1、FOOD TEXTURE ANALYSIS. 食物物性測試分析WHAT IS FOOD TEXTURE 什么是食物的質構All the mechanical, geometrical and surface attributes of a product perceptible by means of mechanical, tactile and, where appropriate, visual and auditory receptors.產品所有的機械性的、幾何性的和表面的特性，可通過機器、感觸和適當的看、聞等手段測量 (ISO 5492, VOCABULARY FOR SENSOR

2、Y EVALUATION)“All encompassing” complex-specific multidimensional attribute 復雜而特殊的多維特性TEXTURE ANALYSIS物性分析.“An empirical measure, which can be correlated with fundamental aspects of structure and macromolecular behaviour”. 它是一個經驗式測量方法，與結構的基本外形和高分子行為有關TEXTURE ANALYSIS: There are a number of typical p

3、arameters associated with this science與這門科學相關的性能參數FUNDAMENTAL 本質特性IMITATIVE模擬EMPIRICAL經驗測試OPTIMUM優化Hardness硬度Springness破裂性Adhesiveness粘附性Cohesiveness內聚性Related to “real-life” characteristics of a product! 都與產品的實際壽命有關系的特性 An integral part of Quality Control testing Quality Control check to establish

4、process capabilities Rheological predictor (process development) Establishment of quality standards Conformance to customers quality requirements New Product Development Sensorial correlationPRODUCT DEVELOPMENT 產品研發- Scale-up Approval 產品等級認證- Specification Development 使用說明- Shelf-life Trials 產品保存時間試

5、驗- Ingredient Changes and product matching 成分改變和產品匹配PROCESS DEVELOPMENT 流程工藝- At-Line Process Control 生產流程控制- Proactive rather than Reactive Processing 幫助生產前做好準備- Process Optimisation 生產優化- Pipeline and Pump Design 對管道和輸送系統的設計有參考價值QA & QC SYSTEMS 質量檢測和控制- CRITICAL QUALITY POINTS 質量點- Integral part o

6、f ISO 9002 ISO質量認證的主要部分Raw material and Supplier conformance 原材料和供應商的一致性PRODUCT EVALUATION 產品評價- Product Improvements 產品改進- Sensory Correlations 與口感有關- Texture Profile Analysis 組織概況分析- Consumer Studies 消費者研究 - Product Matching 產品匹配(Adapted from Borwanka, 1992)TEXTURE TESTING APPLICATIONS. 應用質構儀原理及部分

7、參數定義參數感官定義儀器定義硬度(Hardness) 牙齒間用來壓迫樣品所需要的力，定義為獲得指定的形變所必須的力 第一個壓縮循環的峰值力 彈性(Springness) 當破壞力去掉時，材料回復為其原來狀態的速率 在第一次咬斷末期和第二次咬斷開始的時間內食物恢復的高度 粘附性(Adhesiveness) 用來克服食物表面與接觸物表面之間的吸引力所做的功，接觸物是指與食物相連的物體（如舌頭，牙齒，上腭）第一次咬斷的負數區域的面積代表將壓縮探頭脫離樣品所必須的功 內聚性（Cohesiveness） 組成產品結構的內部鍵力（值越大，內聚力越強） 第二次壓縮與第一次壓縮的正力之比（面積向下的沖擊） 原

8、理：樣品在可控力的作用下，產生形變曲線，測定結果可以用力、變形和時間來確定。TEXTURE PROFILE ANALYSISHardness 硬度 = Peak +ve force Springiness彈性= Height food recoversCohesiveness粘結性 = A2/A1Adhesiveness 粘附度= Negative area from first biteFracturability破裂度= First break in cycleGumminess粘性 = Semi-solid foods calculated from Hardness x Cohesiv

9、enessChewiness 咀嚼性= Solid foods calculated from Hardness x Cohesiveness x SpringinessFtHARDNESSADHESIVENESSA2A3A1SPRINGINESSVARIABLE: TEST CONFIGURATION可變參數：測試結構Variables to Texture Analysis 物性分析測量中可變的參數 Texture analysis procedures are generally empirical in nature. Variation in test parameters must

10、 be understood and eliminated in order to maximise the benefits and relevance of data generated.Instrument Specific Variables:Test Speed 測試速度Test Direction 測試方向Distance of Penetration 穿透距離Probe Type 探針型號VARIABLE: PROBE TYPE 探頭型號 DOWNWARD FORCES向下施力COMPRESSION: Probe (cylindrical probe or flat plate)

