Obtaining and characterizing polyphenol extracts based on anthocyanins from Melinis minutiflora inflorescences and Plinia cauliflora fruits and application in gelatins

Anthocyanins are a class of compounds potentially used as food dyes. Thus, this study aimed to obtain and characterize natural extracts from Melinis minutiflora inflorescence (M), Plinia. cauliflora peel (JP) and P. cauliflora peel and seeds (JPS) and apply them as natural food dyes in gelatins. The extracts did not show statistically significant differences in pH values and water activity. The M and JPS extracts showed similar values of anthocyanins and total phenolic compounds and were higher than those from the JP extract. The M and JPS extracts showed a bathochromic effect, which was not observed for the JP extract. The bathochromic effect may indicate a possible complexation of anthocyanins. The color composition analysis revealed that the JP extract has a higher absorbance at a wavelength of 520 nm, indirectly suggesting the presence of more monomeric anthocyanins in its composition. The extract application test in gelatin did not change the texture properties of the gelatins. In addition, our findings revealed that the JPS extract had the best color stability after ten days of analysis, indicating that anthocyanin complexation with the phenolic compounds of P. cauliflora seeds contributed more effectively to anthocyanin stability in the model used.

Automated summary

In this study, natural extracts from Melinis minutiflora inflorescence, Plinia cauliflora peel, and P. cauliflora peel and seeds were obtained and characterized for their potential use as natural food dyes in gelatins. The extracts did not show significant differences in pH values and water activity. The extracts from Melinis minutiflora inflorescence and P. cauliflora peel and seeds had higher values of anthocyanins and total phenolic compounds compared to the extract from Plinia cauliflora peel. The bathochromic effect observed in the extracts suggested a possible complexation of anthocyanins. Color composition analysis indicated a higher absorbance at 520 nm wavelength in the Plinia cauliflora peel extract, suggesting the presence of more monomeric anthocyanins. The extract application test in gelatin did not affect the gelatin's texture properties. Moreover, the P. cauliflora peel and seeds extract showed the best color stability after ten days, indicating that anthocyanin complexation with phenolic compounds contributed to the stability of anthocyanins.