Barleyleaf powder is rich in protein, vitamins, minerals,chlorophyll, flavonoids and γ-aminobutyric acid. In this paper, the nutritional components and the products of barley leaf powder were reviewed, which provided some reference for the development of related products containing barley leaf powder.

Food packaging prevents food from being affected by external factors and keeps food properties,and it has the function of convenient transportation,beautiful utility and advertisement. With the improvement of living standards,the demand for food packaging materials is becoming more and more safe, environmental and healthy.Plastics,glasses,metals,papers,nano and other packaging materials and their application in all kinds of food are reviewed. Additionally,research progresses in recent years,particularly studies about packing materials are summarized in detail. Finally,the current problems and future research of food packaging materials are discussed. Food packaging materials are gradually green,safe,multi-functional aspects of development,in order to the sustainable development of the new packaging materials are widely used in food industry.

Lemon is rich in vitamins,minerals,flavonoids and other nutritional substances,and has the functions of beautifying skin,eliminating the free radica,lowering high blood pressure and blood lipids and blood sugar and anti-cancer effect. It is a fruit with high nutritive and medicinal value.Yunnan and Sichuan Province are the main lemon planting areas in China. In many countries,lemon has become a common and even indispensable fruit in daily life. There are many researches on the nutrition and functional components of lemon in the world,the effects of lemon juice and fruit extracts on reducing uric acid,lowering blood lipid,lowering blood pressure,preventing cancer and resisting cancer were studied through cell models,animal models,human volunteers.The researches of lemon functions in China are still at starting stage. The present study reviewed the literature of previous researches on lemon fruit nutrition,functions and present situation of lemon products with aview to providing the reference and instruction for lemon cultivation and processing.

In order to deepen the research on the control system of the warehousing and logistics handling robot based on Bluetooth control,the software and hardware system of the handling robot was designed.The ultrasonic module,infrared module,Bluetooth module,car model and AT89C52 single-chip microcomputer were used to realize the switching between the robot's self-tracking and obstacle avoidance mode and the mobile phone control mode.It can be seen from the test results that the handling robot can deliver the goods to the specified location by completely following the specified path;When encountering obstacles,the error between the distance measurement value of the ultrasonic obstacle avoidance module and the actual distance measurement value of the ruler is less than 1%,realizing autonomous obstacle avoidance;When the robot fails,the robot's travel path can be controlled through the QX Bluetooth controller APP.When the test distance is within 12 m,the accuracy rate is 100%; The accuracy rate is more than 90% when the test distance is within 13 m.The research provides a reference for the further study of unmanned warehousing.

In order to improve the preservation method of peanuts and ensure the quality improvement of peanuts during storage period,four kinds of storage methods were summarized.The physical method has little damage and can delay rancidity of peanuts.The chemical method obviously inhibits rancidity and microorganism growth,but has influence on human body.Biological methods are almost nondestructive,have no effect on human body,can delay rancidity,and inhibit microorganisms; Coating storage method has little effect on peanut quality and can prolong peanut storage period.Reasonable storage and preservation method has obvious inhibition effect on peanut deterioration and can prolong the storage period of peanuts.This study provides theoretical support for the research and development of peanut preservation methods and for reducing the loss during storage.

The basic principle and generation condition of FRET technology were introduced, the recent progress in application study of FRET technology in the fields of mycotoxin residues, antibiotic residues, excessive heavy metal ions and other pathogenic microbial residues were reviewed, and the future development direction and application prospects of FRET technology were forecasted.

The design scheme of quantitative filling control system based on PLC and MCGS was discussed. The system uses Siemens PLC as the controller and Kunlun MCGS touch screen as the host computer,which can satisfy automatic filling of liquid within 40 kg. The filling accuracy is high and the filling parameter is adjustable. The visual man-machine interface design realizes real-time and effective monitoring of the filling process and is easy to operate. Through online commissioning,the system runs stably and reliably, has achieved the expected objective,and has the prospect for extensive application in industry.

