Volume 34, Issue 3 (2018)
Authority Forum
Innovation status and prospect of food safety science and technology in China
ZANG Mingwu, MO Yingjie, WANG Shuo, CHEN Fang, WANG Jing, LI Xiaoman, and HOU Wei
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.001
Technology is an important support factor for food safety and plays an important role in controlling food safety risks and ensuring food safety. In recent years, support for food safety R&D in China has been significantly strengthened, and the supporting role of food safety technology has been continuously promoted. From the basic research, R&D of common technology and equipments, and whole controlling of food chain, this article comprehensively expounds the achievements of food safety science and technology innovation in China, analyzes the problems still existing in food safety science and technology, and summarizes the international experience of food safety science and technology innovation and development aims to provide reference for the innovation development of food safety science and technology in China.
Fundamental Research
Effect of fermented wheat bran on biochemical and baking properties of dough and bread
YANG Wendan, ZHANG Binle, ZHUANG Jing, YANG Zixuan, JIANG Hui, XU Yan, ZHENG Jianxian, HUANG Weining, and OMEDIJacob Ojobi
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.002
The biochemical, rheological and scanning electron microscope (SEM) analysis were respectively used to evaluate the effect of added wheat bran fermented with Marx Kluyveromyces on dough and bread biochemical and baking properties. The results showed that fermented wheat bran was rich in natural enzymes such as cellulase, xylanase and feruloyl esterase. The enzymes produced enhanced the solubilization of arabinoxylan and the release of phenols during bread making, thereby improving nutrition of the bread. Compared to dough with added xylanase, gas retention, continous wheat gluten networks and the baking characteristics of bread with added Marx Kluyveromyces fermented bran significantly improved, especially, the texture and specific volume. These results indicated that fermented bran with Marx Kluyveromyces could be used as a natural and functional ingredient for bread making.
Influence of alkaline-ethanol filming system for wheat gluten-based films containing wheat-bran cellulose
YU Guoxian, XIAO Liyuan, WU Hejun, LI Shanshan, LUO Qingying, LIU Xingyan, CHEN Anjun, SHEN Guanghui, and ZHANG Zhiqing
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.003
Wheat gluten and wheat-bran cellulose were mixed into alkaline-ethanol system. The blend dispersions were used to prepare composite films using a film casting method in this study. The effects of solid-liquid ratio, wheat-bran cellulose content, the additive amount of glycerol, ethanol concentration, pH values and xanthan gum content in film forming system on physical properties of composite films were investigated. The physical properties contain tensile strength, elongation at break, water vapor permeability, water solubility and light transmittance etc. In the results, wheat-bran cellulose could significantly enhance the tensile strength, and decreased the water vapor permeability and water solubility. The highest tensile strength was 20.44 MPa, which was 140% higher than pure wheat gluten film. The factors of film forming system have different effects on the physical properties of the composite films. The glycerol content was the most important for the physical properties, followed by wheat-bran cellulose content and xanthan gum minimum. The results have carried on the preliminary exploration to wheat gluten composite films with excellent properties.
Study on properties of cross-linked oxidized acetylated waxy corn starch
HUANG Xiujin and TONG Qunyi
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.004
The cross-linked oxidized acetylated compound modified starch was prepared by using waxy corn starch as raw material, sodium trimetaphosphate as cross-linking agent, sodium hypochlorite as oxidant and acetic anhydride as acetylation reagent. The morphology and structure of the starch granules were analyzed by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR). The whiteness, transparency, gelatinization characteris-tics, acid and shear resistance of the compound modified starch were measured. The results showed that the whiteness of the modified starch was increased to 97.2, the light transmittance of the paste was up to 71.0% as well as the acid and shear resistance were also improved. The picture of SEM showed the changes about the starch particle morphology. The infrared spectrum manifested the characteristic absorption peak of each group, confirming the change of its molecular structure. The preparation of compound modified starch is beneficial to improve the application value of waxy corn starch in the food industry.
Chemical mechanism of antioxidation of theaflavin
XIE Hong, LUO Zhicong, and LI Xican
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.005
To research the antioxidant chemical mechanism of theaflavin, the antioxidant activities of theaflavin were measured in vitro using several chemical models, including DPPH· (1,1-diphenyl-2-picryl-hydrazyl) scavenging, ABTS+· \[2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)\] scavenging, and Cu2+-reducing power assays, which was compared with the positive control Trolox. In these assays, theaflavin along with positive control Trolox exhibited dose-dependently antioxidant abilities. The relative antioxidant levels of theaflavin vs Trolox (i.e. IC50,Trolox/IC50,theaflavin value) were calculated as 2.57, 3.13 and 3.74, respectively for DPPH·-scavenging assay, ABTS+·-scavenging assay, and Cu2+-reducing power assay. In conclusion, theaflavin possessed higher antioxidant levels than Trolox. Its antioxidant mechanisms may include hydrogen atom transfer (HAT) and electron transfer (ET). Through HAT mechanism, theaflavin may be transferred into stable ortho-quinone form.
