关键词: 板栗壳, 原花青素, 提取, 稳定性

Abstract: To make full use of chestnut shell resources, the optimum extraction process for procyanidins from chestnut shells (CSPCs) with aqueous ethanol was investigated by response surface analysis, and the stability of CSPCs was explored for its best storage conditions. The effects of ethanol concentration, ratio of solid to liquid, extraction temperature and time on the yield of CSPCs were evaluated, and the effects of pH, light, temperature, additives and metal ions on the stability of CSPCs were also investigated. The optimized extraction conditions were as follows: extraction with a 14.5-fold volume of 51% aqueous ethanol solution at 69.3 ℃ for 2 h. Under these conditions, the theoretical yield of CSPCs was 40.35 mg/g, and the measured value was 40.23 mg/g. The results of stability experiments showed that CSPCs was stable at pH 2.2－6, whereas it had poor light stability and should be consequently stored in darkness at low temperature (4－20 ℃). NaHSO3 could protect CSPCs to some extent. Na+, K+, Mg2+, and Al3+ were found to have positive contribution to CSPCs stability, while sodium benzoate, Ca2+, Fe2+ and Cu2+ could not coexist with CSPCs. Therefore, to maintain the stability of CSPCs, it is necessary to control temperature, light and metal ions. An acidic environment and the presence of NaHSO3 can improve the stability of CSPCs.

Key words: chestnut shell, procyanidins, extraction, stability