What is MAP?
modified atmosphere packaging
- food preservation technique
- comp of the atmosphere around the food is diff than comp of the air
how is MAP different than controlled atmosphere?
in map, there is no way of controlling the atmosphere components at specific concentrations once the package has been hermetically sealed
what are market demands for MAP?
- natural
- good quality
- longer shelf life
- convenience
- good protection from environment
what are effects of O2 on food?
what do all of these result in the loss of?
- deterioration from oxidation
- discoloration
- decomposition (Microorganisms
- damage due to insects
loss of
- freshness
- quality
- taste and flavour
- nutrients
what are advantages of MAP?
- extended shelf life and increased market areas
- better use of labour and equipment
- better economies of scale (by purchasing larger quantities of raw materials)
- reduces transportation costs
- less frequent loading of display shelves and checking “sell by” dates
- enhancement of sales
- reduction of costs associated w/ freezing
what are disadvantages of MAP?
- cost of packaging, equipment, films, etc…
- slower throughput of packages
- leakage
- secondary spoilage problems
- potential growth of organisms of public health concerns
what are methods of atmosphere modification?
- vacuum packaging
- gas packaging
- gas absorbents
- gas generators
describe vacuum packaging
removal of all or most of the air within a package without deliberate replacement with another gas mixture
what are properties of vacuum packaging?
- 5 times longer storage as refrigerated food
- no more freezer burn
- uses laminated films for strength and barrier properties
what are 3 types of vacuum packaging?
chamber vacuum packaging machine
belt vacuum chamber machine
thermoform fill seal machine
which molecule forms bright red?
a) oxymyoglobin
b) myoglobin
c) metmyoglobin
oxymyoglobin
which molecule forms dark red?
a) oxymyoglobin
b) myoglobin
3) metmyoglobin
myoglobin
which forms brown?
a) oxymyoglobin
b) myoglobin
3) metmyoglobin
metmyoglobin
what are factors influencing shelf life of VP pdts?
- raw material quality (affects microbial quality and pH)
- temp control
- hygiene control
- time before packaging
- film permeability
what is the spoilage defect of beef?
acidifying
greening
what is the spoilage defect of pork?
flavor (rancidity)
greening)
what is the spoilage defect of lamb?
color and fat appearance
describe gas packaging
the physical displacement of air by a new gaseous composition
what are 3 techniques used to replace air in gas packaging?
what equipment do each of them use?
- gas flushing: horizontal/vertical form fill seal (H/VFFS)
- compensated vacuum: thermoform-fill seal (TFFS)
- passive modification: no equipment needed. Takes place within sealed package
compare gas flushing to compensated vacuum
gas flushing
- uses the form-fill-seal machine
- continuous flushing
- fast
- residual O2
compensated vacuum
- thermoform-fill-seal machine
- slower
- less residual O2
- used for O2 sensitive pdts
what are characteristics of GP films?
- resistant to puncture
- sealing reliability
- anti-fog
- CO2 permeability
- O2 transmission rate (OTR)
- water vapour transmission rate (WVTR)
what are major gases used in MAP?
other gases?
major gases
N2
CO2
O2
other SO2 CO N2O Ar
why is CO2 a major gas in MAP?
- not inert
- bacteriostatic
- fungistatic
- prevents insect attack
- fat and water soluble
describe the antimicrobial action of CO2
- displacement of O2
- extracellular pH reduction
- intracellular pH reduction
- disruption of cell membrane and enzymes associated w/ metabolism
- increase lag phase = extend shelf life
