Quality and Safety Assessment of Edible Seaweeds <i>Alaria esculenta</i> and <i>Saccharina latissima</i> Cultivated in Scotland

• Main Authors: Anastasia E. Lytou, Eirini Schoina, Yunge Liu, Kati Michalek, Michele S. Stanley, Efstathios Z. Panagou, George-John E. Nychas
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Foods
• Subjects: macroalgae; microorganisms; spoilage; nutrition facts; drying; rehydration
• Online Access: https://www.mdpi.com/2304-8158/10/9/2210

Within Europe over the last 10 years, there has been an increase in seaweeds cultivated for human consumption. For food safety reasons, it is important to assess the microbiological and nutritional quality of the biomass. The fresh and dried edible seaweeds <i>Alaria esculenta</i> and <i>Saccharina latissima</i> were assessed over two consecutive years for the presence of microorganisms. Seaweed samples supplied from Scotland were stored under isothermal conditions for specific time intervals depending on the sample’s condition (fresh, dried or rehydrated). During storage, microbiological analyses were performed for the enumeration of Total Viable Counts (TVC), <i>Pseudomonas</i> spp., Enterobacteriaceae and <i>Bacillus</i> spp., as well as yeasts and molds. Additionally, bacterial colonies from the Marine Agar growth medium were isolated and subjected to PCR-RAPD analysis for characterization of the bacterial diversity of seaweeds. Bacterial isolates with different fingerprint patterns were further subjected to sequencing (16S rDNA, V1–V4 region). The presence of human pathogenic bacteria was also investigated. Results showed that the initial population of TVC was differentiated depending on the year of seaweed harvest, being closer to the enumeration limit (1.0 log CFU/g) in fresh samples from 2020 and higher in samples from 2019 (6.7 and 3.9 log CFU/g in <i>A. esculenta</i> and <i>S. latissima</i>, respectively). DNA-based analysis revealed the presence of <i>Psychrobacter</i>, <i>Cobetia</i> and <i>Pseudomonas</i> species in <i>A. esculenta</i>, while <i>Psychrobacter</i> and <i>Micrococcus</i> species were present in <i>S. latissima</i>.