Determination of Carbohydrate Composition in Mealworm (Tenebrio molitor L.) Larvae and Characterization of Mealworm Chitin and Chitosan

Abstract

Mealworm (Tenebrio molitor L.) is a classic edible insect with high nutritional value for substituting meats from vertebrates. While interest in mealworms has increased, the determination of carbohydrate constituents of mealworms has been overlooked. Thus, the aim of the present study was to investigate the carbohydrate content and composition of mealworms. In addition, the characteristics of mealworm chitin were determined as these were the major components of mealworm carbohydrate. The crude carbohydrate content of mealworms was 11.5%, but the total soluble sugar content was only 30% of the total carbohydrate content, and fructose was identified as the most abundant free sugar in mealworms. Chitin derivatives were the key components of mealworm carbohydrate with a yield of 4.7%. In the scanning electron microscopy images, a lamellar structure with α-chitin configuration was observed, and mealworm chitosan showed multiple pores on its surface. The overall physical characteristics of mealworm chitin and chitosan were similar to those of the commercial products derived from crustaceans. However, mealworm chitin showed a significantly softer texture than crustacean chitin with superior anti-inflammatory effects. Hence, mealworm chitin and chitosan could be employed as novel resources with unique advantages in industries.

Systematic Studies on the Antioxidant Capacity and Volatile Compound Profile of Yellow Mealworm Larvae (T. molitor L.) under Different Drying Regimes

“…At least this is reflected in the colour evaluation of this study, which shows that the rack oven-and high-frequency dried larvae were the darkest samples. In addition to free amino acids, amino sugars (e.g., D-glucosamine (chitosan monomer) or N-Acetyl-D-glucosamine (chitin monomer)) [23,56] or proteins typically found in the larvae/insects [71] might contribute to non-enzymatic browning reactions during drying. The aforementioned study from Grossmann et al [71] reveals alterations of partially proteolyzed mealworm extracts under Maillard conditions toward more complexity, both in gas-chromatographyolfactometry and in sensory evaluation.…”

“…T. molitor breeding and harvesting ranges nowadays from small to large-scale automated mass approaches [18][19][20] and almost any of the steps from insect rearing to the edible products is addressed from economical, food safety and nutritional quality perspectives [15,16,21,22]. Mealworms are generally high in protein (30-65% of dry matter), carbohydrates (2.2-11.5% of dry matter), fat (10-30% of dry matter) and particularly rich in unsaturated fatty acids [9,23]. This macro-composition and the high moisture content of fresh larvae with a water activity near to 1 favours lipid oxidation and non-enzymatic Maillard browning reactions already during the drying procedure [24].…”

Optimized Clarification Technology of Bayberry Juice by Chitosan/Sodium Alginate and Changes in Quality Characteristics during Clarification

“…Determination of total soluble solids was performed by a pocket Brix-Acidity meter (PAL-BXIACID F5, Atago Co. Ltd., Tokyo, Japan) as previously described [ 6 ]. The carbohydrate content was analyzed, according to phenol-H 2 SO 4 colorimetric method described by Zhu et al [ 1 ] and Son et al [ 16 ], with some modifications. The juice sample (2 μL) was diluted in 1998 μL water, then mixed with 1 mL phenol solution (6% v/v ) and 5 mL sulfuric acid.…”

Tenebrio molitoras a source of interesting natural compounds, their recovery processes, biological effects, and safety aspects

“…In addition, Son et al highlighted the excellent antiinflammatory effects of chitin and chitosan obtained from TML, tested in the lipopolysaccharide (LPS)-induced murine macrophage cells. In particular, TM chitosan showed notable nitric oxide reduction activity on the macrophage cells, with an efficacy relatively higher than that achieved by using chitosan obtained from other animal sources (Son et al, 2021). Nitric oxide is a soluble endogenous gas produced by immune myeloid cells, like macrophages, in response to inflammatory signals for pathogen killing (Palmieri et al, 2020).…”