Combination of Solid State and Submerged Fermentation Strategies to Produce a New Jellyfish-Based Food.

This study describes the set-up and optimization of a fermentation strategy applied to a composite raw material containing jellyfish biomass as the principal ingredient. New fermented food was developed by combining fresh jellyfish Rhizostoma pulmo and the sequential solid-state submerged liquid fermentation method used in Asian countries for processing a high-salt-containing raw material. Aspergillus oryzae was used to drive the first fermentation, conducted in solid-state conditions, of a jellyfish-based product, here named Jelly paste. The second fermentation was performed by inoculating the Jelly paste with different selected bacteria and yeasts, leading to a final product named fermented Jellyfish paste. For the first time, a set of safety parameters necessary for monitoring and describing a jellyfish-based fermented food was established. The new fermented products obtained by the use of Debaryomyces hansenii BC T3-23 yeast strain and the Bacillus amyloliquefaciens MS3 bacterial strain revealed desirable nutritional traits in terms of protein, lipids and total phenolic content, as well as valuable total antioxidant activity. The obtained final products also showed a complex enzyme profile rich in amylase, protease and lipase activities, thus making them characterized by unique composite sensory odor descriptors (umami, smoked, dried fruit, spices).

Effect of different inoculation strategies of selected yeast and LAB cultures on Conservolea and Kalamàta table olives considering phenol content, texture, and sensory attributes.

BACKGROUND: The effects were studied of different inoculation strategies for selected starters -yeasts and lactic acid bacteria (LAB) - used for the fermentation process of two Greek olive cultivars, Conservolea and Kalamàta. The LAB strains applied were Leuconostoc mesenteroides K T5-1 and L. plantarum A 135-5; the selected yeast strains were S. cerevisiae KI 30-16 and Debaryomyces hansenii A 15-44 for Kalamàta and Conservolea olives, respectively. RESULTS: Table olive fermentation processes were monitored by performing microbiological analyses, and by monitoring changes in pH, titratable acidity and salinity, sugar consumption, and the evolution of volatile compounds. Structural modifications occurring in phenolic compounds of brine were investigated during the fermentation using liquid chromatography / diode array detection / electrospray ion trap tandem mass spectrometry (LC/DAD/ESI-MSn ) and quantified by high-performance liquid chromatography (HPLC) using a diode array detector. Phenolic compounds in processed Kalamàta olive brines consisted of phenolic acids, verbascoside, caffeoyl-6-secologanoside, comselogoside, and the dialdehydic form of decarboxymethylelenolic acid linked to hydroxytyrosol, whereas oleoside and oleoside 11-methyl ester were identified only in Conservolea olive brines. CONCLUSION: Volatile profile and sensory evaluation revealed that the 'MIX' (co-inoculum of yeast and LAB strain) inoculation strategy led to the most aromatic and acceptable Kalamàta olives. For the Conservolea table olives, the 'YL' treatment gave the most aromatic and the overall most acceptable product. © 2019 Society of Chemical Industry.

An optimized procedure for the enological selection of non-Saccharomyces starter cultures.

The apiculate yeasts are the species predominating the first stage of grape must alcoholic fermentation and are important for the production of desired volatile compounds. The aim of the present investigation was to establish a protocol for the enological selection of non-Saccharomyces strains directly isolated from a natural must fermentation during the tumultuous phase. At this scope, fifty Hanseniaspora uvarum isolates were characterized at strain level by employing a new combined PCR-based approach. One isolate representative of each identified strain was used in fermentation assays to assess strain-specific enological properties. The chemical analysis indicated that all the analyzed strains were low producers of acetic acid and hydrogen sulphide, whereas they showed fructophilic character and high glycerol production. Analysis of volatile compounds indicated that one strain could positively affect, during the alcoholic fermentation process, the taste and flavour of alcoholic beverages. The statistical evaluation of obtained results indicated that the selected autochthonous H. uvarum strain possessed physiological and technological properties which satisfy the criteria indicated for non-Saccharomyces wine yeasts selection. Our data suggest that the described protocol could be advantageously applied for the selection of non-Saccharomyces strains suitable for the formulation of mixed or sequential starters together with Saccharomyces cerevisiae.