Study of inhibition of black tea theabrownin and tea polysaccharides on lipase
LI Xianglong, LI Xiaomei, YANG Xu, TANG Lei, and XU Jingyi
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.006
In order to investigate the inhibition of lipase by theabrownin and polysaccharide of black tea, the theabrownin and polysaccharides were extracted from the same black tea in different regions. The inhibition rate of lipase activity of theabrownin and polysaccharide was analyzed by p-nitrophenol method, and the inhibitory mechanism of theabrownin and polysaccharide on lipase was discussed. The results showed that the inhibition of lipase by theabrownin and polysaccharide of black tea was significant. The IC50 of Pu-er theabrownin and polysaccharide were 25.96 and 47.57 mg/mL, respectively, which were the minimum, and the inhibitory effect was the best, secondly for liupu tea. The worst inhibitory effect was that the theabrownin and polysaccharide of fu-brick. The inhibition effects of theabrownin and polysaccharide of Kang brick were between those of the liupu tea and fu-brick. The inhibition types of theabrownin of each black tea were the complex of reversible competitive and noncompetitive, while the liupu tea was closed to the competitive inhibition type. The inhibition types of polysaccharide of Pu-er tea, liupu tea and Kang brick were the complex of reversible competitive and noncompetitive, while the polysaccharide of fu-brick was reversible competitive inhibition.
Effect of different broken methods on gel structure of silver carpsurimi
WANG Lei, FAN Daming, HUANG Jianlian, ZHAO Jianxin, YAN Bowen, ZHOU Wenguo, ZHANG Wenhai, and ZHANG Hao
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.007
Compared with chopping method, the effect of stirring method on the gel properties of surimi products was studied. The results showed that this method of stirring-broken method increased the gel strength and water holding capacity of silver carp surimi, increased the hardness, adhesiveness, adhesiveness and chewiness, but had no effect on the whiteness. Under the conditions of 2% and 3% of salt addition, this kind of stirring-broken method had a significant effect on texture improvement of the surimi product, with the gel strength increasing by 70.2% and 66.7% respectively. The results of the content of salt-soluble protein, active sulfhydryl group, chemical reaction and turbidity of actomyosin showed that stirring-broken method increased the content of active sulfhydryl group, so that more sulfhydryl group oxidationed into disulfide bond to improve hydrophobic interactions, promoting the aggregation of protein molecules, resulting in increased turbidity of actomyosin, making the three-dimensional gel network more compact.
Study on the effect of protease on the quality of biscuits
YAO Xiaodan, XU Xueming, WU Fengfeng, and ZHOU Xing
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.008
The effect of Papaya protease(PAP), Neutral protease(NEP) and Bromelain protease(BRP) on the qualities of biscuit with different dosages were studied on specific volume, texture and color of hard biscuit compared with the addition of Sodium metabisulfite (SMS) and cysteine(CYS), respectively. The results showed that all the 3 proteases could improve the specific volume, texture of biscuit. With the same amount of addition, PAP has the best effect of improving the qualities of biscuit than SMS and CYS. NEP and BRP were weaker than SMS, but better than CYS. It was found that degradation of glutenin macromolecule polymer in gluten was the major factor to weaken the gluten and improve the quality of biscuit for the proteases’ addition after the parameters of dough rheology, flour solvent retention capacity(SRC) and gluten protein molecular weight distribution. were determined. Essential differences between the proteases and the chemical additives in the way to weaken the gluten were found.
Study on physical properties and oxidation stability of oil-in-water emulsions based on different vegetable oils
LIU Ning, CUI Junjie, JIN Yuchen, LI Cheng, CHEN Qiannan, and DAI Chunji
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.009
In the present study, four types of O/W emulsions were prepared by using perilla oil, olive oil, palm oil and sunflower oil as the oil phase, and whey protein isolate was, as the emulsifier. The physical properties were studied, containing particle size, ζ-poten-tial, flocculation index and others. Meanwhile, the oxidation stabilities of different emulsions in storage were compared. The results showed that among the selected emulsions, perilla oil emulsion showed the smaller volume average diameter D4,3 (0.824 μm) and higher ζ-potential absolute value (37.5 mV), which resulted in a good storage stability. However, due to the perilla oil was mainly composed of polyunsaturated fatty acid, the system was easily oxidized. Palm oil emulsion showed good oxidation stability, namely, the lowest primary and secondary oxidation product concentration. But this emulsion had larger particle size (1.845 μm of D4,3), and its physical stability was poor. Moreover, it was found that there was a relevance between protein oxidation and lipid oxidation in emulsions through endogenous fluorescence assay.
Study on adsorption of lead by two Lactobacillus strains
XU Ying, LI Jie, HE Dandan, and LU Jiali
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.010
Bifidobacterium and Lactobacillus rhamnosus were studied about their the tolerance and adsorption of lead. The single-factor experiments were carried out by pH, the initial amount of bacteria and the initial lead concentration. The process of two strains combined with lead ion was simulated by thermodynamics and kinetic models. The state of lead ion was analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy. The results showed that two strains had good tolerance to lead. The optimal conditions of adsorption were as follows: pH was 6, initial amount of bacteria was 1 g/L, initial concentration of lead was 50 mg/L, and the adsorption rates of lead were 97.44% and 96.87%, respectively. Langmuir-Freundlich model was more suitable than the Langmuir and Freundlich ones. Pseudo second order model had dominance in comparison to pseudo first order model. It showed that the mechanism of two strains combined with lead was chemical adsorption and physical adsorption.
Screening of lipase producing yeast and optimization of fermentation conditions from Kazak artisanal cheese in Xinjiang uighur autonomy region
LIU Fei, ZHENG Xiaoji, LI Baokun, SHI Xuewei, DONG Juan, LI Kaixiong, and ZHUGE Bin
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.011
100 strains were isolated from traditional Kazak cheese in different parts of Xinjiang Uygur Autonomous Region. Four yeast strains Y-2, Z-5, S-6 and N-5 of producing lipase were screened by RB and Rhodamine B medium and they were identified by 26S rRNA gene D1/D2 and internal transcribed spacers. The results showed that strains Y-2 and Z-5 were belonged to Kluyveromyces marxianus, while S-6 and N-5 belonged to Pichia kudriavzevii and Kluyveromyces lactis, respectively. The lipase producing activities of the 4 strains were determined by p-nitrophenol method, and the K. marxianus Z-5 was the highest, up to 23.00 U/mL. The optimum lipase production conditions of K. marxianus Z-5 were determined as follows: fermentation temperature 30 ℃, pH 7.5, inoculum 2.5 mL/100 mL. The obtained enzymatic activity was 25.99 U/mL.
