xiu Zhi Wang ◽  
Bao Sheng Huang
Keyword(s):  
Hydrochloric Acid ◽  
Linear Relationship ◽  
Regression Equation ◽  
Common Method ◽  
Chitosan Oligosaccharide ◽  
Average Recovery ◽  
Good Linear ◽  
Good Linear Relationship

Objective: To establish a common method to detect the content of chitosan oligosaccharide. Methods: Chitosan oligosaccharide was hydrolyzed completely by concentrated hydrochloric acid, and the solution was regulated into neutral with NaOH. Then, determined the absorbance in 525nm, and substituted into the regression equation to determine the results. Results: The results showed there was a good linear relationship when the concentration of chitosan oligosaccharide ranged from 0.02 mg/mL to 0.12 mg/mL, r2 = 0.999. The average recovery of chitosan oligosaccharide samples was 99.25%. Conclusion: The method is sensitive, accurate and simple. It is applied to determine of the content of chitosan oligosaccharide.

Carbon Nanoparticle Spectrophotometric Determination of Glucose

2013 ◽  
Vol 726-731 ◽  
pp. 1453-1456
Author(s):  
Ai Hui Liang ◽  
Jing Peng ◽  
Yuan Li ◽  
Ling Ling Ye ◽  
Gui Qing Wen
Keyword(s):  
Linear Relationship ◽  
Spectrophotometric Determination ◽  
Glucose Concentration ◽  
Carbon Nanoparticles ◽  
Absorption Peak ◽  
Carbon Nanoparticle ◽  
Good Linear ◽  
Good Linear Relationship ◽  
Glucose Injection

In the presence of NaOH, glucose hydrolyze and polymerize to generate yellow carbon nanoparticles that had an absorption peak at 336 nm. Under the selected conditions, result showed the concentration of glucose have a good linear relationship between absorbance value and glucose concentration in the range of 0.0005-0.060 mol/L. This method has been used for the assay of glucose injection sample, with simplicity, rapidity, and accuracy.

Research on the Physical Characteristics in Maize Deep-Bed Drying Process

2011 ◽  
Vol 314-316 ◽  
pp. 1478-1482
Author(s):  
Ye Zhang ◽  
Chang You Li ◽  
Zhi Wei Mai ◽  
Feng Ying Xu ◽  
Li Xu
Keyword(s):  
Linear Relationship ◽  
Pressure Loss ◽  
Static Pressure ◽  
Physical Characteristics ◽  
Test Stand ◽  
Thermal Engineering ◽  
Drying Process ◽  
Good Linear ◽  
Good Linear Relationship ◽  
The Relationship

In order to investigate the static pressure loss of the maize deep-bed drying related to the ratio of air flux to grain mass, the experiments based on the theory of thermal engineering and deep-bed drying were engaged in. These experiments conducted on the ventilation test stand indicate the relationship between static pressure loss, depth of the bed, ventilative dimensions and the ratio of air flux to grain mass. The investigation results that during the drying, the static pressure loss increases related to the increased ratio of air flux to grain mass with the constant bed depth. The good linear relationship between the static pressure loss and ventilative dimensions was indicated. With the control of the constant ventilative dimensions, the static pressure loss increases related to the decreased ratio of air flux to grain mass and it will dramatically increased when the ratio of air flux to grain mass is small enough. To reduce the static pressure loss, enlarging the ventilative dimensions, reducing the thickness of the drying layer and reducing the speed of the wind will be the proper methods.

Studies of the measurement and interpretation of potato sprout growth

1978 ◽  
Vol 90 (2) ◽  
pp. 335-340 ◽  
Author(s):  
D. C. E. Wurr
Keyword(s):  
Linear Relationship ◽  
Field Performance ◽  
Tuber Weight ◽  
Potato Tubers ◽  
Good Linear ◽  
Potato Sprout ◽  
Good Linear Relationship ◽  
Sprout Length ◽  
The Relationship ◽  
Sprout Growth

SummaryTotal sprout length and the length of the longest sprout were shown to be the most universally useful measurements to estimate sprout development in batches of potato tubers. A good estimate of sprout weight was also derived from measurements of total sprout length. There was a good linear relationship between total sprout length and initial tuber weight but the relationship varied considerably with the time of measurement and the temperature of storage.It is suggested that if sprout measurements are to be used to predict the field performance of a batch of tubers the changing pattern of sprout vigour with time needs to be more closely understood.

Intact Loess Structural Loss Parameter in Humidification Process

2013 ◽  
Vol 655-657 ◽  
pp. 1868-1873
Author(s):  
Xi Chen ◽  
Bin Bin Chen
Keyword(s):  
Linear Relationship ◽  
Water Content ◽  
Good Linear ◽  
Good Linear Relationship ◽  
Loss Parameter ◽  
Structural Loss ◽  
Set Up ◽  
Intact Loess

Based on soil structural view, the mechanism of loess structure is analyzed in humidification process. The concept of the loess structure loss is proposed.And quantitatively parameter described the loess structure loss is set up, that is structure loss parameter. And then the influence laws of humidification and loading on loess structure loss are discussed. The results show that structure loss parameters is increasing with the increase of the humidification water content. The moistening collapsibility has a good linear relationship with loess structure loss parameters.