11、 comes into contact with sample exerting force upon it. 壓擠試驗：探頭（圓柱形或扁平盤狀）盡力壓向樣品Cake Compression 蛋糕壓擠試驗FtInitial surface fracture 開始表面破裂DOWN STROKEUP STROKEHARDNESS 硬度Probe area equal to or greater than that of sample 探頭面積要等于或大于樣品的接觸面積VARIABLE: PROBE TYPE 探頭型號DOWNWARD FORCES向下施力PUNCTURE AND PENETRATI

12、ON: Probe comes into contact with surface creating both compressive and shear forces as penetration increases.穿透試驗：探頭向下接觸樣品表面，當穿透力度加大時產生壓力和剪切力GELATIN BLOOM TEST 凝膠試驗Negative force = Tackiness of gelatin sample 反向力FtBloom value is taken as final force attained at given deformationBLOOM STRENGTHArea =

13、 Work to attain deformationNegative area = Adhesion of gelatin sample 反向面積DOWNWARD FORCES向下施力PUNCTURE AND PENETRATION: Conical probe comes into contact with surface generating increased forces with increased contact areas as test proceeds.圓錐形探頭與樣品表面接觸不斷增加接觸面積VARIABLE: PROBE TYPE 探針型號Consistency稠度Har

14、dness 硬度 Adhesion Characteristics 粘附性 Soft Cheese Spreadability 軟奶酪的涂布性FtGIVES GOOD INDICATION OF PARTICLE FLOW 對粒狀物的流動有很好的指示DOWNWARD FORCES向下施力CUTTING AND SHEARING: As the blade or cutting wire comes into contact with the samples cutting forces are generated as probe distance increases.切割和剪切：刀片或切割線

15、往下接觸樣品，當探針的距離增加時，產生切割力。VARIABLE: PROBE TYPE 探針型號Measurement for Cheddar CheeseHardness 硬度 Adhesion Characteristics粘附特性FtInitial resistance to cutting shown by slope followed by plateau of forces indicative of consistency DOWNWARD FORCES向下施力SPHERICAL PROBES: Compression using rounded spherical ball p

16、robe. Probe comes into contact with surface creating predominantly compression forces until point of rupture or end of test.球形探針：向下接觸物體不斷產生壓力，直到樣品接觸點破裂或結束試驗。VARIABLE: PROBE TYPE 探針型號FtSurface Compression Test on Brie CheeseHARDNESS 硬度APPARENT 外觀MODULUS 模量AREA OF WORK INDICATIVE OF INTERNAL CONSISTEN

17、CY 作用面積指示內 部稠度Rounded edges give good probe sample contact圓形刀口，與樣品更好接觸VARIABLE: TEST ACCESSORIES 附件DOWNWARD FORCES 向下施力CUTTING WITH A SHEAR BLADE: Blade fixtures are used to simulate the action of slicing or cutting. 用刀片切割：刀片夾具模擬切割行為。Cutting Forces of Reformed Ham火腿 Area is indicative of sample cons

18、istency 面積對應樣品稠度Hardness硬度Modulus is generated from initial slope模量產生于初始斜率Meat & meat products 肉類Fish 魚Vegetables 蔬菜Cheeses奶酪Cosmetics 化妝品DOWNWARD FORCES 向下施力CUTTING WITH A WARNER-BRATZLER BLADE: A notched blade centrally locates cylindrical samples such as sausages. The notched shape gives increase

19、d contact area throughout the test generating more constant results.切割實驗：將圓筒狀的樣品如香腸放在一個帶凹口的刀片里。刀片的接觸面積增加，試驗結果為一個常數。FtInitial fracture 破裂點Gradual decrease in forces as fracture continues. Slower the decrease greater sample consistency e.g. work to breakArea is indicative of sample consistencyWarner-B

20、ratzler Cut of a Sausage 香腸切割VARIABLE: TEST ACCESSORIES 附件 DOWNWARD FORCES 向下施力CUTTING WITH VOLODKEVICH BITE JAWS: Used to simulate the biting action with the front incisors. Peak force generated is of key interest.模仿（人的）前面門牙撕咬的行為。產生的最大力是我們關注的重點。Cereals 谷類食品Meats 肉類Fruits and 水果vegetables蔬菜Confectio

