Contents lists available at ScienceDirect Journal of Food Composition and Analysis journal homepage: www.elsevier.com/locate/jfca Original Research Article Effect of developmental stage on the nutritional value of edible insects. A case study with Blaberus craniifer and Zophobas morio Martin Kulma a, *, Lenka Kouřimská b , Dana Homolková b , Matěj Božik c , Vladimír Plachý b , Vladimír Vrabec a a Department of Zoology and Fisheries, Czech University of Life Sciences, Prague, Kamýcká 129, 165 00, Praha-Suchdol, Czech Republic b Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences, Prague, Kamýcká 129, 165 00, Praha-Suchdol, Czech Republic c Department of Quality of Agricultural Products, Czech University of Life Sciences, Prague, Kamýcká 129, 165 00, Praha-Suchdol, Czech Republic ARTICLE INFO Keywords: Death’s head cockroach Edible insects Fatty acid composition Hemimetabolous Holometabolous Protein quality Superworms ABSTRACT As the demand for sustainable, cost-effective food production increases, edible insects are an important alter- native to traditional livestock as a source of human food. Understanding the differences in the nutritional composition of edible insects is essential for the optimization of rearing process. This study investigated the effects of developmental stage on the quantity and quality of nutrients in “superworms” (Zophobas morio), and the death’s head cockroach (Blaberus craniifer). Superworms at 60, 90, and 120 days of age showed no significant variation in basic nutrient content, and no significant differences were found in protein quality (expressed as the essential amino acid index). In contrast, adult cockroaches contained significantly more digestible protein than either small or large nymphs, but of lower quality. Cockroach nymphs contained significantly higher amounts of fat than the adults, and the lipid quality (described by the atherogenicity and thrombogenicity indices) increased over time. Conversely, the lipid quality of superworm larvae decreased with age. The study provides a better understanding of the chemical composition of insects over their lifespan and may help to optimize rearing technology in order to harvest insects as high-quality nutritional biomass, facilitating their application as a potential food source for humans. 1. Introduction The per capita food consumption of the increasing global population currently places a significant burden on the agricultural sector, and many resources are overexploited. Moreover, intensive agriculture is one of the main contributors to climate change and biodiversity loss (Herrero et al., 2015; Newbold et al., 2015; Ramankutty et al., 2018). These facts highlight an urgent need to find an alternative and sus- tainable protein source to feed the world, and insects are considered to be a potential food source. In comparison with conventional livestock farming, insect farming is believed to be more environmentally friendly as it produces lower gas emissions and requires less space, water, and feed (van Huis and Oonincx, 2017). Further, insects have been shown to be a safe source of high-quality nutrients (Payne et al., 2016; Stull and Patz, 2019). However, some commonly consumed species contain substances that can cause allergic reactions in predisposed individuals, such as serine and aspartic proteases, chitinases, calycin, troponin, tropomyosin, arylphorin, glutathione-S-transferase, and chitin (Patel et al., 2019). Therefore, safety-related factors, including the potential for allergic reactions, microbial contamination, and toxicological ha- zards, should be high-priority research areas when contemplating the intensive rearing of insects for human consumption (Raheem et al., 2019). Worldwide, there are around one million known insect species, all of which play a crucial role in food chains and whole-ecosystem func- tioning. Although the majority of Western society still considers insects to be noxious pests, rather than a protein source, almost 2000 insect species are consumed traditionally in more than 100 countries throughout the world, predominantly in Africa, Asia, and Latin America (Durst et al., 2010). However, a willingness to accept insect protein as https://doi.org/10.1016/j.jfca.2020.103570 Received 19 October 2019; Received in revised form 3 June 2020; Accepted 8 June 2020 Abbreviations: CP, crude protein; CHCP, chitin-chained protein; DM, dry matter; DPC, digestible protein content; E, energy; EAA, essential amino acid; EAAI, essential amino acid index; FA, fatty acid; IA, index of atherogenicity; IT, index of thrombogenicity; MUFA, monounsaturated fatty acids; NFE, nitrogen-free extract; PUFA, polyunsaturated fatty acids; SFA, saturated fatty acids; TF, total fat ⁎ Corresponding author. E-mail addresses: kulma@af.czu.cz (M. Kulma), kourimska@af.czu.cz (L. Kouřimská), homolkova@af.czu.cz (D. Homolková), bozik@af.czu.cz (M. Božik), plachy@af.czu.cz (V. Plachý), vrabec@af.czu.cz (V. Vrabec). Journal of Food Composition and Analysis 92 (2020) 103570 Available online 18 June 2020 0889-1575/ © 2020 Elsevier Inc. All rights reserved. T