To determine the size of food oxygen absorber to be used, it is necessary to calculate two data:((1) the volume of oxygen in the food packaging; (2) the volume of oxygen that penetrates into the food packaging during the shelf life)). Finally, according to the oxygen absorption of the deoxidizer, the corresponding model and specifications can be selected.
①The formula for calculating the oxygen volume in food packaging is:
Oxygen in the stereotyped container (ml)=[volume of the stereotyped container (cm3)-weight of the packaged food (g)/specific gravity]×0.21
Oxygen in amorphous packaging (ml) = [increase in water (ml) – packaged food weight (g) / specific gravity] × 0.21
- The specific gravity in the formula refers to the relative density (g/cm3) of this kind of food. The volume of space occupied by the food can be calculated by the weight (g)/specific gravity of the packaged food.
- 0.21 in the formula means that the proportion of oxygen in the air is 20.947%, which is approximately equal to 0.21.
- The added amount of water (ml) refers to the volume of the amorphous package measured by the drainage method.
②The formula for calculating the volume of oxygen that penetrates into food packaging during the shelf life is:
Oxygen penetrated during the shelf life (ml) = [Oxygen permeability of the packaging material (ml/㎡·24h·25℃) × surface area of the packaging (㎡) × shelf life (days)]
- The oxygen permeability of the packaging material (ml/㎡·24h·25°C) in the formula can be obtained from the supplier of the selected packaging material. Food packaging should choose packaging materials with oxygen permeability below 20ml/㎡·24h·25℃, such as KOP/CPP, NY/PE, KNY/PE, KPET/PE, PET/AL/PE, etc. OPP/CPP, PP or PE film bags cannot be used.
- The surface area of the package (㎡) in the formula can be calculated and obtained by measuring the unfolded package.
According to the above formula, ① the volume of oxygen in the food package ② the sum of the volume of oxygen that penetrates into the food package during the shelf life is the total amount of oxygen that needs to be absorbed, and then select the corresponding deoxidizer specification and model according to this data. However, it should be noted that there is no unified specification and model specification for deoxidizers, and it cannot be selected based on the specification of the CC.
An example of how to calculate the amount of food oxygen absorber:
Example: If the total amount of oxygen that needs to be absorbed is 400ml calculated from the above formula, what specification of oxygen absorber is needed?
Since national standard stipulates that the oxygen absorption of oxygen absorber must reach 3 times, the specifications calculated according to the requirements of the national standard 3 times the oxygen absorption are:
Therefore: 150CC deoxidizer can be selected.
However, if the high-quality oxygen absorber can reach 8 times the oxygen absorption, the required specifications are different:
Therefore: 50CC oxygen absorber can be selected.
So, it can be seen from the example that since the specifications and models of oxygen absorber are not uniformly specified, some manufacturers produce oxygen absorber with 3 times the oxygen absorption capacity, and some manufacturers produce oxygen absorber with 8 times the oxygen absorption capacity. The dosage is determined by the specification and model of the CC. In order to ensure the safe dosage, it is recommended to consult the manufacturer before purchasing oxygen absorber.