Multi-stage block freeze concentration via gravitational method applied to increase of the nutritional content of Morinda citrifolia L. tea

The processing of Morinda citrifolia fruit normally results in a large number of waste leaves that hold many bioactive compounds with nutritional and pharmacological properties. This work aimed to evaluate the effects of a multi-stage block freeze concentration (BFC) via gravitational method on the physicochemical properties of the leaf extract (noni tea). The results in solid retention showed fractions almost 7 times most concentrated than the initial feed. In addition, when compared to the initial content, the BFC process showed an efficiency higher than 90% in the retention of phenolic compounds. Assays in liquid chromatography allowed the detection and quantification of phenolic compounds, in which the total amount increased by more than 1000% in relation to the initial content after each BFC step. Finally, it was also possible to observe a significant increase in the antioxidant activity of the concentrated product after the simulated in vitro digestion process. It was concluded that using a non-thermal, sustainable, low-cost processing, promoted the obtaining of concentrated fractions with high biological and nutritional values with promising properties for application in the development of functional foods from agroindustrial wastes.

Automated summary

The study aimed to evaluate the effects of a multi-stage block freeze concentration (BFC) on the physicochemical properties of Morinda citrifolia leaf extract. The results showed that the BFC process resulted in significantly higher concentrations of phenolic compounds and increased antioxidant activity. The findings suggest that this non-thermal, sustainable, and low-cost processing method can produce concentrated fractions with potential applications in functional food development from agroindustrial wastes.