The paper reviews the preparation of domestic and foreign buckwheat peptides enzymatic digestion,microbial fermentation,artificial synthesis and genetic engineering and cholesterol-lowering,hypotension,hypoglycemia,antioxidant,antitumor,antibacterial and other functional activities,as well as the prospect of buckwheat peptides in general food,health food and food preservation applications,in order to provide reference for the further use of buckwheat peptides.

Bag feeding mechanism is an important part of rotary packaging machine.Its performance directly affects the packaging speed and accuracy of the packaging machine.Based on the working principle of the packaging machine and its bag-feeding parts, the process flow of automatic bag feeding was designed.Then,the structure of the bag-feeding parts and its working cycle diagram were designed.The secondary bagging mechanism analysis model was established and its solution was obtained by using closed vector method.Lastly,the size and structure of bag-feeding mechanism was optimized by comprehensive considering the overall layout of the machine and the size of the mechanism.

For the problems of motion trajectory singularity and long motion beat time existing in the handling process of milk cartons, the simulation design was carried out based on RobotStudio software.First, the production process plan was completed for the work task; secondly, the production line work logic was created and the I/O signal required for the simulation was set; then, through the Rapid offline programming control simulation, the B-spline curve was used to optimize quintic polynomial to plan the robot motion trajectory in order to solve the motion singularity and path interference and collision problems found in the debugging process; finally, through analysis of three TCP speed curves and energy consumption curves of the robot, it was found that 1000 mm/s was the optimum value, at which, the time spent for the beat was 13.9 s and energy consumption was 5 055 J.This scheme determined the optimum speed value, reduced the vibration amplitude of robot effectively.It conforms to the law of robot movement and provides a theoretical basis for reducing production costs and improving handling efficiency.

In this test,the commercial pure milk,hawthorn and dried tangerine peel were used as the main raw materials to make the yoghurt with the flavor of dried tangerine peel and hawthorn through a series of process controls after addition of lactic acid bacteria fermenting powder and sugar.The single factor test and orthogonal test were used to determine the optimal fermentation conditions for production of dried tangerine peel and hawthawn yoghurt. The best formula of yogurt obtained by single factor test and orthogonal test was:ratio of hawthorn to tangerine peel=1:2,tangerine peel juice 12%,sucrose 9%,lactic acid bacteria fermentation powder 0.1%,fermentation time 6.5 h,and fermentation temperature 43℃.The yoghurt produced was uniform in color,refreshing and delicate,with appropriate sourness and sweetness,strong milk aroma and the fragrance of hawthorn and dried tangerine peel.

In order to effectively solve the problems of high labor input cost of the sorting link,slow background information update speed and low sorting efficiency,a simultaneous positioning and recognition method of one-dimensional code and three-segment code based on machine vision was proposed.It mainly includes improving one-dimensional code positioning method and using"line scanning" to improve the decoding accuracy of one-dimensional code.Faster R-CNN target detection method was improved to achieve classification and positioning of three-segment code in different regions.The experimental results show that this method has a good recognition effect on different styles of waybill.The recognition rate and accuracy rate of bad one-dimensional code is more than 60%,the accuracy rate of three-segment code positioning in different regions reaches 98.47%,the overall recognition rate of single waybill reaches 98.03%,and the overall recognition time is between 105 ms and 146 ms.The research results can provide technical reference for efficient sorting of waybills.

In order to investigate the effects of food bags with different thickness and sterilization time on the storage quality of sweet corn in vacuum packaging,packaging materials with two thicknesses(100,120 μm) and two sterilization times(10,15 min) were used to treat sweet corn,and the changes of color difference value,water content,hardness,ascorbic acid,soluble protein,soluble sugar and soluble solids content of sweet corn were measured during storage.The results show that:after 49 days of storage,the sweet corn packed in 120 μm vacuum bags and sterilized for 10 min has a moisture content of 75 g/(100 g),VC content of 26 mg/(100 g),soluble protein content of 4.1 mg/g,soluble sugar content of 51 mg/g,and soluble solids content of 11.8%,which is better than other treatment groups.After being packaged in 120 μm vacuum bags and sterilized for 10 min,the decrease of VC and soluble sugar content can be significantly delayed,and the increase of grain browning degree can be inhibited,which has the best effect on maintaining the edible quality of sweet corn.This study provides a certain reference for the storage and preservation of sweet corn.

