QUALITY EVALUATION AND CONTROL 3202

1
QUALITY EVALUATION AND CONTROL3202

• Luke Howard
• Professor
• Food Science Department
• University of Arkansas

2
INTRODUCTION

• This module represents a brief overview of the
  course FDSC 4203 Quality Evaluation and Control
  taught by Dr Luke Howard at the University of
  Arkansas.
• It is narrated by Dr Steve Seideman, Extension
  Food Processing Specialist of the Institute of
  Food Science Engineering, University of
  Arkansas.

3
INTRODUCTION

• The module will cover quality assurance, plant
  sanitation, GMPs, cleaning and disinfection
  methods, quality factors and standards, flavor
  and color determination, food additives and HACCP

4
Quality Assurancein the Food Industry
(Portions of this section are from the book
entitled Total Quality Assurance for the Food
Industries by Dr Wilbur Gould and Ronald Gould.
CTI Publications,Inc)
5
Quality Assurance

• Modern term used for describing the control,
  evaluation and audit of a food processing system
• Its primary function is to provide confidence
  for management and the ultimate customer
  (consumer)
• The customer establishes the level of quality the
  firm must manufacture

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Canning Quality Assurance
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Quality Control

• A large part of a QA program is built around
  quality control
• Quality control means to regulate to some
  standard
• It is an important tool for the production worker
  to help operate the line in conformance with the
  predetermined parameters for any given quality
  level

8
Quality Evaluation

• Is also part of a QA operation
• It is used to describe or appraise the worth of a
  product
• It generally involves taking a measurement of the
  product in a laboratory
• It includes the evaluation of all incoming
  materials, products in process, and/or finished
  products

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Quality Audit or Verification

• Goal is to audit or verify the products or
  processes over time
• Used for firms having many plants
• Part of the QA program to verify products in the
  warehouse, in distribution, and/or competitors
  products in the market place

10
Quality

• Makes a product what it is, varies among
  consumers
• Is the combination of attributes or
  characteristics of a product that have
  significance in determining the degree of
  acceptability of the product to a user
• Repeat sales are related to QA practices

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Standards for Quality

• Legal standards
• Company or voluntary label standards
• Industry standards
• Consumer or grade standards

12
Subjective Methods for Determining Quality

• Based on the opinion of the investigators
• Usually involves sensory perception i.e.
  flavor, color, odor, touch, freedom from defects
  etc.
• Requires training and experience

13
Objective Methods for Determining Quality

• Physical - size, texture, color, consistency,
  imperfections, headspace, drained weight, vacuum
• Chemical - enzyme conc., moisture, fiber, pH,
  acidity
• Microscopic - used for adulteration and
  contamination, and differentiation between cell
  types, tissue types and microorganisms

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QA Program Functions (1)

• Raw materials specifications for QC
• Improvement of product quality
• Improvement of processing methods with resulting
  savings in cost of production and gt profits

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QA Program Functions (2)

• Standardization of the finished product according
  to label specifications
• Increased order and better housekeeping of a
  sanitary plant
• Greater consumer confidence (uniform high
  quality)

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Basic Fundamentals for a Successful QA Program

• Organization of the QA department
• The personnel
• Sampling
• Standards and specifications
• Measurement
• A. laboratory C. procedures
• B. equipment D. reports
• Interpretation (SQC and SPC)

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Examples of QE Functions (1)

• Determination of germination and purity of seed
• Soil and tissue analysis
• Collection and summarization of weather data for
  use in scheduling of raw products, packaging
  materials, or labor
• Identification of crop diseases and insects

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Examples of QE Functions (2)

• Determination of raw product quality and other
  in-coming raw materials
• Evaluation and continuous monitoring of
  processing variables affecting quality
• Determination of the efficiency of each
  processing operation as related to finished
  product quality

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Examples of QE Functions (3)

• Periodic and continuous monitoring of water
  supply, equipment, plant sanitation, and the
  waste disposal system
• Evaluation of the finished product quality and
  assurance of the storage life of the finished
  product
• Development of new products and improvement of
  present processing, production and quality
  evaluation methods

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Basic Equipment for QE

• Can opener
• Vacuum gauge
• Headspace gauge
• Grading scale, screens and trays
• Sizing gauges
• Brine and syrup cylinders
• Hydrometers and salometers
• Thermometers

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Specialized Equipment for QE

• Colorimeter
• pH meter
• Refractometer
• Viscometer
• Moisture analyzer
• Microscope

22
Factors Affecting Quality

• Cultivar
• Maturity
• Cultural practices
• Harvesting and handling
• Processing
• Shelf-life
• Use

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Food Plant Sanitation
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Plant Sanitation Industries Responsibility

• Moral and legal obligation to perform all
  operations in clean surroundings, and with due
  regard to the basic principles of sanitation
• FDC Section 402a4 states that a food shall be
  deemed to be adulterated if it has become
  contaminated with filth, or whereby it may have
  been rendered injurious to health
• Sanitation is every persons job in the plant

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Reasons for Plant Sanitation

• A better product, competition demands high,
  consistent quality
• A more efficient operation, efficiency equates to
  planned sanitation
• Greater employee productivity
• Improved safety
• Is a barometer of overall plant conditions

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Plantkeeping - Exterior

• Grounds maintained
• Storage for equipment.
• Exterior openings screened
• Free from insects, rodent proof
• No uncovered openings
• No chemical spills

