Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province

Zhenjiang, China

Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province

Zhenjiang, China
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Sun L.,Jiangsu University | Sun L.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Liu B.,Chinese Academy of Agricultural Sciences | Cai J.-R.,Jiangsu University | And 3 more authors.
Food Analytical Methods | Year: 2015

A machine vision system based on the fusion of X-ray imaging and the binocular stereo vision was developed for the online estimation of net content in block frozen shrimp. Supported algorithms were specifically developed and programmed for the online system, including image acquisition, processing, controlling the whole process, and saving the classification results. The results indicated that the relationship between mean gray value of X-ray image and net content of shrimp is linearity. Meanwhile, the coefficient of linear model also can be represented by the thickness of block frozen shrimp. An online estimation model was built with mean gray value and thickness as dependent variables. Binocular stereo vision technology was also employed to acquire thickness information of samples to revise the estimation model. The performance of the predictive model using two variables was achieved, with R (correlation coefficient) of 0.9475 and root-mean-square error of prediction (RMSEP) of 22.0993 in prediction set. Good consistence confirmed that the proposed method has significant potential application in online estimation of content in block frozen shrimp. © 2015, Springer Science+Business Media New York.


Huang L.,Jiangsu University | Huang L.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Ma H.,Jiangsu University | Ma H.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | And 4 more authors.
Protein Expression and Purification | Year: 2012

To produce more angiotensin converting enzyme inhibitory peptides (ACEIP), we have established a high-efficiency Escherichia coli expression system. The DNA-coding sequence for the recombinant protein, which was subcloned into the vector pET-30a(+), has been expressed as inclusion bodies in E. coli BL21 (DE3). The influences of induction time and concentration of isopropyl-β-d- thiogalactopyranoside (IPTG) on the expression of recombinant protein were studied. The resulting expression level of the protein accounted for about 31% of cellular protein at a temperature of 37 °C, IPTG concentration of 0.6 mM and induction time of 7 h. The inclusion bodies were washed, separated from the cells, and solubilized with urea. After purification by affinity chromatography, the recombinant protein was recovered with a high purity of about 90%. Molecular weight of the recombinant protein was measured using Tricine-SDS-PAGE. Peptide IYPR was obtained by cleavage of the recombinant protein with trypsin and the IC 50 value was 61 mg/L. The antihypertensive activity in spontaneously hypertensive rats (SHRs) was also investigated. Single oral administration of this peptide in 10-week old SHRs resulted in a significant reduction of systolic blood pressure to 50 mm Hg at 4 h. The data obtained provide a good reference for further development of peptide Ile-Tyr-Pro-Arg into an effective antihypertensive agent for prevention and treatment of hypertension. © 2012 Elsevier Inc. All rights reserved.


Sun L.,Jiangsu University | Sun L.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Zhu Y.,Jiangsu University | Gu H.,Jiangsu University | And 2 more authors.
Jiangsu Daxue Xuebao (Ziran Kexue Ban)/Journal of Jiangsu University (Natural Science Edition) | Year: 2015

An online system was developed based on acoustic resonance with digital signal processing (DSP, TMS320C5509A) system for eggshell crack detection. Signal acquisition and processing, automatic impact and upper computer sub modules were improved to meet the requirements of automatic and industrialized production. Acoustic signals of egg were motivated, acquired and processed by the proposed system. Based on experiments, differences between the signals of intact and cracked eggs were analyzed by spectral analysis. Five egg excitation resonant characteristics of zero-pass points in time signal, the frequency bands and amplitudes of the first two characteristic peaks in frequency signal were used as input vectors of identification model to discriminate intact and crack eggs. The results show that the identification rates of cracked eggs and the detecting speed can reach above 90% and 4 eggs per second, respectively. The proposed system has significant potential for online detection of cracked eggs. ©, 2015, Journal of Jiangsu University (Natural Science Edition). All right reserved.


Sun L.,Jiangsu University | Sun L.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Yuan L.-M.,Jiangsu University | Cai J.-R.,Jiangsu University | And 3 more authors.
Food Analytical Methods | Year: 2014

This paper proposed a non-destructive method for online estimation of egg freshness based on machine vision and dynamic weighing. The machine vision system and the dynamic weighing system were developed for the measurement of egg external physical characteristic and weight. Digital signal processing was employed to denoise, analyze, and extract the effective feature information from the images and vibration signals. Then, the method of multiple linear regressions was used to build model for Haugh unit prediction using the parameters of long axis, minor axis, and weight. The performance of the predictive model using six variables was achieved, with R (correlation coefficient) of 0.8653 and RMSEP (root mean square error of prediction) of 3.7454 in prediction set. The speed of the system reaches four eggs per second for every measurement. Good consistence confirmed that the proposed method has a significant potential application in online estimation of the egg freshness. © 2014 Springer Science+Business Media New York.


