Michalska Anna, Wojdyło Aneta, Łysiak Grzegorz P, Figiel Adam
Institute of Agricultural Engineering, Wrocław University of Environmental and Life Sciences, 51-630 Wrocław, Poland.
Department of Fruit, Vegetable and Cereals Technology, Wrocław University of Environmental and Life Sciences, 51-630 Wrocław, Poland.
Int J Mol Sci. 2017 Jan 17;18(1):176. doi: 10.3390/ijms18010176.
Among popular crops, plum ( L.) has received special attention due to its health-promoting properties. The seasonality of this fruit makes it impossible to consume it throughout the year, so new products in a powder form may offer an alternative to fresh consumption and may be used as high-quality natural food ingredients. A 100% plum (cultivar "Valor") juice was mixed with three different concentrations of maltodextrin or subjected to sugars removal by amberlite-XAD column, and dried using the freeze, spray, and vacuum (40, 60, and 80 °C) drying techniques. The identification and quantification of phenolic acids, flavonols, and anthocyanins in plum powders was performed by LC-MS QTof and UPLC-PDA, respectively. l-ascorbic acid, hydroxymethylfurfural, and antioxidant capacity were measured by the Trolox equivalent antioxidant capacity (TEAC) ABTS and ferric reducing antioxidant potential (FRAP) methods in order to compare the influence of the drying methods on product quality. The results indicated that the profile of polyphenolic compounds in the plum juice powders significantly differed from the whole plum powders. The drying of a sugar free plum extract resulted in higher content of polyphenolic compounds, l-ascorbic acid and antioxidant capacity, but lower content of hydroxymethylfurfural, regardless of drying method applied. Thus, the formulation of plum juice before drying and the drying method should be carefully selected in order to obtain high-quality powders.
在常见作物中，李子（李属）因其促进健康的特性而备受关注。这种水果的季节性使得人们无法全年食用，因此粉末状的新产品可能为新鲜食用提供替代选择，并可用作优质的天然食品成分。将100%李子（“Valor”品种）汁与三种不同浓度的麦芽糊精混合，或通过Amberlite-XAD柱去除糖分，然后分别采用冷冻干燥、喷雾干燥和真空干燥（40、60和80°C）技术进行干燥。分别通过液相色谱-质谱联用飞行时间质谱仪（LC-MS QTof）和超高效液相色谱-光电二极管阵列检测器（UPLC-PDA）对李子粉中的酚酸、黄酮醇和花青素进行鉴定和定量。采用特洛克斯等效抗氧化能力（TEAC）ABTS法和铁还原抗氧化能力（FRAP）法测定l-抗坏血酸、羟甲基糠醛和抗氧化能力，以比较干燥方法对产品质量的影响。结果表明，李子汁粉中多酚类化合物的谱图与全李子粉有显著差异。无论采用何种干燥方法，无糖李子提取物干燥后多酚类化合物、l-抗坏血酸和抗氧化能力的含量较高，但羟甲基糠醛的含量较低。因此，为了获得高质量的粉末，应仔细选择干燥前李子汁的配方和干燥方法。
