Microbiological and physical-chemical characteristics of the Peruvian fermented beverage "Chicha de siete semillas": Towards the selection of strains with acidifying properties

Traditional fermented beverages have been consumed worldwide for centuries. Such is the case of "Chicha de siete semillas" which is originally from the province of Huanta, in Ayacucho, Peru. In this work we have analyzed the chemical composition and bacterial diversity of products manufactured from six producers, who have used different combinations of cereals, pseudocereals, legumes and aromatic herbs, although maize was present in all of them. The fermented beverages had a low pH, mainly due to the production of lactic acid, whereas ethanol was, in general, present in low concentrations. Most of the products were rich in GABA, the content of biogenic amines being very low, as corresponds to a product with a short maturation time (less than 4 days). A metataxonomic analysis revealed that Streptococcaceae and Leuconostocaceae families were dominant in the majority of the beverages, Streptococcus spp. and Leuconostoc spp. being the representative genera, respectively. The result was corroborated by culture-dependent techniques, since these were the most abundant genera isolated and identified in all samples, with Streptococcus macedonicus and Leuconostoc lactis as representative species. In lower proportions other isolates were identified as Lactobacillus delbrueckii, Lactiplantibacillus plantarum, Furfurilactobacillus rossiae, Weissella confusa and Enterococcus faecium. The genetic profile of 26 S. macedonicus isolates was determined by RAPD-PCR and REP-PCR, showing five different patterns distinguishable with the first technique. One representative strain from each genetic pattern was further characterized and used to ferment a maize-based matrix (with saccharose) in order to know their technological potential. All strains were able to ferment the beverage at 30 °C in a short time (about 6 h) reaching a pH below 4.5 and they remained viable after 24 h; the main organic acid contributing to the pH decrease was lactic acid. Therefore, S. macedonicus is a good candidate for being part of a putative starter culture, since it is a species well adapted to this cereal-based food niche.

This research was funded by the Ibero-American Program on Science and Technology for Development (CYTED) [grant number 917PTE0537]. The Spanish team was funded by the “Agencia Estatal de Investigación” and the “Fondo Europeo de Desarrollo Regional” (AEI/FEDER, UE) [grant number PCIN2017-075]. The Peruvian team was funded by the National Council of Science and Technology and Innovation of Peru through its execution unit National Fund for Scientific, Technological and Technological Innovation Development (CONCYTEC/FONDECYT) [grant No. 001–2017]. We are truly grateful to the “Chicha de siete semillas” manufacturers who have kept traditional practices for the elaboration of this ancestral fermented beverage. Isabel Cuesta, Begoña Redruello and Ana M. Hernandez, from the Scientific-Technical service (chromatography) at IPLA-CSIC, as well as Lydia Sariego technician of MicroHealth group, are acknowledged for their excellent technical assistance.

Peer reviewed