SPOILAGE

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SPOILAGE

• IN THE MIND OF THE CONSUMER SPOILAGE IS FAILURE
  OF A PRODUCT TO MEET THE CONSUMERS EXPECTATIONS
  PROMISED BY THE DEVELOPER.
• THIS CAN INCLUDE BAD TASTING, BAD TEXTURED,
  DOESNT LOOK RIGHT,
• MOLDY , ETC.

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SHELF-LIFE

• SHELF-LIFE REFERS TO THAT AMOUNT OF TIME IN
  DISTRIBUTION AND IN THE CONSUMERS HOME BEFORE
  FINAL CONSUMPTION, DURING WHICH THE PRODUCT
  RETAINS ALL OF ITS ATTRIBUTES THE SAME AS WHEN IT
  WAS PRODUCED

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SHELF-LIFE CLASSIFICATION

• HIGHLY PERISHABLE FOODS - MEASURED IN DAYS (MILK,
  MEAT, FRESH PRODUCE)
• SEMI-PERISHABLE FOODS - MEASURE IN WEEKS
  (CHEESES, CONSERVED MEAT PRODUCTS - SUCH AS HAM,
  SOME BAKERY PRODUCTS
• HIGHLY STABLE FOODS - MEASURED IN MONTHS OR YEARS
  (PASTAS, BREAKFAST CEREALS, CONFECTIONARY
  PRODUCTS, JAMS JELLIES, CANNED FOODS

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SHELF-LIFE RELATIONSHIP TO PRODUCT TYPE

• AS THE SHELF-LIFE OF PRODUCT BECOMES LONGER, THE
  CAUSE OF INSTABILITY CHANGES FROM BIOLOGICAL
  (MOSTLY MICROBIOLOGICAL) TO PHYSICAL AND
  CHEMICAL.
• FOR LONG-LIFE PRODUCTS -- LIGHT, OXYGEN, MOISTURE
  UPTAKE, AND HANDLING ABUSE BECOME MORE IMPORTANT

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MAXIMIZING SHELF-LIFE

• PREVENTING SPOILAGE ALL OF THE FACTORS CITED
  BELOW..
• PREVENTING DETERIORATION BECAUSE OF MICROBIAL
  GROWTH
• PREVENTING ENZYMATIC ACTIVITY
• PREVENTING OXIDATION
• PREVENTING COLOR DETERIORATION
• PREVENTING TEXTURAL CHANGES
• PREVENT FLAVOR DETERIORATION

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STRATEGIES FOR IMPROVED SHELF-LIVE

• THERMAL PROCESSING
• CHILLING (FREEZING, REFRIGERATION)
• FERMENTATION
• CONTROL OF WATER ACTIVITY
• ACIDIFICATION
• CHEMICAL ADDITIVES
• CONTROL OF OXIDATION/REDUCTION CONDITIONS

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SHELF-LIFE CHANGESMAY BE PHYSICAL

• EVAPORATION
• CONCENTRATION
• CRYSTALLIZATION
• PHASE CHANGES
• MASS MIGRATION
• IRRADIATION

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SHELF-LIFE CHANGESMAY BE CHEMICAL

• OXIDATION
• REDUCTION
• HYDROLYSIS
• CONDENSATION
• DECARBOXYLATION
• DEAMINATION
• MAILLARD REACTIONS

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SHELF-LIFE CHANGESMAY BE BIOLOGICAL

• RESPIRATION
• OXIDATION
• AUTALYSIS
• FERMENTATION
• PURIFICATION
• HYDROLYSIS

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PHYSICAL CHANGES IN FOODS INCLUDE

• EXUDATION
• SEPARATION
• PRECIPITATION
• TEXTURAL CHANGES (GRITTINESS, STALING,
  TOUGHENING)
• DISCOLORATION(FADING, OPACITY)

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CHEMICAL CHANGES CAN INCLUDE

• OFF-FLAVORS
• OFF-ODORS
• DISCOLORATION (BROWNING, FADING)
• EXUDATION
• TEXTURAL CHANGES
• CONTAINER INTERACTIONS

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BIOLOGICAL CHANGES CAN INCLUDE

