Estimation of nutritional energy values, mineral ratio and mineral safety index in the Royal spiny lobster, Panulirus regius (De Brito Capello, 1864)

Abstract

Royal spiny lobster is a marine crustacean with a significant economic value as a popular consumer product. However, information on the energy-providing nutrients of lobster is scarce, especially on those living in the southern coast of Nigeria. This study provides information about the nutritional quality and metabolizable energy of flesh and shell of the Royal spiny lobster, Panulirus regius. Proximate and mineral compositions were analyzed, while energy contributions, mineral ratio and mineral safety index were estimated. Higher concentrations of moisture, crude protein and fat were recorded in flesh, while crude fibre, total ash, and nitrogen free extract were more in shell. The proximate with the highest values were crude protein (57.71 g100g-1) and total ash (40.67 g100g-1) in flesh and shell samples, respectively. The flesh had higher total metabolisable energy (1375 kJ 100g-1) and utilizable energy due to protein (38.62). The minerals, with the exception of Na, were concentrated more in the shell. In the flesh sample, Na/K and Na/Mg ratios were within the acceptable ideal range of 1.4 – 3.4 and 2 – 6, respectively, while other ratios were below ideal range. In shell samples, Ca/K (3.55) was within the ideal range of 2.2 – 6.2, while Ca/P (5.23) was higher than the reference balance of 2.6. Mg in shell sample was the only mineral whose safety index value (21.85) was higher than the table value (15) with negative difference (-6.85). K, P and Na showed negative relationships with all the proximate compositions except for the moisture and protein in shell sample, while only K showed positive relationships with moisture (???? = 0.68), protein (???? = 0.63), fat (???? = 0.64) and nitrogen free extract (???? = 0.17) in the flesh sample. The flesh and shell of the lobster will be good alternative sources of nutrients in human diet and animal feed, respectively.