Abstract:Millet glutenin and gliadin was obtained by alkali extraction and acid precipitation and millet gliadin was distracted by ethanol. Then their structural characteristics were analyzed. SDS-PAGE electrophoresis results showed that the molecular weight of the millet gliadin was small, while millet glutenin was distributed from high molecular weight to low molecular weight. Furthermore, the XRD analysis showed that both the two kinds of proteins were amorphous structures. The secondary structure was measured by circular dichroism. Millet gliadin belonged to all alpha structure, and its order was better than that of millet alkali soluble protein. Moreover, by atomic force microscopy analysis, millet gliadin was spherical and its distribution was rather dispersed. In contrast, the distribution of millet glutenin was more concentrated.

Abstract:The preserved eggs were processed by immersion method. The effect of internal interactions on the formation of egg yolk gel during salting and ageing were determined by fluorescence spectrophotometer and FTIR et al. The sum of α-helical and β-turn of the secondary structure of the exterior egg yolk protein decreased by 54.71% under strong alkaline environment, with the surface hydrophobicity decreased significantly (P＜0.05), and the dramatic increase of ion bonds and disulfide bonds promoted the egg yolk proteins to form a gel. The sum of α-helical and β-turn of the secondary structure of the interior egg yolk protein increased by 54.05%, and the changes of surface hydrophobicity was not obviously (P＞0.05). The obvious increase of hydrophobic interaction and disulfide bond caused the interior egg yolk to transform into the exterior egg yolk gradually, which also enhanced the gel strength of the egg yolk. The result of gel electrophoresis showed that the exterior egg yolk protein was alkaline denatured earlier than interior egg yolk, and the more stable protein was high-density lipoprotein.

Abstract:Formed constant temperature boundary with constant temperature bath and combined with the brass short cylindrical sample box, the formation of multi-dimensional heat flow is guaranteed in the test sample. The unsteady thermal conductivity multiplication method and parameter estimation method were used to calculate the thermal conductivity and specific heat capacity of grain. At the same time, considering the effect of opening holes on the thermostat, and increasing the difficulty of experimental operation, the ZigBee wireless data acquisition module is used for signal acquisition and transmission. By analyzing the thermophysical parameter sensitivity analysis of corn and paddy, the sensitivity coefficient of specific heat capacity is found to be low. In view of this, the calculation system first estimated the thermal diffusivity, and then compared the results of heat capacity estimation. An experimental test device was set up to calculate the thermal properties of four kinds of food including “Wandao 121”. The results were consistent with the relevant literature. At the same time, the thermal properties of “Wandao 121”, the theoretical calculation and the numerical simulation were used to monitor the temperature rise over time. The results show that the theoretical trend of temperature rise is consistent with the measured temperature rise, further verifying the value of the parameter estimation accuracy and reliability.

Abstract:To analyse the variation of reducing sugar, total acid, total flavonoids, ethanol content and aroma compounds in brewing process of mulberry wine. The fermentation processes were: fermentation temperature of 15.3 ℃, inoculation quantity of 8.00 g/L, sucrose content of 12.80 g/100 g, total fermentation time 24 days, and sampling every 3 days to determine reducing sugar, total acid, total flavonoids, and ethanol content of mulberry wine. The aroma components were determined by gas chromatography-mass spectrometry. Results: The reducing sugar in mulberry wine decreased quickly at the first nine days and levelled off. The total acid content were steady between 5~6 g/L during the 15^th day and the 18^th day, peaked 6.61 g/L at the 24^th day of fermentation. The concentration of ethanol increased rapidly at the first three days, and reached to 13.56% at the 18^th day after quick increasing at the 15^th day. From the initial fermentation 112.01~274.83 mg/L at the 15^th day, the total flavonoids was about 274.83 mg/L and reached in steady state after a maximum of 417.19 mg/L at the 21^th day, and the aroma components of mulberry wine were identied. The relative contents of esters, alcohols, and acids from area normalization method were 43.5%, 25.0%, 16.1%, respectively, at the 18^th day, as well as 34.5%, 31.1%, 12.7%, respectively, at the 24^th day. According to the changes of the main ingredients of the wine, the total fermentation time can be shortened to 18 days at fermentation temperature of 15.3 ℃, inoculation quantity of 8.00 g/L, sucrose content of 12.80 g/100 g. The mulberry wine aroma components in alcohols and acids as the main body, the ester content is relatively less.