• WILTING
• DISCOLORATION
• SLIME FORMATION/COAGULATION
• EXUDATION
• OFF-FLAVORS
• OFF-ODORS
• EXCESSIVE MICROBIAL NUMBERS/TOXINS

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CONTROLLING MICROBIAL SPOILAGE

• DESTRUCTION OF ALL ORGANISMS
• CONTROL OF GROWTH OF RESIDUAL ORGANISMS
• -REFRIGERATION/FREEZING
• -WATER ACTIVITY
• -pH
• -OSMOTIC PRESSURE
• -REDUCING ENVIRONMENT
• -ADDITION OF CHEMICAL AGENTS TO
• SUPPRESS GROWTH

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CONTROL OF PHYSICAL CHANGES

• HOMOGENIZATION TO PREVENT OIL SEPARATION
• AGGLOMERATION AND CRYSTALLIZATION TO CONTROL
  CAKING
• PROPER CHOICE OF INGREDIENTS (CRYSTALLIZING AND
  NON-CRYSTALLIZING SUGARS) (EMULSIFIERS TO RETARD
  STALING OF BREAD)
• ENCAPSULATION TO PROTECT LABILE COMPONENTS

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CONTROL OF CHEMICAL CHANGES

• AVOID EXCESSIVE HIGH TEMPERATURES
• AVOID EXPOSURE TO LIGHT
• MINIMIZE EXPOSURE TO OXYGEN
• PROPER PROCESSING TO MINIMIZE MAILLARD REACTIONS
  DURING PROCESSING

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SHELF-LIFE TESTINGSELECTING CRITERIA

• WHAT TO TEST
• HOW MANY ATTRIBUTED TO EVALUATE
• HOW ARE RESULTS TO BE USED
• USE BY DATE COMPARED TO TEST
• RESULTS (2/3RDS RULE)

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SHELF-LIFE TESTING

• NO TESTS CAN BE RELIED UPON ABSOLUTELY TO PREDICT
  THE SHELF-LIFE OF A PRODUCT -- ONLY GIVE AN
  ESTIMATION
• SHOULD BE CARRIED OUT ONLY ON FINISHED PRODUCT IN
  FINAL PACKAGE
• ANY CHANGE IN FORMULATION OR PROCESSING CAN
  CHANGE SHELF-LIFE
• EXTRAPOLATION OF ACCELERATED TESTING MUST BE
  INTERPRETED WITH CARE
• CLEAR CRITERIA FOR EVALUATION MUST BE ESTABLISHED
  - CONSUMER IS ULTIMATE DETERMINANT
• ALWAYS COMPARE TO A REFERENCE SAMPLE
• WHAT TO TEST?
• HOW MANY ATTRIBUTES TO EVALUATE?
• HOW ARE RESULTS TO BE USED?
• USE BY DATE COMPARED TO TEST RESULTS (2/3RDS
  RULE)

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SHELF-LIFE TESTQUALITY DETERMINANTS

• PRESERVATIVE SYSTEMS DESIGNED INTO THE FOOD
  PRODUCT
• PHYSICAL ABUSE THAT PRODUCT RECEIVES BEFORE FINAL
  USE
• ENVIRONMENTAL ABUSE THAT PRODUCT AND PACKAGE
  ENCOUNTERS FROM MANUFACTURE AND PACKAGING UNTIL
  FINAL USE

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SHELF-LIFE TESTINGASSESSING ABUSE

• TEMPERATURE CHANGES ANTICIPATED DURING
  WAREHOUSING, TRANSPORT, ARRIVAL AT STORE?
• VENDING MACHINE STORAGE?
• VIBRATION ABUSE IN SHIPPING
• EXPOSURE TO EXTREME MOISTURE
• EXTENT OF EXPOSURE TO LIGHT
• DEGREE OF POTENTIAL DAMAGE TO PACKAGE