• Remove broken containers from shipping, receiving
• No trash in parking lot
• Paved roads
• No litter or waste accumulation
• Roofs leak proof

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Plantkeeping - Building

• Floors water tight, smooth surfaced, and sloped
  1/8 to 1/4 per foot to floor drains every 10
  apart
• Drains covered with grates
• Walls doors, partitions, pipes, ceilings kept
  cleaned and painted

• Proper ventilation to prevent condensation, mold
  growth, or deterioration of structures
• All windows, doors and openings should be
  screened
• Good lighting, ranges from 25 to 150 foot candles

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Plantkeeping - Equipment

• Constructed in regard to cleanability and
  protection from contamination
• Materials should be smooth, hard, non-porous,
  preferably stainless steel
• Pipe lines, fittings handling food should be
  sanitary
• Eliminate sharp corners

• Equipment should be directly accessible for
  cleaning (CIP)
• All open equipment should be covered
• Containers should be clean, and not used for
  other purposes (tight lids)
• Waste should be collected in proper containers
  (removed daily)

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Plantkeeping - Storage

• Aisles should be kept clean and well marked
• Food materials, packaging should be protected
  from damage, rodents, insects, dirt, dust
• Stored products should be stored away from walls
  at proper storage temperatures

• Storage areas cleaned weekly
• Inventory and evaluation of warehouse products
  should be conducted frequently
• Storage temperature is critical for perishable
  ingredients/products
• Policy of FIFO should be strictly adhered to

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Plantkeeping - Employees

• Must wear caps, hair nets, hair restraints
• Pins, curlers, jewelry, fingernail polish should
  not be worn
• Pens, pencils, watches should not be worn above
  the waistline
• Protective clothing worn at all times

• Gum chewing and tobacco use restricted to
  confined areas
• Glass bottles not permitted in working areas
• Employees must report any skin breaks to
  supervisors
• Observe proper habits of cleanliness

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Plantkeeping - Employees

• Hands shall be washed and sanitized at the
  following times
• A. When reporting to
• work
• B. After breaks
• C. After smoking or
• eating
• D. After picking up
• objects from the floor
• E. After blowing nose

• F. After coughing,
• sneezing and covering
• mouth with hand
• G. After using the toilet
• Signs should be posted throughout the facility as
  to smoking, eating and washing habits, and
  general sanitary requirements

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Plantkeeping - Special Areas

• Special storage areas should be provided for
  handling of clean uniforms, towels, toilet
  articles, soiled uniforms and linens, custodians
  supplies and equipment, pesticides, employees
  belongings, and garbage and wastes

• Restroom facilities should include liquid soap,
  drying towels
• Restrooms should not open to processing areas
• Toilet facilities should be scrupulously clean
• Lunchroom facilities should be provided and kept
  clean

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Plantkeeping - Materials

• In-coming materials should be carefully inspected
  and inventoried
• Outgoing materials should be properly identified
  in terms of shipments and quality
• Great losses occur in warehouses by improper
  housekeeping practices i.e. breakage, pilferage,
  looting etc.

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Plantkeeping - Sanitary Organization

• The authority to uphold standards of sanitation
  is the responsibility of the plant sanitarian (in
  small plants might be the QA director or plant
  supervisor)
• Sanitarian should be well trained in
  microbiology, chemistry, entomology,
  parasitology, and sanitary engineering
• Sanitarian should be directly responsible to
  management

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Plantkeeping - Sanitary Organization

• Required tools for sanitarians
• Ample supply of potable water
• Different types of brushes
• Detergents and knowledge of their use
• Chlorination and chlorinating equipment
• Steam and/or high pressure equipment fitted with
  proper nozzles

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Plantkeeping - Sanitary Organization

• Flashlights for inspection of out of way places
• Black light for detection of rodents
• Camera
• Attire consisting of white cap, clean white
  overalls, or white shirt and pants
• Is responsible for training courses, workshops,
  seminars on sanitation and GMPs

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Plant Inspection

• Plant inspection may be conducted by company
  personnel from either the home office, or the
  local plant, or by a third party
• A written report should be made in all observed
  conditions listed as satisfactory, needs
  improvement or unsatisfactory
• A manual should be written documenting minimum
  standards for each of the plant areas
• Report should be acted on accordingly

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Sanitation Evaluation

• Physical cleanliness - absence of visual product
  waste, foreign matter, slime etc.
• Chemical cleanliness - freedom from undesirable
  chemicals i.e. cleaning compounds, germicides,
  pesticides, which might be present on the product
  or equipment
• Microbiological cleanliness - controlled by the
  amount of microorganisms that may be present in
  the product, or on the equipment, building or
  people

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Suppliers

• Chemical supplier can assist in plant audit for
  developing a sanitation program
• Supplier can outline specific cleaning methods,
  products, and exact amounts, times and temps
• Labor amounts to 90 of a cleaning program
• Supplier can provide control and feeding
  equipment, engineering services, technical
  assistance, laboratory services, and sound
  planning for future needs

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Sanitation Program

• Plant sanitation committee should meet monthly
• Sanitation committee may consist of plant
  manager, production supervisor, QA supervisor,
  food technologist, maintenance engineer,
  personnel supervisor and sanitarian
• Training and retraining is critical
• Break down each job into components to instruct,
  try to get people to think about what they are
  doing, stress important repetitive situations