A twin-screw mixer model was designed for flour-water two-phase mixture,and its three-dimensional flow field was numerically simulated by FLUENT. Moreover,ICEM was used to divide the unstructured grids for the model,Euler multiphase flow model and RNG k-ε turbulence model were used for simulation. Under steady-state conditions,the pressure distribution,velocity distribution and solid particle volume fraction distribution in a twin-screw mixer were simulated. The results show that the twinscrew propeller has better stirring effect on the multi-phase flow in the tank,the peak and valley values of velocity tend to appear near the incident flow and backflow surface,producing obvious vortices,making the mixing more uniform. The results provide a theoretical basis for further optimization of the performance of the mixer.

Fermentation technology of edible mushroom has undergone extensiveapplication in food industry. More recently,profound studies have been conducted into the fermentation liquor. This fermentation liquor and it contains abundant functional ingredients for antineoplastic effect,immunity enhancement and oxidation resistance,taking the form of protein,polysaccharose,terpenoid,and polyphenols,etc. Through a comprehensive review of previous studies on fermentation liguor and its major ingredients as protein, polysaccharide,triterpenoids,nucleic acid and polyphenols,this paper mainly focuses on the physical and chemical properties,the analysis of the separation and purification technologies in application, their functional effect and production auxiliary components to provide theoretical basis for research and development of health products in near future.

The goal of this study is to design a kind of air column bag packaging machine which can realize continuous automatic packaging of spherical fruits. For the characteristics of spherical fruits,the packaging process scheme of air column bag was presented,including the steps of automatic bag loading,fruit feeding,fruit loading,inflating and automatic discharge of finished fruits.The design of key parts of the packaging machine was confirmed.By holding up the air column bag and fixing it using the positioning half cylinder,the packaging and inflating can be carried out simultaneously.The simulation results show that the packaging machine has reasonable structural design.The machine can realize continuous automatic packaging function.The spherical fruit packaging machine has the characteristics of compact structure,high degree of automation,etc.It is suitable for mass packaging production mode.

For the problems of limited cargo information,collision and physical stability limitation in the 3D boxing problem,an online 3D boxing method based on constrained deep reinforcement learning was proposed.This method uses the improved heuristic search algorithm to predict the feasibility mask of placing actions,and uses this mask to adjust the action probability output by the policy network during training.The experimental results show that the algorithm improves the boxing efficiency of disordered mixed goods,the average placement time of a single cargo is only 3.9 ms,and the space utilization rate reaches 68%.The study provides a useful reference for the application of reinforcement learning in the field of combinatorial optimization.

With respect to the nonlinear,timevarying and timedelay characteristics of weighing control system of weighing packaging machine,which leads to low accuracy and poor stability of weighing,an improved fuzzy PID algorithm was proposed by introducing the universe scaling factor of fuzzy variables on the basis of traditional fuzzy PID control algorithm.First,the scaling factor of the variable universe was designed to make the fuzzy variable universe follow the change of weighing error and the error rate to lengthen and reduce,so that the fuzzy variable universe is the best scope.This method can avoid the control error caused by inappropriate domain of dependent variables. Then the improved fuzzy control algorithm was used to tune the PID parameters online to achieve the highefficiency,accurate and stable control effect of the weighing control system. The simulation results show that the improved fuzzy PID control algorithm has the advantages of small overshoot,fast response speed and strong antiinterference ability.The control algorithm can effectively improve the weighing efficiency and accuracy of the packaging machine.

