Insect protein enhances trout immunity performance and lowers mortality

South African insect company Maltento tested its high protein digest product in rainbow trout obtaining enhanced performance.

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July 9, 2024

A recent study has revealed that Maltento’s high protein digest product, Palate+, has led to substantial changes to the well-being of rainbow trout, including increased immune system responses and a lower mortality rate. The high protein digest is produced from protein-rich larvae that are farmed from black soldier flies (BSF).

The study was conducted between October and November 2023 by Cape Town-based marine surveyor company MariHealth Solutions and took place at the Sanlei trout farm in Lesotho. Sanlei is the first African aquaculture business to obtain the Best Aquaculture Practices certification as developed by the Global Seafood Alliance, indicating the farm's commitment to established industry standards for environmentally and socially responsible seafood practices. The study compared the blood proteome profiles between two groups of fish; one was fed food supplemented by Palate+, and the other was fed a standard basal diet.

Dean Smorenburg, CEO of Maltento, explained that the analysis demonstrated enhanced immunity in trout fed Palate+. These fish exhibited stronger immune defense responses compared to those on the basal diet. The boost in immunity is likely due to the presence of chitin and unique proteins in Palate+, which have been shown to stimulate the fish's immune system.

The Palate+-fed fish also displayed lower mortality rates than expected. In the study’s report, Professor Vernon Coyne, MariHealth Solutions’ chief scientific officer and co-founder, stated that “in terms of mortalities, it is important to note that C4 (the Palate+ trout cohort) performed better than what would normally be expected at certain periods during the trial compared to C5 (basic diet trout cohort).”

In his veterinarian comment for the report, Dr. B. Spolander added that “it is both very encouraging and interesting that C4 showed such a notable upregulation of immune function pathways compared to C5 where so many important variables regarding immune system comparison were kept the same: genetics, location of cages, water quality variables, and the infectious agent challenge would have been very similar.”


Figure 1. Daily % mortality of the C4 and C5 groups. The digest treatment commenced on 16/10/2023 and ended on 22/11/2023. The C5 blood samples were collected on 13/10/2023 and the C4 fish were sampled on 16/10/2023.

The report recommended further studies due to the “impressive results demonstrated.” Smorenburg is thrilled with the findings and believes this signals a promising future for continued product development at Maltento. “The ground-breaking insights of this initial study underscore the undeniable health benefits of Maltento’s product and demonstrate the advantages of an insect-based, sustainable, protein-rich feed for animals, where Maltento’s products have been proven to increase gut health, immune response and decrease mortality in fish.”

Maltento is a South-African-based biotechnology company that transforms up to 400,000kgs of agro-processing waste monthly, including spent grains from breweries as well as left-over rusks and baked goods from bakeries, into insect meal and oil. The company now boasts a 7,000-metre square facility in Epping, Cape Town and has successfully produced 75 metric tonnes of product since its operations began, with the goal of producing 90 metric tonnes by month end and thereafter scaling in its current footprint to 150 by 2025. Its products are currently being exported to markets in the United States, the European Union, the United Kingdom, and Norway.