Abstract:The effects were andyzed, including different various methods (steaming, boiling, frying and baking) on meat quality, routine nutrient composition, amino acid and fatty acid content of pork. The results showed that the pH value and water content after cooking were significantly lower than those of fresh control (P＜0.05), while, the hardness, elasticity, adhesion, ash, crude protein and PUFA content were significantly increased (P＜0.05). The cooking loss rate of frying and microwave was significantly higher than that of steaming, boiling and baking (P＜0.05). The ash content of boiling have no significant change (P＞0.05), while the other cooking methods were significantly increased (P＜0.05). The fat content of frying significantly decreased (P＜0.05), while the other cooking methods were significantly increased (P＜0.05). The baking significantly reduced the TAA content (P＜0.05), while the other cooking methods were significantly increased (P＜0.05). The contents of DAA and EAA in baking were not significantly changed (P＞0.05), but the other cooking were significantly increased (P＜0.05). The EAA/TAA ratio of all cooking methods reached 40.00% and EAA/NEAA＞67.00%. The essential amino acid score after cooking was much larger than the FAO/WHO scoring model, and the first restricted amino acid was Val. Cooking treatment had an adverse impact on the physical properties of pork, but could improve its nutritional value in different degrees. Therefore, appropriate cooking methods should be selected according to the actual needs to achieve a purpose of reasonable diet in daily life.

Abstract:Heat-not-burn tobacco product, a novel tobacco product with low harmful substances deliveries, is developing rapidly under current severe tobacco control policies. To better understand the characteristics of heat-not-burn reconstituted tobacco（HnB Recon）, 3 different kinds of HnB Recon were collected, including papermaking process(PP), rolling process(RP), and slurry process(SP) HnB Recon, and studied systematically in microstructural, fiber shape, strength tensile, chemical constituents, smoke constituents and sensory quality. Results, the microstructure of PP HnB Recon which completely different from RP HnB Recon and SP HnB Recon, was a network consisted of different fibers twisted randomly, while the microstructure of RP HnB Recon and SP HnB Recon was unsmooth plane consisted of particle clusters, and their tensile strength was inversely proportional to their rupture elongation; The contents of water and glycerol were relatively high in 3 different HnB Recons, and they had the same trend as in corresponding smoke, and in a proportion relationship between HnB Recon and its corresponding smoke. The Tar (without glycerol) deliveries was much lower than traditional flue-cured cigarette; The sensory quality of RP HnB Recon and SP HnB Recon was similar, and better than that of PP HnB Recon.

Abstract:The dynamic changes of the main active components in purple potato leaves were studied. The optimal sampling period was determined, and the content of main active components in purple potato leaves, sweet potato leaves and purple potato tuber were compared. The content of total polyphenols, flavonoids and anthocyanins were determined by ultraviolet spectrophotometer, and chlorogenic acid and rutin were determined by HPLC. The results showed that the dynamic characteristics of active components in different varieties of purple sweet potato leaves showed a similar trend, but the content were not exactly consistent in different sampling time, and the content of active components in different varieties were significantly different. The content of active components in purple sweet potato leaves were higher than those in sweet potato leaves and purple potato tuber. The accumulation of several active components in the purple potato leaves was the maximum in the 150 d harvesting period, and the purple sweet potato leaves were abundant. The exploitation and research of purple potato leaves during the harvesting of purple potato tuber are beneficial to the comprehensive utilization of the purple potato resources.

Abstract:In this study, we presented a simple, rapid and sensitive colorimetric assay for the detection of cadmium (Cd) based on enzyme-linked oligonucleotides. The specific binding of aptamer to Cd²⁺ led to the decrease of horseradish peroxidase(HRP) on the microtiter plate, since HRP could not be bind onto through the hybridization of the aptamer and complementary DNA strand. It resulted in the change of characteristic peaks at 450 nm, helping to quantitatively detect Cd²⁺. Under the optimal conditions, the detection limit could be as low as 0.05 ng/mL, and the linear response for Cd²⁺ in a concentration range from 0.1 to 5 ng/mL(S/N=3). This method was simple and rapid, resulting in high sensitivity and specificity, and could be used in food safety analysis and environment monitoring.

Abstract:In order to screen a probiotic strain against foodborne pathogens and aquatic pathogens, the main zoonotic pathogenic bacteria of mariculture Vibrio parahaemolyticus ATCC17802 was used as indicator bacterium. The target probiotics was screened using the spot-on-lawn method and rescreened by the agar diffusion method, and the diameter of inhibition zone of antibacterial substances reached (17.16±0.28) mm. Through the combination of morphology and 16S rDNA sequence analysis, strain H19 was identified as Bacillus subtilis (GenBank accession number: MG383451). Antimicrobial spectrum of B. subtilis H19 was tested, meanwhile the physical and chemical properties of antimicrobial substances produced by H19 was studied. The supernatant of the H 19 fermentation broth was subjected to ammonium sulfate precipitation and dialysis against several different pore-size membranes, and two novel kinds of antibacterial peptides with molecular weight of 6.5~9.5 kDa and 27.0～35.0 kDa respectively were obtained based on Tricine-SDS-PAGE protein gel electrophoresis and protease treatment. It had broad-spectrum antimicrobial activity, which could inhibit both Gram-positive bacteria and most of Gram-negative bacteria, and showed good heat, pH and UV stability. Consequently, the antibacterial peptide produced by B. subtilis H19 had the potential to antagonize the pathogenic bacteria for the prevention and control of foodborne and aquatic diseases.

