Department of Fruit, Vegetable and Plant Nutraceutical Technology, the Faculty of Biotechnology and Food Science, Wrocław University of Environmental and Life Sciences, 51-630 Wrocław, Poland.
Institute of Agricultural Engineering, the Faculty of Life Sciences and Technology, Wrocław University of Environmental and Life Sciences, 51-630 Wrocław, Poland.
Molecules. 2019 Aug 19;24(16):3008. doi: 10.3390/molecules24163008.
Plum pomace, an agro-industrial waste product has received attention due to the worldwide popularity of plums. During convection, the content of flavan-3-ols decrease, except drying at 90 °C, whereas the content of i.e., chlorogenic, 3-- and 4--coumaroylquinic acids, quercetin rutinoside, and galactoside was observed to increase along with the increase in process temperature. The highest content of all identified polyphenols was found in plum pomace powders obtained using a combination of convective at 90 °C and microwave vacuum drying (MVD) at 120 W, whereas the highest retention of the group consisted of phenolic acids, flavonols, and anthocyanins was noted when CD 70 °C/MVD 120 W was used, pointing to a strong influence of the type of polyphenols on their changes caused by drying. The correlations between TEAC ABTS and the sum of flavonoids ( = 0.634) and anthocyanins ( = 0.704) were established. The multiple regression analysis showed that polyphenol content was more strongly affected by drying time than by maximum temperature, whereas antioxidant capacity was more influenced by maximum temperature of sample than by drying time.
李果渣是一种农业工业废料，由于李果在世界范围内广受欢迎，因此受到了关注。在对流干燥过程中，除了在 90°C 下干燥外，黄烷-3-醇的含量会降低，而绿原酸、3--和 4--咖啡酰奎宁酸、槲皮苷、芦丁糖苷的含量会随着加工温度的升高而增加。在使用对流 90°C 和微波真空干燥（MVD）120 W 的组合获得的李果渣粉末中，发现所有鉴定出的多酚含量最高，而在用 CD 70°C/MVD 120 W 干燥时，酚酸、类黄酮和花青素的保留率最高，这表明不同类型的多酚对其干燥引起的变化有强烈影响。建立了 TEAC ABTS 与总黄酮（ = 0.634）和总花青素（ = 0.704）之间的相关性。多元回归分析表明，多酚含量受干燥时间的影响比受最高温度的影响更大，而抗氧化能力受样品最高温度的影响比受干燥时间的影响更大。