Sun L.,Jiangsu University | Sun L.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Cai J.-R.,Jiangsu University | Cai J.-R.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Zhao J.-W.,Jiangsu University
Intelligent Automation and Soft Computing | Year: 2015

This study was conducted to develop a fast machine vision system based on TOF (time of flight) three-dimensional (3D) imaging technology for automatic citrus recognition and location. Supported algorithms were specifically developed and programmed for image acquisition and processing. An adaptive filter coupled between partial differential equations filter and shock filter was presented to remove noise and sharpen edges efficiently. Image analysis algorithms integrated both range and amplitude information to generate regions of interest and parameters that are characteristic or very likely to belong to spherical objects. The three-dimensional position of the fruit and radius are obtained after the recognition stages. The total classification results showed that approximately 81.8% were detected and false detection occurred only once. On the whole, the process of imaging, recognition and location consumes less than 50 ms/fruit. © 2015, © 2015 TSI® Press.


Huang L.,Jiangsu University | Huang L.,Key Laboratory for Physical Processing of Agricultural Products of Jiangsu Province | Zhang X.,Jiangsu University | Li Y.,Jiangsu University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2016

Peanut protein, an abundant and low-cost by-product of peanut oil production industry, is rich in essential amino acids. Traditionally, this protein has been used for animal feed and fertilizer, and it is desirable to find new uses for peanut protein. The ultrasound technology, as an emerging non-thermal processing physical technology, has extensive applications in food system. To improve the functional properties and expand its application range, peanut protein isolate was treated with ultrasound and acid. A volume of 100 mL of peanut protein isolate solution (the concentration was 0.01 g/mL) was prepared and adjusted to pH value of 3.0 with 0.1 mol/L HCl. The mixtures were immediately treated using an ultrasonic cell crusher with a flat tip probe at 20 kHz at 600 W ultrasonic power for 5 min (ratio of work time to break time was 2 s:2 s). The effects of acid, ultrasound and coupled ultrasound-acid pretreatments on the solubility, ultraviolet spectra, fluorescence spectra, secondary structure and nanostructure of peanut protein isolate were investigated. The transformation mechanism of the peanut protein aggregation state induced by ultrasound and acid was also discussed. Results of solubility showed that the ultrasound pretreatment promoted the transformation from insoluble aggregates to soluble aggregates. With the pretreatments of ultrasound and coupled ultrasound-acid, solubility of peanut protein isolate was increased by 12.9% and 15.3% respectively (P<0.05). There was no significant difference (P>0.05) in solubility between control and acid pretreatment. Acid and ultrasound pretreatments caused the increase of absorbance in ultraviolet spectra and the red shift of maximum emission wavelength in fluorescence spectra, which indicated that more phenylalanine, tryptophan, and tyrosine residues were exposed outside the polypeptide chains due to molecular unfolding and subunit dissociation. The CD spectra showed that coupled ultrasound-acid pretreatment resulted in the increase in the α-helix content by 21.9 % and random coils content by 1.8%, while β sheet decreased by 3.6% (P<0.05). The changes in the contents of the secondary structure might have been attributed to the disruptions of the interactions between local sequences of amino acids and between different parts of the molecule. Moreover, the analyses of microstructure by atomic force microscope revealed that the particle height and size decreased significantly with the pretreatments of ultrasound, acid and combination of both. Combination of ultrasound and acid was especially effective to promote dissociation of protein. Through the investigations of solubility, ultraviolet spectra, fluorescence spectra, secondary structures and nanostructure, we could find that acid and ultrasound pretreatments destroyed hydrophobic interactions of protein molecules, induced molecular unfolding, and caused more hydrophobic groups and regions inside the molecules to be exposed to the outside. As a result, the maximum emission wavelength of fluorescence shifted and particle size decreased. Therefore, we conclude that ultrasound pretreatment under acid condition can remarkably promote subunit dissociation and unfolding of peanut protein, which will provide the theoretical basis and technological support for the preparation of functional protein obtained by subunit recombination. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.

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