21、nery 糖果VARIABLE: TEST ACCESSORIES 附件Cutting Force of a Carrot 胡蘿卜 Sample Area is indicative of sample consistencyHardness 硬度Bio-Yield point生物屈服點DOWNWARD FORCES 向下施力CUTTING WITH KRAMER SHEAR CELL: This texture press consists of ten precision blades which move through a box compressing, shearing and e

22、xtruding the food. 由十個刀片組成，對物體產生壓力、剪切力和擠壓的力。Multiple blades make the cell particularly suited to the assessment of multi-particle products or those which have variable properties across their cross-section. 多刀片試驗單元特別適合于評估多顆粒產品或那些具有多種特性的物體，例如：Breakfast 早餐 cereals 谷類食品Pie fillings 餅餡Pastes 面食Prepared

23、rice, beans and pulses 精制大米，豆類Meats 肉類VARIABLE: TEST ACCESSORIES 附件 DOWNWARD FORCES 向下施力BACK EXTRUSION: Compression-extrusion tests consist of applying force to a food until it flows through an outlet. In back extrusion this is area X and Y in the illustration. 反向擠壓：施加一個擠壓的力直到食物從出口流出。在反向擠壓試驗中要說明的是面積

24、X和Y。Forces involved are extremely complex 施加的力非常復雜Generally record the max force required to accomplish extrusion and the work done during the test. Average forces generated post plateau are also sometimes quantified. 通常紀錄到達擠出的最大力和功。有時也會量化穩態下的平均壓力。XYVARIABLE: TEST ACCESSORIES 附件BACK EXTRUSION反向擠出: T

25、hese tests work particularly well with viscous products such as: 這種測試特別適用于粘性物體，如：Soft Gels and yogurts 軟凝膠和酸奶酪Fruit and Vegetable Purees 水果和蔬菜湯Cosmetics 化妝品Sauces and pastes 醬料和面糊Greases 油脂Negative area of graph caused by weight of sample on probe and adhesive characteristics.圖表上的凹陷區是由于探頭上的樣品的重量和其具有

26、的粘性特點導致的。VARIABLE: TEST ACCESSORIES 附件FModulus(Gradient)模量（斜率）tHardness 硬度Consistency稠度Adhesive ForceLight Mayonnaise 輕蛋黃醬 Standard Mayonnaise 標準蛋黃醬DOWNWARD FORCES 向下施力FORWARD EXTRUSION順向擠出: Measures the compression force for a “piston” disc to extrude a product through a standard sized outlet in th

27、e base of the container. 測試將樣品從容器底部的標準尺寸的開口處順向擠出的力量。Excellent imitative test of many commercial applications 非常好地模仿許多商業應用Used on wide range of samples: 適用于大量樣品- Gels and Semi-solids 凝膠和半固體- Pastes and Pie fillings 面糊和餅餡- Fruit and Vegetables purees水果和蔬菜湯- Creams and hair care products面霜和頭發護理品- Any t

28、ube packaged products 任何管狀包裝的產品VARIABLE: TEST ACCESSORIES 附件 DOWNWARD FORCES 向下施力FORWARD EXTRUSION WITH OTTAWA CELL帶OTTAWA單元的順向擠壓: This test measures the compression force for a loose fitting square plunger to extrude a product through a base plate.測試一個正方形活塞對底盤上物體的向下擠壓力 。Breakfast cereals 谷類早餐Fruit,

29、 vegetables and pulses 水果、蔬菜和豆類 Meats 肉 Fish 魚VARIABLE: TEST ACCESSORIES 附件Extrusion plates supplied comprise of bars, holes and a blank plate. FORWARD EXTRUSION 正向擠壓Zone 1Compress and deform sample 使樣品壓縮和形變Ottawa cell becomes tightly packed until almost solidZone 2Steep increase in forces 力的急劇增加Air

30、 and liquid are expressed until rupture and extrusionZone 3Force plateaus until probe changes direction 力達到穩定直到探針改變方向Peaks indicative of particulates and sample variationFtFORWARD-EXTRUSION CURVE FROM OTTAWA CELLSteep increase in forceas target deformation reached當目標形變達到時力急劇增加 Force to rupture and e

31、xtrude 破裂和擠出的力Probe Withdraws 探頭撤回Zone 1Zone 2Zone 3DOWNWARD FORCES 向下施力THREE POINT BEND ASSEMBLY三點彎折實驗: This test measures the fracture and bend characteristics of many different materials: 測試樣品的破裂和彎折特性Adjustable support spanSample樣品Probe探針 Biscuits 餅干 Confectionery糖果 Plastics 塑料 Cosmetics化妝品 Veget

