Metabolites and bioactivities of Caulerpa lentillifera waste and food grades

Abstract

Importance of the work: Caulerpa lentillifera is widely consumed as human food, resulting in the production of large amounts of agricultural waste on a farming scale.
Objectives: To compare the bioactive compounds and biological activities of food and waste grades of fresh C. lentillifera and their crude extract.
Materials & Methods: A fresh sample of C. lentillifera was divided into two grades (commercial-grade A and waste-grade B) and two parts (fronds and stolons) for metabolite and biological activity analysis. Subsequently, the sample was further categorized into two grades (food and waste grade) for ethanol extraction and subsequent metabolite and biological activity analysis.
Results: The results for fresh C. lentillifera showed that, compared to other samples, the stolons of grade B contained higher amounts of chlorophyll, protein and sugar, while stolons of grades A and B had elevated levels of phenolic compounds and flavonoids. Stolons of grade A, as well as the fronds and stolons of grade B, had greater antioxidant and tyrosinase, α-amylase and α-glucosidase inhibitory activity levels than the fronds of grade A. The results for the crude extract showed that the waste grade had chlorophyll, phenolic compounds, flavonoids, ascorbic acid, antioxidants and anti-enzyme activities at higher levels than for the food grade. The crude extract of the waste grade showed inhibition of tyrosinase, α-amylase and α-glucosidase with effective concentrations of samples required to scavenge DPPH radicals by 50% of 37.59 mg/mL, 13.34 mg/mL and 38.46 mg/mL, respectively.
Main finding: C. lentillifera waste could be a valuable source for the extraction of industrial chemicals for medicine, food production and the cosmetics industry.