响应面法优化枸杞无硫促干护色工艺及其对品质的影响

为研究鲜枸杞促干护色工艺，选取碳酸钠、柠檬酸和浸泡时间为自变量，以水分含量和色差值为响应值，采用响应面优化法对此工艺进行优化，并测定各品质指标。结果表明，枸杞最佳促干护色条件为:碳酸钠1.1%，柠檬酸0.6%，浸泡时间10 min，浸泡温度为30 ℃，经50 ℃热风干燥42 h后，枸杞含水量降至12.41%，色差值为11.09，颜色较好且干制速度快，相比未处理的枸杞干燥速度提高42%。测得枸杞多糖2%，总糖52.89%，总类胡萝卜素0.54 g/100 g，总酚7.16 mg/g，总黄酮1.57 mg/g。得到的枸杞干中总类胡萝卜素、总酚和总黄酮含量显著高于未处理的枸杞干（P<0.05），多糖和总糖含量与未处理的枸杞无显著差异（P>0.05）。相比对照组，此促干护色方法可使枸杞干制过程中保留较多营养成分，具有实际参考价值。

Optimization the Sulfur-free Drying and Color Protection Process of Lycium barbarum by Response Surface Methodology and Its Effect on Quality

In order to study the process of promoting drying and color protection of fresh wolfberry, sodium carbonate, citric acid and soaking time were selected as independent variables, and the water content and color difference were used as response values, the process was optimized by response surface optimization method, and the quality indicators were determined. The results showed that the optimal conditions for promoting drying and color protection of wolfberry were as follows: Sodium carbonate was 1.1%, citric acid was 0.6%, soaking time was 10 min, soaking temperature was 30 ℃, after 50 ℃ hot air drying for 42 h, the water content of wolfberry decreased to 12.41%. The color difference value was 11.09, the color was good and the drying speed was fast, which was 42% faster than that of the untreated wolfberry. Measured Lycium barbarum polysaccharide 2%, total sugar 52.89%, total carotenoids 0.54 g/100 g, total phenols 7.16 mg/g, total flavonoids 1.57 mg/g. The content of total carotenoids, total phenols and total flavonoids in the obtained dried wolfberry was significantly higher than that of the untreated dried wolfberry (P<0.05), and the content of polysaccharide and total sugar was not significantly different from that of the untreated wolfberry (P>0.05). Compared with the control group, this method of promoting drying and color protection can retain more nutrients during the drying process of wolfberry, which had practical reference value.