Palatability Enhancement Potential of Hermetia illucens Larvae Protein Hydrolysate in Litopenaeus vannamei Diets

David Terrey,Ivan Tankovski,Eric Schmitt,Jack James,Arpita Chakraborty,Michel Van Spankeren,Aman Paul,Monika Dalim

doi:10.3390/molecules26061582

Abstract

Marine feed ingredients derived from cephalopods (e.g., squid) and crustaceans (e.g., krill) are commercially used to improve the palatability of shrimp diets. Increase in global demand for shrimps has resulted in overfishing of these marine organisms and is a matter of concern. Insect protein hydrolysate could be a sustainable alternative for the possible replacement of these marine feed ingredients. During this study, four formulations: diet A (control: not containing any palatability enhancer), diet B (containing squid meal and krill oil), diet C (containing 1% insect protein hydrolysate), and diet D (containing 2% insect protein hydrolysate) were tested for (1) time required by first subject to begin feeding (time to strike) and (2) palatability in Litopenaeus vannamei. Additionally, the chemical composition of all four diet formulations was also analyzed. Results indicate that all diets had similar crude composition. The major essential amino acids in all diets were leucine and lysine, whereas eicosapentaenoic acid was the major omega-3 fatty acid in all diets. There were no significant differences between the mean time to strike for all the tested formulations. Palatability of tested formulations was found in the following order: diet D > diet C > diet B = diet A (p < 0.05), indicating that addition of squid meal and krill oil has no effect on palatability in comparison to control, whereas inclusion of insect protein hydrolysates significantly improves the palatability of formulations. Palatability enhancement potential of insect protein hydrolysate could be attributed to the high free amino acid content and water solubility in comparison to squid meal.

Highlights

Around 15 million tons of whole fish is used for the production of fishmeal [1].These figures have raised serious concerns related to the overfishing of pelagic fishes that are used for the production of fishmeal [2]
The current study reports the evaluation of palatability aspects of insect protein hydrolysate by replacement of squid and krill derived ingredients in L. vannamei diets
Molecules that can interact with these crustacea chemoreceptors to generate positive response are known to effectively enhance palatability

Summary

Introduction

Around 15 million tons of whole fish is used for the production of fishmeal [1] These figures have raised serious concerns related to the overfishing of pelagic fishes that are used for the production of fishmeal [2]. Researchers and industries are currently evaluating the potential of plant proteins (mainly soymeal) for the partial substitution of fishmeal in aquaculture feed formulations [3]. In order to overcome this challenge, companies are currently including other marine feed ingredients (e.g., squid and krill derived ingredients) for palatability improvement. These ingredients contain molecules such as short chain peptides, free amino acids, etc., that are recognized by the sensory system of crustaceans for the location and oral ingestion of feed [3]. Researchers believe that overfishing combined with deteriorating environmental conditions could push the population below critical levels [7]

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