Abstract:

In order to develop a new technology to extract proanthocyanidins, a 2 L equipment of subcritical water extraction (SWE) suitable for industrial production was designed and used to extract proanthocyanidins from grape seeds. SWE conditions for the extraction of proanthocyanidins were optimized by response surface methodology based on Box-Behnken experimental design, followed by a comparison between this technique and other extraction techniques. The results indicated that the optimal SWE conditions were determined as follows: extraction temperature 151 ℃ and extraction pressure 12 MPa for an extraction duration of 21 min; under such condtions, the extraction yield of proanthocyanidins was 3.88%. SWE required shorter length of extraction time and yielded a higher efficiency when compared with conventional Soxhlet extraction and ethanol reflux extraction. The designed 2 L equipment of SWE was highly automatic and convenient to operate.

Key words: response surface methodology, subcritical water extraction, proanthocyanidins