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Cleaning and Disinfection Methods
Portions of this section were taken from an
article entitles Sanitation The Key to Food
Safety and Public Health by James H. Giese. Food
Technology. December 1991.
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Challenges for Food Sanitation

• Increasing number of older consumers
  (immuno-compromised individuals)
• New products and processes (egs MAP, sous vide,
  aseptically packaged foods
• high pressure, pulsed electric fields)
• Sanitation programs are a prerequisite for HACCP
  programs

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Plant Design

• Layout and functioning of the processing line
  should facilitate the flow of food material from
  one operation to the next with a minimum of delay
  
• Walls, floors and ceilings should be made of
  impervious, easily cleaned, non-painted inert
  material
• Positive air pressure should be maintained

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Plant Design

• Raw materials should be isolated from processed
  food
• Adequate hand-washing stations should be provided
  in food processing areas
• Horizontal structures such as pipe hangers,
  beams, and duct work over exposed product areas
  should be eliminated

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Plant Design
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Plant Design
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Sanitation A Four Step Process

• A pre-rinse with high pressure water to remove
  gross soil
• Physical removal of soil by detergents and
  mechanical aids
• Another rinse to remove the detergent and loose
  soil
• The application of sanitizers to prevent
  recontamination before processing

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Water Functions and Quality

• Carrier for detergents and sanitizers
• Carries soils or contaminants away from the
  surface that has been cleaned and sanitized
• Water hardness is responsible for excessive soap
  and detergent consumption, mineral deposits,
  undesirable films, and precipitates

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Rinsing Step
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Efficacy of Detergents

• Should wet and penetrate soil
• Should emulsify fat
• Should disperse and suspend soil
• Should counteract water hardness
• Should rinse well to prevent soil from
  redepositing on clean surfaces and be
  non-corrosive to equipment

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Alkaline Detergents

• Compounds used for removal of organic soils, such
  as oils, grease, proteins and carbohydrates
• Strongly alkaline compounds (pH gt 13) egs NaOH
• Moderately alkaline compounds (pH 10-12) egs
  sodium metasilicate
• Mildly alkaline compounds (pH 7-12) egs sodium
  carbonate and sodium sesquicarbonate
• Complex phosphates egs TPP, SHMP

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Acid Detergents

• Compounds for removal of encrusted soils and
  deposits formed from application of alkaline
  detergents
• Strong inorganic acids egs hydrofluride,
  hydrochloride (scale removal in boilers, are
  corrosive to stainless steel)
• Organic acids egs citric and hydroxyacetic acids
  (used in manual cleaning formulations, also
  function as water softeners)

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Detergent Auxiliaries

• Incorporated with cleaning compounds to improve
  their performance, provide filler material or
  bulk, condition water and protect sensitive
  surfaces
• Surfactants are organic compounds used in both
  alkaline and acidic formulations to increase soil
  penetration, improve rinsing, or to control
  foaming
• Sequestrants combine with magnesuim and calcium
  salts egs SPP, EDTA, sodium gluconate

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Sanitizers

• Soil should be completely removed prior to
  sanitizing You cant sanitize a dirty surface
• Efficacy is affected by time, pH, temperature,
  concentration, water hardness and surface
  cleanliness
• Chambers test requires that sanitizers produce a
  99.999 kill of 75-125 million E. coli and
  Staphylococcus aureus within 30 sec. After
  application at 20oC

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Regulation of Sanitizers and Cleaners

• FDA approves components of sanitizers by their
  chemical names, and determines a maximum use
  concentration on product contact surfaces
• EPA requires specific label information regarding
  usage and application requirements
• USDA authorizes cleaning and sanitizing compounds
  for use in federally inspected meat poultry, and
  egg processing plants

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Important Properties of Sanitizers

• Ability to provide a rapid antimicrobial activity
  against a range of organisms
• Be readily available, inexpensive and ready to
  use
• Have stability and resistance to the presence of
  organic matter, detergent and soap residues
• Ability to work in a wide range of pH, water
  hardness, and temperatures
• Lack of toxicity to humans, and non-corrosive,
  and water soluble

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Halogens

• Chlorine compounds - most popular and commonly
  used sanitizers
• Hypochlorous acid (HOCL) is the active killing
  agent, is strongly affected by pH (opt. 6.5-7.5)
• Kills bacteria by reacting with and disrupting
  cell walls
• Sodium hypochlorite is the most common form, but
  calcium hypochlorite, and Cl- gas are also used

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Chlorine Reaction in Water

• Cl2 H2O HOCL H Cl-
• NaOCL H2O HOCL Na OH-
• NH2CL H2O HOCL NH2 OH-
• HOCL H OCL-

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Chlorine Dioxide

• Widely used in water and sewage treatment,
  becoming more popular with food processors
• Has 2.5 times the oxidizing power of chlorine
• Can be used at much lower concentrations
• Less sensitive to pH
• Must be generated on-site

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Iodine Compounds

• Free elemental iodine and hypoiodous acid are
  frequently used antimicrobial compounds
• Alcohol-iodine solutions and iodophors are also
  commonly used
• Iodophors are aqueous solutions of a nonionic
  surfactant and complexed elemental iodine
• Iodophors are used for sanitizing utensils,
  equipment and as skin antiseptics
• Narrow pH range (2.5-3.5)

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Quaternary Ammonium Compounds

