Optimization of blueberry flour processing and anthocyanin extraction

Abstract The objective of this work was to determine the ideal conditions for the processing of flour and extraction of anthocyanins from blueberries (Vaccinium corymbosum). A central composite design (CCD) with response surfaces was used. For the processing of blueberry flour, different dehydration temperatures (53ºC-67ºC) and times (43.18-48.82 hours) were used. The extraction of anthocyanins was performed with ethanol solutions (15-85% v/v) at different pH values (1.0-4.0). ). The total monomeric anthocyanin content was 1,538.39±25.63 mg 100 g-1 (0.89 desirability value) for fresh blueberries in the optimal extraction condition (53.5% ethanol, 2.5 pH) and 3,101.04±11.57 mg 100 g-1 (0.96 desirability value) for blueberry flour in the optimum processing condition (53ºC, 46 hours). The optimized extraction and dehydration of blueberries provide high levels of anthocyanins in the samples.

摘要：本研究旨在确定越橘（Vaccinium corymbosum，即高丛蓝莓）制备蓝莓粉及提取花青素（anthocyanins）的最优工艺条件。实验采用中心复合设计（central composite design, CCD）结合响应面法开展。在蓝莓粉制备环节，设置了53℃~67℃的脱水温度与43.18~48.82小时的脱水时长两个变量；花青素提取环节则采用15%~85%（v/v）的乙醇溶液作为提取溶剂，并设置1.0~4.0的不同pH值梯度。在最优提取条件（乙醇体积分数53.5%、pH 2.5）下，新鲜蓝莓的总单体花青素含量（total monomeric anthocyanin content）可达1538.39±25.63 mg·100g⁻¹，对应合意指数为0.89；而在最优加工条件（脱水温度53℃、时长46小时）下制备的蓝莓粉，其总单体花青素含量可达3101.04±11.57 mg·100g⁻¹，对应合意指数为0.96。经优化的蓝莓提取与脱水工艺可使样品获得较高水平的花青素含量。