Shelf Stable Liquid Foods – Technology And Applications(1)

Esta é uma pré-visualização de arquivo. Entre para ver o arquivo original

Slide No. *
Shelf Stable Liquid Foods – Technology And Applications
School Nutrition Association – 59th Annual Conference Baltimore, July 17 – 20, 2005
Gail Barnes PhD MBL, Business Development North America 
Tetra Pak Carton Chilled Inc.
gail.barnes@tetrapak.com
Slide No. *
 
“We Commit To Making Food Safe And Available, Everywhere”
Slide No. *
Juice
Milk
Nutritional Supplements
Soups
Ice Cream Mixes
Chili
Vegetables
Nectars
Smoothies
Broths
Sauces
Gravies
Hispanic Products
Some USA Examples
Slide No. *
Producing a commercially sterile liquid food product 
Filling into sterilized package 
Within the confines of a sterile environment
What Does “Shelf Stability” For Liquid Foods Involve?
Slide No. *
For Milk, The Road To Product Quality / Shelf Stability Starts With The Cow
Raw milk 
quality
Processing
Filling
Storage
Packaging
Distribution
Slide No. *
HTST / Pasteurized, ESL / Ultrpasteurized And UHT Processing For Low Acid Products
ESL / Ultrapasteurized
HTST / Pasteurized
Minimum 289 °F (142.9) °C for 2 / 4 
seconds
UHT / Aseptic / Shelf Stable
161 °F (72 °C) for 15 seconds
Minimum 280 °F (137.8 °C) for 2 seconds 
Time (Seconds)
N.B. Graph not drawn to scale
Temperature (oF)
Slide No. *
HTST / Pasteurized Processing For Low Acid Products
Normal HTST processing at minimum 161 °F (72 °C) / for 15 seconds or comparable
Shelf life of milk varies depending on many factors such as raw milk, manufacturing practices and cleaning routines - up to 28 days at 39 °F (4 °C) storage
Slide No. *
ESL / Ultrapasteurized Processing For Low Acid Products
 Process at minimum 280 ºF (137.5 ºC) for 2 sec.
Shelf life of products: 39 ºF (4 ºC) storage
45 - 80 days on milk
60 - 90 days on non-dairy cream, soy 
Slide No. *
 A continuous process where pumpable products are:
Heated to a temperature sufficient for sterilization
Held at that temperature for a specified period of time
Cooled to filling temperature
Delivered to an aseptic filling machine in a commercially sterile condition
 Packaging material is:
Sterilized 
Maintained in a sterile region
Filled with product
Hermetically Sealed
UHT Processing For Low Acid Products
Minimum 289 °F (142.9) °C for 2 / 4 seconds
Shelf life – 6 to 12 months – any temperature
Slide No. *
ESL / Ultrapasteurized vs UHT Processing
 
 ESL / Ultrapasteurized - Ability to extend the shelf life of a chilled distributed 
 product beyond the shelf life of the traditional HTST / pasteurized
 equivalent in a specific market. In the USA, depending on the product type this
 could mean between 60 – 90 days
 UHT – A commercially sterile, shelf stable product that maintains product
 freshness for extended periods of time – up to 12 months - under ambient
 distribution 
 
Slide No. *
Shelf Stability Begins With Sterile Processing, But Also Requires A Sterile Package, A Sterile Environment
Producing a commercially sterile liquid food product
 
Filling into sterilized package
 
Within the confines of a sterile environment
Slide No. *
Composition Of A Non-Shelf Stable Package
LDPE = low density polyethylene
Slide No. *
Inner LDPE or LLDPE Layer
Adhesive Layer
Aluminum foil
Adhesive Layer
Fiber Base Material
“Décor” LDPE Layer
Composition of A Shelf Stable Package
LDPE = low density polyethylene
LLDPE = low low density polyethylene
Slide No. *
Shelf Life Expectations
HTST /
Pasteurized
ESL / 
Ultrpasteurized
Chilled distribution
UHT
Ambient distribution
14 – 28 Days
6 - 12 Weeks
9 – 12 Months
Slide No. *
Why ESL / Ultrapasteurized Results In Longer Shelf Life Than HTST / Pasteurized Under Chilled Distribution
HTST /
Slide No. *
Why UHT Results In A Longer Shelf Life Than ESL / Ultrapasteurized – And No Refrigeration Is Necessary
A very high temperature process (UHT), for a short time results in a commercially sterile product
Packed into a sterile package 
Under sterile conditions 
The result is a product in which the nutritional quality has been preserved
And which allows the convenience and lowered cost of ambient distribution!
Time (Seconds)
Temperature (oF)
Slide No. *
Choosing A Processing Solution
HTST / Pasteurized (Chilled Distribution)
Simple, commodity products with low differentiation
Shorter, local transport distance
Direct, established chilled supply chain
ESL / Ultrapasteurized (Chilled Distribution)
Longer, regional transport distance
Direct, established chilled supply chain
UHT (Shelf Stable / Ambient Distribution)
National transport distance
Indirect supply chain
Established ambient supply chain / or chilled chain could be used
Slide No. *
The Quality Remains The Same
Slide No. *
Same Milk – Just Different Processes / Different Packaging
Slide No. *
Advantages Of Longer Ambient Shelf Life
Product safety – regardless of storage temperature
Free from bacteria and contaminants without preservatives 
Retention of nutritional value
Increased distribution area
Extended usage occasions
End of term
Field trips….etc 
Ease of use
Portable and lightweight
Shatterproof
Easy to open and drink from
Easy to dispose
Variety – in both product and flavor!
Chocolate!
Strawberry!
Vanilla!
*
*
*
Thermisation	 63–65 °C/15 sec	Preliminary heating
Pasteurisation	 63 °C/30 min	Pasteur´s method (batch	storage
 		pasteurisation), rare today
HTST pasteurisation	 72–75 °C/15 sec	Milk
"	"	 85–90 °C/2–5 sec	Cream
"	"	 90–120 °C/2–5 sec	Fermented products
Juice pasteurisation	 90–120 °C/15–30 sec	Fruit juice
Ultra pasteuriastion	125–138 °C/2–4 sec	Cold storage
UHT			135–150 °C/4–15 sec	Ambient 				storage
Conventional sterilisation	abt 116 °C/abt 20 min	Ambient
*
There is no global definition of ESL, so we have reverted to the use of the shelf life of the equivalent product in a specific market as a benchmark. Any extension of the shelf life of the local equivalent product in a specific market therefore qualifies as shelf life extension.
*
This schematic diagram gives an overview of ESL processing and filling compared to regular pasteurised processing and filling procedures…….
 Vertical axis - microbial count
 Horizontal axis - shelf life
Starting off with the same quality of raw milk, it can be seen that ESL processing technology reduces the microbial load by a much greater degree than regular pasteurisation. 
Then, due to the superior hygienic design, ESL filling technology provides a much greater degree of protection against recontamination from the filling environment.Thus in effect, the quality of the product fed to the filler is largely maintained without recontamination.
The combined effect of the processing and filling, results in the ESL product having a reduced microbial load compared with a regular pasteurised product - which will be spoiled in shorter time, due to this load. 
Broadly, this means that an ESL product will tend to be safer and of superior quality than a past. product, as a result of having been produced in a more hygienic and tightly controlled environment. 
This slide also acknowledges the fact that ESL technology is not only related to hardware/equipment related factors. Also environmental and operational factors have the potential to influence product quality, safety and shelf life
*
When the supply chain is a challenge – UHT is great. UHT does not have the problems of milk being cold enough – no safety concerns.