Abstract:In order to reveal the contamination, population characteristics and antimicrobial resistance of Campylobacter jejuni isolated from commercial chicken in Northeast China, 1 000 chicken samples were collected from the Northeast China. C. jejuni was isolated and identified.The genetic diversity of C. jejuni was analyzed by multilocus sequence typing (MLST). The antimicrobial resistance of C. jejuni to 8 antibiotics was detected by K-B AGAR diffusion method. The results indicated that 62 C. jejuni strains were isolated from 1 000 chicken samples with a contamination rate of 6.2%, and were divided into 14 sequence types (STs). Among them, ST1 and ST5 were the dominant STs. The results of antimicrobial resistance analysis showed that 62 C. jejuni strains were highly sensitive to ciprofloxacin, compound sinomin and cefotaxime.

Abstract:Salmonella enterica serovar Heidelberg,（SH）is pathogenic serotypes within Salmonella. Using BLAST and PCR validation for all CDSs of SH, four serovar-specific genes were identified including SeHA_C2639, SeHA_C2640, SeHA_C3259 and SeHA_C3258. A PCR protocol was developed by pHAm8 (350 bp) of SH-specific primer and 139-141 (284 bp) of Salmonella-specific primer and evaluated for the detection of SH. The result showed that the 55 strains of serotype of Salmonella and other common foodborne pathogens proved that the PCR assay had very good specificity for the detection of SH. The detection limit was 6.1 × 10² CFU/mL in pure culture. It was shown that S. Typhimurium and Escherichia coli as interfering bacteria up to concentrations of N×105~N×101 CFU/mL, respectively, did not interfere with PCR detection of SH. In artificially contaminated milk, the protocol could detect less than 1.52 CFU/mL after 8 h enrichment. The detection method could quickly and accurately detect food SH, application in the field of food safety in favor.

Abstract:In this study, a gas chromatography-mass spectrometry (GC/MS) method was established for the determination of geranyl nitrile, 2-pentyl-2-cyclopenten-1-one and phenyl cyanide in fragrance compound, and the method was also validated. The method had good linearity (>0.990 0) with the concentration from 0.000 5 mg/mL to 0.100 0 mg/mL and low limits of detection (LOD) (<0.005 μg/mL) for these three target compounds. And the recovery was from 90% to 116% with relative standard deviation (RSD) from 4.2% to 5.4% at quality control concentration. In a word, the method met the need of trace detection, which can be used to test geranyl nitrile, 2-pentyl-2-cyclopenten-1-one and phenyl cyanide in fragrance compound. When the GC-MS method was applied to detect these three components in different pepppermint fragrance samples, none of them was detected out.

Abstract:Based on a microwave drying system，automatically and continuously regulating microwave power and temperature control, a drying model composed of three different temperature and power controls was used to investigate the potato chips. After analyzing the drying quality and energy consumption of the three drying models, a good microwave drying process for potato chips was found. The research showed that the microwave drying without temperature control was easy to overheat in the last drying stage and made the product burnt. However, the optimal temperature control effect and product quality could be obtained by combining the variable microwave power with the feedback temperature control based on the scheduled power distribution. Moreover, in the microwave drying process, taking the temperature control scheme of variable power could save about 35% energy consumption than fixed microwave power.

Abstract:The stirring medium mill was employed to prepare lotus leaf powder. The Variation of particle size of lotus leaf powder within 30 min at different stirring speeds were investigated. The grinding kinetics of the lotus leaf powder was studied using the analytical model of the crushing process. The grinding chamber shear rate distribution and the average collision energy of the grinding media were analyzed at different stirring speeds coupling CFD-DEM method. The results showed that the grinding rate of the lotus leaf powder increased with the increase of the stirring speeds in the range of 500～3 000 r/min. The fluid shear rate and the average collision energy of the grinding media increased with the increase of the stirring speeds.

Abstract:To obtain the regularity between the heat transfer characteristics of wok and the control of Chinese cooking operation and establish a Chinese wok performance evaluation method, three kinds of Chinese woks were selected to study the influence of the thermal resistance coefficient on the maturation time and the initial scorching time of pork tenderloin at different preheating temperature and mixing frequency. The results showed that the quality characteristics of pork tenderloin, such as color, moisture content and shear force, were obviously changed when it was fry to matured and scorched, and the color could be used as an intuitive judgment indicator of the culinary end point and scorch in oil frying.

Abstract:In view of the excessive local control conditions, the power of the cam curve designed by traditional polynomial interpolation method got too high to control, which was not conducive to the processing of capping machine cam. The global 5, 6 and 7 polynomial fitting methods were separately used to design the cam curve, so that it could control the power of the polynomial while satisfying the local control conditions. When the parameters of the cam curve got optimized, constructed the cam mechanism into a three-dimensional model and carried out the dynamic simulation analysis. After comparing to the kinematic and dynamic properties of mechanism, finally the optimal curve was determined.

