Abstract
Wet preservation of algae allows us to bridge the time period between algae harvest and processing while avoiding the costs and nutritional losses associated with algae drying. This study aimed to identify suitable storage conditions for the wet preservation of Nannochloropsis gaditana concentrates. The impact of storage temperature, time and the way of closing the storage recipient was evaluated using a full factorial design. The effect of acetic acid addition was tested for one storage condition. Storage temperature was the main factor determining the microbial count and had a vast impact on the formation of odorous metabolites. Storage at 20 °C in closed recipients led to rapid O2 consumption, accumulation of malodorous short-chain fatty acids above their odor thresholds, and the production of H2S and methanethiol. These odorous metabolites were not formed or to a much lower extent during 4 °C and 8 °C storage in closed recipients. Acetic acid supplementation (50 mM) suppressed the formation of short-chain fatty acids during 8 °C storage in unsealed recipients and reduced the aerobic microbial count and the number of yeasts and molds by approximately one log unit after 14 days. Yet, acetic acid addition also induced lipid hydrolysis and decreased chlorophyll levels when algae were stored for more than one week. This study demonstrated that temperature control is needed and that acetic acid addition is a promising approach when N. gaditana concentrates are stored for less than one week.
Highlights
Nannochloropsis is of interest for commercial applications due to its high growth rate, high lipid levels and peculiar lipid profile [1]
This study demonstrated that temperature control is needed and that acetic acid addition is a promising approach when N. gaditana concentrates are stored for less than one week
Storage temperature had a significant impact on microbial numbers of these concentrates (p < 0.001) and higher numbers were observed after 8 ◦ C and 20 ◦ C storage than after
Summary
Nannochloropsis is of interest for commercial applications due to its high growth rate, high lipid levels and peculiar lipid profile [1]. Lipids constitute up to 60% of the Nannochloropsis biomass and contain a considerable amount of n-3 polyunsaturated fatty acids [2,3,4]. Eicosapentaenoic acid (C20:5, EPA) is noteworthy as it exerts several important physiological functions and its consumption has beneficial effects on cardiovascular disease risk factors [5]. Autotrophic microalgae growth encompasses greenhouse gas capture without using arable land. It is a textbook example of sustainable land management, which is a critical aspect of mitigating the climate crisis according to the latest report from the intergovernmental panel on climate change [7]. Its sustainable cultivation and high lipid content make Nannochloropsis an interesting lipid source for food, feed and nutraceuticals [8]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.