• Quats are cationic surfactants used on floors,
  walls, and aluminum equipment
• An excellent application is on equipment in
  storage or when contact time will exceed 24hr
• Effective over a wide pH range (6-10), and at
  high temperatures, noncorrosive to metals, and
  unaffected by high levels of organic matter
• Effective against molds and gram negative slime
  formers

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Acid-Anionic Sanitizers

• Commonly used in automated cleaning systems,
  which combine sanitizing with a final rinse
• Phosphoric acid is the most common form, with
  maximum antimicrobial activity below pH 3
• Particularly suited for stainless steel, they can
  be used to help prevent mineral deposits by
  neutralizing excessive alkalinity
• They have rapid activity against most
  microorganisms, a low corrosive effect,
  resistance to organic matter and hard water salts

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Hot Water and Steam

• Antimicrobial activity depends on the
  temperature, humidity and exposure time
• Hot water is convenient and cost effective, and
  is commonly used for sanitizing food contact
  surfaces, small equipment parts, utensils, and
  heat exchangers
• Steam is sometimes used to sanitize conveyor
  belts or other equipment in-place

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Equipment and SystemsManual Aids

• Brushes should have a block constructed of
  durable material resistant to heat, chemicals and
  moisture
• Bristles should be nylon, with good water holding
  capacity to carry cleaning solution to contact
  surfaces
• Scrapers and scouring pads should be used to
  remove baked-on deposits and encrusted soil from
  equipment and other surfaces

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High Pressure Systems

• Utilize high pressure hot water to remove soil
• Provides a very effective cutting action to
  remove gross soil build-up from equipment
• It is best utilized to clean hard-to-reach areas,
  conveyor systems, and outside surfaces of
  equipment, walls and floors
• Provide a good way to reduce manual labor costs

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Foam Cleaning Systems

• These systems mix a metered amount of air and
  detergent solution to form a clinging foam
• Can be applied to areas that are inaccessible for
  hand cleaning
• Major difference between high pressure and foam
  cleaning are the application of foam at a lower
  PSI and its longer contact time
• Longer contact time allows soil to loosen and
  then removed

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Foam Cleaning System
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Clean-Out-of-Place (COP)

• Requires disassembly of equipment after rinsing
  so that parts and short pipe sections may be
  placed in a recirculation tank for cleaning by
  physical and chemical action
• Normal length of time for wash solution
  recirculation is ca. 30-40 min with an additional
  5-10 min for a cold acid or sanitizing rinse
• Typically used for filling machine parts,
  centrifuge parts, pump heads and parts, pipe
  sections, take down fittings, homogenizer parts

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Clean-In-Place (CIP) Systems

• Becoming popular due to labor savings and
  automated control (milk plants, aseptic systems)
• One shot systems have one tank for circulating
  the wash water and then discharging at the end of
  the rinse cycle
• Two tank systems consist of one tank for rinse
  water and another tank for reclaiming the
  cleaning solution, while three tank systems
  contain one tank for cleaning solution, one for
  reclaiming pre-rinse solution, and one for a
  final water rinse

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Clean-In-Place System
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Sanitizer Application Equipment

• Portable pressure sprayers
• Centralized systems can provide consistent
  sanitizer concentration and convenient hookups

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Factors Affecting Sanitizer Efficacy

• Initial microbial load on raw product
• Water quality, chemistry and temperature
• Biofilm formation
• Concentration, temperature and contact time of
  sanitizer
• Organic matter content on the product and in the
  water

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Quality Factors and Standards
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Appearance FactorsSize and Shape

• Can be easily evaluated and are important factors
  in federal and state grade standards
• Performed manually or by automated separating and
  grading equipment
• Eggs pass through different sized openings, and
  rollers, separation by weight after manual
  grading
• Curvature of cucumbers for pickling

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Size and Color Sorting
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Sorting
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Weigh Grading
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Color Sorting
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Color Sorting
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Appearance FactorsColor and Gloss

• Indicates degree of ripeness of fruits/vegetables
• Quality of fried potatoes
• Bleaching of dried tomato powders
• Surface color of chocolate indicates storage
  history
• Color of a food foam or batter varies with the
  density and can indicate a change in mixing
  efficiency

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Food Color
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Color Measurement
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Appearance FactorsColor Measurement

• Color of transparent liquids such as beer, wine,
  grape juice are measured using spectrophotometers
  and colorimeters
• Color of liquid or solid foods are measured by
  comparing the reflected color to defined colored
  tiles or chips
• Color of many foods is measured using
  colorimeters, define the hue, chroma, and
  brightness of reflected light from food surfaces

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Colorimeters
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Hunter Color Solid
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Color Wheel
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Appearance FactorsGloss Measurement

• Light measuring instruments are available that
  measure the shine, or gloss of a food surface
• Gloss is important to the attractiveness of
  gelatin deserts and buttered vegetables

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Gloss Meter
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Appearance FactorsConsistency

• Textural as well as appearance factor
• Consistency of foods is measured bt their
  viscosity, higher viscosity products being of
  higher consistency and lower viscosity being
  lower consistency
• Measuring devices include, consistometers
  (Bostwick), and viscometers (Brookfield,
  Cannon-Finske)
• Used for ketchup, honey, syrups, purees

90
Viscometers
91
Viscometers On-Line
92
Viscometers
93
Rheological Properties
94
On-Line NIR for Chemical Analysis
95
Textural Factors

• Texture refers to those qualities of food that we
  can feel either with the fingers, the tongue, the
  palate, or the teeth
• Texture is an important quality attribute for
  many foods including chewing gum, crackers,
  chips, fruits, bread products, meats etc.