In order to realize the automatic boxing function of the gift box of canned products,a set of overall solutions based on the Cartesian coordinate robot,equipped with functions of alignment,cardboard addition,paper lining forming and addition was designed.Based on the analysis and calculation of the demand process and production capacity rhythm,the overall design scheme was proposed,the virtual prototype technology was adopted to design each functional module in detail,and the control system of the boxing machine based on Siemens SIMOTION was developed.Through field debugging,the automatic boxing function was realized,the system’s stable capacity can reach 40 boxes/minute,and a single line reduces the labor demand by more than 60%.It has the promotion and application value in the field of automatic boxing of canned gift boxes.

At present,descaling is a technical difficulty in the processing technology of the whole freshwater fish. In this paper,a whole fish descaling machine was mainly designed. It is the equipment for mass descaling of freshwater fish by such structures as spring type descaling brush. The whole fish descaler studied in this paper features easy operation,simple structure,high descaling efficiency,good descaling effect and strong adaptability to the fish body,and can meet the requirements for the industrialized mass descaling processing of freshwater fish.

A labeling machine control system was designed based on Siemens S7-200 Smart PLC,it uses the motion axis with motion control function contained in S7-200 Smart PLC to control the position of the servo motor of the label output mechanism to paste the label to the object smoothly without bubbles so as to realize labeling function. This method has the advantages of high labeling precision and high stability,etc.

To improve the utilization rate and added value of black wolfberry,using black wolfberry extract as the main raw material,adding maltodextrin,sucralose,xylitol,2% white granulated sugar and 0.3% citric acid,the freeze-drying black wolfberry powder was prepared by vacuum freeze-drying,the formulation of freeze-drying black wolfberry powder was optimized based on single factor test and fuzzy mathematic sensory evaluation method combined with response surface method,and the quality analysis was carried out.The results showed that the sensory score reached (8.45±0.04) when adding 70% black wolfberry extract,21% maltodextrin,3% xylitol,0.02% sucralose,which was closed to the theoretical prediction.Under these conditions,freeze-drying black wolfberry powder was bright in color,sweet and delicious,with the contents of low water,solubility,fluid- ity,packing density were(4.37±0.25)%,(42.20±1.35)%,(42.69±0.5)°,(26.84±0.01)g/mL and contents of anthocyanin,total sugar,total phenol and total acid were (202.23±0.62)mg/100g,(35.60±0.04)g/100g,(34.74±0.35)mg/g and (20.14±1.43)mg/g.Additionally,it had good nutritional quality,and its microstructure appeared irregular shape,uneven granules,fold or fracture surface.The study provided reference value for industrial production of freeze-drying black wolfberry powder.

In order to realize the packaging of most odd objects,an intelligent packaging labeling machine was designed.The solution of modular mechanism was proposed.Firstly,the type of packaged odd items was identified by visual module.Secondly,the label information was transmitted to the marking module for marking.Finally,the packaging task of bulk items was completed by the packaging module.The rationality of the design of each module mechanism was verified by experimental simulation.The verification results show that the stress of each part of the key structural members of the duck tongue claw,the movable claw and the bucket connecting rod is 380.1,480.7,14.57 MPa,respectively.The three all have practical application conditions in terms of tensile and shear strength.The research and design can intelligently complete the production operation in packaging and labeling,effectively alleviate the labor pressure of relevant personnel,improve labor efficiency,and provide reference for the production and packaging of odd materials.

In order to improve the current status of single bread ferment, the compound healthy steamed bread with unique flavor was made by lactic acid bacteria instead of yeast.Based on sensory evaluation, the proportion of lactobacillus and yeast, the amount of starter, the amount of honey and the time of fermentation were determined by single factor and response surface methodology were analyzed to determine the best processing technology.The experimental results show that:the steamed bread made according to the following technological conditions has a light yellow color, uniform and delicate tissue, sweet and soft taste:200 g of high gluten flour as the base weight, 50% pumpkin mud, 1.2% amount of mixed strains, ratio of lactic acid bacteria and yeast 2.5:1, 6% honey powder, and 120 min fermentation time.The specific volume, moisture and pH value all meet the requirements of national standards.The research results enrich the flavor of steamed bread and improve the nutritional value and quality of steamed bread, which provide data and theoretical reference for developing new products.

