**4. Discussion**

## *4.1. Microethnographic Aspects*

The ethnographic goal of this study was to document the anthropological and cultural tensions found in the social representations of the Llayta feeding practice and relate them to the knowledge and value given by the communities to Andean algae.

Ethnographic registries allow the collection of evidence and social representations from people on a particular subject, to discover what people think, believe, and know about their surroundings, and understand how people see it and fit it in their particular interpretations of realities [21,25,26]. The knowledge people may have on a particular natural situation is a good example of where social representations can be collected and interpreted from social and cultural perspectives [26]. Also, descriptions and references from participants are essential in the field of representation for an event of ethnographic interest [22].

In the study of the Llayta feeding practice, the ethnographic registry can be supported by anthropological, socio-cultural, and nutritional referents [20]. The first two provide information on the meaning(s) of the term Llayta, the identification of sites where Llayta grows naturally, and where it is commercialized and consumed.

Our results indicated that nearly 40% of the participants declared they knew Llayta and described it as a moss or an alga, without clarifying whether it grows in fresh water or seawater (Table 2). They also provide names for the sites of origin of Llayta: Parinacota, Putre, Caquena and Visviri in Chile, and Sucuro, Juliaca and Puno in Peru (Table 2, Figure 2). The participants knew that Llayta is used to prepare "*picante*", a typical dish from rural areas in the Andes; however, they were unaware of its nutritional properties. All fourth-grade students from Putre did not know Llayta (11 out of 12 students; 58% of the participants of this study).

It is of considerable concern to confirm that a large proportion of the participants, all young people, did not know Llayta. This apparent loss may be explained by considering the impact of new technologies on rural life, cultural changes and migration from rural regions into urban centers, as described for the Aymara people in northern Chile [24,27].

The cultural and anthropological tensions observed in this study stemmed from a lack of knowledge on the following subjects: (a) conceptual limitations to explain what is an Andean alga or a microalga; (b) geographic locations where Llayta can be found and commercialized; (c) weak descriptions to explain how Llayta is cooked; and (d) the benefits obtained from its consumption. Also, this low or absence of knowledge on Llayta can be explained by how people perceive and relate to the world around them and, most stressfully, by a probable extinction of an Andean cultural practice. The massive ignorance about Llayta found in discussions with children in Putre is a clear example of it.

These anthropological tensions are indication of a paucity of information on Llayta. There is therefore an urgen<sup>t</sup> need to educate people about all the cultural and nutritional knowledge accumulated on Llayta, so that it can be properly valued as a nutritional foodstuff.

#### *4.2. Biochemical Characterization of Llayta*

Llayta consumption is a traditional practice whose future revitalization can be supported by ethnographic information and evidence on the nutritional quality of Llayta [4].

The first biochemical evaluation of colonies of *Nostoc* cells from Peruvian wetlands were published by Aldave-Pajares [16,17]. Later, Gómez-Silva et al. [18] registered the proximal composition of Llayta colonies sold and consumed in Chilean territory, and also for the biomass from the isolated Llayta cyanobacterium. Both studies are in agreemen<sup>t</sup> on the total protein (30–35% *w/w*) and carbohydrate (50–60% *w/w*) content of the Andean *Nostoc* biomasses. More recently, it was informed that 60% of Llayta amino acids can be classified as indispensable; total lipids accounted for 2% of the biomass dry weight; and 32% of total fatty acids were polyunsaturated fatty acids, Vitamin E content was 4.3 mg% *w/w*, total polyphenols was 64 mg (as equivalent to gallic acid), with an antioxidant activity of 17.4 μmoles (as equivalent to Trolox), and total fiber content was 56% of dry weight [4]. Galetovic et al. [4] inferred that Llayta biomass is a nutritious dietary ingredient.

One reason for the need for safety assessments of foods and food ingredients based on microalgae and cyanobacteria biomasses to protect public health is the potential presence of cyanobacterial toxins active at low doses (e.g., microcystin and nodularin). In particular, *Arthrospira platensis* (Spirulina) is considered a safe food based on centuries of human consumption [23]. Comparatively, some species of the *Nostoc* genus have toxic members that synthesize microcystine-like cyanotoxin [28]. However, the genome of the colony-forming *Nostoc* strain isolated from the *Llayta* biomass did not show the presence of *mycE*, a key gene in the microcystine biosynthetic pathway, rendering it as a non-toxic *Nostoc* strain [4,28]. In addition, the absence of epidemiological records associated with Llayta consumption diminishes but does not remove the potential presence of toxic secondary metabolites in this cyanobacterial biomass [4].
