Edible insects have recently attracted research attention due to their nutritional value and low environmental footprint. Tenebrio molitor larva was the first insect species to be classified by European Food Safety Authority (EFSA) as safe for human consumption. However, it is thought that the incorporation of edible insect as an ingredient in a food product would be more appealing to consumers than being visible. The aim of the present study was to determine the physicochemical properties of the larvae meal and protein concentrates. Different methods to extract and recover proteins from defatted (DF) Tenebrio molitor larvae were applied; i.e., alkaline extraction (DF-ASP); isoelectric precipitation after alkaline extraction (DF-AIP); and NaCl treatment (DF-SSP), and the obtained protein fractions were characterized. The DF-ASP exhibited the highest protein extraction/recovery efficiency (>60%), while it was the most effective in decreasing the interfacial tension at the oil/water (o/w) interface. The DF-AIP had the highest protein content (75.1%) and absolute values of ζ-potential and the best ability to retain water (10.54 g/g) and stabilize emulsions at pH 3.0. The DF-SSP protein preparation had the highest oil binding capacity (8.62%) and solubility (~88%) at acidic pHs and the highest emulsifying activity (~86 m2/g). Electrophoresis of the protein preparations revealed proteins with different molecular weights, while the protein secondary structure was dominated by β-structures and α-helix. Protein concentrates with different properties were able to be recovered from Tenebrio molitor larvae, that could affect their interactions with other food ingredients and their behavior during processing or storage. These findings would be valuable guidance for the technological exploitation of larvae protein preparations in the development of food formulations.
Edible insects are considered among the most promising sustainable sources of protein to address the predicted deficiency of conventional food protein. Due to their nutritional and environmental benefits, there is an increasing interest in the ways insects could become part of the Western diet. Little is known about Greek consumers’ attitudes toward the habit of consuming insects as food. This study provides insight into Greek consumers’ preferences for insect-based food products. The data were collected through an online questionnaire (n = 1531). A two-step cluster analysis and a categorical regression were employed to classify the respondents into discernible clusters and determine the relationship between their socioeconomic characteristics and their willingness to adopt insect-based food products. Feelings of disgust and rejection were the predominant reactions to the concept of insects as food. The acceptance of novel foods derived from edible insects could be potentially enhanced by providing information regarding their positive effects, using familiar food products, and decreasing the insect’s degree of visibility by employing processed forms. Finally, the categories of insect protein-enriched food products (bakery, meat, snacks) that Greek consumers are more likely to consume were revealed. Such findings may be useful for promoting strategies regarding consuming insect-based products.