A sensitive Pb2+ testing method based on aptamer-functionalized peroxidase-like 3D-flower MoS2 microspheres

2017 ◽  
Vol 41 (15) ◽  
pp. 7052-7060 ◽  
Author(s):  
Xiu Wang ◽  
Chunlei Yang ◽  
Mei Yan ◽  
Jinghua Yu
Keyword(s):  
Linear Relationship ◽  
Current Response ◽  
Good Linear ◽  
Testing Method ◽  
Good Linear Relationship ◽  
Target Molecules

We, herein, report a sensitive EC bioanalytical protocol for the detection of Pb2+ based on AuPt–MCNTs as a platform and 3D-flower MoS2–GR hybrids as signal probes. This method showed a good linear relationship between the current response and the Pb2+ concentration. It can be widely utilized for the identification of other target molecules.

scholarly journals Application of the log k pair linearity rule and proportionality rule to the RPP mobile phase scales estimation on cyano-silica column

2001 ◽  
Vol 66 (3) ◽  
pp. 173-178
Author(s):  
Tomislav Janjic ◽  
Gordana Vuckovic ◽  
Milenko Celap
Keyword(s):  
Linear Relationship ◽  
Satisfactory Agreement ◽  
Linear Dependence ◽  
Mobile Phase ◽  
Silica Column ◽  
Good Linear ◽  
Good Linear Relationship ◽  
Solvent Strength ◽  
Proportionality Rule

On the basis of literature-reported log k values, the Log k pair linearity rule and the Proportionality rule were found to be also valid in the case of cyano-silica sorbent, whenmethanol, acetonitrile or propane-2-olwere used as modifiers. The RPPscales, reflecting the solvent strength, are in good linear relationship with the experimentally determined log k values. Furthermore, in the case of methanol and acetonitrile, the linear dependence: log k = f(mol%of modifier) was also established. In the function obtained in a such way, the intercept and the slope exhibit an approximate linear dependence. Finally, in the case of methanol, the experimentally obtained log k values are in a satisfactory agreement with the values calculated by the above equation.

scholarly journals Study on the Fluorescence Spectra Characteristics of Vinegar-Water Solutions

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Dan Li ◽  
Xuan Wang ◽  
Caiqin Han
Keyword(s):  
Molecular Orientation ◽  
Fluorescence Spectra ◽  
Ph Value ◽  
Uv Light ◽  
Chemical Properties ◽  
Polarization Degree ◽  
Water Solutions ◽  
Peak Intensity ◽  
Polarization Spectra

Fluorescence spectra and polarization spectra of vinegar-water solutions with different concentration of CH3COOH have been studied. The characteristics and mechanism of fluorescence spectra are discussed, and polarization degree is calculated. Vinegar-water solutions are excited by ultraviolet (UV) light at 380 nm. The characteristic fluorescence peaks of the solution were identified at 445 nm and 470 nm. The type of emission fluorescence isπ⁎→n. With the increasing concentration of CH3COOH/pH value, the peak intensity is enhanced first, and then fluorescence quenching occurs. The polarization degree confirms the molecular orientation of different sample solutions. This research provides theoretical and experimental basis for the physical/chemical properties and quality of vinegar detection by florescence spectroscopy.

Relationship between axial motion and volume displacement of the diaphragm during VC maneuvers

1992 ◽  
Vol 72 (4) ◽  
pp. 1536-1540 ◽  
Author(s):  
J. A. Verschakelen ◽  
K. Deschepper ◽  
M. Demedts
Keyword(s):  
Theoretical Analysis ◽  
Linear Relationship ◽  
Vital Capacity ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Axial Motion ◽  
Cross Sectional ◽  
Good Linear ◽  
Good Linear Relationship ◽  
The Mean

During semistatic inspiratory and expiratory vital capacity (VC) maneuvers, axial motion of the diaphragm was measured by lateral fluoroscopy and was compared with diaphragmatic volume displacement. Axial motion was measured at the anterior, middle, and posterior parts of the diaphragm, and the mean of these measurements was used. The volume displacement was calculated in two ways: first, from respiratory inductive plethysmograph-(Respitrace) derived cross-sectional area changes of rib cage and abdomen (Vdi,RIP) by means of a theoretical analysis described by Mead and Loring (J. Appl. Physiol. 53: 750–755, 1982) and, second, from fluoroscopically measured changes in position and anteroposterior surface of the diaphragm (Vdi,F). A very good linear relationship was found between Vdi,RIP and Vdi,F during inspiration as well as expiration (r greater than 0.95), indicating that the analysis of Mead and Loring was valid in the conditions of the present study. The diaphragmatic volume displacement (active or passive) accounted for 50–60% of VC. A very good linear relationship was also found between mean axial motion and volume displacement of the diaphragm measured with both methods during inspiration and expiration (r greater than 0.98). Our data suggest that, over the VC range, diaphragmatic displacement functionally can be represented by a pistonlike model, although topographically and anatomically it does not behave as a piston.

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