In order to solve the problem that the high pressure jet mill equipment has low production capacity and cannot meet the needs of industrial production,the key component——interaction chamber of high pressure jet mill equipment was studied,and a compound large flow interaction chamber was proposed.Firstly,based on the Mixture multiphase flow model and the Realizable k-ε turbulence model,the internal flow channel of the interaction chamber was simulated by computational fluid dynamics,and the pressure,velocity,and turbulent kinetic energy distribution of the flow field were obtained,and a better split angle and runner dimensions were obtained.Secondly,a prototype of large flow high pressure jet mill equipment was developed,and the mill experiments and productivity tests were carried out on the prototype.The experimental results show that the average crushing particle size d[4,3] is reduced from 75.6 μm to 32.7 μm,and the production capacity of the equipment is stabilized at about 4.2 m³/h.The study provides theoretical and experimental support for the design of high-flow high-pressure jet mill equipment for industrial use.

In order to improve the palletizing speed of high-level palletizer,a high-level palletizing system was established considering both performance and safety in view of the problems of slow response speed,low positioning precision and poor working reliability of the existing palletizer,and a servo drive control system of high-level palletizer based on PROFIBUS-DP expansion bus communication was designed. The servo drive was used at the key stations of the high-level palletizer,such as transposition,grouping,pushing,stratification, lifting,etc.,meanwhile the servo controller equipped with integrated PROFIBUS-DP communication board card was equipped to achieve the unified management and control of the whole movement process by PLC master station. This palletizer production line features reasonable structure,stable performance,and safe and reliable operation. The test results of the prototype indicate that the designed high-level palletizer system can effectively improve the response speed and positioning accuracy during the operation process,and significantly improve the production capacity of the palletizer on the premise of ensuring structural safety and reliability.

Industrial production is the main development trend of the pasta processing industry,and roll-pressing is an important process for pasta production.However,due to the high water content of the dough,the dough sheet is very easy to be stuck on the roll and broken. Preventing the dough sheet from sticking on the surface of the pressing roll is a key technology for efficient and reliable operation of pasta processing machinery. In this paper,first,researches were conducted from present status of adding amount of water in pasta and the adhesion mechanism of the dough sheet;second,the existing techniques for solving the adhesion problem of the dough sheet were overviewed,they are respectively:mechanical stripping;Reduction of water content;Reduction of the surface tension of the pressing roll;Adjustment of the rheological characteristics of dough sheet;And the use characteristics and principles of different methods were systematically discussed. Finally,the anti-adhesion technology of dough sheet was prospected from the angle of surface engineering technology,which provides a reference for the food industry professionals to solve the problem of adhesion in pasta processing.

In view of the problem that existing starter pressing machine can not realize the surface pulp lifting of the formed starter billets,which will affect the quality of the late fermentation of the billets,a multi-station rotary compound starter pressing machine was designed,which mainly includes mechanical system,hydraulic system,pneumatic system and PLC electrical control system.Multi-time multi-point pressing mechanism and water spraying system were combined to simulate the artificial starter pressing process so as to realize multi-time alternate slapping of the surface of the starter billets and slide pulp lifting.The results show that the appearance of the starter blocks produced by the equipment is complete in shape and has good air permeability.After culture,the skin size is less than 2 mm,and the color is mainly gray white and black brown,with good flavor and quality.The research provides reference for the design and development of the starter-making equipment.

In order to realize the packing of oral liquid bottled products with two different packaging methods and specifications, namely, self-locking bottom box and book gift box under compact layout of packing equipment, an oral liquid bottle packing system suitable for fast switching between vertical and horizontal packing was developed and designed.According to the requirements and process, the layout of the vertical and horizontal integrated packing system was designed; Each functional module was designed in detail using virtual prototype technology; The control system of the packing machine was developed based on the Omron servo system.The field debugging realized the automatic packing function of fast switching between the two specifications of the design function, and the packing speed has reached 12 000 bottles/h.The study provides a reference for the development of high-speed and multi-specification packing equipment with compact layout.

