Shelf life of food

Determination of shelf life of foods

1. SHELFLIFE OF FOODS
A.Poshadri
Asst.Professor–Food Technology

2. Introduction Shelf-life:
Timeduringwhichthefoodproductwill:
- remainsafe;
- retain desired sensory, chemical, physical and microbiological
characteristics;
- comply with any label declaration of nutritional data, whe n stored under
the
recommended
conditions
AItbeginsfromthetimethefoodisfinishedprocessingandpackaged. AShelf Life
is the period between manufacture and retail purchase of a
foodproductduringwhichtheproductisofsatisfactoryquality
.

3. Benefits of shelf Life studies
Operational Benefits
–Improve food safety aspects
–Increase risk management and reduce recalls
Marketing and Sales
–
Support quality promises
–
Support quality promises
–Avoid brand damage
Commercial benefits
–Enhance brand protection
–Establish extent of liability
•Avoid recall costs

4. Factors Affecting Shelf life

5. Usebydate
-foodsthathaveausebydatearegenerallyregarded
as
unsafetoeatafterthedesignateddate
becauseabuild-upof
bad bacteria may have occurred – even if the food in question
stilllooksandsmellsgoodenoughtoconsume.
Shelf life indication on food As per FSSAI regulations
:
“
Use by” or “expiry
” means the date,
whichsignifiestheendoftheestimatedperiod
underanystated
storageconditions,afterwhichtheproductmaynotremainsafe
andthefoodproductprobablywillnothavethequalityofsafety
attributes normally expected by the consumers and the food,
shallnotbesoldordistributedforhumanconsumption

6. Best before date
:means the date which
signifiestheendoftheperiodunderany
stated storage conditions during which
the food product shall remain fully
marketableand shall retain any specific
qualities for which tacit or express
claims
have
been
made,
and
beyond
thatdate,thefoodmaystillbeperfectly
safetoconsume,though,itsqualitymay
have diminished. However the product
shall not be sold if any stage the
productbecomeunsafe.

7. (i) the day, month and year using the
DD/MM/YY
format for
productswith
ashortshelflifeofupto3months;
(ii) the
monthandtheyearforproductswithashelflifeofmore
The manner of declaration of date of manufacture or
packaging/Expiry/Useby/BestBeforeshallbeasfollows:
than three months
, shall be declared in un-coded numerical
sequenceexceptthatthemonthshallbeindicatedbycapital
letters and abbreviations (at least first three letters of the
month)maybeused.

8. c) In addition to the expiry or Use by, any special conditions for the storage
of the food shall be declared on the label if the v alidity of the date depends
thereon. If required, storage conditions after ope ning the pack may also be
specified.
(d)
Notwithstanding anything contained in this regulati on, an indication of
the “Expiry” shall not be required for:
(i)
Fresh fruits and vegetables, including potatoes whi ch have not been peeled, cut or similarly treated;
(ii) All types of wine;
(iii) Alcoholic beverages containing 10% or more by volume of alcohol;
(iv) Vinegar;
(v) Sugar boiled confectionery;
(vi) Food grade salt for industrial use;
(vii) Solid sugars;
(viii) Chewing gum and bubble gum.

9. Evaluation in a shelf life analysis
•The following common shelf life assessment tests wi ll be conducted at regular
intervals to determine the shelf life of a particul ar foods.
Physico-Chemical analysis •Physical changes/ Changes in properties of foods
•Moisture
•Acidity
•Salt content (In terms of Sodium chloride)
•Peroxide value (All fat rich and fried snacks)
•Free fatty acids
•Nutritional analysis
•Alcoholic acidity of food etc.,

10. Evaluation in a shelf life analysis
Organoleptic analysis/Sensory evaluation •They following parameters will be checked at regula r intervals through a trained
, semi trained panelists with the help of different sensory evaluation methods.
Microbiological analysis:
It determine microbial growth, which leads to
the spoilage of a food product and the growth of microbial the spoilage of a food product and the growth of microbial pathogens that affect the safety of the product.
•Total plate count
•Yeast and mould count
•Aerobic microbial count
•Salmonella, E.coli, total coliformsand other bacter ial pathogens

13. Shelf life analysis methods
Accelerated shelf-life testing
-The food product is conditioned and stored
at elevated temperature and/or humidity and the qua lity changes of
the product are evaluated at a specific sampling ra te.
eIt can be two to four times faster than the real sh elf life study.
e
Shelf
life analysis will be carried by storing the food a t an accelerated
e
Shelf
life analysis will be carried by storing the food a t an accelerated
storage conditions using the concept of Q10.
•The concept of Q10:
Q10 is the increase in the rate of the reaction
when the temperature is
increased by 10 degrees centigrade
(18°F).
E.g. If a food has a stability of 20 weeks at 20°C and 10 weeks at 30°C, thus
the Q10 will be 20/10

14. An accelerated shelf life assessment
:
by increasing the storage temperature (38±1 and 80% RH)
(for long shelf life products)
Advantages of accelerated shelf life assessment Advantages of accelerated shelf life assessment R&D new Products
Time Sensitive introduction (Real time recommended as back
Up)

17. Shelf life analysis methods
Real Time shelf life testing
–Food products are Stored under stated
or selected conditions for longer than the expected shelf life and
check at regular intervals to see when spoilage begins.

18. Conclusion…..
T
Shelf life of food vary with different food items, p ackaging,
storage, distribution etc.
TAccelerated shelf life test (ASLT) and Real time are 2 methods for
calculation.
TSensory, physico-chemical, microbial analysis used t o determine
shelf life.