Fat from Tenebrionidae Bugs - Sterols Content, Fatty Acid Profiles, and Cardiovascular Risk Indexes

Abstract

It is a good source of protein and fat. The highest protein content (637.0-676.5 g/kg in dry matter (DM)) and lowest fat content (148.8-184.0 g/kg DM) was determined in adult specimen. However, larvae and pupae are more nutritionally benefi cial because of their better digestibility and sensory properties. For larvae, the total protein content is usually reported in the range from 477.6 to 527.0 g/kg DM and total fat content from 189.0 to 382.9 g kg DM. Sterols are key nutritional elements of insects. They are precursors of steroid hormones and development process regulators [Mondy et al., 2006]. Phytosterols, typical plant sterols, were found in insect samples [Piironen, 2000], because insects cannot synthesize cholesterol de novo [Behmer & Nes, 2003] and have to use plant phytosterols (β-sitosterol, campesterol, stigmasterol) to synthesize cholesterol. Cholesterol is the most abundant sterol present in insects. Mealworm (Tenebrio molitor) sterols contain about 17% of 7-dehydrocholesterol and about 67% of cholesterol [Ikekawa et al., 2013]. Insects need cholesterol to synthesize vitamin D 3 and steroid hormones known as ecdysteroids. These hormones are indispensable for the individual developmental stages of the instar [Nation, 2001; Klowden, 2007]. Cholesterol is found in foods of animal origin, but it is also the only sterol the human body can synthetize by itself. Too high cholesterol intake causes increased levels of low-density

Fatty and amino acid profile of mealworm larvae (Tenebrio molitor L.)

“…Our results of fatty acid profile are in accordance with the findings of Zielinska et al (2015), who compiled the nutritional composition of mealworm larvae and found content of oleic acid (40.86%) and linoleic acid (29.68%) as well as palmitic acid (18.0%). Similar results have also been found by Mlcek et al (2019) for palmitic (18.6%) and oleic acid (36.9%), while the content of linoleic acid was much higher (30.9%). The contents of palmitic, linoleic and eicosanoic acid were in close agreement with previous report of Gnosh et al (2017) that amounted to 4.71; 7.57 and 0.2 g/100 g DM, respectively.…”

Agri-Food Side-Stream Inclusion in The Diet of Alphitobius Diaperinus. Part 2: Impact on Larvae Composition

“…Essential fatty acids' linoleic acid (C18:2) and linolenic acid (C18:3) represented about 22-41% and 0.6-2.6% of the total fatty acids measured. This corresponds well with other published data on the LM (17-36% for C18:2 and 0.4-0.7% for C18:3 [6]) and the YM (23-31% for C18:3 and 0.6-1.1% for C18:3 [23]). The total saturated fatty acids (SFA) ranged between 28 and 75 g/kg, the total monounsaturated fatty acids (MUFA) between 39 and 88 g/kg and the total polyunsaturated fatty acids (PUFA) between 23 and 91 g/kg.…”

“…This could imply that the larvae of these trials were not yet mature and thus in another larval stage. As the composition, and especially the lipid content, of the larvae can differ between development [23,24] a lower larval yield corresponded in some cases (diets 5 and 6) with a lower lipid content, explaining the large variance in lipid content. Yet, diets 3 and 4 also resulted in a low larval yield, but an average lipid content was measured.…”

Nutritional value of insects and ways to manipulate their composition

“…Total sterol content and the variation seems a function of species, diet, life stage and season (Connor et al, 2006;Koštál et al, 2013;Liland et al, 2017). While insects contain a variety of sterols often β-sitosterol, cholesterol, or 7-dehydrocholesterol are the most abundant (Cerda et al, 2001;Cheseto et al 2015;Connor et al, 2006;Jing and Behmer, 2020;Koštál et al, 2013;Liland et al, 2017;Mlček et al, 2019;Sabolová et al, 2016;Svoboda et al, 1995). High dietary levels of sterols, such as cholesterol, can increase the risk of atherosclerosis in humans and some species of monkeys (Hopkins, 1992;Rudel et al, 1998).…”