Analysis of functional components and organic selenium in Se-enriched Citrus vesscosa
YANG Xu
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.012
The contents of total phenolics, flavonoids, ascorbic acid, glutathione and carotenoid were examined in five different processed and utilized parts, which were peels, pulps, juices, pomaces and seeds. The optimum extraction process of inorganic selenium was determined by single factor and response surface design. Combining with total selenium and inorganic selenium contents, analyzed the ratio of organic selenium in various parts. Results indicated that there were significant differences in the contents of these functional nutrients, while the peels had the highest contents. When the materials were extracted with the ratio of 115.20 (material to water) at 91.22 ℃ for 7.42 min, the inorganic selenium content in the extracts was highest. By this processing of inorganic selenium extraction, the measured ratios of organic selenium in peels, pulps, juices, pomaces and seeds were 78.42%, 82.85%, 79.92%, 80.26%, 83.88%, respectively.
Analysis of fatty acid composition and content in three strains of Stropharia rugoso-annulata by GC-MS
ZHAO Yan, REN Yunfei, CHEN Mingjie, ZHA Lei, SONG Xiaoxia, GUO Ligang, and WANG Chenguang
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.013
The fatty acids composition and relative content were analyzed by gas chromatography-mass spectrometry (GC-MS), which were extracted from the mycelia of Stropharia rugoso-annulata Farlow apud Murrill strains Gaoyou, Zhaoyang and Tufei. The results showed that 15 kinds of saturated fatty acids and 18 kinds of unsaturated fatty acids were found in Gaoyou and Zhaoyang mycelia. The fatty acids composition in Tufei mycelia consisted of 11 kinds of saturated fatty acids and 17 kinds of unsaturated fatty acids, which were less than those in Gaoyou and Zhaoyang mycelia. The relative content of unsaturated fatty acids was higher than that of saturated fatty acids in three stains of Stropharia rugoso-annulata, accounting for 77.4%, 77.5% and 78.7% of the total fatty acids in Gaoyou, Zhaoyang and Tufei, respectively. Linoleic acid was the main unsaturated fatty acid, which were 76.8%, 88.5% and 72.8% of the total unsaturated fatty acids in mycelia of Gaoyou, Zhaoyang and Tufei, respectively. Palmitic acid was the main saturated fatty acid, which accounted for 64.3%, 69.2% and 62.5% of the total saturated fatty acids in mycelia of Gaoyou, Zhaoyang and Tufei, respectively.
Safety & Inspection
Fisher discriminant analysis for moldy degrees of maize samples based on the feature selection of hyperspectral data
DAI Songsong and YIN Yong
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.014
In order to improve the identification accuracy of moldy degrees of maize samples using hyperspectral, the identification effects of moldy maize at the full wavelength and the characteristic wavelength were investigated in this study, respectively. Firstly, the hyperspectral data of 250 moldy maize samples were obtained by hyperspectral image acquisition system, and the standard normal variate (SNV) and multiplicative scatter correction (MSC) were employed to preprocess the original data; and then the MSC was adopted by comparing the results of the preprocessed and non-preprocessed data. Secondly, nine characteristic wavelengths were selected by using the partial least squares regression coefficients. Finally, Fisher discriminant analysis (FDA) was used to analyze the training set at full wavelengths and characteristic wavelengths, and examined by the corresponding test set. The FDA results showed that the accuracy of the training set and test set were 97.71% and 97.33% for full wavelengths case, respectively, and were 100.00% and 98.67% for characteristic wavelengths case, respectively. The accuracy of the training set and test set at 9 characteristic wavelengths were 100.00% and 98.67% respectively. The research findings showed that the characteristic wavelengths could be used to represent the moldy degrees of maize samples, which was helpful to improve the identification correct rate of moldy maize. Moreover, the research findings might provide a reference for identifying the other agricultural products using hyperspectral technology.
Effect of degradation of nitrite by organic acids in pickles
SHANG Jingtian, WANG Xiujun, and WANG Jihui
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.015
In order to investigate the degradation of nitrite by organic acids during the fermentation of pickles, the organic acids were analyzed by high performance liquid chromatography (HPLC), and 6 different kinds of organic acid for nitrite degradation in vitro were studied. The results showed that the pickles contained oxalic acid, tartaric acid, lactic acid, acetic acid, succinic acid and other organic acids. In 72 hours, all 6 kinds of organic acid could degrade nitrite; the order of ability of nitrite degradation was: oxalic acid > tartaric acid > citric acid > malic acid > lactic acid > succinic acid > acetic acid, and the nitrite degradation rate also increased with the increase of the initial concentration of organic acid. The temperature could also improve the degradation of organic nitrite.
Uncertainty evaluation of the determination of Aflatoxin B1 in peanut butter by high performance liquid chromatography
XIAO Lilong and HUA Jin
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.016
In order to evaluate the uncertainty of determination of Aflatoxin B1 in peanut butter by high performance liquid chromatography. According to the uncertainty assessment described in CNAS—GL06-2006 Guidance on evaluation the uncertainty in chemical analysis and JJF 1059.1—2012 Evaluation and expression of uncertainty in measurement, the components of uncertainty in the measuring process were studied and analyzed, and the related expanded uncertainty was calculated and evaluated. The results of method showed the content of Aflatoxin B1 in peanut butter was 25.12 μg/kg, the related expanded uncertainty was 2.1%, and the determination result was X=(25.12±0.528) μg/kg, k=2. Among the 6 factors of uncertainty, the content of targeted ions from liners fitting and sample preparation was the main factors which influenced the results mostly. Through reducing the amounts of these factors, the quality of the determination results can be increased. It could improve the accuracy of measurements in routine tests.