Abstract:In order to investigate the characteristics of pressure fluctuation in cycloid rotor oil pump, based on RNG k-ε turbulence model and moving mesh, the transient flows for different operating conditions in cycloid rotor pump were investigated numerically and the computational results of flow and efficiency were obtained. The pressure fluctuation at different monitoring points were measured and analyzed in time and frequency domains. The results show that the pressure fluctuation of the flow field in the cycloid rotor oil pump is periodical obviously, the amplitude of pressure fluctuation is smaller in the oil inlet chamber and decreases gradually along the oil pipeline of the outlet, the dominant pressure fluctuation frequencies of different monitoring points are fundamental frequency and the second harmonic under corresponding working conditions, the amplitude of pressure fluctuation increases gradually with the increasing of rotational speed. The pressure pulsation test is performed on the outlet of the rotor oil pump and the results shows a good agreement with the simulation results, which verifies the reliability of simulation results.

Abstract:A variable crank length device with cam slot was added to the slide mechanism for achieving the uniform motion of the slider in the working stroke. The kinematics and dynamics analysis of this mechanism was carried out by using complex vector method and dynamic statics theory. Finally, the motion module of SolidWorks was used for the Motion analysis of this mechanism, and the motion characteristics and dynamic characteristics of the mechanism were obtained. The results showed that it was feasible to achieve uniform motion of slider in variable length crank slider mechanism.

Abstract:In this study, a set of real-time measuring device was designed based on LabVIEW virtual instrument technology to measure the fruit removal force, acquiring the signal of force, storing and displaying real-time data and etc. Wanshu 1, Changlin 1 and Dabieshan 1 were selected as experimental subjects. The diameter of the stalk and the geometric mean diameter and the degree of the ripeness of Camellia oleifera fruit were used as the experimental factors to design the orthogonal test. The fruit removal force of C. oleifera at different levels in three test factors was determined, and analyses about the relevant testing data based on SPSS software were conducted. The results showed that, there were significant differences in fruit removal force among different cultivars of camellia. The results of range and variance analysis of orthogonal test showed that degree of the ripeness was highly correlated to its fruit removal force. With the degree of the ripeness higher, the fruit removal force gradually decreased.

Abstract:Through analysis and research, this paper proposed a multidimensional constraint design model for food packaging, and clarified its advantages to the traditional packaging design. The model was built from the three dimensions of demand constraints, goal constraints, and resource constraints. Through the researches of user requirements, market requirements, first party requirements, resource limitations, etc., the corresponding design mapping domains under the relevant constraints were obtained, to clarify the elements of food packaging design, color, graphics, specifications, style, culture, and completed the design ultimately. The feasibility of the method and the model was verified by the actual case of the Qian Zhou fine dry noodle packaging design.

Abstract:In order to evaluate the effect of glue penetration on cigarette filter ventilation rate, and provide the basis for tipping glue and tipping paper selection, using the PVC rectangular pore pressure plate control the area of the original coating area, calculate the penetration area of coloring glue using pixel method, estsblished a method to measure the natural permeability of the tipping glue, and the natural permeability of 2 kinds of tipping glue on 12 kinds of tipping paper was measured and analyzed. The results showed that: ① the natural permeability of 2 kinds of tipping glue on 12 kinds of tipping paper was between 0.024 5%～0.138 0% and 0.011 8%～0.112 0%, and RSD was less than 10%; ② The ANOVA results showed that the types of tipping glue and tipping paper had a very significant effect on the natural permeability; ③ K-means clustering analysis results showed that the proper combination of tipping glue and tipping paper would help reduce the natural permeability of glue.

Abstract:Analyzed the neglects of body perception on current food package design, emphasized the significance of the research on experiential food package design and through practical examples explained the five types of experiential food package, which are sensory package, sustainable package, interesting package, situational package and emotional package.

Abstract:Yuexi Nianli food packages have demands of blessing culture, the diet culture and regional culture, through analyzing the history and culture, the specific form and the humanities spirit in local cultural, refined the culture symbol elements in west of Guangdong. With the help of regional cultural symbol of translation technique, took the concept of Yuexi Nianli’s packaging design system: expressing of advancing with The Times’ spirit of “simple modelling＋ingenious structure＋AR technology applications”; conveying of the low-key and pragmatic attitude of “local materials＋green processing technology”; transmitting of the hope of “auspicious patterns and lucky colors”, aimed to promote the inheritance and development of the Yuexi Nianli culture from the perspective of design.

