桑葚果粉的制备工艺及其稳定性研究

Study on the Preparation Technology and Stability of Mulberry Powder

以速冻桑葚为原料,通过湿法粉碎和冻干工艺制备桑葚冻干果粉,以期制备出溶解度好、花色苷保留率高、营养接近新鲜果的桑葚果粉。以果粉中花色苷含量和溶解度为指标,选择液料比、麦芽糊精添加量和匀浆时间三个因素,通过单因素和正交试验优化桑葚冻干粉的最优制备条件。并考察最优条件的果粉花色苷在酸、糖、防腐剂、盐、温度等条件下的稳定性。结果表明桑葚匀浆时间3 min,添加麦芽糊精3%,液料比2.5∶1 (m L/g),此条件下制备的桑葚粉花色苷含量为14.90 mg/g,溶解度为41.27 g/100 g。稳定性实验表明桑葚果粉中的花色苷在pH4.0以下的酸性条件下稳定;温度60℃以下较稳定;葡萄糖、蔗糖添加量低于10%时对果粉花色苷的影响不显著(p> 0.05);防腐剂添加量小于1 g/L时显著降低花色苷含量(p <0.05);氯化钠添加量低于5%时显著增加花色苷含量(p <0.05)。该技术所得桑葚果粉溶解度较好、花色苷保留率高、营养成分损失小,且产品风味接近原料果。

To prepare mulberry fruit powder products with good solubility,high retention rate of anthocyanin and the nutrient close to fresh fruit,the quick-frozen mulberry were used as raw material to prepare freeze-dried mulberry powder. The wet pulverization and lyophilization processes were used,with anthocyanin content and solubility in fruit powder as indicators. The optimal preparation parameters of freeze-dried mulberry powder were optimized by single factor combined with orthogonal optimization experiments.To study the stable of anthocyanin in mulberry powder.The effects of aqueous solution of anthocyanin on acid,sugar,preservatives,sodium chloride and temperature were investigated.The results showed that the optimal parameters were as follows: homogenization time was 3 mins,the addition of maltodextrin was 3%,and the ratio of liquid to solid was2.5∶ 1( m L/g). The anthocyanin content in mulberry powder prepared by the optimal technology was 14.90 mg/g and its solubility was 41.27 g/100 g.Moreover,it found that anthocyanin in mulberry powder was stable in the acidic environment when pH was below 4,and temperature below 60 ℃. For the investigated food additives,glucose and sucrose had no significant influence( p > 0.05) on the anthocyanin content within 8% of the mass concentration. However,the preservatives significantly( p < 0.05) reduced the content of anthocyanins when the amount of addition was less than 1 g/L.When the sodium chloride concentration was less than 5%,it significantly( p < 0.05) increased the content of anthocyanins.With the present technology,the solubility of mulberry fruit powder was good,the anthocyanin retention rate of mulberry fruit powder was high,the nutrient component loss is small,and the product flavor was close to the raw material fruit.