Optimization gelling medium and color developer for bacterial testing slip
GUO Dengfeng, WANG Lingjia, SHU Xiaomeng, YANG Xiao, ZHANG Wei, and ZHANG Guangfeng
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.017
The cold water-soluble gel agent was screened and the gel medium composition and developer concentration were optimized，by comparing with colony count test results between bacterial testing slip and pour-plate culture method. The best composition was that carrageenan and CMC mixed in 21 (W/W), the gel powder and the medium powder mixed in 21 (W/W) and TTC actual concentration of 0.025 mg/mL. The colony count test results were no significant difference compared with the pour-plate culture method. The optimized gelling agent and color developer could be used to prepare bacterial testing slip.
The influence of online meal ordering on food safety and its legal regulation
CHEN Li
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.018
Because of the big difference between the network ordering mode of operation and the traditional food and beverage industry, the current “food safety law” has made special provisions on its food safety. However, due to the existing time of network ordering is not long, it still has some hidden trouble on food safety, such as administrative supervision vacancy, the lack of the necessary food safety audit and management mechanism for third party platform, the lack of consumer awareness of food safety. It is necessary to take some legal regulation measures, including establishing a supervision system based on food and Drug Administration, strengthening the self-discipline management of third party platform, and establishing food safety prompting duty for third party platform, so that to ensure the healthy development of the network ordering.
Machine & Control
Computational fluid dynamic simulation flow field and pressure drop characteristics of the gas-liquid two phase flow in a static spiral cutter
XU Zhenwei, CUI Zhengwei, YUAN Fangyang, and WU Can
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.019
The internal oxygen-water two-phase flow in a static spiral cutter with special spiral structure was simulated employing ANSYS Fluent. The flow field and pressure drop characteristics inside the static spiral cutter was analyzed under different Reynolds numbers. The pressure dropping of gas-liquid two phase flow in the helical of cutter mixer showed an increase trend obviously with the increase of Reynolds number. The pressure dropping in the helical was larger than that in the horizontal circular straight tube. When Reynolds number changed from 800 to 26 000, the ratio of pressure of the spiral cutter to horizontal circular straight tube increased from 150 to 260.
Study on inverse design of screw rotor profile based on NURBS curve
HUANG Hainan, HE Xueming, ZHANG Rong, and JIANG Zhengang
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.020
The design method of screw rotor based on meshing method and NURBS curve is proposed. In the process of the designing, the formula of the quadrature was obtained. This paper solveed the envelop condition of NURBS curve, and realizes the reverse design of the whole line of NURBS curve which was determined by the control point, weight factor and node vector. Through this method, the compound line of the error was obtained within 0.5 μm microns and the relation between the performance and meshing lines is explored. The feasibility of reverse design of screw rotor by using NURBS curve wes verified. Using the local modification of NURBS curve to optimize the type line, the leakage triangle area of the rotor was reduced by 5%, and the area utilization coefficient increased by 1%. The theory and method for the optimization design of rotor line of double screw compressor is provided.
Research on the polynomial cam curve of variable coefficient of high-speed cam
ZHAO Manman, WU Jia, HE Xueming, and QIAN Zhifang
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.021
For polynomial function method is simple and easy to understand, it is widely used in designing cam curves.However,when in the design of high speed cam, it is often required that the cam curve can realize high order and be continuous, then the number of polynomials should be increased to realize the design requirements. It no doubt increases the difficulty and reduces the precision of procession, eventually leads to the cam corresponding movement rule cannot be realized. In view of the above, a polynomial curve design method of the 7, 9 and 11 powers variable coefficient. Then by calculating the cam curve equation and characteristic parameters, drawing the characteristic parameters, the effects of changing the kinematics and kinetic characteristics of cam curve was achieved, and improving the flexibility and selectivity of cam curve design was improved.
Experimental study on the R404A single machine two-stage refrigeration system used for marine ultra-low temperature
WANG Lei, XIE Jing, WANG Jinfeng, YANG Dazhang, and ZHOU Hongjian
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.022
The R404A single machine two-stage compression refrigeration system for marine ultra-low temperature was simulated by EES when the evaporation temperature or the condensation temperature changes. Experimental verification of simulation results was carried out on the basis of the ultra-low temperature experimental platform consisting of R404A single machine two-stage compression refrigeration system with different conditions. The effect of evaporating temperature and condensing temperature on the performance of the single stage two-stage compression refrigeration system such as compressor exhaust temperature, COP and the compressor power was analyzed. The results indicated that with the decrease of evaporation temperature or increase of condensing temperature, the exhaust temperature of the compressor increased. The simulation results were in good agreement with the experimental results, the deviations value of the refrigeration performance between the experimental test and the simulation results was about 0.5, and the reliability of the model was verified. Experimental results showed that when the evaporating temperature rises or the condensation temperature drops by 5 ℃, the effect of evaporating temperature on COP was up to 7.8% than that of condensing temperature. The research results can provide reference for the follow-up work and have great practical engineering significance.
