Yield and antioxidant capacity of total carotenoids from lemon peels extracted via enzyme-assisted extraction using microbial cellulase and xylanase

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Bachelor of Science in Biochemistry




Different parameters in an enzyme-assisted extraction such as incubation time and enzyme concentration that would yield the highest amount of total carotenoids extracted from lemon peels were optimized. Microbial enzymes, xylanase and cellulase were used in a pH 5.0 buffered medium to extract carotenoids at different incubation periods (30, 60 and 90 min) and enzyme concentrations (50, 65 and 80 U/mL at a constant temperature of 60°C. Total carotenoid content (TC) measured via UV-Vis spectrophotometry showed that the use of xylanase alone would yield the highest TC with a value of 21.35 μg phytofluene equivalent/g of lemon peels (μg/g) as compared with the yield from any treatment using the mixture of enzymes, xylanase and cellulase. The optimum enzyme concentration was 80U/mL with an incubation time of 90 min at 60 °C. Selected extracts with highest and lowest TC were partially characterized using FTIR and antioxidant activity via DPPH assay. The extract with TC of 19.76 μ/g showed the highest antioxidant activity of 31.52% while the extract with TC of 8.31 μ/g yielded the lowest antioxidant activity of 21.32%. Antioxidant activity of the carotenoid extracts showed no significant difference indicating that the capacity of the lemon peels carotenoids, extracted via enzyme-assisted extraction protocols, to act as antioxidant was not affected by the extraction parameters whether it be the enzyme concentration or incubation time.

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