Ignaczak Anna, Woźniak Łukasz, Marzec Agata, Kowalska Jolanta, Chobot Małgorzata, Kowalska Hanna
Department of Food Engineering and Process Management, Institute of Food Sciences, Warsaw University of Life Sciences, 159c Nowoursynowska St., 02-776 Warsaw, Poland.
Department of Fruit and Vegetable Product Technology, Institute of Agricultural and Food Biotechnology, State Research Institute, 36 Rakowiecka St., 02-532 Warsaw, Poland.
Molecules. 2025 Apr 23;30(9):1877. doi: 10.3390/molecules30091877.
The study investigated the effect of osmotic treatment, edible coatings, and reduced pressure on the quality of carrots dried by the microwave-vacuum method (MVD) at 3.5 or 6.5 kPa and microwave power of 250 W. Initial osmotic enrichment (OE) of carrots was carried out in chokeberry NFC juice, and osmotic dehydration (OD) in chokeberry juice concentrate. Coatings were prepared using sodium alginate or citrus pectin solutions of 1.0 or 1.5%. Osmotic treatment, and then drying pressure, had the greatest effect on increasing the dry matter (DM), total phenolic content (TPC), and color changes, but also on decreasing the water activity (AW) of dried carrot. The highest DM (average 98.7%) and the lowest AW (average 0.25) were obtained in OE carrots and dried at 3.5 kPa. Drying carrots, combined with osmotic treatment and coating, increased TPC by 13-fold, from 225 in fresh to 3229 mg GAE/100 g d.m. in dried carrots. Osmotic treatment did not affect the antioxidant activity of DPPH•, but OD significantly increased ABTS•+ compared to the raw material. Coatings had a smaller effect on color changes and antioxidant activity (DPPH• and ABTS•+) and no significant impact on DM and AW. The color changes of the control and coated samples were an increase in color lightness, redness, yellowness, and saturation (vividness), and those subjected to osmotic treatment showed a decrease in these parameters. The lower AW of dried carrots positively affected higher hardness. All samples were sensory accepted, including color, texture, and smell, especially after OD in chokeberry juice concentrate, while crunchiness was the lowest (five out of nine points).
该研究调查了渗透处理、可食用涂层和减压对采用微波真空法（MVD）在3.5或6.5 kPa以及250 W微波功率下干燥的胡萝卜品质的影响。胡萝卜的初始渗透富集（OE）在黑果腺肋花楸NFC汁中进行，渗透脱水（OD）在黑果腺肋花楸浓缩汁中进行。使用1.0%或1.5%的海藻酸钠或柑橘果胶溶液制备涂层。渗透处理，然后是干燥压力，对增加干物质（DM）、总酚含量（TPC）和颜色变化影响最大，但也对降低干燥胡萝卜的水分活度（AW）有影响。在经OE处理并在3.5 kPa下干燥的胡萝卜中获得了最高的DM（平均98.7%）和最低的AW（平均0.25）。将胡萝卜干燥与渗透处理和涂层相结合，使TPC增加了13倍，从新鲜胡萝卜中的225增加到干燥胡萝卜中的3229 mg GAE/100 g干物质。渗透处理不影响DPPH•的抗氧化活性，但与原材料相比，OD显著增加了ABTS•+。涂层对颜色变化和抗氧化活性（DPPH•和ABTS•+）的影响较小，对DM和AW没有显著影响。对照样品和涂覆样品的颜色变化表现为颜色亮度、红色度、黄色度和饱和度（鲜艳度）增加，而经过渗透处理的样品这些参数则下降。干燥胡萝卜较低的AW对较高的硬度有积极影响。所有样品在感官上都是可接受的，包括颜色、质地和气味，特别是在黑果腺肋花楸浓缩汁中进行OD处理后，而脆度最低（9分制中的5分）。