Finite element simulation on plastic forming process of multi-interface tube material in lightweight food equipment
ZHU Chengjun and WANG Jing
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.023
This paper studied the plastic forming process of multi-interface tube materials in lightweight food equipment. Taking the multi-interface pipe of the food machinery spindle head as the research object, the plastic forming method was determined. The effects of temperature and friction coefficient on the tube wall thickness increment, the end inner diameter and the load were studied by DEFORM software, and a plan was designed to optimize the common problem. Studies have shown that this process combines the advantages of cold extrusion and warm extrusion, saving materials and losing the weight, and can meet the needs of small food machinery parts production.
Storage Transportation & Preservation
Study on the low temperature dormancy and survival technology of Pengze crucian carp in summer
QIN Xu, TU Zongcai, WANG Hui, ZHANG Lu, SHA Xiaomei, and ZHANG Nanhai
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.024
Firstly, the dormancy temperature and freezing tempera-ture of Pengze crucian carp were determined, and the ecological ice temperature range of Pengze crucian carp was 0~7 ℃ through the principle of ecological ice temperature. By single-factor experiments and orthogonal experiments, the optimized conditions for survival technology were determined: stop feeding time 24 h, cooling dormancy, fish/water mass ratio 11 (g/g), addition of NaCl 0.3%, survival temperature (13±1) ℃ in pure oxygen. The survival time of Pengze crucian carp under the optimized conditions was 148 h. Therefore, this survival technology can prolong the survival time of crucian carp, decrease the use of water, reduce pollution.
Effects of different storage temperature on quality and fresh-keeping of Cynoglossus Semilaevis Gunther
LI Na and XIE Jing
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.025
The effect of storage temperatures (such as 10, 4, 0 and -3 ℃) on the change of quality characteristics and fresh-keeping of cynoglossus semilaevis gunther was investigated. The changes in TVC, dripping loss, cooking loss, electric conductivity, TVB-N, K value, biogenic amines and total amino acid were studied. Combined with sensory evaluation, it could be concluded that with the extension of storage time, water hold capacity decreased, and electric conductivity, TVB-N, K value, total amino acid, and TVC increased. The change rate of every index decreased by the decreasing of storage temperature. The biogenic amines accumulated during the storage period of cadaverine, putrescine and tyrosine, and only a small amount of spermine was detected. Low temperature could significantly inhibit the information of biogenic amines. Shelf lives of cynoglossus semilaevis gunther were 8 d, 13 d and 15 d at 10 ℃, 4 ℃ and 0 ℃ respectively. Compared with 10 ℃, 4 ℃ and 0 ℃, -3 ℃ could extend shelf life with 19 d, 14 d and 12 d respectively. The results showed that decreasing storage temperature can obviously prolong the shelf life of cynoglossus semilaevis gunther.
Effects of different frozen temperatures on the quality of freshwater prawn (Macrobrachium rosenbergii)
YU Lixia, JIANG Qixing, XIA Wenshui, XU Yanshun, WANG Bin, GAO Pei, and YANG Fang
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.026
Effects of different frozen temperatures on the quality of freshwater prawn (Macrobrachium rosenbergii) were investigated in this study. The thawing loss, cooking loss, TVB-N, K value, hardness, the shear force and color properties were evaluated. The results showed that after freezing by liquid nitrogen, the water holding capacity and texture properties of freshwater prawn were deteriorated with the extension of storage time. After 20 weeks, the hardness of prawn decreased by 55.79% and 59.45%. The TVB-N value and K value increased with storage time, however, the TVB-N value and K value of prawn frozen at -50 ℃ increased more slowly compared with frozen at -18 ℃. These finding indicated that the lower frozen temperature could maintain the better quality of prawn during storage.
Effects of the fresh-keeping modes on quality of flowering Chinese cabbage under simulated transportation
YANG Songxia, LU Enli, ZHU Lixue, and ZHAO Junhong
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.027
In order to obtain the effects of three fresh-keeping modes including the atmosphere controlling fresh-keeping mode, refrigera-ted-humidified fresh-keeping mode and refrigerated fresh-keeping mode on the quality of flowering Chinese cabbage in transportation，the fresh-keeping transportation experiments for flowering Chinese cabbage were carried out applied transportation compartment of multi fresh-keeping modes as experiment platform. The results indicated that, for the transportation within 2 days, the quality of 3 kinds of fresh-keeping modes had no significant difference (P>0.05), and they could maintain flowering Chinese cabbage better quality. For the transportation more than 2 days, controlled atmosphere fresh-keeping mode and refrigerated-humidified fresh-keeping mode could significantly (P＜0.05) inhibited water loss and decay, but the inhibition of TSS and Vitamin C decomposition was not obvious. For the transportation more than 4 days, the quality of controlled atmosphere fresh-keeping mode and refrigerated-humidified fresh-keeping mode had little difference, and they were better than the quality of refrigerated fresh-keeping mode obviously, in conclusion, any kind of three fresh-keeping modes was appropriate for the transportation within 4 days. However, both of controlled atmosphere refrigerated-humidified fresh-keeping modes was appropriate for the transportation more than 4 days.
Effects of storage temperature and duration on quality properties of fresh rice noodles
ZHU Hong, WANG Fang, and YI Cuiping
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.028
Fresh rice noodles at the different temperatures（4, 25, 37 ℃）during 0～30 h storage, the total plate count (TPC), textural properties, cooking properties, color and sensory properties were analyzed. The results indicated that TPC of fresh rice noodles at 4 ℃ were within the safe range during 30 h, the hardness and chewiness of the products were higher than those of the 25 ℃ and 37 ℃ groups at the same storage time, the flexibility was relatively low; at 25 ℃, the TPC of fresh rice noodles were within the safe range during 18 h, the textural properties better than 4 ℃ and 37 ℃ groups; at 37 ℃, the TPC of fresh rice noodles were within the safe range during 12 h, the hardness, elasticity and chewiness were higher than thoes of the 25 ℃ and 4 ℃ groups, the sticky was relatively low. Different temperatures at the same time, the cooking properties of fresh rice noodles increased with the storage temperature and time. There was no significiant change in the brightness of rice noodles placed at 4 ℃ within 30 h (P＞0.05), the brightness of rice noodles gradually darkened with the time at 25 ℃ and 37 ℃, the color of rice noodles were darkest at 37 ℃. The results of sensory evaluation were consistent with the above results.
