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Description
A recent analysis on opinions in social media regarding consumption of microalgae-based food products (especially Spirulina) indicated that are very few negative sentiments, but most that were negative, were related to smell (unpublished results, EU project PROFUTURE). The incorporation of microalgae has limitations in terms of sensory properties and consumer acceptance, mainly due to coloration and marine flavor.
YUM ALGAE aims to improve the overall sensory quality of microalgal ingredients by using enzymes, which will target two of the major organoleptic bottlenecks: the fish-like smell associated to volatile compounds and the green dark color from the microalgal pigments. Microalgae subjected to the enzymatic process developed within the project can be used as natural, innovative and sustainable ingredients to nutritionally enrich food products, using high incorporation levels, reaching higher sensory analysis scores in terms of global appreciation and buying intention.
Microalgae have an increasing role in direct use in food products, be it for their health benefits, natural pigments, or as vegan protein source. In addition to the nutritional value, the incorporation of microalgae in food matrices can lead to changes in the sensory properties.
In this project, two staple foods will be considered as case studies: bread and cheese, in which microalgae subjected to enzymatic treatment and produced without treatment will be incorporated, in order to assess the impact on the sensory profile.
Summary of project results
YUM ALGAE aimed to improve the overall sensory quality of microalgal ingredients by using enzymes, targeting two of
the major organoleptic bottlenecks: the fish-like smell associated to volatile compounds and the green dark colour from
the microalgal pigments.
Project Activities
1. Production of Microalgae (ATI1): NORCE successfully produced dry biomass from five microalgae strains. Partner PMS produced up to 5 kg of biomass from three strains in industrial photobioreactors under controlled conditions. The chemical composition of the biomass was analysed at ISA.
2. Sensory Enzyme Discovery Pipeline (ATI2): NORCE identified and cloned genes for pigment and trimethylamine (TMA) converting enzymes; Microalgae biomass was tested for decolorization and deodorization, with limited success in pigment removal. Since the enzymes sent by NORCE did not present activity, the IST team searched for bacteria and Archaea with suitable activities in samples collected in Graciosa Island and Samouco salterns. One of the isolates was able to convert significant amounts of both TMA and dicyclopentadiene (DCPD). A system combining volatile extraction from microalgae and simultaneous consumption of these compounds by bacterial cells was developed at IST.
3. Chemical Trait Analysis (ATI3): Methods for monitoring chlorophyll and TMA conversion were established at IST. Volatile organic compounds in microalgae biomass were characterized by IST and ISA.
4. Proof of Application and Sensory Quality Testing (ATI4): Three different microalgae, C. vulgaris, Spirulina and Microchloropsis sp., received from PMS in the 1 kg scale, were treated with enzymes. The volatile composition of the treated and not treated biomass was compared. All batches were sent to ISA and SenseTest for evaluation. The treated biomass was incorporated into food products, the impact of microalgae on cheese and bread products was evaluated.
Identification of compounds responsible for the overall aroma of microalgae using GC–MS was done at ISA. Based on the naïve tasters'' evaluation, all the samples had a high mean acceptance score (>6.0). Regarding the sensory profile, the sea-like odour intensifies, and the cheese/bread odour decreases for the samples with enzymatic treatment.
Main Results and Impact
Chemical and sensory analyses affirmed microalgae''s potential as a functional food ingredient. Despite the challenges in obtaining microalgae biomass ready for food incorporation after the enzymatic treatment, innovative methods allowed us to tackle this issue and to obtain treated microalgae biomass that could be incorporated into food products such as cheese and bread. Introducing microalgae as a viable ingredient reduces dependence on traditional agriculture, contributing to sustainable food production. Advances in enzymatic processing and large-scale production techniques promise substantial impact on the microalgae and food industry, promoting environmental sustainability and expanding dietary choices.
Summary of bilateral results
The consortium of the YUM Algae project significantly benefited from having a donor project partner (NORCE) by enhancing knowledge exchange and mutual understanding among all involved entities. All partners had complementary expertise in key areas for the successful accomplishment of the project’s objectives and this was central in order to mitigate some unexpected deviations to the work plan. This bilateral collaboration has not only led to shared results, but also broader impacts, such as knowledge exchange, thus influencing practices beyond the project’s scope. For example, it is worth mention that the entire consortium came together for project meetings, with fruitful discussions, but also that two scientific exchanges were made, thus enabling teams from both countries, Portugal and Norway, to learn from working closely together.For instance, the knowledge created within YUM Algae has a broad significance and our findings are now being applied in related contexts, leading to post-project ongoing cooperation on recently emerged issues.Finally, this partnership has also heightened visibility through media coverage tied to bilateral activities, which is important for bridging the gap between science and the final consumer, especially for increasing public awareness about the environmental and health benefits of adopting microalgae as a food ingredient. All dissemination activities for the general public undertaken by the partners also contributed for this objective, allowing us to cover a broad geographic scale, i.e., Portuguese and Norwegian communities, within different social and cultural contexts.As a result of very positive interactions between consortium partners, both personally and scientifically, a proposal for an EU project is underway, to be submitted in September 2024. In this proposal, much of the knowledge generated will be capitalized for new applications. It will be another collaboration with NORCE.