Nutrient composition of the Indonesian sago grub (Rhynchophorus bilineatus)

Abstract

The sago grub (Rhynchophorus bilineatus) [Montrouzier, Coleoptera, Dryophthoridae] is a local delicacy in the Papua Province in Indonesia. In this study, the nutrient content of the edible insect was measured using chromatographic and spectrometric methods. The results showed that it contains 10.39 g protein and 17.17 g oil/ 100 g fresh weight. The sago grub meets the FAO/WHO requirements of 40% essential amino acids and a 0.60 ratio between essential to non-essential amino acids. Its limiting amino acid is methionine + cysteine. The major fatty acids found in the sago grub are palmitic (42%), oleic (45%), and linoleic (3%) acids. Although vitamin E is exclusively produced by photosynthetic organisms, a gram of sago grub oil contains 51 μg vitamin E, which is composed mainly of tocopherols (92%). In contrast with palm oil, the sago grub oil contains δ-tocopherol (0.12 μg/g oil), and a significantly high amount of β-tocopherol (3.85 μg/g oil). It is a source of zinc and magnesium and contains safe levels of heavy metals. Based on these nutritional properties, the Indonesian sago grub can be considered as a good source of nutrients, and its propagation and utilization should be encouraged especially in other areas of Indonesia and maybe in neighboring countries where they are also endemic, and where malnutrition is prevalent. The consumption of edible insects should be considered as a component of dietary diversification – a sustainable way of alleviating the nutritional status of the population.