Effect of low-power microwave treatment on storage quality of Kyoho Grape
CHEN Mengya, LU Jiahui, and ZHANG Haiwei
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.029
In order to study the effect of low-power microwave treatment on the postharvest quality of Kyoho grape, the grapes were treated with 32.5, 65.0, 97.5 and 130.0 W microwave respectively. The untreated grapes were used as the control, and all Kyoho grape stored at 0～2 ℃ for 40 days. The results showed that the low-power microwave treatment below 97.5 W had positive effect on the preservation of grape, which could prolong the ripening and senescence of Kyoho grape.The group with 32.5 W low-power microwave treatment had the best effect compared with the control in the end of storage period.which inhibited the rapid increase in the content of malondialdehyde, and the DPPH radical scavenging rate was higher than the control group about 33%. The shattering rate was decreased by 10% and the enzyme activity of PPO and POD was lower about 1/3 than the control.
Apple surface defect detection research based on improved particle swarm optimization algorithm
CHENG Lei
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.030
Premature judgment mechanism of particle swarm is established with fitness function. Adaptive adjustment of particle inertia weigh and acceleration factor of anti cosine strategy are optimized particle swarm to give the apple surface defect process. Simulation results show that improved particle swarm algorithm is more clearer detecting the defect of apple surface, the maximum missing rate test index is 4.5%, and less than other algorithms, and the least time comsuming in complete the missing rate, so that it is the new method for quality detection of apple.
Research on strawberry automatic classification based on the machine vision
YANG Tao, ZHANG Yunwei, and GOU Shuang
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.031
Aiming at the shortcoming of using a single feature to measure the quality of strawberry in traditional strawberry automatic grading system, we proposed a new method to evaluate the quality of strawberry from the aspects of maturity, mass and shape. Firstly, the H parameters in the HSV color model was calculated and analyzed to determine the maturity of strawberries. Secondly, the mass of strawberry was measured by the image projection area-mass function, and then the K-means clustering method and the discriminant analysis were used to obtain the shape classification of strawberry. Finally, the composite score of strawberry mass and shape might be calculated by weighting method to determine strawberry quality grade. Compared to the manual rating, the results showed that the accuracy rate of this new method was more than 90%.
Extraction & Activity
Isolation and identification of immunoactive peptides from rice protein hydrolysates with medium-pressure ion exchange chromatography
CHENG Yunhui, MAO Tianmi, HUANG Lu, CHEN Maolong, WEN Li, and XU Zhou
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.032
Medium-pressure ion exchange chromatography was used for further fractionation of rice immunoactive peptides obtained from Trypsin hydrolyzation and gradient ethanol elution with DA201-C macroporous adsorption resin (40% ethanol fraction). The results showed that the optimal parameters for fractionation of RPHs-A3 fractions by WorkBeads 40 Q on a 2.6 cm×40 cm columns were as follows: Sample: 5 mL, 30 mg/mL 40% ethanol fraction; Equilibration buffer A: pH 9.0, 0.01 mol/L Tris-HCl; Elution Buffer B: pH 9.0, 0.01 mol/L Tris-HCl containing 1 mol/L NaCl; Sample flow rate: 1 mL/min; Elution flow rate: 10 mL/min. Five fractions were obtained after NaCl gradient elution. The results of MTT assay and LPS-stimulated RAW264.7 macrophages inflammation model showed that fraction RPHs-A3-B3 had the highest immune activity. RPHs-A3-B3 produced a significant effect on the proliferation of RAW264.7 macrophages with a stimulation index value of 1.315. Meanwhile, RPHs-A3-B3 significantly decreased the production of NO in LPS-stimulated RAW264.7 macrophages (P＜0.05). The inhibition rate was 8.28%. The research indicated that medium-pressure ion exchange chromatography can effectively fractionate rice immunoactive peptides. The SI value increased from 1.273 to 1.315. And RPHs-A3 had a significant inhibitory effect on intracellular NO release.
Study on umami peptide extracted from three enzymatic hydrolysates with ethanol
YAO Yujing, YANG Zhao, HUANG Jiajia, HAN Jinhui, LIANG Zhili, and CUI Chun
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.033
The compound enzyme composed of trypsin and flavour protease was used to hydrolysate the oyster, chicken and antarctic krill. Taking sensory score, peptide molecular weight distribution and amino acid composition as indexes, the change of them was investigated during ethanol extraction of umami peptide from 3 kinds of hydrolysates. Results showed that the sensory evaluation of supernatant of the 3 enzymatic hydrolysates extracted by 90% ethanol showed strong umami taste and the peptide ratio of the peptide molecular weight distribution < 5 ku from oyster, chicken and Antarctic krill was 93%, 86.82%, 87.86%, respectively . The peptides of 3 enzyme hydrolysates > 10 ku and 5~10 ku were significantly reduced after 90% ethanol extraction. The small molecular peptides of the supernatant of three kinds of hydrolysates extracted by 90% ethanol contained a high proportion of sweet and umami amino acids. The 90% ethanol extraction method can be used for rapid extraction of umami peptide from oysters, chicken and antarctic krill hydrolysates.
