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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