An analysis on the effect of Arthrospira platensis composition on the food and sensory characteristics of white chocolate

Arthrospira platensis is a filamentous, gram-negative cyanobacterium. This bacterium is non-nitrogen-fixing photoautotroph. It has been isolated in Chenghai Lake, China, soda lakes of East Africa, and subtropical, alkaline lakes. Search on development of food enrichment with Arthrospira platensis biomass remains scarce, which is important for human health. The present study aimed to improve nutritional and sensory properties of white chocolate by incorporation of A. platensis. Arthrospira platensis is a cyanobacterium widely used in food formulation and mainly consumed as a food supplement because of its high amount of proteins, vitamins and minerals. Different probiotic food supplements are present in the market, and a lactic acid fermented food product like dried spirulina could be useful not only to introduce lactic acid bacteria (LAB) with beneficial effects to the diet of consumers, but also to improve or change the aromatic profile of the substrate. Therefore, the aim of this study was the evaluation of lactic acid fermentation of A. platensis biomass, focusing on the consequent changes in the aromatic profile. For this purpose, two different stabilization treatments (UV light treatment and sterilization) were applied prior to fermentation with two LAB strains, Lacticaseibacillus casei ۲۲۴۰ and Lacticaseibacillus rhamnosus GG. The biomass proved to be a suitable matrix for solid-state fermentation, showing a LAB growth of more than ۲ log CFU/g in ۴۸ h. The fermentation process was also useful for off-flavor reduction. In particular, the fermentation process significantly influenced the concentration of those compounds responsible for aldehydic/ethereal, buttery/waxy (acetoin and diacetyl), alkane and fermented aromatic notes (isoamyl alcohol). The heat treatment of the matrix, in addition to guaranteed safety for consumers, led to an improved aroma after fermentation. In conclusion, a fermented spirulina powder with a different aromatic profile was obtained with the applied heat treatment. Fermentation with lactic acid bacteria can be an interesting tool to obtain cyanobacterial biomasses with more pleasant sensory properties for potential use in food formulations.

Keywords:

Arthrospira platensis , fermentation , lactic acid bacteria , food supplement , aromatic profile.