Investigation of Drying Methods, Storage Effects, and Quality Attributes of Dried Okra for Soup Production: A Comprehensive Nutrient Content Analysis

Abstract

This study investigated the effects of different drying methods on the nutritional composition and microbiological quality of okra (Abelmoschus esculentus) intended for soup production. Fresh okra samples were processed using solar drying and oven drying at 50 °C and 60 °C, and the resulting products were evaluated for proximate composition, vitamin content, mineral composition, and microbial quality using standard analytical procedures. Drying significantly (p < 0.05) reduced moisture content compared with fresh okra, with values ranging from 9.56–16.10% for solar-dried samples and 12.41–17.34% for oven-dried samples at 50 °C, compared to 28.19–39.04% in fresh samples. Crude protein (19.80–21.71%) and crude fibre contents increased after drying, while ash content showed slight variation. Carbohydrate content increased markedly in dried samples (28.08–50.84%) due to moisture loss. Vitamin C and β-carotene contents decreased significantly following drying, with values ranging from 4.17–6.84 mg/100 g and 0.95–13.25 mg/100 g, respectively, reflecting the heat sensitivity of these vitamins. Mineral contents, including potassium (353.30–524.12 mg/100 g), iron (0.67–4.50 mg/100 g), zinc (0.60–3.86 mg/100 g), and calcium (82.71–802.00 mg/100 g), were higher in dried okra than in fresh samples, attributable to concentration effects following dehydration. Microbiological analysis showed total aerobic plate and fungal counts within acceptable limits for all samples, although solar-dried okra exhibited relatively higher microbial loads compared to oven-dried samples. Predominant microorganisms identified included Lactobacillus, Bacillus, Pseudomonas, Proteus, Enterobacter, and Escherichia coli. Overall, oven drying at 50 °C emerged as the most effective method, offering superior retention of nutrients and better microbial quality, while solar drying provided acceptable preservation under controlled conditions. These findings demonstrate that appropriate drying techniques can enhance the shelf life, nutritional quality, and safety of dried okra, supporting its suitability for household and small-scale soup production.