All-time avocado? Dried 'chunks' enable timely, nutrient-dense inclusion
Writing in their international patent, researchers from the National University of Colombia said they had developed “solid avocado-based compositions” that had a high nutritional value, were “safe from the microbiological point of view” and had the color, flavor and aroma typical of avocado pulp.
The avocado solids, they said, could be incorporated into a variety of foods, including guacamole, avocado oil and avocado spread or purees.
Better access and improved stability
The researchers said the invention overcame several short-comings typical when working with fresh avocado fruit. Firstly, avocados were not always continuously available to industry, due to harvest periods, and secondly handling presented “serious limitations” because of oxidation due to high levels of unsaturated fatty acids in the fruit. When manufacturing products using avocado pulp, therefore, this oxidation could cause shelf-life issues, the researchers said.
Whilst there were a number of preservation methods available to industry, including antioxidants, preservatives, enzymatic inhibitors, the researchers said most produced “considerable changes” to the properties of the avocado, such as the nutritional value, color, taste and aroma.
Some work had been done in developing avocado pulp powders via freeze-drying, dehydration or heat treatment which had allowed a “considerable increase in the stability of avocado pulp”, the researchers said. However, such methods involved process steps, like grinding, that also directly impacted the final physio-chemical, nutritional and sensory properties of the final powder.
There was therefore a need to find a method that maintained the biological value of the avocado, enabling its proper inclusion into food matrixes with minimal negative interactions, they said.
A productive alternative...
Solid avocado compositions or 'chunks', the researchers said, provided a “productive alternative” not only for manufacturers – enabling easier product development and processing – but also the entire agroindustrial chain, as the solid form was advantageous for handling and transport. Importantly, it increased the availability of avocado as a raw material for the food sector in times of non-harvest.
To make the chunks, the researchers said mature avocados were selected, washed and sanitized before removing the pulp. The pulp was then homogenized with lemon juice and water and given time to achieve a solids content of 11-15%. This step could be done using a knife homogenizer, piston, mill or rotor homogenizer. When using the latter, the ideal mixing time was between 3-7 minutes at rotor speeds of 10,000rpm.
Once blended, it was important the mixture had a final solids content of 31-44% and moisture content of 56-69% ahead of drying, the researchers said. Spray-drying was the ideal final step with carefully monitored inlet and outlet temperatures of 140-170 °C and 80-90°C, respectively.
Ready-to-use 'conditioned compositions'
Beyond simple avocado solids, the researchers said it was also possible to add active compounds like antioxidants, vitamins and minerals to the chunks, as well as spices and seasonings, flavorings and dyes or vegetables to achieve a 'conditioned composition'.
It was possible, for example, to make a solid avocado composition ready to make guacamole – already containing the appropriate spices and vegetable chunks. Onions, garlic, paprika, tomato, chilli and ginger, among other ingredients could all be incorporated at the mixing/homogenization step, the researchers said.
When adding vitamins, they said it was favorable to select liposoluble varieties like vitamin A and vitamin D and when adding minerals, it was best to select macrominerals like iron and calcium.
Source: WIPO Publication No. WO2017203453
Published: November 30, 2017. Filed: May 5, 2017.
Title: “Solid avocado compositions and production method”
Authors: National University of Colombia – M. Cortes Rodriguez et al.