Dados do Trabalho

Título

ENZYME-ASSISTED EXTRACTION OF ANTIOXIDANT COMPOUNDS FROM DIFFERENT SPECIES OF PUMPKIN SEEDS

Introdução

Pumpkin seeds are known for their rich nutritional value and the presence of bioactive compounds with antioxidant activity, such as phenolics and peptides.

Material e Métodos

Three proteases (Alcalase® 2.4L, Flavourzyme® 500L and Neutrase® 0.8L) were used to verify the effect of enzymatic hydrolysis on the recovery of antioxidant compounds from the pumpkin seeds from Cucurbita moschata D (Cmos) and Cucurbita maxima (Cmax). Suspensions (50 mL) containing 5% (w/v) pumpkin seeds flour were dispersed in phosphate buffer (100 mmol/L, pH 7) and the enzymes were applied singly or in binary/ternary mixtures with final concentration adjusted to 100 U/mL. The antioxidant properties were evaluated by four methods: ABTS, DPPH, FRAP expressed as µmol of Trolox equivalents per gram of sample (µmol TE/g) and Total Reducing Capacity (TRC) expressed as mg of gallic acid equivalent per gram of sample (mg GAE/g). The enzymatic hydrolysis was performed at 50°C at 100 rpm for 120 min. A control assay was prepared without enzymes.

Resultados e Discussão

The enzymatic hydrolysis process using seeds from two pumpkin species proved to be efficient in recovering antioxidant compounds. TRC for hydrolyzed Cmos showed the highest percentage variation, ranging from 105 to 157%, while Cmax showed increases ranging from 77% to 124% compared to the control. These increases were also observed for other antioxidant methods, as follows: i) ABTS-radical scavenging showed variations between 88 and 128% for Cmos and between 27 and 40% for Cmax; ii) DPPH-radical scavenging showed increases ranging from 27 to 69% for Cmax and up to 33% for Cmos; iii) FRAP showed increases of up 58% for Cmax and 47% for Cmos. The use of enzyme mixtures (binary/ternary) resulted in greater recoveries of antioxidant compounds, as highlighted below: Cmos extracts obtained using equal proportions of the three enzymes reached 6.62 mg GAE/g and 49.36, 4.31, 1.72 µmol TE/ g for TRC, ABTS, DPPH and FRAP, respectively. Cmax extracts obtained using 2/3 of Alcalase® 2.4L, 1/6 of Flavourzyme® 500L and 1/6 of Neutrase® 0.8L reaching the following values: 5.97 mg GAE/g, 49.68, 3.33 and 2.44 µmol TE/g in TRC, ABTS, DPPH and FRAP, respectively.

Conclusão

The use of enzyme mixtures (binary/ternary) resulted in greater recoveries of antioxidant compounds, as highlighted below: Cmos extracts obtained using equal proportions of the three enzymes reached 6.62 mg GAE/g and 49.36, 4.31, 1.72 µmol TE/ g for TRC, ABTS, DPPH and FRAP, respectively. Cmax extracts obtained using 2/3 of Alcalase® 2.4L, 1/6 of Flavourzyme® 500L and 1/6 of Neutrase® 0.8L reaching the following values: 5.97 mg GAE/g, 49.68, 3.33 and 2.44 µmol TE/g in TRC, ABTS, DPPH and FRAP, respectively.