Simulated Digestion Status of Intact and Exoskeletally-Punctured Insects and Insect Larvae: A Spectroscopic Investigation

• Published in: Folia primatologica Vol. 74; no. 3; pp. 126 - 140
• Main Authors: Prinz, J.F, Silwood, C.J.L, Claxson, A.W.D, Grootveld, M
• Format: Journal Article
• Language: English
• Published: The Netherlands Brill 01.05.2003; Karger; S. Karger AG
• Subjects: Acheta domesticus; Animal Nutritional Physiological Phenomena; Animals; Animals, Wild; Biochemistry; Biological and medical sciences; Biology; Chitin; Diet; Digestion; Feeding Behavior; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Gryllidae - chemistry; Gryllidae - metabolism; Hydrochloric acid; Insects; Larva - chemistry; Larva - metabolism; Larvae; Magnetic Resonance Spectroscopy; Mammals - physiology; Models, Biological; Nutrition; Primates; Primatology; Reviewed Article; Tenebrio - chemistry; Tenebrio - metabolism; Tenebrio molitor; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Spectroscopy; Biochemistry; Digestion; Insects; Vertebrata; Mammalia; Investigation method; Nutrition; Diet; Chitin; Skeleton; Spectrophotometry; In vitro; Insectivora; Feeding
• ISSN: 0015-5713; 1421-9980
• DOI: 10.1159/000070646

In this study, we tested the hypothesis that puncturing the chitin exoskeleton of insect and insect larvae food sources aids the ingress of digestive fluids and increases the rate of digestion and energy uptake in insectivorous mammals. For this purpose 10 crickets (Acheta domesticus) and 10 mealworms (Tenebrio molitor larvae) were divided into two groups of 5; one group was punctured using a small blade to mimic the effect of a single bite, the remainder serving as controls. The insects were then individually immersed in 5 ml of a1 3 10–2 mol ? dm–3 solution of hydrochloric acid (pH 2.0) for a period of 2 h in order to mimic digestion in the stomach. The matrix was then centrifuged and the supernatant fluid subjected to spectrophotometric and high-resolution proton (1H) NMR analysis. Electronic absorption spectra of these supernatants revealed that puncturing the exoskeleton of mealworms and crickets gave rise to substantial elevations (up to 14-fold) in the concentrations of UV-absorbing biomolecules (p - 0.025 for both species). The 400-MHz 1H NMR profiles of supernatants derived from mealworm and cricket specimens with punctured exoskeletons contained a wide variety of prominent biomolecule resonances, whereas those from unpunctured (control) insects contained signals of a much lower intensity, ascribable only to selected biomolecules. We conclude that puncturing the cuticle of insects and insect larvae prior to swallowing confers significant nutritional advantages over swallowing prey whole.