Effects of various drying methods on the physical and nutritional characteristics of carrot powder

Abstract

Drying vegetables enhances their value by reducing moisture content and inhibiting microbial growth, thereby extending shelf-life. It minimizes post-harvest losses and enables off-season availability. However, drying methods can significantly affect the properties of dried vegetables. Among root crops, carrot holds high nutritional and economic importance. This study evaluates the impact of four drying methods on the physical and nutritional characteristics of carrots. Cleaned samples were dried using four different drying methods: freeze drying (FD), cabinet drying (CD), microwave drying (MD), and oven drying (OD), followed by characterization of the ground powder, with statistical analysis performed using R (version 4.2.1) software was used for statistical analysis. Based on the analysis, the moisture content of the fresh sample (85.78 ± 0.49%) decreased through drying, with powders ranging from 8 to 9.6%, where CD samples had the lowest. Ash content of raw carrots was 2.20 ± 0.07% (wet basis) and ranged from 2.56% (FD) to 3.66% (OD) in dried powders. Protein content increased after dehydration, ranging from 7.15% to 8.9% (wet basis), with no significant differences (p > 0.05) across different drying methods. Fat content of fresh carrots (1.22 ± 0.14% dry basis) increased to 4.7%–9.8% after drying, with the highest value in FD samples. Crude fiber in fresh carrot was 43.17 ± 0.43% (dry basis), which decreased to 6.44%–8.51% after drying. Carbohydrate content increased from 22.43 ± 0.43% (raw dry basis) to 64%–68% in dried samples. Total phenolic content (TPC) of raw carrot was 46.55 ± 1.5 mg Gallic acid equivalent/100 g (wet basis), with no significant differences in TPC (p > 0.05) across dried samples. Total flavonoid content (TFC) was 3.01 ± 0.21 mg Quercetin equivalent/100 g (raw, wet basis) and ranged from 3.98 to 10.69 in dried samples. Color analysis using L*, a*, and b* values showed that OD had the highest lightness (62.61 ± 0.39), while CD was best preserved redness (28.76 ± 0.1). Among the methods evaluated, CD was found to be the most found to be most suitable for producing carrot powder, offering an optimal balance of nutritional quality, making it ideal for extended storage and health-focused applications.