Abstract:In order to solve the problem of hickory nuts’ material mixing which was difficult to screen after breaking the shells, an image processing algorithm for hickory nuts color and texture selection was proposed based on fuzzy c-means clustering algorithm. The program with user interface for the separation of hickory nuts’ shells and kernels was developed on the Labview software platform. By extracting the characteristic data the hickory nuts with separation substances value of hue, saturation, value, angular second moment, entropy, inverse different moment and correlation, building a sample set of characteristic data, optimal data subset is preferred in accordance with the principal component analysis. After using fuzzy clustering algorithm to calculate the cluster center of corresponding object feature set, the membership degree of the test sample to the corresponding cluster center was calculated. According to the principle of maximum degree of membership, the rational classification of the shells, inner septa（including the inner wall of the shell）and kernels from hickory nuts was realized and the kernels were successfully separated from the breakages. As an experimental result of the separation of shells and kernels, this system could correctly classify the test samples and the correct rate of sorting can reach more than 83%. This study provided a reference for the extensive research on testing the color selection and separation of nuts shelled.

Abstract:The quality change and shelf life of Guangdong packaged salted chicken were studied, which was storaged in 4 ℃. Results: Ssensory score decreased significantly in the 15th, 18th and 21th days (P<0.05), while, it exceeded acceptance in the 18th day, with the brightness L^* value and yellowing a^* value decreasing significantly (P<0.05); pH increased first and then decreased (P>0.05). The difference was not significant, volatile salt nitrogen and acid value were all increasing, and the variation of volatile salt nitrogen and nitrogen in chicken skin was significantly different (P<0.05), in the 18th day, the volatile salt based nitrogen in the chicken was 15 mg/100 g and the chicken acid value was significantly different in the 15th, 18th and 21th days (P<0.05); the shear force decreased significantly (P<0.05), while the hardness, chewiness and the tensile strength of chicken skin increased significantly (P<0.05); the total number of Escherichia coli and colonies were not beyond the limit of going abroad, and Salmonella was not detected. Therefore, the quality of cantonese style salt baked chicken with vacuum packaging decreased with the prolongation of storage time at 4 degree storage, suggesting that the longest storage period less than 15 days.

Abstract:The shelf life and survival bacterial species of ready-to-eat Penaeus vannamei during ambient temperature storage were studied. The quality changes and shelf life were observed by the sensory, physico-chemical, microbiological evaluation and electronic nose analysis, the bacteria species were identified by 16S rRNA sequencing. The results showed that initial sensory quality, physical and chemical indicators was pretty good. In the first 4 months, the water content, water activity, pH, sanility and color (red degree and yellow degree) had no significant differences, and then, the water content and Aw decreased, but pH and sanility increased, while the red degree and yellow degree fluctuated; The chewiness, hardness and elasticity had no siginficant differece in the first 3 months, and then increased firstly and decreased secondly, which kept fluctuating in cohesive force in the storage. TVBN and TBA did not exceed the limited value during the 9 months ambient temperature storage, with the total colony lower than 1 000 CFU/g; Bacillus licheniformis and Bacillus subtilis were found to be residue in individual expansion bags. In conclusion, through previous criteria of sensory, physicochemical and microbiological evaluation, the shelf life of Penaeus vannamei was 9 months.

Abstract:Effects of air packaging and modified atmosphere packaging on the quality of fresh beef during postmortem aging was studied using vacuum packaging as control treatment. Six left side of longissimus dorsi muscles of yellow cattle were precooled at 4 ℃ for 24 h. After 24 h postmortem, beef samples (2.54 cm thick) were trimmed and mixed, and randomly divided into three groups. The beef samples were stored for 4 d, 7 d and 10 d in dark refrigeration house at 4 ℃ to mimic commercial storage conditions. At the end of each point, the meat color, tenderness, purge loss, centrifuge loss, cooking loss and the state of moisture distribution were determined immediately to evaluate the effect of different packaging methods on beef quality during postmortem aging. The results showed that the cooking loss of samples from air packaging and modified atmosphere packaging was not different significantly compared to vacuum packaging (P＞0.05), while the purge loss of samples from air packaging and modified atmosphere packaging was significantly different (P＜0.05). Air packaging and modified atmosphere packaging presented better improvement on CIE a^* values and higher population of free water and lower tenderness compared to vacuum packaging (P＜0.05). In conclusion, air packaging and modified atmosphere packaging could improve the color of beef samples compared to vacuum packaging. However, air packaging and modified atmosphere packaging could not improve the tenderness and the state of moisture distribution.