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SHELF-LIFE TESTINGMETHODS

• STATIC TESTS - PRODUCT STORED UNDER A GIVEN SET
  OF ENVIROMENTAL CONDITIONS - SELECTED AS
  REPRESENTATIVE
• ACCELERATED TESTS - PRODUCT STORED UNDER A RANGE
  OF ENVIROMENTAL CONDITIONS (USALLY TEMPERATURE
• USE/ABUSE TESTES - PRODUCT CYCLED THOUGH
  ENVIROMENTAL VARIABLES

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STATIC TESTING

• REQUIRES A LONG TIME TO SEE CHANGES
• HIGH COST
• GIVES NO INFORMATION OF EFFECTS OF STRESS
• COMES CLOSEST TO DISTRIBUTION CONDITIONS

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ACCELERATED TESTING

• CONDITONS SELECTED TO COVER EXPECTED RANGE
  ENCOUNTERED
• CAN BE ACHIEVED IN A RELATIVE SHORT PERIOD OF
  TIME
• PROVIDES KINETIC DATA
• TEST CONDITIONS SHOULD NOT ALTER THE NORMAL OF
  ANTICIPATED PATH AFFECTING SHELF-LIFE
• RESULTS MUST BE INTERPRETED WITH CARE

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ACCELERATED TESTINGFACTORS TO EVALUATE

• DIFFERENT TEMPERATURES CAN BE USED TO OBTAIN
  INFORMATION IN RESPECT TO
• -EQUILIBRIUM MOISTURE CONTENT
• -PERMEABILITY OF PACKAGE TO MOISTURE
• AND OXYGEN
• -FILL WEIGHT OF PACKAGE OVER TIME
• -SLOPE OF PRODUCT ISOTHERM

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USE/ABUSE TESTING

• USED TO ASSESS PRODUCT AND PACKAGE AS A UNIT
• USE CYCLES OF VARIABLE THAT ARE EQUAL TO OR
  BEYOND THAT EXPECTED UNDER ACTUAL CONDITIONS
• OFTEN USED TO DETERMINE EFFECTS OF TRANSPORT
• USED TO DETERMINE LIMITS AND TO TRAIN
  DISTRIBUTION PERSONNEL IN PROPER CARE OF PRODUCT

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PREVENTING ABUSE IN DISTRIBUTION

• EDUCATING STORE PERSONNEL ABOUT
• -DOCK HANDLING OF PRODUCT
• -PROPER STOCK ROTATION
• -PRODUCT RETURN PROTOCOLS
• -INTERPRETATION OF DATE CODING

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MATHEMATICAL MODELING

• GROWING IN USE, BECAUSE
• -COMPUTER HARDWARE AND
• SOFTWARE DEVELOPMENTS
• -GROWING CONSUMER DESIRE
• FOR MINIMALLY PROCESSED
• FOOD
• -NEED TO QUANTIFY EFFECTS OF THE
• MULTIPLE FACTORS AFFECTING SHELF-LIFE

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TYPES OF MODELS

• PROBABILISITIC MODELS - BASED ON PROBABILITIES
• KINETIC MODELS - BASED ON DATA
• -ARRHENIUS EQUATION
• -RAKOWSKI SQUARE ROOT
• EQUATION BASED ON GROWTH RATE
• CONSTANT, REGRESSION COEFFICIENT,
• STORAGE TEMERATURE AND
• TEMPERATURE AT WHICH GROWTH 0

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DISTRIBUTION - WHERE CAN CHANGES OCCUR?

• WAREHOUSE
• SHIPPING
• WHOLESALE
• RETAIL
• IN-HOME

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DISTRIBUTION - FACTORS TO CONSIDER

• MUST UNDERSTAND THE FACTORS THAT MAY AFFECT
  PRODUCT ATTRIBUTES DURING DISTRIBUTION
• -SENSITIVITY TO OXYGEN
• -SENSITIVITY TO LIGHT
• -SENSITIVITY TO MOISTURE
• -SENSITIVITY TO AGITATION
• -SENSITIVITY TO TEMPERATURE