PENGENDALIAN MUTUHASIL PERTANIAN
QUALITY CHARACTERISTICS
SENSORY Sight – Appearance
o Coloro Glosso Viscosityo Size and shapeo Defect
Touch-Kinesthetic (texture)o Hand or finger feelo Mouth feel
Smell and Taste – Flavouro Odouro Taste
HIDDEN Nutritive value Harmless adulterants Toxicity
QUALITY CHARACTERISTICS
• VARIABLES
Characteristics that are measurable and are expressed on numerical scale
Ex.:diameter, weight
• ATTRIBUTES
Characteristics which can be classified as conforming or nonconforming to stipulated specifications requirement
• acceptable or not acceptable• go or not go to the next step
May be numerous or notEx.: colour and flavor of candy
diameter of potato passing through a go/not go gage
QUALITY CONTROL CYCLE
Customer specificationsfor each
Quality factor
Action Testing when needed methods
Reporting ControlControl Chart Stations
MEASUREMENTS
• DIRECT
• CORRELATED
* OBJECTIVE
DESTRUCTIVE
SUBJECTIVE
NON DESTRUCTIVE
OBJECTIVE vs SUBJECTIVE MEASUREMENTS
SUBJECTIVEProduct is being evaluated with the aid of human sense
Environmental healthCondition
personal bias
Lack of absolute pointTend to compare rather than absolute evaluation
OBJECTIVEInstrumental physical or chemical measurement
Precise Accurate
Method of Measurements
Rapid Simple
Inexpensive
OBJECTIVE METHODS SHOULD BE USED WHEN AVAILABLE
SIZE AND SHAPE
SIZE• Length, width, diameter• Volume : space occupied Apparent displacement
Absolute displacement• Weight• Weight-Volume Ratio Relative density
Absolute densitySHAPE• Symmetry• Curvature• Regular vs irregular• Cutting : Cube, Slice (flat, zig-zag, wave) etc
COLOUR MEASUREMENT
• DescriptionFree descriptionStandardized description
• Comparison – colour chart
• SpectrophotometryAbsorbance / TransmitanceReflectance
DEFECT• is associated with quality characteristic that does not meet a certain
standard• Imperfections due to the absence of something for perfection or the
presence of something that distract from perfectionNatural product:Genetic physiologicalEntomologicalPathologicalExtraneous foreign material
• Instrumentation:» Improve visibility» Standardize condition of examination» Reference standard» Count and measure» Isolation of defect : flotation, electronic sorting, etc.
TEXTURE
RHEOLOGY(physical)
• Young’s modulus• Shear modulus• Poisson’s ratio• Viscosity• etc
HEPTAESTHESIS(perceived)
• Mouthfeel– Hardness– Chewiness– Gumminess– Adhesiveness– etc
PENGUKURAN SIFAT TEKSTURAL SECARA OBYEKTIF
FUNDAMENTAL TESTPengukuran sifat sifat rheologi
Young’ modulus : rasio stress thd strain bila bahan elastis ditekan atau diregang E = stress / strain
Shear modulus : rasio shearing stress thd shearing strain
G = sheaing stress / shearing strain
Bulk modulus : rasio stress thd perubahan volume
K = tek. Hidrostatik / strain volumetric
Poisson’s ratio : rasio strain lateral thd strain axial
U = perub. ketebalan per tebal / perub.pjg per unit pjg
PersyaratanStrain rendah (1- 3%)Bahan bersifat kontinyu, isotropik, homogenSampel uniform dan regular
SULIT DIPENUHI DALAM BAHAN MAKANAN
EMPIRICAL TESTDikembangkan untuk pengukuran melalui percobaan dan pengamatan, sederhana, cepat dan sesuai untuk pengendalian mutuContoh : Adam/ USDA consistometer
IMITATIVE TESTDikembangkan berdasar meniru penggunaan bahan makanan dalam praktekContoh: GF texturometer
Lloyd Texture AnalyzerUniversal Testing Mechines
Basic principles of texture measurements • Distance measuring
Penetrometer: needle, cone, ball Deformation : Ridgelimeter, Adam consistometer Bostwick consistometer
Viscosity newtonian vs non-newtonian
Basic principles of viscosity measurements Resistance to flow:• Capilarry tube : Ostwald viscosimeter• Orifice : Saybolt viscosimeter• Falling weight : gardner Mobilometer• Rotation of cylinder : Brookfield, stormer• Power consumption : Brabender Farinograph• Flow of material : Adam consistometer
Basic principles of texture measurements • Force measuring
Puncture/compression: Magness Taylor tester Shear pressure : UTM, GFT
• Adhesiveness = A3
• Elasticity = springiness
• Cohesiveness = A2 / A1
• Gumminess = hardness x cohesiveness
• Chewiness = gumminess x springiness
Basic principles of texture measurements • Correlated method