Abstract:In order to explore the physico-chemical quality changes of vacuum packaging and nitrogen-filled packaging salmon fillet stored at 4 ℃ and 10 ℃, and some indicators were analyzed periodically, including the sensory evaluation, texture, pH value, and the values of TVB-N and TBA. Volatile components of salmon fillet with different treatments, detected by an electronic nose, were analyzed by loading analysis (LA) and principal component analysis (PCA). The results showed that the sensory scores, elasticity, resilience and chewiness values decreased gradually with the extension of storage time; TVB-N values and TBA values decreased gradually, while hardness values of fillet increased first and then decreased, and pH values were in the opposite. Vacuum packaging salmon fillet and nitrogen-filled packaging salmon fillet had been odvious corruption on 4th day at 10 ℃, simultaneously salmon fillet was degenerating on 6th day at 4 ℃. Analysis of electronic nose could distinguish freshness of fillets stored during different time. LA analysis showed that the main volatile components were nitroxides, aromatic compounds, ethanol, inorganic sulfide and so on.

Abstract:Extracted lignan from flaxseed meal by reflux method. The crude extract was preliminary purified by D101 macroporous adsorption resins which was followed by semi-preparation HPLC separation. The semi-preparative HPLC conditions were as follows: column was Megres C₁₈(30 mm×250 mm，10 μm), mobile phase was a mixture of acetonitrile(A)-0.1% phosphoric acid water solution(B), gradient elution,flow rate was 35 mL/min, wavelength was 280 nm, column temperature was 30 ℃ and injection volume was 2 mL. In the conditions, 98% purity flax lignans were obtained. Investigated the protecting activity of lignan against DNA damage that caused by UV photolysis and H₂O₂ treatment, it reveals that flax lignans has a significant effect on the protection of DNA oxidative damage while the concentration is 0.07~0.40 μg/μL.

Abstract:Extraction yield of polysaccharides from Achyranthes bidentata Radix (AbR) was increased by steam explosion pretreatment. Based on the results of single-factor experiments, the response surface methodology was employed to further optimize the steam explosion pretreatment conditions. The effect of steam explosion pretreatment on the DPPH radical scavenging activity and O^2- radical scavenging activity of Achyranthes bidentata Polysaccharides (AbPS) was evaluated. The optimum conditions was determined as follows: the water/AbR ratio 11%, steam explosion pressure, 1.6 MPa; residence time 63 s. After pretreatment under the optimum conditions, the extraction yield of polysaccharides from AbR was found to be 11.88%, which was twice as much as that from the untreated AbR．It maybe caused by the physical damage on the surface of AbR, including partial rupture with deep longitudinal cracks and micro-holes, due to the pretreatment of steam explosion, which can be seen from the SEM micro photographs. Furthermore, the antioxidant activity of AbPS was enhanced strongly after steam explosion pretreatment. The DPPH radical scavenging activity of AbPS increased from 77.9% to 90.1%, while the O^2- radical scavenging activity of AbPS was around 1.3 times as much as that from untreated AbR.

Abstract:Response surface methodology based on single-factor experiment was applied to optimize the extraction conditions of polysaccharide. As a result, the optimum extraction conditions were extraction temperature 65 ℃, ultrasonic time 22 min, liquid to material ratio of 221 （mL/g）. Under the control of such conditions, the extraction rate of polysaccharide from Radix Glehniae was 12.13%. The polysaccharide from Radix Glehniae had typical characteristics of polysaccharides, containing 90.4% of the total sugar and 1.22% protein, and the thermal degradation temperature was 300.32 ℃. The scavenging abilities of DPPH free radicals (IC₅₀=1.99 mg/mL), OH free radicals (IC₅₀=1.71 mg/mL) and the inhibiting ability of α-glucosidase (IC₅₀ =5.23 mg/mL) were investigated. The results showed that polysaccharide from Radix Glehniae had certain free radicals scavenging and potential hypoglycemic activities.

Abstract:Investigated the effect of different color Maca on energy metabolism of rats. 40 SD female rats were randomly assigned to 5 groups according to their body mass, which includes one control group and four experimental groups. Respectively, the four experimental groups were gavaged with 1% carboxymethylcellulose sodium suspension with 0.42 g/kg·BW black Maca, purple Maca, yellow Maca and white Maca powder daily; the control group was gavaged with 1% carboxymethylcellulose sodium solution without Maca powder daily. For 28 days, determinated content of blood glucose, glycogen, insulin and insulin-like growth factor 1 in serum, amino acid content in serum and liver. In addition, detected the mRNA level of AMPK (AMP activated protein kinase)、mTOR (mammalian target of rapamycin), AKT (protein kinase B) and LKB1 (liver kinase B1) by qRT-PCR (quantitative Real-time Polymerase Chain Reaction). These results showed that compared with the control group, relative skeletal muscle mass of rats was significantly increased (P＜0.05), the content of Asn, Arg, Ser and Leu in serum and the content of Asp, Ser, Thr, Ala, Val and Leu in liver also were significantly increased by black and purple Maca (P＜0.05). However, there is no significant change in the content of Ins and IGF-1 in serum of rats gavaged with black and purple Maca. In the liver of rats, the mRNA level of mTOR were significantly upregulated by four colors Maca (P＜0.05), the mRNA level of AKT were significantly upregulated by black and purple Maca (P＜0.05), however, there is no significant difference in the mRNA levels of AMPK and LKB1(P＞0.05). Overall, Maca can change body compositions by regulating the energy distribution, amino acids may be signal molecules that mediate mTOR activation.

