Effect of processing on nutritional and sensory quality of orange-fleshed sweet potato’s porridge and Ugali (stiff-porridge) consumed in the Lake Zone, Tanzania

Abstract

The orange-fleshed sweet potato (OFSP) is a nutrient-rich crop with high β-carotene content, which helps prevent vitamin A deficiency (VAD). However, its semi-perishability requires proper processing to preserve its nutritional and sensory properties. This study assessed the effects of sun and solar drying on the proximate composition, β-carotene, vitamin C, mineral content, and sensory attributes of OFSP porridge and Ugali (stiff porridge) consumed in the Lake zone of Tanzania. Three variety of OFSP; Ejumla, Jewel, and Carrot Dar, were subjected to solar or sun-drying and subsequently processed into flour. The resulting flours were used to produce porridge and Ugali (stiff porridge). Conventional techniques were employed to evaluate the proximate composition, β-carotene, vitamin C, and micronutrient content of porridge and Ugali (stiff porridge). Additionally, sensory analysis was performed to assess the level of acceptability of the items' sensory qualities. There was a significant difference in moisture content, crude protein, and crude fat between porridge and Ugali (stiff porridge) for all three varieties of OFSP (p<0.05). Moreover, solar-dried products had higher retention of β-carotene (28.79 mg/100 g) and vitamin C (3.29-10.45 mg/100 g). Sun-dried products had lower mineral content than solar-dried products. There was also a significant difference (p<0.05) between solar and sun-dried products in all tested essential minerals. The nutrients analyzed were more concentrated in stiff porridge than in regular porridge, such as calcium (21.65mg/100g), potassium (90.70mg/100g), Sodium (169.98mg/100g), magnesium (13.26mg/100g) and zinc (0.51mg/100g). Solar-dried items had the highest acceptability scores (3.0–3.9) compared to sun-dried products, with Ejumla being the most preferred. The findings depict that solar drying preserves OFSP-based food's nutritional and sensory quality better. Solar-dried OFSP may reduce vitamin A deficiency (VAD) and improve nutritional security in Tanzania.

Description

Journal Article

Keywords

OFSP, Solar Drying, Sun-drying, Ugali, Porridge, Proximate Composition, β-carotene, Vitamin C, Mineral Content

Citation

https://doi.org/10.11648/j.jfns.20251303.12