Separation and identification of the hypnotic active ingredients of Schisandra chinensis
ZHANG Ziyu and XU Deping
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.034
To screen the constituents with dormant activity in Schisandra chinensis and analyze the active ingredients. The content of dopamine (DA) in mouse cerebral cortex was detected by high performance liquid chromatography (HPLC), and the sleeping effect was observed by sleep method. The effects of S. chinensis on the hypnotic effect were studied by using macroporous resin column, MCI column and ODS column. Active ingredients with hypnotic effect were separated, and the compounds isolated from active ingredients were structurally identified by nuclear magnetic resonance (NMR). The elution fraction of MCI and the elution fraction of 95% ethanol in macroporous resin significantly increased the sleep rate and sleep time in mice. The compounds α-amino-β-hydroxyisobutyric acid, β-ethoxyaminopropionic acid were obtained from the water elution part, and Gomisin N were from 95% ethanol elution part. Amino acids and lignin in S. chinensis had the same good hypnotic effect.
Comparison on functional properties of oat protein extracted from different ways
XU Yingyi, XU Yanxia, and WANG Yu
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.035
The oat flour as raw material, the oat proteins by alkali extraction and acid precipitation (AOP) and enzymatic method (EOP) were comparatively evaluated for functional properties ( solubility, foaming properties, emulsifying properties, amino acid compositions). The results showed that at the isoelectric point of the protein, solubility, foaming and emulsifying properties of AOP and EOP reached minimum, and emulsion stability of AOP and EOP were the highest; with the increase of NaCl concentration, the solubility, foamability, foam stability and emulsifying properties were basically increased first and then decreased, and emulsion stability decreased;The total amino acids of AOP and EOP were 57.27% and 22.82%, respectively.The solubility, emulsifying properties of EOP were higher than those of AOP, while AOP had higher foaming properties，foam stability，emulsion stability and total amino acids than EOP.
Optimization of extraction process for total triterpenoids in Alisma orientalis (Sam.) Juzep. by response surface methodology
SHI Feng, CHEN Yu, ZHANG Yaqin, MA Liuhui, DOU Mingming, YANG Zhengming, and CHEN Xingfu
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.036
The optimum conditions of ultrasonic extraction of total triterpenoid from leaves of Alisma orientalis (Sam.) Juzep. were investigated in this study. On the basis of single factor experiments, with yields of total triterpenoid as indexes, the three levels of four factors of Box-Behnken experimental design and response surface methodology was adopted to optimize extraction conditions by taking extraction temperature ,ethanol concentration, extraction time and the ratio of material to solvent as factors. Results: Optimal extraction technology was as following, i.e. the ethanol concentration of 70%, the extracting for 46.00 min at 57.00 ℃, and the ratio of material to solvent was 114 (g/mL), ultrasonic time for 30 min. Then the total triterpenes extraction rate reached 2.98% in this condition.
Isolation and purification of polysaccharides fromforage mulberry (Morus alba L.) and the research of their biological activity
WANG Lingjia, SHU Xiaomeng, XIN Wen, ZHANG Chisong, CHEN Xianggui, and YANG Xiao
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.037
Purpose Optimization of enzymatic extraction process for total polysaccharides from mulberry (Morus alba L.) leaves and comparison of biological activity before and after purification. Methods The polysaccharide from mulberry leaves was extracted by cellulase and the optimal extraction parameters were optimized by single factor and orthogonal experiment. The primary purification was carried out by Sephadex G-100. The antioxidant activity and α-glucosidase inhibitory activity of polysaccharides before and after purification were compared. Result The optimal process parameters was pH 6, enzyme concentration 1.0%, extraction temperature 50 ℃, time 50 min; total polysaccharides after purification had higher total antioxidant capacity and DPPH, hydroxyl radical scavenging capacity; but the inhibitory effect of α-glucosidase was lower than the before. Conclusion The optimized process parameters had better extraction effect, and the primary purified total polysaccharides had stronger antioxidant activity.
Process optimization for purification and preparation of hairy antler grounds antioxidant peptide assisted by high-intensity pulsed electric fields
JIANG Wei, JIN Shenglang, and YIN Yongguang
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.038
Antioxidant peptides were prepared from hairy antler grounds by high-intensity pulsed electric fields (PEF) jointed bromelain, and then they were isolated and purified. The degree of hydrolysis and scavenging rates of DPPH· was considered as test indexes. According to the results of the single factor experiment, the response surface methodology (RSM) experiment was conducted on three factors at five levels to analyze the factors and interaction effects on the scavenging rates of DPPH·. Then the macroporous resin was used to desalt, separate and purify hairy antler antioxidant peptides, and the antioxidant activities of hairy antler peptides were also analyzed. The optimal conditions of enzymatic hydrolysis are as follows：the substrate concentration 15%, bromelain concentration 7.04 U/mg, electric filed intensity 17.3 kV/cm, pulse number 7, the scavenging rates of DPPH· by hairy antler antioxidant peptides was (74.76±2.03)%. The scavenging rates of DPPH·, ·OH and O-2· of 75% ethanol elution component C3 were the highest, and the antioxidant activity of elution component C3 sharply increased compared with crude peptide, when hairy antler peptides were featured with a considerable antioxidant activity, and hairy antler could be a potential source of preparing peptide with the strong antioxidant activity.
