Minimal processing

Brief description about minimal processing.

1. Minimal Processing

2. WHAT IS MINIMAL PROCESSING
•MinimallyProcessedFoodsarethosewhich
minimallyinfluencesthequalitycharacteristicofa
food,whichatthesametimegivingthefood
sufficientshelflifeduringstorageanddistribution.
•Minimallyprocessedtechnologiesaretechniques
thatpreservefoods,butalsoretaintoacertain
extenttheirnutritionalqualityandsensory
characteristicsbyreducingtherelianceonheatas
themainpreservativeaction.

3. WHY MINIMAL PROCESSING?
•Studiesshowthatconsumersneedfor
conveniencearecorrelatedwithfoodchoice,
thereforethefreshcutfruitandvegetable
industryisworkingtoincreasetheassortment
ofminimallyprocessedvegetableproductsthat
meetstheconsumersneedsforquickand
convenientproductsthatpreservetheir
nutritionalvalue,retainanaturalandfresh
colour,flavourandtextureandcontainfewer
additivessuchaspreservatives.

4. Minimally or light processing refers to:
trimming
peeling
sectioning of fruits and vegetables
slicing
coring
Demand for minimally processed (MP) fruits
and vegetables has increased due to
•busy life style
•increased purchasing power
•health conscious trends

5. Consumers are increasingly demanding
*convenient,
* ready-to-use fruits and
*ready-to-eat vegetables
*with a fresh-like quality
*containing only natural
ingredients
Europe(France&UK)marketsforMPfruitsand
vegetablegrowexplosivelyinthestartofthe1990’s.
USA-marketshareoffresh-cutproduceaccounts
for25%ofallproducesalesintheretailmarket.

6. Flow chart of minimal processing of fruits-

7. Flow chart of minimal processing of vegetables-

8. Minimal processing of Onion-

9. Minimally processing of raw fruits and
vegetables has two purposes:
Itisimportanttokeeptheproducefresh,yet
supplyitinaconvenientformwithoutlosingits
nutritionalquality.
Theproductshouldhaveashelflifesufficient
tomakeitsdistributionfeasibletoitsintended
consumers.

10. Inanidealcase,minimalprocessingcanbe
seen as “invisible”processing
Themicrobiological,sensoryandnutritional
shelflifeofMPfruitsorvegetablesshouldbe
atleast4-7daysbutpreferablyevenlongerup
to21daysdependingonthemarket
Lossofascorbicacidandcarotenesisthemain
limitingfactorofnutritionalquality.

11. MPfruitsandvegetablesareproductsthat
containlivetissuesorthosethathavebeenonly
slightlymodifiedfromthefresh-conditionand
arefresh-likeincharacter.
Thetissuesdonotexhibitthesame
physiologicalresponsesasthenormal(raw)
untreatedliveplanttissues.
RespirationgreatlyincreasedinMPfruitsand
vegetables.

12. Diagrams of intact and processed (cut) fruit or vegetable cell.
Intact cell is expected to be more resistant to oxidative
browning and entrance of bacteria compared to the cut
cell (MP).

13. The presence of cut surface complicate the modeling of
gas exchange in polymeric package
Diagram of product in package and product with surface modification such
as from peeling or slicing.
A -shows intact vegetable product in a package.
B -shows condition of some cut surface cells within the majority of intact interior cell.

15. Reasons for quality changes in MP produce
MP produce deteriorates because of :
* physiological ageingwhich may result in
* biochemical changes degradationof thecolour,
* microbial spoilage texture, flavourof the
produce
During peeling and grating operations,
* many cells are ruptured
* intracellular products such as oxidizing enzymes are
released.

16. Main spoilage characteristics indicating loss of
quality include:
*development of soft rots
*mould growth
*fermentation
*browning
*production of off-odours
Tominimizephysiologicaldecay,bothquality
ofrawmaterialsandmanufacturingprocesses
mustbeoptimized.

17. 1. Physiological and Biochemical
Changes
Most important enzyme with regard to MP fruits and
vegetables is
polyphenol oxidase (PPO)
which causes
browning
Enzymatic browning requires the present of four
different components:
-oxygen -oxidizing enzyme
-copper -a suitable substrate
To prevent browning, at least one of these components
must be removed from the system.

18. Lipoxidase
Another important enzyme which catalyzes
peroxidation reactions
causes
formation of numerous bad smelling aldehydes
and ketones

19. Ethylene production
Minimal processing increases ethylene (C
2H
4)
production
C
2H
4involves in the biosynthesis of enzymes
involved in fruit maturation
partially responsible for softening of sliced
fruit.

20. Respiration activity
Respiration activity of MP produce will increase
1.2 -7 fold or even more depending on
*type of produce
*cutting grade
*temperature
If packaging condition are anaerobic
leads to anaerobic respiration
formation of ethanol, aldehydes and ketones

21. 2. Microbiological Changes
Minimal processing damages tissues of produce
resulting in leakage of cellular fluids containing
nutrients and intercellular enzymes
creates a favourable environment
for microbial growth
Minimalprocessing(peeling,cuttingandshredding)
exposesurfaceofproduce
*toair
*possiblecontaminationwithbacteria,yeastand
moulds.

22. Factors Affecting the Microbial Stability
and Quality of MP Vegetable Salads
Intrinsic factors
Processing factors
Extrinsic factors
Implicit factors

23. Effect of unit operations of commercial processing lines on
aerobic microbial plate counts from various vegetables