Challenges While Preserving Avocados


Avocado is one of the most demanded products on the market today, because of its nutritional value and its benefits for health in general. However, this trend is also bringing new challenges for the food processors: preserve a highly perishable and sensitive fruit.

The market is very pretentious when it comes to avocado. Fresh avocados that present imperfections are most of the times rejected. More than that, the avocados require special handling because they start to ripen immediately after the harvest and turn bad very quickly. Therefore, the avocado growers and processors are more and more interested in improving their methods of preservation so that they keep up with the fast ripening process of the avocado.

Until the last century, the avocado was predominantly cultivated in Central America and southern Mexico, but today it is one of the trendiest fruits in the whole world, grown in many countries outside the American continent. From a botanical perspective, the avocado is classified into three types:

  1. West Indian (WI) – tropical, with various shapes and lower oil content
  2. Mexican (MX) – semitropical, with smaller elongated shape, thin skin and higher oil content
  3. Guatemalan (G) – subtropical with round shape, thick skin and medium level of oil content

The most cultivated types are G-MX hybrids. One of the most common and appreciated avocado on the market is the Hass variety because it produces fruit in all seasons, all year-round. 80% of the grown avocados in the entire world are derived from the Hass variety. Also, the Hass avocados are preserved more easily compared to other cultivars, which makes them the top candidates for the avocado market and avocado processors.

Time is the most important aspect to be aware of, when processing avocado. Like we previously mentioned, once the avocado is harvested, it begins to ripen. This is the moment where the challenging part begins, due to the fact that avocados contain more than 30% oil and a very small amount of water, which speeds up the process of decay. However, ripening and softening of this fruit can be postponed by immediate cooling after harvest and storing at a temperature between 5 to 15°C. Most methods for preserving avocado, such as canning for example, will inflict changes in the avocados’ texture, flavor and color.

So how do we preserve avocados with the best results? Today’s innovative freezing technologies bring the solution: Individual Quick Freezing (IQF). The avocado needs a proper pre-freezing treatment in order to guarantee a high-quality final IQF product. For good IQF results there are a few aspects to keep in mind by the processors:

  1. The right ripeness degree is crucial for freezing – an overripe avocado can affect the quality of the whole batch of IQF product therefore good sorting must be put in place.
  2. Too much water on the surface of the avocado will generate corals during the process of freezing. This makes a good dewatering system – an important stage of the pre-processing.
  3. Avocado is a sticky product so shakers and vibrators can contribute to a better separation of the product.

A typical pre-processing line for IQF avocado could include:

  1. Cut the avocado in two halves
  2. Scoop out the fruit stone and remove the flesh manually
  3. Insert the flesh into a hydro cooler water bath
  4. Dice or slice the flesh of the avocados
  5. Spray or bathe the avocado in citric acid or lemon juice
  6. Remove surface water using a dewatering shaker or air knives
  7. Transport the product to the IQF tunnel freezer

As avocado is a delicate product and very sensitive to mechanical impact, optimal equipment must be chosen. In terms of IQF tunnel freezers which achieve best results with sensitive products like IQF avocado, OctoFrost ™ IQF tunnel freezer is highly recommended by processors. With its gentle bedplate movements and the adjustable freezing zones, the OctoFrost™ IQF tunnel freezer is one of the very few types of freezing solutions able to provide remarkable results in preserving the natural appearance, creamy texture, color and buttery flavor of IQF avocado.