西兰花热风干燥特性及品质研究

Study on hot air drying characteristics and quality of Brassica oleracea L. var. italica Planch.

中文关键词:  西兰花粉  热风干燥  萝卜硫苷  萝卜硫素

英文关键词:broccoli powder  hot air drying  glucoraphanin  sulforaphane

中文摘要:

      目的 探究不同切分大小和不同干燥温度对西兰花粉品质的影响。方法 新鲜的西兰花经过汽蒸 80 s处理后进行切分(3 cm×3 cm、0.5 cm×0.5 cm)和干燥(55、60、65、70、75、80 ℃)处理, 并对干燥后制得的西兰花粉的含水量变化以及叶绿素、花色苷、总酚、维生素C、可溶性蛋白、萝卜硫苷含量和萝卜硫素形成量进行研究。结果 随着干燥温度的升高, 切分程度越小的西兰花干燥速率增长越快。高温使西兰花粉中绿色损失, 80 ℃ (0.5 cm×0.5 cm) 处理的粉末颜色较差, 叶绿素损失显著多于其他粉末。西兰花粉总酚含量随温度变化无显著差异(P>0.05)。70 ℃ (3 cm×3 cm)处理的西兰花粉花色苷、维生素C和可溶性蛋白含量最高。65 ℃ (3 cm×3 cm)的西兰花粉中萝卜硫素形成量最高, 为5.37 mg/g, 与70 ℃ (3 cm×3 cm)的无显著差异。结论 西兰花粉花色苷、维生素C和可溶性蛋白均随干燥温度升高呈先升高后降低的趋势, 3 cm×3 cm的切分可以更好的保留西兰花粉中营养品质。经80 s汽蒸预处理, 花球直径和茎梗长度切分为3 cm, 在70 ℃热风干燥处理200 min制得的西兰花粉品质最佳。

英文摘要:

      Objective To explore the effects of different cut sizes and different drying temperatures on the qualities of broccoli powder. Methods Fresh broccoli was steamed for 80 s, and then processed with different cut sizes (3 cm×3 cm, 0.5 cm×0.5 cm), and dried under different temperatures (55, 60, 65, 70, 75, 80 ℃). The changes of water content, chlorophyll, anthocyanins, total phenols, vitamin C, soluble protein, glucoraphanin content, and sulforaphane formation in broccoli powder were studied. Results With the drying temperature increased, the drying rate of broccoli increased. High temperature reduced the green color of broccoli powder. The powder at 80 ℃ (3 cm×3 cm) had poorer color and lower chlorophyll content than other powders, the content of chlorophyll and glucoraphanin in broccoli powder were increased firstly and then decreased with the increasing of drying temperature. The drying temperature had no significant effects on the total phenol content (P>0.05). Broccoli powder dried at 70 ℃ (3 cm×3 cm) contained the highest content of anthocyanin, vitamin C and soluble protein. Dried at 65 ℃ (3 cm×3 cm) led to the highest sulforaphane formation, which reached 5.37 mg/g; there was no significant difference between 65 ℃ (3 cm×3 cm) and 70 ℃ (3 cm×3 cm). Conclusion The content of anthocyanin, vitamin C and soluble protein in broccoli powder are increased firstly and then decreased with the increasing of drying temperature. Nutritional quality of broccoli power divided by 3 cm×3 cm is better preserved. The quality of broccoli powder prepared by the pretreatment with the diameter of the flower bulb and the length of the stem cut into 3 cm, and dried at 70 ℃ for 200 min after steaming for 80 s.