Sustainable biopackaging solutions from Hermetia illucens chitosan, proteins, and lipids

Project Plan

• Black soldier fly rearing: BSF larvae were reared on various biological substrates derived from agri-food by-products supplied by local companies. The existing BSF rearing at UNIBAS were enhanced through the integration of artificial intelligence systems to optimise all the bioconversion phases.
• Larvae biomass harvesting: At the end of the larval feeding, larval biomass (rich in proteins and lipids) and waste biomasses from rearing (pupal exuviae and adults) were collected separately.
• Extraction of chitosan, proteins, lipids and chitosan production and characterization: Pupal exuviae and dead adults were employed for chitosan extraction and for subsequently chitosan production using both chemical methods and innovative green methodologies. After the physical-chemical characterization of the produced chitosan, the antimicrobial and antioxidant activity were evaluated. Proteins were extracted through alkali treatment followed by a precipitation step in an acid solution to ensure denaturation. Lipids were extracted from BSF larvae using both chemical methods and environmentally friendly techniques. The activity of chitosan, lipids and proteins on gut commensal bacteria and any deleterious effect on intestinal cellular model systems were evaluated.
• Edible coating with polyphenolic enriched chitosan: Given the successful testing of edible coatings using BSF chitosan compared to commercial chitosan on certain fruits, an edible coating enriched with extracts from fruit by-products were formulated and tested on fresh fruits. The biochemical and physiological processes of the resulting fruit coating were monitored during the storage period.
• Chitosan-proteins-lipids-based films: Besides the edible coating, chitosan served as a biomaterial for innovative food packaging, together with proteins and lipids derived from BSF larvae. The biomolecules were combined to create functional multilayer films. The resulting multilayer films underwent mechanical and physical characterisation (by both standard and advanced tests) to evaluate the properties that directly affect their manufacture and use. The formulation with the best performances were selected as the pilot packaging.
• Prototypes of paper or PLA coated with chitosan for food packaging: Chitosan formulations were applied as coatings on the most promising flexible substrates (PLA and paper) in terms of sustainability and end-of-life disposing. The developed coatings aimed to introduce novel properties to both PLA and paper, thereby expanding the range of products in which these materials can serve as primary packaging. Indeed, the chitosan-based coatings enhanced the oxygen barrier properties of PLA and exhibit antimicrobial effects. The resulting prototypes of PLA and paper coated with BSF-produced chitosan formulas underwent comprehensive chemical and physical characterisation.

The achieved results were the following:

• Rearing of Hermetia illucens larvae on fruit by-products: peach, orange, lemon and apple.
• Selection of the most suitable hardware technologies and AI methodologies.
• The hardware–software architecture for data collection was built and made operational. This includes the physical installation of sensors (N, P, K, pH, temperature, humidity) and the infrared camera.
• Continuous data collection was initiated according to defined experimental protocols (e.g., testing different substrate depths and humidity levels), generating the necessary dataset for the next phase.
• The two artificial intelligence systems were developed from scratch and trained: the LSTM Autoencoder for analysing sensor time-series data and the computer vision pipeline for analysing infrared images.
• The two AI models were integrated to enable multimodal analysis, combining sensory and visual data.
• Test on antimicrobial activity of fruit bioactive compounds.
• Extraction and characterization of H. illucens components (the antimicrobial and cytotoxic activities were evaluated).
• Biofilm production (at laboratory scale) started from chitosan produced from chitin extracted from pupal exuviae and adults of H. illucens and protein extracted from larvae of H. illucens.
• Characterization of produced biofilm.
• Peaches, apricots and nectarines were treated with enriched chitosan coating and, after the treatment, nutraceutical components were evaluated.
• Evaluation of physico-chemical and nutraceutical properties of apricot preserved in an innovative packaging based on chitosan produced from chitin extracted from pupal exuviae and adults of H. illucens.
• Development of flexible packaging prototypes based on paper substrates functionalized with insect-derived molecule coatings. Preliminary trials with PLA substrates, even after corona treatment to enhance surface wettability, demonstrated incompatibility with the coating formulations. Prototype preparation was performed at laboratory scale using a rod coating technique.

The obtained materials were subsequently characterized in terms of grease resistance, mechanical performance, water uptake, coefficient of friction, and oxygen barrier properties, in order to establish the property range and evaluate the technological potential of the developed packaging solutions.