Analysis Of Beetroot Bulbs (Beta Vulgaris) From Selected Geographical Regions In Kenya: Contents Of Essential Nutritional Elements

Abstract

Beetroot is the taproot part of a Beet plant, which is among one of the several cultivated varieties of Beta Vulgaris. It has medicinal value especially for cardiac and cancer treatment. It is also a potential antioxidant and blood cell count booster. Other uses include; source of nutrients, sugars and as a livestock feed. Beetroot is not a popular vegetable among most Kenyans, but is occasionally used as a blend in juices and salads. In this study, thirty-four (34) beetroot bulb (Crimson globe variety) samples were collected, from selected areas in Karatina, Naivasha, Gilgil, Kisumu and Joska-Machakos. The samples were analysed for potassium, calcium, iron, manganese and zinc using Energy Dispersive X-ray Fluorescence (EDXRF). EDXRF method of analysis is used worldwide for elemental analysis since it is a fast, easy, reproducible and non-destructive. Prior to analysis, the bulbs were dried in the oven for 56 hours at 60oC to constant weight, ground, and sieved using a 75-micron sieve to homogenize them. Approximately 0.5-0.6 g of the powder sample was prepared into thin pellets, with a diameter of 25mm and analysed for essential elements using EDXRF. The results of the concentration of the essential elements had a range of: 11000 mg kg-1 to 50000 mg kg-1 for potassium, 94.0 mg kg-1 to 4500 mg kg-1 for calcium, 36.0 mg kg-1 to 230 mg kg-1 for manganese, 12.0 mg kg-1 to 770 mg kg-1 for iron and 14.0 mg kg-1 to 680 mg kg-1 for zinc. In general, the trend in the concentration levels of the essential elements was K > Ca > Fe > Mn > Zn. Karatina beetroot samples recorded the highest concentrations for all the elements of interest in the study. The results of Analysis of variance (ANOVA) for all the five sampled regions show that there is a significant difference in the Ca, Fe and Mn concentration levels. In general, the concentration of essential elements in beetroots are comparable to those found in most commonly consumed tubers and leafy vegetables. Beetroots were found to contain sufficient amounts of the essential elements, therefore, are a suitable vegetable source of essential elements and can be used as an immune system booster. In addition, the study recommends for further research to determine the optimum growing conditions and age of harvesting the beetroot bulbs in terms of bio-accumulation of essential elements. This study is supportive to the Government’s efforts of improving health care and in the fight against “hidden hunger-malnutrition” in the country.