96
Measuring Texture

• Measurements of resistance to force
• Many different types of instruments are available
  to measure different types of force
  (e.g.succulometers, penetrometers,
  consistometers, tenderometers).
• Force-distance curves give important information
  about the rheological properties of foods

97
Texture Changes in Foods

• Water content plays a major role (e.g. firmness
  of fruits and vegetables, bread staling, freezer
  burn etc ).
• Food composition is also important
• Lipid, starch, protein, and sugar content affects
  functional properties of foods
• Many food ingredients may affect textural
  properties

98
Texture Analyzers
99
Texture Analyzers
100
Texture Profile Analysis
101
Texture Profile Analysis
102
Flavor Factors

• Flavor is a combination of taste and smell, is
  largely subjective and thus, difficult to measure
• Flavor is affected by the basic taste attributes
  (sweet, sour, bitter, salty), and numerous
  volatile compounds which affect aroma
• Flavor is measured using analytical
  instrumentation and sensory tests
• A goal of many QC groups is to identify chemical
  measurements that may be used to predict sensory
  quality

103
Odor Determination
104
Electronic Nose for QC
105
Sensory Panels

• Consumer preference groups - untrained panels
  that can provide a good insight into what
  consumers generally will prefer
• Trained panels - are selected on the basis of
  their flavor sensitivity and trained to recognize
  attributes and defects of a particular product
• Triangle and preference tests are commonly used
  for QC functions

106
Sensory Analysis
107
Additional Quality Factors

• Nutritional quality - assessed by chemical or
  instrumental analyses
• Sanitary quality - measured by counts of
  bacteria, mold, yeast, insect fragments, also
  rocks, stones, glass fragments, metals are
  identified using x-ray machines and metal
  detectors
• Keeping quality - shelf life studies, ASLT

108
Quality Standards

• Research - internal standards set up by a company
  to help ensure the excellence of its products
• Trade - standards set up by members of industry
  on a voluntary basis to assure at least minimum
  acceptable quality
• Federal grade standards - have been set up mainly
  to help producers, dealers, wholesalers,
  retailers and consumers in marketing food
  products, provide a common language for trading

109
Federal Grade Standards

• Standards of quality administered by the USDA
  Marketing Service and the FSIS
• Grading - is voluntary and is used to determine
  the quality of products such as meats
• Inspection - is mandatory and assures the
  wholesomeness of products
• Uniform grades of quality established for gt 100
  foods (meat, dairy, poultry, fruits, vegetables,
  seafood)

110
Federal Grade StandardsMeats

• Age of the animal
• Amount and distribution of muscle fat (marbling)
• Firmness and texture of the flesh
• Color of the lean meat
• Federal grade marks for beef are Prime, Choice,
  Select, Standard, Commercial, Utility, Cutter,
  Canner

111
USDA Standards of Composition and Identity

• Minimum content requirements for federally
  inspected meat and poultry products (canned or
  frozen)
• For example, the USDA minimum requirement for
  beef stew specifies the minimum percentage of
  beef only (25), that the stew must contain
• Complete standards of identity have been
  established for chopped ham, corned beef hash,
  and oleomargarine

112
FDA Standards of Identity

• Establishes what a given food product is
• Example - what a food must contain to be labeled
  preserves
• Includes both mandatory ingredients and optional
  ingredients

113
Minimum Standards of Quality

• Have been established for many canned fruits and
  vegetables to supplement standards of identity
• Examples include tenderness, color and freedom
  from defects
• If a food does not meet the FDA quality standards
  it must be labeled below standard in quality

114
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115
Flavor Determination
116
Food Flavor

• Involves at least two phenomena, taste and odor
• When we say a food tastes good, we actually mean
  it has a good taste and aroma
• Taste is the subjective experience (sensation)
  resulting from stimulation of the chemosensory
  receptors (taste buds) located on the oral cavity
  by chemicals or chemical components of food in
  solution with saliva

117
Basic Taste Attributes

• Salty
• Sweet
• Sour
• Bitter

118
Taste

• Strictly tongue taste, not flavor
• Taste originates from compounds in solution
  (saliva)
• All taste buds can detect all four qualities, but
  some respond to one quality better than the other
  three

119
Salty Quality

• Is the result of ionic stimulation
• Na is responsible for eliciting salty taste,
  while anions especially Cl- are inhibitory
• Many inorganic salts in solution taste
  differently depending on molecular concentration
  eg. at low concentration many salts taste sweet,
  with increasing concentration the taste may be
  salty, sour or bitter

120
Sour Quality

• Chemical stimulus is the hydrogen (H) ion
• The threshold number of hydrogen ions necessary
  for perception of a sour taste is smaller for
  weak acids than for strong acids
• Indicates that the anion or undissociated acid
  may modify the taste of these compounds

121
Sweet Quality

• Is elicited by a variety of food related organic
  compounds
• Most common sweetners are sugars, which vary
  considerably in sweetness
• Based upon equimolar solutions
• fructose gt sucrose gt maltose gt glucose gt
  lactose
• Sweetness is affected by concentration, food
  medium, and temperature of food medium

122
Bitter Quality

• Is difficult to associate with a specific
  stimulus
• Most prominent class of bitter tasting compounds
  are the alkaloids (caffeine, quinine and
  nicotine)
• Other include heavy halide salts, amino acids and
  phenolics