China is a major feed producer in the world,and the feed mill has an irreplaceable position in the feed production process.Feed hammer mill is very popular because of its strong crushing ability,simple operation and convenient maintenance.The development status of the feed hammer mill and the research and development of the gas-solid circulation layer in the feed hammer mill,the numerical simulation of the multiphase flow field,and the noise reduction of the mill were reviewed.The research on the feed hammer mill was summarized,and the future development was prospected.It provides a reference for further innovative research and development of crusher equipment.

In order to solve the problem of screw conveyor blocking,a screw conveyor control system based on IAR visualSTATE was proposed. Firstly,the hardware section of the screw conveyor control system was designed,including design of both the zero crossing detection circuit and thyristor conduction angle drive circuit. Secondly,the visualSTATE software was used to establish the system control model to embed corresponding program into the STM8S207 microcontroller.The experiment demonstrated that the graphical modeling method (GMM) based on visualSTATE can clearly and conveniently express the control logic.It not only improves system debugging and development efficiency,but also improves the program design reliability,and effectively solves the problem of material jam in the process of spiral conveying.

For the problem of unclear characteristics of the flexible screw blade conveyor such as the range of conveying angles during the transportation process,a performance test platform for the flexible screw blade conveyor was designed,the transmission route was planned,and the inclination angle adjustment mechanism was designed.The discrete element simulation method was used to compare the conveying efficiency of flexible screw conveyors for flour materials under different structural parameters,different conveying angles,and different rotating speeds.The results show that the conveying efficiency of flexible screw conveyor is the highest when the conveying angle is 90 °.When the rotational speed and spiral angle are fixed,the conveying efficiency increases monotonously in the range of 10 °-20 ° and 600-1 000 r/min respectively.The study provides a basis for conveying performance test of the flexible screw.

In view of the problems such as lack of technical equipment for picking peppercorns, low manual picking efficiency, high cost, high labor intensity and easy injury to the arms of picking persons, a peppercorn-branch splitter was designed based on the method of branch picking.Using the principle of cutting and separation, two groups of toothed and edged annular cutters were designed, with inner diameters of 18 and 23 mm respectively; Circular arc hub with diameter and width of clamping conveyor wheel of 30 mm was designed, the diameter of the spring wire on the conveyor wheel was 1.2 mm, the length of the steel wire was 30 mm, and the end face of the steel wire was set in an arc shape.The simulation analysis results show that the maximum stress of the spring steel wire is 1 045.5 MPa, which meets the design and use requirements.The machine can realize the separation of fruit ears and branches after picking peppercorns.This study provides a new reference scheme for the research and design of peppercorn harvesting equipment.

Aiming at the problem that empty cans' defect may cause products' leakage,deterioration and pollution,an empty cans' intelligent defect detection system was designed. The design of negative pressuredelivery system,optical path of visual detection and defect detection system was included. High speed CCD camera and OPENCV image processing technique was used in defect detection. It can achieve stable image acquisition,high speed image processing,accurate defect extraction and elimination. It can realize the targeted intelligent defect detection of empty cans' top,body and bottom,shielding body structure interfering,and realize high speed and accurate detection of defects,such as cans' deformation and foreign matters.

Modified atmosphere packaging (MAP) is an important method of food preservation,which can effectively extend products' shelf life. When using MAP to preserve food,there are three main factors that af-fect the preservation. The first is the initial component of packaging gas. The second is the change of packaging gas during the process. The third is the temperature and humidity conditions. Two common respiration models of fruits and vegetables usually used at present were summarized. And their scopes of application were analyzed. Initial gas composition for the preservation of fresh fruits and vegetables,fresh-cut vegetables and meat products was summed up. The effect of gas exchange inside and outside using different packaging films was introduced. Studies of temperature and humidity in MAP were summarized. Finally,some suggestions for MAP technology research were proposed.