Abstract:In this study, Maojian, crushed black tea and zymic Pu'er tea were chosen as representative of non-fermented, fully-fermented and post-fermented tea, respectively. The composition profiles of ethanol/water extracts were compared, and the antioxidant activities in vitro were detected by oxygen radical absorbance capacity (ORAC) and DPPH assay. In order to confirm the contribution of each key functional contributors, recombination model of antioxidant compounds in tea have been built and studied. The results showed that ethanol extracts contained higher contents of tea polyphenol, caffeine and prolamin, and higher antioxidant activities detected by ORAC and DPPH assay, while higher amounts of tea polysaccharide, gallic acid and theanine were found in water extract. Correlation analysis showed that antioxidant capacities of tea extracts were mostly influenced by ester catechins, such as ECG and EGCG. The results of recombination test showed that catechins and gallic acid were the major compounds responsible for antioxidant activity of Maojian extract, whereas other bioactive compounds might also exist in fermented tea, i.e., crushed Black tea and zymic Pu'er tea.

Abstract:In order to further develop and utilize the polysaccharides in tea residue, taking tea residue after green tea water extraction as raw material, and the yield of water-soluble reducing sugar was taken as the index, the effects of irradiation degradation + alkali degradation + acid degradation on green tea residue preparation of water-soluble reducing sugars were discussed on the basis of optimization of radiation degradation, alkali degradation and acid degradation for preparation of water-soluble reducing sugars. Results: The best degradation rate of irradiation was 1 200 kGy with a yield of 4.13%. The best combination of alkali degradation was 0.05 mol/L sodium hydroxide at 90 ℃ for 1 h, the yield was 2.08%. The optimal process of acid degradation was 9% nitric acid at 100 ℃ for 2 h, and the yield was 10.57%. The best combination of radiation degradation + alkali degradation + acid degradation was that the tea residue was firstly irradiated by irradiation at 1 000 kGy, degraded by the best combination of alkali degradation, and then degraded by the best combination of acid degradation, with the water-reducing sugar yield of 13.18%. The combination of degraded water-soluble reducing sugar has the highest yield.

Abstract:The osbrone classification method was used to extract bamboo bean albumin, the response surface method was designed to optimize the extraction technology, and its subunit component was analyzed. Design-Expert 8.05b software was used to establish mathematical models for the extraction process of bamboo bean albumin. The best extraction technology was obtained: stirring rate: 356 r/min, extraction temperature: 44 ℃, extraction time: 1.5 h, ratio of material to liquid: 111.20 (g/mL). Under this condition, the extraction rate is 27.56% (n=3), which had no obvious difference with the predicted value of 27.25%. In this case, the purity of bamboo bean albumin was (86.50±2.17)%. The analysis of SDS-PAGE gel electrophoresis showed that the main subunit molecular weight of bamboo bean albumin was 49.6 kDa and 27.6 kDa.

Abstract:To improve the yield and quality of Osmanthus extracts, several techniques were applied including the enzymatic hydrolysis by β-glucosidase and pectinase complex along with petroleum ether extraction and GC-MS analysis. The enzymatic hydrolysis process was optimized usingresponse surface methodology, and a reliable multiple quadratic regression model was established. The results showed that the best levels of the factors were as followed: pH 4.7, time 2.6 h, temperature 46 ℃, ratio of material to liquid 19.81 (mL/g), and the amount of enzyme complex 54.4 IU/g with 48.1% β-glucosidase activity, which was confirmed by experiments with an extraction yield of 3.32%, an increment of 62.75% compared to direct extraction. The results of GC-MS indicate an increase of main compounds, revealing that the hydrolysis by enzyme complex is more effective than direct extraction in terms of the extraction quality improvement. Compared with the control, the contents of the main aroma substances ,such as dihydrolinalool, γ-decalactone, dihydro-β-ionone, β-ionone, geraniol, and limonene, were increased by 27.27%, 116.36%, 100.00%, 247.06%, 72.84% and 14.29%, respectively. Meanwhile, nerolidol and β-ionol were also detected by GC-MS. After treating by β-glucosidase-pectinase enzyme, the yield and aroma quality of Osmanthus abstracts improved effectively.

Abstract:The equipment that impinges the object with high velocity airflow and freezes it quickly is called impingement quick-freezing equipment. The nozzle form of the equipment is one of the important factors to determine the flow field in the freezing zone, which affects the heat transfer characteristics between the object and the surrounding environment. Based on the nozzle structure of the impingement quick-freezing equipment, the influence of the inclined angle, arrangement and shape of the nozzle on the heat transfer characteristics of the flow field in the impingement quick-freezing equipment is discussed in this paper. Find that the nozzle-to-plate spacing（H/d）and the Reynolds numbers of the fluid play a decisive role in the relationship between the nozzle inclination angle and the average Nusselt numbers. In addition, the different shapes and arrangement of the nozzles also have a great influence on the airflow organization in the system.