Purification of lignans from camphor tree leaves by macroporous adsorption resins
WU Pingxiang and LI Zhonghai
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.039
In this study, six different macroporous adsorption resins were evaluated for their use to purify lignans ethanol-extraction of camphor tree leaves，a suitable macroporous adsorption resin was selected as the purification material. The effects were investigated, such as sample concentration, flow rate, volume of sample on adsorption rate of macroporous resin, and the effects of concentration, flow rate and dosage of eluent on desorption rate of the macroporous resin were also studied . The optimal purification process of lignan with the macroporous resin was studied by the orthogonal experiment. The purication parameters optimized by adsorption and desorption were determined as follows: sample loading amount 7 BV, sample concentration 2.12 mg/mL, ow rate 1.0 mL/min, dosage of desorption ethanol solvent 80%, ow rate 2 BV/h, eluent volume 8 BV. Under the optimized conditions, the yield and purify of lignans were 66.68% and 15.91%, respectively, which indicated that the macroporous resin has better purification effect on lignans in camphor leaves.
Development & Application
Effects of rice bran oil on quality of the spread processed Cheese
XU Hangrong, ZHENG Yuanrong, and LIU Zhenmin
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.042
To provide a theoretical basis for the research and development of high-quality processed cheese with rice bran oil, the effects of different levels of rice bran oil instead of butter on the quality of the spread processed cheese were studied. The determination of the pH, firmness, stickness and sensory evaluation of the processed cheese with various substitution ratios of rice bran oil were compared and analyzed. The results showed that the pH values of the samples were in the normal pH range, and the firmness and stickiness of samples decreased with the increase of the amount of rice bran oil. Cheddar cheese and milk flavor sensory score is minimum with 75% rice bran oil, and sensory score of rice bran oil samples with different added amount had no significant difference (P＞0.05) in total score. Rice bran oil as a substitute for butter as a raw material for repainting cheese is a viable option.
Optimization of alcohol fermentation and acid characteristics analysis in loquat vinegar production
DUAN Zhenzhen, ZHOU Caiqiong, YUAN Min, and CHANG Rong
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.043
Red flesh loquat named Jinhua No.1 was used as experimental material to optimize alcohol fermentation process and analyze the acidity characteristics of loquat vinegar in this study．The effects of yeast species and inoculation amount, pH, fermentation temperature and initial sugar content on the quality of loquat vinegar were studied, and the optimal fermentation conditions were determined by the alcoholic degree as the response value. The results showed that the yeast strain Yb was the dominant yeast strain of loquat vinegar, the optimal process parameters were that the yeast inoculation amount 0.05% was fermented at 25 ℃ and pH 3.5. Under the optimum process conditions, the loquat vinegar base possessed 8.5% Vol alcohol, 12.228 g/L organic acid. Malic acid, lactic acid, acetic acid and succinic acid were the main organic acids that made up the taste of loquat vinegar, accounting for 95.4% of total organic acids, which constituted 94.7% of the vinegar sour taste of loquat vinegar. High content alcohol and suitable organic acid were the guarantee of acetic acid content after acetic acid fermentation and the important components that the acid taste and function of the loquat vinegar.
Optimization of the compound fermentation process of red chili and pickled chili juice
WANG Wancheng, ZHAO Lingyan, and DENG Fangming
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.044
Red line chili and pickled chili juice were mixed in a 11 (w/w) ratio, and inoculated with Lactobacillus plantarum, Lactobacillus acidophilus and Leu-conostoc mesenteroides to get fermentation. The lactobacillus inoculation quantity, fermentation temperature and fermentation time were selected as the experimental factors, and the lactic acid content was used as the response value. The single factor and response surface test were designed to optimize the fermentation process. The best conditions for optimization were as follows: inoculation 6%, fermenting at 35 ℃ for 6 days. The validation test results showed that the fermented pepper products’ lactic acid content was 0.74% and the products had a good flavor.
Optimization of the quantitative determination method of the burning cigarette ash integration based on ImageJ
FENG Yajie, WANG Jianmin, LIANG Miao, MU Lin, MA Shengnan, WANG Huaixu, and XU Linghe
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.045
In order to improve the accuracy and repeatability of the integration quantitative determination method based on ImageJ for the ash from the burning cigarette., an optimized scheme was conducted in this study. The scheme was optimized from three aspects, including the selection of cigarette combustion surface, the selected height as well as the width of the burning cigarette columnar ash. The established optimal scheme was as follows: ① Taking pictures of the burning cigarette when it was burned to 1 cm away from the tipping paper. ② Using a height of 25 mm, 6.46 mm width rectangular box to select the bottom of the gray column as a starting point for analysis of the picture area. ③ The final result of the ash integration was taken from the average of three cigarettes and three burning surfaces (the surface, opposite face and the side face of lapped cigarette paper ). This program could weaken the influence of the lapped cigarette paper, the curvature of the ash as well as the outer ash on the repeatability of measurement results. In addition, this optimized method could reflect the true ash integration character more comprehensively. The application of this method indicated that the RSD of the four samples reduced from 26.18% ~ 34.52% to 15.3% ~ 20.6%, suggesting a significant improvement in accuracy and repeatability.
Advances
Research progress on extraction technology and functional activity of purple sweet potato pigment
ZHAO Erlao, YAN Wei, GAO Ziyi, HUANGFU Yangxin, and ZHAO Sanhu
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.040
Based on the literature learning method and summariz-ation, the domestic research progresses on the extraction technology and the functional activity of purple sweet potato pigment were reviewe. The application prospect of the purple sweet potato pigment had also been presented in this paper, which provided a reference for its further research and development.
Date posted: 3-28-2018
DOI: https://doi.org/10.13652/j.issn.1003-5788.2018.03.041
As a non-thermal technology, ozone is being applied to food and fruit which become more and more popular. On the basis of the analysis of the influencing factors for preservation effect of ozone, the latest process in effects of ozone on post-harvest physiology and storage quality of fruits were reviewed, providing a basis and reference for the ozone better applied to fruit storage and preservation.