The physicochemical characteristics of purple yam starch and resistant starch produced by autoclaving, enzyme-autoclaving and double enzyme purification preparation method have been analyzed and compared in the paper.The results showed that native starch granules exhibited showed oval,circular shapes with smooth surface.Resistant starch granules exhibited irregular shapes and were destroyed.Both of them were similar in chemical structure without new functional group in resistant starch granules.With the increased content of amylose,the retrogradation speed of starch samples rose gradually with reduction in freeze-thaw stability; meanwhile,absorption curve of resistant starches prepared from purple yam complexed with I shifted to amylopectin absorption wavelength.Rheological analysis showed that apparent viscosity of resistant starches were increased with the decrease in the shear restoring force compared to native starch.

Ordinary paste cartons can only be stored and transported in the form of fixed box after forming,resulting in a lot of transport cost and wastage of storage space. In addition,the structure of the carton is complex and requires manual completion of many manufacturing procedures. Therefore,the production efficiency is low and it is difficult to realize automatic mass production of the cartons.Through the innovation of new type of the carton structure form,segmented forming of the cartons is achieved,that is,the packaging enterprises make the foldable paste carton blanks,and the user enterprises complete the final forming.This process scheme is favorable to the storage and transportation of carton blanks in the form of flat boards,carton online forming and automatic loading of products.

In order to solve the problem of timeconsuming and laborious manual detection of the quality change in the drying process of jujube slices,a realtime monitoring system of quality indicators in the drying process of jujube slices was designed. Through hardware and software design of machine vision module and automatic weighing module,realtime monitoring of sensory quality indicators (color and moisture content) commonly used in the drying process of jujube slices by the upper computer was realized.According to the correlation model of color change and nutritional quality indicator change in the drying process of jujube slices,the prediction module for nutritional quality change was designed to realize the realtime prediction of nutritional quality indicator (reducing sugar and VC) content commonly used by the upper computer in the drying process of jujube slices. Finally,based on LABVIEW,the realtime monitoring system software and manmachine interaction interface for the quality indicator of Chinese date slices during drying process were developed,and the system was tested. The experimental results show that:for color monitoring,the average error of L^*,a^*,b^* valuse were 0.1,0.69 and 0.61,respectively.In terms of moisture content monitoring,the average error between manual detection and system detection was 2.47%;In terms of reducing sugar and VC content monitoring,the average error between manual detection and system detection was 1.35 g/100g and 15.06 mg/100g,respectively.The research results can be used as reference for the realtime monitoring of quality indicator changes in the drying process of fruits and vegetables.

The characteristics of horizontal straight pipe pneumatic swirling conveying for long distance bulk grain were studied to provide theoretical basis for the development of pneumatic swirling conveying equipment for long distance bulk grain.Based on the Realizable k-ε turbulence model,parameter simulation of flow field characteristics in swirling generator with different spiral angles and different guide blade lengths was carried out by Fluent.The results show that the velocity of the flow field decreases first and then increases with the increase of the spiral angle of the swirling generator,and then decreases again,from 19.4 m/s to 19.2 m/s,and then increases to 19.8 m/s and then decreases to 19.6 m/s.With the increase of the blade length of the swirling generator,it increases from 19.2 m/s to 19.7 m/s.The static pressure of the flow field increases with the increase of the spiral angle of the swirling generator and the length of the guide blade,from 191.1 Pa to 584.2 Pa and from 267.5 Pa to 304.0 Pa respectively.When the spiral angle of the swirling generator is 25 °and the length of the guide blade is 0.3m,the velocity of the flow field reaches a maximum of 19.8 m/s.The energy in the swirling field is higher than other flow fields of the same working condition,and the system has higher conveying efficiency.

Fast freezing technology can effectively maintain the freshness of the foods,but the "by product" -ice crystals brought by fast freezing can cause damage to the inside and outside of the food,resulting in the loss of nutrients and the deteriorated appearance and taste. In this paper,the formation mechanism and detection method of ice crystals,the factors affecting the formation of ice crystals,methods of controlling the formation of ice crystals and the future development direction,etc. were discussed. The purpose is to improve the existing methods and the quality of fast frozen foods by understanding ice crystals.