Profile, antioxidant potential, and applicability of phenolic compounds extracted from <i>Spirulina platensis</i>

Abstract

This work aimed at an investigation of the profile of free phenolic compounds (PC) of Spirulina platensis and assesses their antioxidant potential, applying them as a natural conservative in minimally processed apples. The phenolic extract showed 396 &µg g^-1 gallic acid, 347 µg g^-1 of caffeic acid, 54 µg g^-1 salicylic acid and 3.5 µg g^-1 trans^-1-cinmamic a total of 608 µg PC g^-1 of S. platensis. With the use of PC, it was possible to inhibit the radical DPPH over 180 min with IC₅₀ of PC 202 µg mL^-1. The inhibition of polyphenol oxidase and peroxidase of PC were 19.9 and 9.7%. In addition, verifying the constants Km and Vmax, it was concluded that  inhibition of the peroxidase and polyphenol occurs in an uncompetitive manner. Application of crude extract of PC under minimally processed apples showed  inhibition of browning by 40%. The general acceptance of apples was not affected by the addition of PC.

Key words: Apple, enzymatic browning, peroxidase, phenols, polyphenol oxidase.