Абстрактный

Effects of different drying methods on selected essential macro-mineral contents of four vegetable leaves

Aderonke MOSURO

The high nutrient content, all year-round availability and selfpropagating nature of green leafy vegetables (GLV) in tropical climates make them a viable nutritional option for humans and livestock. Their inherent high moisture is however a major barrier to potential preservation, packaging, storage and inclusion in dietary formulation. Effective dehydration without significant losses to inherent nutrients such as vitamins, minerals, amino acids and energy is a major challenge where GLV are concerned. This experiment was conducted to identify the drying method with the least impact on the macro-mineral profile of seven leafy vegetables. Five essential macro-mineral profiles of seven phytonutrients-rich GLV (Telfaria occidentalis, Celosia argentea-green, Vernonia amygdalina, Moringa oleifera, Launea taraxacifolia, Curcubita maxima, Celosia argentea-red) were investigated in this study using 3 × 7 factorial arrangements in a completely randomized design. Samples were air-dried (AD), oven-dried (OD) and freeze-dried (FD) The dried, milled GLV leaves were assayed for calcium, magnesium, phosphorus, potassium and sodium. Data were subjected to ANOVA at α0.05. Calcium (0.23%), magnesium (0.27%), phosphorus (0.34%), potassium (0.59%) and sodium (0.17%) in AD samples and 0.23% (calcium), 0.17% (sodium) in FD samples were higher (P<0.05) than all other FD and OD samples. 0.26% (magnesium), 0.58% (potassium) and 0.33% (phosphorus) in FD samples were similar to 0.21% (calcium) and 0.16% (sodium) in OD samples. Least (P<0.05) values of 0.25% (magnesium) 0.30% (phosphorus) and 0.58% (potassium) were in OD samples. Significant interactions of drying methods and leaf types were observed on macro-mineral profiles of GLV in this study. The three selected drying methods successfully preserved inherent macro-minerals, but Air Drying was the preferred method