Inhibition of Enzymatic and Oxidative Processes by Phenolic Extracts from Spirulina sp. and Nannochloropsis sp.
1Laboratory of Food Science and Mycotoxins, School of Chemistry and Food, Federal University of Rio Grande (FURG), Itália Avenue, km 8, Bairro Carreiros, Rio Grande, RS, Brazil
2Chemical Engineering Department, Federal University of São Carlos (UFSCAR), Rod. Washington Luiz, km 235, SP 310, São Carlos, SP, Brazil
3Laboratory of Ecology of Phytoplankton and Marine Microorganisms, Aquaculture and Marine Biotechnology Center, Federal University of Rio Grande, Street of Hotel 2, Querência, Rio Grande, RS, Brazil
Received: 31 August 2017
Accepted: 19 April 2018
amylase, antioxidant activity, peroxidase, phenolic extracts, Nannochloropsis sp., Spirulina sp.
This study investigates the capacity of phenolic extracts from microalgae Nannochloropsis sp. and Spirulina sp. to inhibit enzymes and free radical activities, intending to find an innovative way to slow down food damage. HPLC-UV and LC-MS/MS served to determine and confirm, respectively, the phenolic acid profiles in the soluble methanolic (free phenolic) and ethanolic (conjugated phenolic) fractions, and after hydrolysis (bound phenolic fractions). Different procedures measured the antioxidant activity of the extracts to estimate the minimal concentration for the protective effect, stability and versatility of activity. The ability to inhibit the oxidative process (ABTS and DPPH), α-amylase and peroxidase activities were estimated as specific inhibition (%/(min·μg)) for better comparison between the phenolic sources. The phenolic acid mass fractions in the free phenolic extracts from Spirulina sp. and Nannochloropsis sp. were 628 and 641 μg/g, respectively. Phenolic extract from Nannochloropsis sp. showed the highest value of ABTS inhibition (1.3 %/(min·μg)) and highest inhibition of peroxidase activity (0.4 %/(min·μg)). The extract from Spirulina sp. was a better inhibitor of α-amylase activity (0.07 %/(min·μg)). Therefore, the phenolic extracts from the edible microalgae may be applied in food industry as natural protector against endogenous and exogenous hydrolytic and oxidative processes.
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