Abstract:Hemp seed oil has a good application prospects in function of hypolipidemic, anti-oxidation and anti-aging which can meet the needs of people's diet health. This review summarized different extraction methods and chemical components of Hemp oil, and the research on biological activity, looking forward to the development prospects of Hemp oil and providing the basis for its development and utilization.

Abstract:In order to study the free radical yield variation law of impinging stream-jet cavitation effects and its influence factors, and to better apply in the field of food processing, the impinging stream-jet cavitation was used to be compared with single impinging stream and single jet cavitation respctively. The effects of upstream pressure, solution temperature, cavitation time and other factors on the yield of hydroxyl radicals (·OH) were investigated. The interaction between factors and their optimum conditions were analyzed by response surface analysis. The experimental results showed that ·OH yield increased first and then decreased with the increase of the pressure and the solution temperature, and increased with the increase of the cavitation time. The order of the influence of each factor on the production of ·OH was: cavitation time ＞upstream pressure ＞ solution temperature. The optimum technological conditions were as follows: cavitation time 60 min, upstream pressure 0.44 MPa, solution temperature 39.34 ℃, under this condition, the theoretical value of · OH yield was 1.073 7 μmol/L, the experiment actual value was 1.067 4 μmol/L, predicted values and measured values were basically identical.

Abstract:In order to screen raw and low-yield methanol kiwifruit yeast and provide special strains resources to the kiwifruit wine production. Strains were identified by colony morphology and 18S rDNA sequencing to determine the species relationship of the three strains of yeast. The fermentation capacity, alcohol and sulfur dioxide tolerance were evaluated. Additionally, the three strains were used for kiwifruit wine fermentation, and the physicochemical properties, methanol content and volatile flavor compounds of the product were determined. The three strains were identified as Pichia guilliermondii by molecular biology. Among them, Q3 had the strongest fermentation capacity, it could tolerate 16% of alcohol and 300 mg/kg of SO2. The alcoholicity of brewed kiwifruit wine by Q3 was 11.54% Vol, the vitamin C 390.82 mg/L, the residual sugar 5.35 g/L, and the methanol 87.7 mg/L. In addition, there were 25 kinds of volatile flavor compounds were detected. The strain Q3 screened from the surface of kiwifruit is superior to the strains Q1 and Q2 in the aspects of fermentation ability, alcohol and sulfur dioxide tolerance. And kiwifruit produced by Q3 has good quality and low methanol content, and has bright application prospect in the kiwifruit industry.

Abstract:In this paper, the extruded summer and autumn green tea powder processed with a twin screw extruder, the effects of material moisture, barrel temperature and screw speed on the content of tea polyphenols in green tea powder was studied after extruding. Moreover, the leaching functional components and microstructure changes were also studied. The results showed that the moisture content of the material increased, and the content of tea polyphenols decreased first and then increased; increasing the barrel temperature could increase the leaching of tea polyphenols, while the high temperature would lead to the loss of tea polyphenols; increasing the screw speed could increase the tea powder damageand promote the leaching of tea polyphenols. However, the barrel temperature and screw speed had little effect on the puffing degree of the extrudates, and the influence of material moisture content was relatively large. Compared with unprocessed summer and autumn green tea, the tea polyphenols, crude fiber, total soluble sugar content decreased and theanine content increased in summer and autumn green tea powder processed. After the expansion of summer and autumn green tea, the surface structure was observed to be flat and smooth under a scanning electron microscope, and the mechanical force caused the cleavage of the chemical bond of the material itself.

Abstract:The broken rice starch was prepared from the rice processing by-products. By single factor tests and orthogonal experiments, taking the extracting rate and purity as the indexes, the rice starch was prepared by alkaline hydrolysis method of microwave-assisted with alkaline protease extraction. The optimum conditions were as followed: the ultrasonic time 25 min, enzyme content 5 mg/g, enzyme hydrolysis time 2 h, enzyme hydrolysis temperature 45 ℃, ratio of solid to liquid 14 (g/mL). Under the conditions, starch extraction yield reached 98.56%, and the purity was 99.13%.

Abstract:The experiment used potato starch as raw material to make vermicelli. The effects were studied by Orthogonal test regression analysis, including xanthan gum, konjac powder, locust gum, sucrose ester and compound phosphate to the potato starch. The effect of several additives on the quality of potato vermicelli texture was researched. The best best improver of alum-free potato vermicelli formular as followed: xanthan gum 0.125%, konjac power 0.250%, acacia gum 0.300%, sucrose ester 0.025% and compound phosphate 0.050%. Under this condition, the texture properties of vermicelli is the best.