麦汁生产过程中酚类风味前体物质的释放:工艺参数和原料组成对阿魏酸释放的影响

本文研究了糖化工艺参数如温度、时间、pH值,糖化醪稠度,谷物粗糙度和原料配比,以及搅拌转速对阿魏酸释放的影响.阿魏酸是形成风味活性挥发酚类的前体物质,且是一种啤酒天然抗氧化剂.当大麦芽品种相对固定的情况下,酿造过程不同操作工艺参数以及辅料配比的不同可使麦汁中阿魏酸的含量大不相同.试验发现,水提组分和酶解组分在不同温度和pH条件下的阿魏酸含量存在明显差异.T,t-依赖于阿拉伯木聚糖的降解酶活性与糖化过程中阿魏酸的释放有关.实验室规模的糖化试验结果经中试规模(5h)验证是有效的.提高糖化过程中酚味前体物质的酶解释放量可以大大提高麦汁的潜在酚味.优化糖化过程中该前体物质的释放条件或许是一种控制啤酒中挥发性酚类含量的有效方法.

攀枝花苏铁的化学成分

首次从攀枝花苏铁（Ｃｙｃａｓｐａｎｚｈｉｈｕａｅｎｓｉｓ）的茎、雄花、雌花和种子中共分离出７个化合物．经波谱分析和化学方法分别鉴定为：佳味酚β芸香糖苷（１），穗花杉双黄酮（２），罗汗松双黄酮甲（３），５，５″，７，７″，４′，４－六羟基（２′，８″）双黄酮（４），β谷甾醇（５），胡萝卜苷（６）和棕榈酸（７）．

Total Phenolic Content and Antioxidative Activity in Seasoning Protein Hydrolysate as Affected by Pasteurization and Storage

Protein hydrolysate prepared from fish and shrimp by-products were used to prepare a seasoning protein hydrolysate （SPH）. The effects of pasteurization and storage on total phenolic content （TPC）, DPPH radical scavenging activity, reducing power, and color of the SPH were investigated. Pasteurization at 90 ℃ for 10 minutes led to a reduction of TPC and DPPH radical scavenging activity and an increase of reducing power of solid fraction of SPH by about 30%, 99%, and 100%, respectively. Consequently it increased TPC DPPH radical scavenging activity, and reducing power of the liquid phase by about 32%, 600%, and 100%, respectively. Storage at 28, 35, or 45 ℃ for 12 weeks altered color values and increased brownness intensity （OD420）. The storage led to an apparent increase of the TPC and antioxidative activity of the product. The results indicate the possibility of producing healthy appetizers from protein hydrolysate prepared from by-products of the seafood industry.