Potential of Edible Seaweed of the Kenyan Coast as a Micronutrient Source

Abstract

For centuries, Algae case in point seaweed has been harvested and used for its nutrition benefits in East Asia and western countries but irregularly in Kenya. When compared to plants growing on land or animal food sources, consumption of seaweed as micronutrient source may contribute towards dietary diversification and alleviation of micronutrient deficiencies due to its high micronutrients content. Despite seaweed availability in Kenya farming has just recently been encouraged and supported by the Kenya Blue Economy citing its huge potential. Main objective of the study was to determine the potential of edible seaweeds found at the Kenyan coast as a micronutrient source. Comparative experimental design where 175 seaweed farmers from 5 villages of Kwale County were interviewed and 58 seaweed samples were randomly collected from 5 beaches in Mombasa, Kilifi and Kwale counties. Socio-demographic and seaweed consumption data was collected, presence of micronutrients (Vitamin A, D, B9, B12, Iron, Zinc, Iodine) and heavy metals (Mercury, Lead, Arsenic, Cadmium) was also determined. Seaweed farmers were majorly women (68%) between the ages of 30-40 years (p-value 0.014) with majority (90.8%) having attained upper primary and below. Average income levels per harvest of farmed seaweed ranged from $83-166, price per kg was approximately $0.25. Seaweed farming was practices majorly for purposes of income generation (74.7%) rather than consumption purposes (2.9%) (p-value= 0.043). Consumption was less than once per week (52.1%) with an average serving of 50-100 grams per day (74.4%) (p-value=0.034) preferring the cooked form to the dried or fresh seaweed. Slightly less than two thirds (59.9%) attributed lack of nutritive knowledge as main reason for low consumption, followed by fear of contamination (21.7%) (p-value=0.033).Edible seaweed species included 11 Phaeophyceae (Sargassum, Turninaria, Dictyota, Padina and Eucheuma), 9 Chlorophyta (Ulva and Caulerpa and Eucheuma) 8 Rhodophyta (Gracilaria Hypnea, Soliera and Eucheuma). Seaweeds found in Kilifi had highest mean levels of all tested vitamin, Vitamin B12 (464.9±203.6)g/100g (p-value=0.031),Vitamin A (146.0±49.7)g/100g (p-value=0.047) and Vitamin D (33.4±30.2)g/100g (p-value=0.006) while seaweeds found in Kwale county recorded highest mean levels of Iron (269.9±154.6)mg/kg (p-value=0.047). Mean levels of Vitamin B12 (306.5±287.9)g/100g, D (18.8±24.3)g/100g, Zinc (53.3±60.8)g/100g and Iodine (41.0±34.1)g/100g highest in the Green seaweed Vitamin B9 (73.0±122.3) and A (102.4±104.8) and Iron (274.0±158.6) highest in the Red seaweed, however no significance in difference in vitamin and mineral levels in relation to seaweed phyla was noted. Farmed Eucheuma cotonii (Kappaphychus alvarezii) recorded highest levels of Vitamin B12 (696.6g/100g) and Vitamin A (298.6g/100g), whereas Hypnea cornuta recorded highest levels of Vitamin B9 (153.1g /100g).Caulerpa fastigiata recorded highest level of Vitamin D (77.63g /100g). Ulva intestinalis recorded highest levels of Iron(637.85mg/kg). Caulerpa taxifolia had highest level of Zinc (277.74mg/kg) and Iodine (142.8mg/kg). Mean Lead levels (0.774mg/kg) were highest in species found in Kilifi county whereas mean Cadmium levels (0.021mg/kg/) highest in Mombasa county. Mean Lead levels (0.56mg/kg) were highest in Brown seaweed whereas mean Cadmium levels (0.025mg/kg/) highest in Green seaweed. Caulerpa taxifolia recorded highest levels of Lead (2.0575mg/kg) and Cadmium (0.123mg/kg). Mercury was detected in only 4 species whereas Arsenic metal wasnot detected in all species...