Extra vergin olive oil (EVOO)

Main features:

PET bottles for EVOO give the following advantages:

Light, brilliant, clear;
Good chemical and mechanical performance;
Conversion from glass or metal can;
Unbreakable;
Freedom on design, shape, handle, capacity;
Good protection against UV light with the use of green/amber masterbatch;
Good shelf-life.

Product description & requirements

Olive oil is a natural product that is sensitive to oxygen and light. The oxidation of EVOO can occur principally in two ways: auto-oxidation and photo-oxidation. Oxygen in the air and dissolved in EVOO is not by itself very destructive; the presence of oxygen AND light is however a bad combination because of destructive oxidation chain reactions which occur. Therefore, PET bottles need to be colored with a masterbatch that reduces the amount of UV light passing through its wall. The use of oxygen scavengers will reduce the permeation of oxygen into the bottle and consequently into the EVOO. Also UV-blocking additive could help.

Target

Target was to develop an aesthetically appealing plastic bottle comparable to glass and that would perform well in terms of mechanical and barrier (light and oxygen) properties, to obtain an optimum shelf-life.

Development & challenges

For EVOO the European Official limit for the amount of oxygen present is 20meq/kg. The main challenge at this point is to find the optimum color that gives the best protection against UV light.
EVOO becomes rancid with photo-oxidation. This spectrum shows that EVOO highly absorbs in the UV range once oxidation has occurred.

Fig 1 - EVOO becomes rancid with photo-oxidation.
(Source: Shimadzu, Azom.com)

Results & packaging features

PET bottles for EVOO must fulfill important requirements such as good aesthetic appearance both in brilliance and transparency, as well as good mechanical, thermal and chemical resistance.
With the right green/amber color, the PET bottle can reach the requested shelf-life.

Fig 2 - Wavelength (nm) vs light absorbance (%).

Legenda:
Yellow = PET clear;
Aqua = PET green;
Brown = olive green/brown

(Source: Aromadictionary)

Filling process description

Flextronic W: Electronic Weight Filler
Extremely simple, clean and fast “no contact” valve, with a 3 position membrane valve featuring double speed.
This solution guarantees high flow performace, ideal for edible oil. Weight filling technology is considered the most reliable, clean and efficient system for filling bottles with edible oil.
It is particularly appreciated for the fact that it avoids overfill: by measuring the weight directly in the container (net weight), it takes into account the changes in the tare as well as in the temperature or nature of the oil and adapts to intrinsic changes of the product during the production cycle.

Fig 3 - 3D rendering of the Flextronic W filling valve

Filling main features

Stainless steel load cell with innovative software to enhance both the precision and accuracy of the weighing system;
Special valve nozzle design to create high flow without foam and dripping; perfectly suitable for no contact valve;
3 position membrane valve to control the filling process;
Close loop cleaning with automatic cups insertion;
Double filling speed for “smooth” product handling;
Hygienic design, Ultra Clean configuration in option.

Fig 4- Detail of the Flextronic W filling valve

These are the most significant machines for this application

SIPA's products include a wide range of solutions for the manufacture of preforms and containers, filling, process and secondary packaging, able to satisfy all the needs of the mineral water market in terms of bottle shapes, products and productivity.