123
Typical Thresholds for Taste Attributes

• Sweet (sucrose) 0.250 - 2500 ppm
• Bitter (caffeine) 0.016 - 160 ppm
• Sour (citric acid) 0.200 - 2000 ppm
• Salty (NaCl) 1.500 - 15,000 ppm

124
Food Smell or Odor

• Refers to sensations resulting from stimulation
  of the chemosensory receptors located in the
  olfactory epithelium of the nose by airborne
  chemical compounds
• Chemicals may reach the epithelium directly
  through the nares, or indirectly (rostronasally),
  through food present in the mouth

125
Food Smell or Aroma
126
Color Determination
127
Color

• Consumers typically select a food based upon it
  appearance and color
• Color can be measured more easily than taste,
  odor or texture
• Color is one portion of the input signals to the
  human brain that results in the perception of
  appearance

128
Color

• Color as seen by the human eye is an
  interpretation by the brain of the character of
  light coming from an object
• We need to define color in a physical sense as
  objectively as possible and interpret the output
  in terms of how the human eye sees color

129
Color

• Defined as the aspect of radiant energy of which
  a human observer is aware through the visual
  sensations which arise from the stimulation of
  the retina of the eye
• Color is a characteristic of light, that is
  measurable in terms of intensity and wavelength
• It arises from the presence of light in greater
  intensities at some wavelengths than at others

130
Fates of Light When Illuminated

• Reflected
• Transmitted
• Absorbed
• Refracted

131
Color Perception

• If all light is reflected from an opaque surface,
  the object appears white
• Is some light is absorbed, the object appears
  gray
• If all light is absorbed, the object appears black

132
Color Perception

• The perception of color results from differences
  in absorption of radiant energy at various
  wavelengths
• Maximum reflection in the short wavelength range
  (400-500 nm) results in blue
• Maximum reflection in the medium wavelength range
  (500-600 nm) results in green or yellow
• Maximum reflection in the long wavelength range
  (600-700 nm) results in red

133
Colors in the Visible Spectrum
134
Physiological Basis of Color

• The human eye has two types of sensitive cells in
  the retina
• A. Rods - are sensitive to lightness darkness
• B. Cones - are sensitive to color
• a. one set is sensitive to red light
• b. one set is sensitive to green light
• c. one set is sensitive to blue light

135
Physiological Basis of Color

• Cones send a signal to the brain that sets up a
  response in terms of opposing pairs
• A. One pair is red-green
• B. One pair is yellow-blue
• This is why some individuals are red-green, or
  blue-yellow color blind

136
Color MeasurementMunsell System

• Contains 1225 color chips used for convenient
  visual comparison
• Each chip has a numerical designation
• Advantages simple, convenient, easy to
  understand
• Examples color grades for tomato juice, glass
  color standards for sugar products, plastic color
  standards for peas, lima beans, apple butter,
  peanut butter, canned peaches, mushrooms

137
Color MeasurementMunsell System

• Disadvantages
• Plastic and glass standards are available in a
  limited number of colors
• Painted paper chips come in an array of colors,
  but are fragile, and fade with time
• Repeated visual judgements are tiring and tedious
• Color that fall between existing standards are
  difficult to communicate to other individuals

138
Spectrophotometric Measurement of Color

• Early instrumental methods for color measurement
  were based on transmission, or reflection
  spectroscopy
• Researchers developed the response of the cones
  in the eye in terms of the visible spectrum
• X (red), Y (green) and Z (blue) were used as
  reference stimuli

139
Spectrophotometric Measurement of Color

• If we take the red, green, and blue data for the
  spectral colors, transform them to X, Y, and Z
  coordinates, and plot the response of the human
  cones against wavelength, we get the response of
  the human eye to color
• These curves were standardized in 1932 and called
  the CIE (International Commission of
  Illumination) x, y, z standard observer curves

140
Spectrophotometric Measurement of Color

• Having the data in the standard observer curves,
  it is mathematically simple to calculate color
  from a reflectance or transmission spectrum
• The sample spectrum is multiplied by the spectrum
  of light source and the area under the resultant
  curve is integrated in terms of the x, y, z
  curves
• The resulting figures for X,Y, Z specify the
  color of the sample

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142
Food Additives
143
History of Food Additives

• Smoking and sun drying were early methods used
  for food preservation
• Much of our history is an indirect result of
  mans quest for spices and other flavorings egs
  Marco Polos travels, discovery of America by
  Columbus, Cortez and the vanilla bean
• Texas settlers in the 1800s - chili powder

144
Food Additives

• A substance or mixture of substances, other
  than a basic foodstuff, which is present in a
  food as a result of any aspect of production,
  processing, storage or packaging

145
Food Additive Categories

• Intentional additives - Those which are added to
  perform a specific function. They are measured
  and added in scientifically controlled amounts
  therefore the amounts added are generally small.
• Incidental additives - Substances present in
  foods in trace quantities as a result of some
  phase of production, processing, storage or
  packaging. These are unavoidable from a practical
  viewpoint.

