A COMPARATIVE STUDY ON PROXIMATE AND MINERAL COMPOSITION OF UNPROCESSED AND PROCESSED UNDERUTILIZED JERUSALEM ARTICHOKE TUBER FLOUR

Jerusalem artichoke is one of the underutilized tuber crops distributed worldwide in temperate areas. It is considered healthy and functional food due to its chemical composition as it contains proteins, mono or poly-unsaturated fatty acids, dietary fibers, vitamins, and minerals. In this present research work, the effect of processing on the proximate and mineral composition of Jerusalem artichoke tuber flour (JATF) was studied. The proximate analysis was determined in accordance with AOAC, while mineral estimation was done by the atomic absorption spectrophotometer. The result of the proximate analysis revealed that blanching with sun drying registered a significant increase in fiber content and insignificant reduction (p<0.05) in ash and protein content while it caused a substantial decrease in fat and carbohydrates values when compared with unprocessed-JATF samples. However, autoclaving with sun drying showed insignificant reduction only in ash content and a significant decrease (p<0.05) in fat, protein, and carbohydrates values when compared to unprocessed-JATF samples. The mineral analysis results showed that blanching and autoclaving with sun and oven drying caused a significant decrease in iron, magnesium, phosphorus, sodium, potassium, zinc content and showed a significant increase in calcium value at p<0.05 level. In overall consideration, blanching with sun drying appears to be the recommended processing method to obtain nutritive tuber flour since it caused an insignificant reduction in protein content and a significant decrease in mineral content but had a significantly higher amount of mineral content than autoclaving techniques.