Approximate Analysis and Determination of Chitin Content in Some Insects Used In Poultry Nutrition

Nowadays, there is an abundant interest in the use of insects in poultry and livestock nutrition. All insects produce chitin-based exoskeletons. A precise determination of chitin content of insects is necessary because of its application in various industries and poor digestion in some livestock. Therefore it is necessary to specify their skeleton composition including chitin. Due to the structure of chitin and insolubility in common solvents, the measurement of this compound is difficult and undertaken by estimation. In this study, two different methods are used and compared for chitin content measurement of insects. The experiment was carried out using six different samples of insects including larva of darkling beetle (mealworm) (Tenebrio molitor), crickets (Gryllodes sigillatus), honey bee (Apis mellifera meda) and varieties 31, 51 and 107 of silkworm (Bombix mori). In the first method, chitin content was estimated by measuring the acid detergent fiber. In the second method, the chitin measured by chemical purification method. The measured chitin contents by chemical purification were 12.05%± 0.071 for honey bee, 8.18%± 0.259 for mealworm, 7.79% ± 0.107 for cricket and 7.92% ± 0.058, 4.93% ± 0.091, 6.08% ± 0.116 for variety 31, 51 and 107 of silkworm samples respectively. Due to the recommended maximum amount of chitin in poultry feed at the level of 7g/kg and effect of chitin in determination of total protein, measurement of chitin before usage in feed is necessary and according to the obtained results, for determination of chitin content use of chemical purification method is recommended.