146
Reasons for Using Food Additives

• Rapidly expanding population, and migration of
  the population from rural to urban areas
• With lt 5 of the population growing food for the
  remaining 95, much of the food would never reach
  consumers in edible condition without additives
• Additives help the food supply to be palatable,
  convenient, nutritious, safe, with a long
  shelf-life and pleasing flavor

147
Food Preservative Categories

• 1). Those which act to control or prevent growth
  of microbes
• Salts or various acids such as proprionic, sorbic
  and benzoic
• Calcium proprionate - mold inhibitor in bread
• Potassium sorbate - mold inhibitor in cheeses,
  syrups, jams, mayonnaise and pickles
• Sodium benzoate - mold inhibitor in high acid
  foods, fruit drinks, carbonated beverages

148
Food Preservative Categories

• Nitrates - prevent the growth of Clostridium
  botulinum in cured meats, also fixes the color
  and enhances the flavor of these products
• It is possible that nitrites combine with amines
  in the stomach to form nitrosamines
• These compounds are under investigation as
  possible carcinogens

149
Food Preservative Categories

• 2) Preservatives which act by inhibiting
  detrimental chemical changes
• Prevention of rancidity in fatty foods can be
  accomplished with BHA, BHT, propyl gallate
• Citric acid, phosphoric acid and ascorbic acid
  are often added to enhance the effectiveness of
  BHA and BHT

150
Food Preservative Categories

• Chelating or sequestering agents (EDTA and SHMP)
  are added to foods to bind trace metals which can
  act as catalysts in food spoilage
• These agents are used to prevent or reduce
  discoloration, clouding and rancidity
• Used in products such as soft drinks, cream style
  corn, shrimp and beer

151
Flavoring Agents

• Sugar and salt are the most widely used additives
• Sugar not only contributes sweetness, but it also
  adds body to beverages, tenderness to baked
  goods, and color when caramelized
• Salt and sugar also may be used as preservatives
  at high concentrations

152
Flavoring Agents

• Non-nutritive sweetners such as saccharin and
  aspartame are commonly used
• MSG, combines with protein to enhance the flavor
  of high protein foods, but does not contribute a
  flavor of its own.
• Disodium inositate and disodium guanylate are
  also used as flavor enhancers in dry soup mixes

153
Coloring Agents

• Natural coloring agents include annatto,
  carotenes, cochineal
• Annatto - commonly used in dairy products,
  margarine, cheese and ice cream
• Cochineal - added to meat products, spices and
  baked goods

154
Coloring Agents

• Synthetic agents include FDC yellow 5 and red
  4
• The soft drink industry is one of the prime color
  users

155
Stabilizers and Thickeners

• These compounds may be derived from natural plant
  extracts, chemically modified natural products,
  or may be completely synthetic products
• Stabilizers are added to chocolate milk to
  prevent chocolate particles from settling out, or
  added to ice cream to bind excess water, this
  preventing ice crystals and a grainy texture

156
Stabilizers and Thickeners

• Thickeners are added to icing, cheese spreads,
  salad dressings, pie fillings, soups and gravies
  to provide the desired consistency
• Additives such as sodium alginate, cellulose gums
  and pectins are used to provide body to
  sugar-sweetened soft drinks

157
Emulsifiers and Surface Active Agents

• Emulsifiers permit the dispersion of tiny
  particles or globules of one liquid in another
• An oil and vinegar salad dressing illustrates one
  important use of emulsifiers
• Emulsifiers such as mono-glycerides play an
  important role in the baking industry by helping
  to increase volume, uniformity, fineness of grain
  and shelf life

158
Emulsifiers and Surface Active Agents

• Lecithin, one of the most widely used
  emulsifiers, is a natural substance found in both
  plant and animal tissues
• Surface active agents (surfactants) of which
  emulsifiers are one type are used to lubricate
  foods (reduce slipperiness)
• Applications include prevention of stickiness in
  peanut butter and caramel products

159
Nutrition Supplements

• Fruit acids (citric, malic, acetic, tartaric) are
  used to intensify flavors in many food products
  including sherbets, cheese, grape and lime
  beverages, jams, jellies, candies and pickles
• Ammonium bicarbonate, sodium carbonate and
  calcium carbonate are examples of alkalies which
  are used to prevent a food product from becoming
  too acid
• Compounds are used to reduce the acidity of
  wines, control acidity of in canned peas and
  olives

160
Firming Agents

• Firming agents improve the texture of processed
  fruits and vegetables
• Calcium chloride, calcium lactate and aluminum
  sulfate (alum) are used to improve the texture of
  pickles, maraschino cherries, and canned peas,
  tomatoes, potatoes and apples

161
Anticaking Agents

• Anticaking agents are important in the salt
  industry where sodium silico aluminate is used to
  prevent particle clumping
• Calcium phosphate performs the same function in
  Tangtype drinks
• Corn starch is added to powdered sugar to keep it
  free-flowing
• Calcium stearate in garlic salt is another
  example of the use of anticaking agents

162
Leavening Agents

• A leavening agent is any chemical or biological
  substance that can produce bubbles of gas in
  dough
• These gas bubbles expand, causing the dough to
  rise thus yielding foods which are light in
  texture
• Yeast was originally used, but is not a reliable
  source of gas

163
Leavening Agents

• Baking powders have replaced yeast as the
  preferred leavening agents
• These powders are generally composed of sodium
  bicarbonate, an acid salt such as calcium
  monophosphate, and starch
• The phosphate and bicarbonate readily react in
  the presence of water to produce carbon dioxide
• The starch helps keep these ingredients dry and
  non-reactive, so that a given volume of baking
  powder will create a given amount of gas

