Making low-cost dietary proteins

A European project aims to obtain low-cost dietary proteins for the food industry and the manufacture of animal feed.

Among the scientists working on this project are researchers from the University of Cádiz in Spain, belonging to the Department of Biology and coordinated by Professor Juan Miguel Mancera.

Specifically, professors Juan Miguel Mancera and Juan Antonio Martos-Sitcha have been working on validating proteins obtained from green microalgae through their use in food within the aquaculture sector. Likewise, these researchers are carrying out pilot tests in vivo to determine the effects of the new formulated diets on the growth potential and nutritional use, metabolism and animal welfare of the cultivated specimens. These growth experiments are carried out at the Central Marine Culture Research Service (SCICM), located on the Puerto Real Campus.

The project, called ALEHOOP (Biorefineries for the valorisation of macroalgal residual biomass and legume processing by-products to obtain new protein value-chains for high-value food and feed applications) aims to offer a pilot-scale demonstration focused on obtaining protein low-cost and sustainable alternatives in biorefineries, through methodologies based on the processing of green macroalgae and brown algae, as well as legume by-products.

The objective is to satisfy the market demand of more and more consumers who are looking for formulations with proteins of biological origin, produced at low cost and with better performance in terms of sustainability, compared to conventional proteins, as well as to reduce Europe’s dependence on plant-based proteins such as soy. The resulting proteins will be used in the human and animal food sectors.

The experiments of the project carried out by the University of Cádiz are carried out at the Central Marine Culture Research Service (SCICM), on the Puerto Real Campus. (Photo: University of Cádiz)

Since ALEHOOP started, there have been many advances. For example, the first key task for the first stage of the project was to ensure a stable supply of raw material and then optimize the extraction processes. With these processes already clear and optimized, it was easier to create a protein extraction protocol for legume by-products and also to expand this extraction on a larger scale, as indicated by the project coordination.

Protein extraction from lentil, kidney bean, lupine and pea by-products was optimized at laboratory scale and validated at pilot plant scale. After that, the extracts were characterized in terms of their biochemical properties (moisture, protein, sugar and fat content, mineral analysis and amino acid composition) and technofunctional properties (solubility, fat and water retention capacity, gelation, emulsification and foaming capacity), as well as its antioxidant activity and the presence of anti-nutritional factors. After this characterization, in vivo bioavailability studies and product development tests with end users have begun. Of the protein extracts obtained in ALEHOOP, those of lupine and lentil were selected for showing the best nutritional profile for in vivo studies in metabolic boxes.

The role of green algae

Regarding the algae, some challenges appeared during the project. This raw material usually contains impurities such as mollusk shells or sand, which must be removed before the extraction processes begin, in the words of the researchers. For this reason, a prototype was designed to cut and clean the algae; and then, the proteins from the green and brown algae were also extracted and characterized.

As for the brown algae, a new process was developed to produce alternative proteins and, through a series of filtrations and washes, it was possible to increase the protein content up to 40%. Scaling processes are in place for both types of algae.

ALEHOOP is an EU-funded project, which started in June 2020 and has a consortium of 16 partners from six European countries: Spain, Germany, Belgium, Norway, Ireland and the Czech Republic. The project will last until May 2024. (Source: University of Cádiz)