32、ables蔬菜 Polymers聚合物VARIABLE: TEST ACCESSORIES 附件Ft“Snap” Characteristics of Lipstick唇膏折斷性Initial slope 初始斜率(Modulus)Hardness硬度Force decreases post fracture 力量減少加速破裂 可調節寬度的支撐架VARIABLE: TEST CONFIGURATION可變參數：測試結構UP AND DOWNWARD FORCES REPEATED上下往復施力TEXTURE PROFILE ANALYSIS (TPA):物性結構測試圖分析 Classifies

33、key textural characteristics as a bridge between sensory and instrumental techniques using force/deformation curve. 結構特性是感官和用力/形變曲線量化的儀器測量之間的橋梁Utilises compression forces only 僅僅是利用壓縮力Operates as duplicated profile from which validated textural characteristics can be calculated 食物的結構特性可以通過可重復的結構分析來計

34、算Multifunctional test with wide range of applications within industry 工業應用領域寬廣的多功能測試Considerable historical references utilising TPA texture protocol 利用組織結構測試圖分析具有歷史數據參考作用VARIABLE: TEST CONFIGURATION可變參數：測試結構DOWNWARD FORCE AND HOLD STRESS RELAXATION CURVES: 向下施力和保持應力的松弛曲線 Utilises exponential decay

35、parameter where imposed force is maintained and relaxation within system continuously calculated.在系統連續計算中利用指數性衰減參數Method is empirical in nature 實驗方法本質上是一種經驗法Used in the analysis of experimental results 用于試驗結果的分析Applicable to materials regarded linear or non-linear rheologically 用于具有線性或非線性流變性能的物體檢測Gi

36、ves a good indication of system elasticity 對于分析系統的彈性具有很好的指導作用Food exhibiting visco-elasticbehaviour, where initial force decreases as constant deformation is maintainedFPeak Load 最大負荷 ( selected distance)Initial relaxation rate 初始松弛率Load at 減壓時的負荷DecompressionLoad Relaxation負荷松弛COMPRESSIONtTackiness

37、粘性 Adhesion粘附性Stress Relaxation Tests 應力松弛試驗XFX *100 = % RELAXATIONF0% RELAXATION = % VALUE OF FX TO F0F0FxVARIABLE可變量: TEST DIRECTION測試方向UPWARD FORCES: Adhesion forces are calculated from compressing a product until adequate contact between probe and sample is made. 向上施力：計算支持被壓物體的力，直到探針和樣品的接觸充分為止。C

38、onsidered as both a positive and negative characteristic 要考慮正面和反面的特性Indicative of attractive forces between sample and other materials with which it comes into contact可預測樣品和其它物體之間的吸引力會在接觸中起作用Traditionally quantified as the work required to break interface in: 以下物體常常需要量化打破界面所做的功： Glues 膠水 Confectione

39、ry 糖果 Gums, pastes and Gels 凝膠體，面團Rice and pasta米和面食FtVARIABLE可變量: TEST DIRECTION測試方向Time that the sample remains adhered to the probe樣品保持粘附在探針上的時間ADHESIVENESS粘附度Work required to break probe-sample interface 破壞探針和樣品界面所需的功ADHESIVE FORCE 粘附力Force required to break probe-sample interface(TACKINESS)ADHE

40、SIVE CHARACTERISTICS OF A YOGURT SAMPLE 酸乳酪樣品的粘度特性UPWARD FORCES: Tension is used to stretch samples and generate tensile or break forces within a sample. 向上施力：即施加在樣品上的張力，產生伸長，或導致樣品破壞。VARIABLE可變量: TEST DIRECTION測試方向Samples will fracture at narrowest region due to “necking” where sample thins to point

41、 where it snaps.樣品在最狹窄的地方破裂，因為在此處樣品變薄，最快達到斷裂點Problem is compounded when samples are gripped in jaws of fixture creating weak point. 當樣品被固定夾具夾緊時，就使樣品產生了弱點Geometry and regularity of sample is critical 該試驗對樣品的幾何形狀和均稱性要求很嚴格Area thins as tensile strength increases Spaghetti 意大利式細面條 Noodles 面條 Packaging Seals & Films 包裝密封材料和薄膜 Wire etc. 金屬線 SELECTING THE TEST.A wide range of tests are available, each with specific benefits or disadvantages in specific applications. It is for this reason that Bourne (1982) denoted a 4 stage procedur