164
Maturing and Bleaching Agents

• The bleaching process of milled flour is
  accelerated by the addition of certain chemicals
  such as chlorine or chlorine dioxide in the form
  of a gas
• These compounds make it possible to produce
  consistently high quality flour, and avoid the
  problems created by prolonged storage, with
  little loss of nutritive quality

165
Humectants

• These are substances such as propylene glycol,
  sorbitol, glycerine and mannitol which are added
  to foods to help keep them moist
• Proplyene glycol is added to shredded coconut and
  marshmallows, dried onions and garlic flavored
  croutons to perform this function
• Sorbitol helps maintain the smooth consistency of
  candies and fudges

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HACCP Principles and Produce Operations
168
Produce Associated Foodborne Illness

• According to the Centers for Disease Control and
  Prevention, the number of produce-related
  outbreaks per year doubled between the periods
  1973-1987 and 1988-1992

169
HACCP Background

• HACCP system for food safety was first developed
  by food processors in cooperation with NASA in
  the 1960s to ensure the safety of space foods
• Food microbiology, risk assessment and QC
  principles were joined to form the HACCP system
• The low acid food industry utilized HACCP in the
  1970s in cooperation with the FDA to ensure the
  quality of low acid canned foods

170
Hazard Analysis Critical Control Point (HACCP)
Program

• Is a systematic approach to the identification,
  evaluation, and control of food safety hazards,
  from raw material production and procurement to
  distribution and consumption of the finished
  product (NAC-MCF, 1997)

171
The 5 Pre-HACCP Steps

• Bring together your HACCP resources
• Describe the product and its method of
  distribution
• Develop a complete list of ingredients and raw
  materials
• Develop a process flow diagram
• Meet the regulatory requirements for sanitation
  standard operating procedures

172
HACCP is Based on Seven Principles

• 1. Conduct a hazard analysis
• 2. Determine the critical control points
• 3. Establish critical limits
• 4. Establish monitoring procedures
• 5. Establish corrective actions
• 6. Establish verification procedures
• 7. Establish record-keeping and documentation
  procedures

173
Quality and Safety Begins in the Field
174
HACCP Principle 1

• Assessment of hazards and risks associated with
  growing, harvesting, raw materials and
  ingredients, processing, manufacturing,
  distribution, and marketing, preparation and
  consumption of the food

175
Potential Hazards to be Monitored

• Microbiological E. coli, coliforms, aerobic
  plate count, Salmonella, Listeria, foodborne
  viruses
• Chemical pesticides, detergent cleaners,
  chlorine residue
• Physical insects, wood, glass, sand, rocks, metal

176
HACCP Principle 2

• Determine the critical control points (CCP)
  required to control the identified hazards
• All hazards identified by the hazard analysis
  must be controlled at some point

177
Examples of CCPs

• Raw product temperature
• Storage temperature
• Chlorination
• Sanitation
• Employee hygiene GMP audits
• Foreign objects

178
Monitoring Water Chemistry
179
Gloves and Hand Washing
180
HACCP Principle 3

• Establish the critical limits which must be met
  at each identified CCP
• Critical limits are tolerances established beyond
  which the related CCP is out of control and a
  potential hazard can exist

181
Examples of Critical Limits

• Storage temperature (32-40oF for vegetables)
• Chlorine levels (50-100 ppm)
• Sanitation procedures (frequency)
• Microbiological standards (zero salmonella)
• Residual chlorine (1 ppm)

182
HACCP Principle 4

• Establish procedures to monitor CCP
• Procedure should be reliable enough to indicate
  that the hazard is under control
• Due to short shelf life of pre-cut produce,
  monitoring procedures should be performed quickly

183
Examples of Monitoring Procedures for CCPs

• Thermometer calibration
• GMP audits
• Sanitation swab testing

184
HACCP Principle 5

• Establish corrective action to be taken when
  there is a deviation identified by monitoring of
  a CCP
• Corrective action must eliminate the hazard which
  has resulted by deviation from the HACCP plan and
  must demonstrate that the CCP has been brought
  under control

185
HACCP Principle6

• Establish effective recordkeeping systems that
  document the HACCP program
• The HACCP plan should be on file at the
  processing plant and it should include
  documentation relating to CCP and any action on
  critical deviations and disposition of product

186
Examples of Records in a HACCP Program

• Ingredients supplier certification, audit
  records, storage time temperature recorders
• Product safety safe shelf life records,
  microbiological records, records relating to
  adequacy of processing procedures
• Processing records of all monitored packaging
  CCP, including seal quality and compliance with
  packaging material specifications

187
Examples of Records in a HACCP Program

• Storage and distribution records on
  temperature/truck cleanliness
• Deviation file records of any deviation to the
  HACCP plan
• Only those records pertaining to CCP must be
  available to regulatory agencies at their request

188
HACCP Principle 7

• Establish procedures for verification that the
  HACCP system is working correctly
• Verification consists of methods, procedures and
  tests used to determine that the HACCP system is
  in compliance with the HACCP plan
• Verification confirms that all hazards in produce
  processing are identified in the HACCP plan

189
Examples of Verification Activities

• Periodic review of HACCP
• Review of HACCP records
• Review of deviations and dispositions
• Random sample collection and analysis

190
SUMMARY

• This module has briefly covered food quality
  assurance, plant sanitation, GMPs, cleaning and
  disinfection methods, quality factors and
  standards, flavor and color determination, food
  additives and HACCP.

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