Moisture content Color measurement Sound Consistency
FLAVOR sensory
• Basic requirement of any sensory QC system is the definition of standard and tolerances limits on a sensory basis for the products
• Require a calibration study / research, e.g. identification of standard products and tolerances limits
• Maintaining a reference standard as a standard quality product
• Need to select and train the panels
Pengujian sensoris untuk pengendalian mutu flavor• Metoda in / out• Metoda rating degree of differences from
standard• Metoda quality rating• Metoda Descriptive analysis• Kombinasi / Modifikasi
The valuation may be carried out• In-line process• In laboratory
METHODS FOR SENSORY QC• In/out or pass – fail procedure• Rating for overall degree of differences from
standard or control product• Quality rating• Descriptive analysis method• Quality scoring with attribute scale*
In/out or pass – fail procedureThe simplest procedurePanels : small group company employ, trainedLarge amount of product/session
Rating for overall degree of differences from standard or control product
Training with range of references and establishing the nature and condition for reproducing the control sample are critical
extremely samedifferent asfrom control control
Degree of differences with verbal category scale No Difference Very slight difference Slight difference Moderate difference Moderate/large difference Large difference Very large difference
Degree of differences with numerical category scale0 = No Difference123456789 = Very large difference
Quality rating
• Scale directly represent the quality judgement rather than sensory differencesVerbal category scaleNumerical scaleLine scale
• Poor – to – excellence : motivate the panels involve in the decision making
Descriptive analysis method Using an acceptable range
Panels have been familiarized with standardPanels evaluate the productCut off point are kept by the decision maker
Advantages:• Detail and quantitative, well correlated with
instrumental result• Once panels have adopt the analytical in mind, need
less cognitive load• Reason for correction action easier, since specific
characteristics are ratedBUT• Depend on intensity anchoring• Lab. panels than other• Costly and slow to implement 9from management
point of view)
Evaluation of Potato Chip using Descriptive Spec.Acceptable range Mean panel score
AppearanceColor intensity 5.5-6.0 4.7Color evenness 6.0-12.0 4.8Size evenness 4.0-8.5 4.1FlavorFried potato 3.0-5.0 3.6Cardboard 0.0-1.5 5.0Painty 0.0-1.0 0.0Salty 8.0-12.5 12.5TextureHardness 6.0-9.5 7.5Crispiness 10.0-15.0 13.1Denseness 7.5-10.0 7.4
Quality scoring with attribute scale
1 2 3 4 5 6 7 8 9 10
Reject Acceptable Unacceptable Match
Simple /easy to be done by in line or in lab
SENSORY CHECK LIST
• Test objective• Test type• TEST AREA
– Separation of panelists– Temperature– Humidity– Light conditions– Auditory (noise)– Clean-air handling/background odor– Accessability– Security
PANELIST– Recruitment– Screening– Training– Panelist control
SAMPLE– Size and shape– Volume– Carrier– Serving temperature– Maximum holding time
TEST SET-UP– Panelist check in– Palate cleansers– Instructions– To technicians– To panelists– Score sheets– Instructions– Type of scale– Attribute words– Anchor words
– Coding– Randomization/counterbalancing– Booth items– Pencils– Napkins– Spit cups– Clean-up– Disposal arrangements (important if security risk)– Receipts (if incentive is monetary)– Panelists debriefing
TEST CONTROL• Location• Test room design• The booth• Descriptive evaluation and training area• Preparation area• Office facilities• Entrance and exit area• Storage• Color and lighting• Air circulation, temperature and humidity• Construction materials
PRODUCT CONTROL• General equipments• Product sampling• Source of product• Testing need• Storage• Sample preparation• Supplies preparation• Materials• Preparation procedures• Sample presentation• Container, sample size, and other particular• Order, coding, number of samples
PANELIST CONTROL• Panelist or orientation• They should thoroughly familiar with:• Test procedure• Score sheet design• Type of evaluation required• Product/time of day• Panelist/environment