The threshold of toxicological concern (TTC) is a pragmatic risk assessment tool that is based on the principle of establishing a human exposure threshold value for all chemicals, below which there is a very low probability of an appreciable risk to human health. The concept that there are levels of exposure that do not cause adverse effects is inherent in setting acceptable daily intakes (ADIs) for chemicals with known toxicological profiles. The TTC principle extends this concept by proposing that a de minimis value can be identified for many chemicals, in the absence of a full toxicity database, based on their chemical structures and the known toxicity of chemicals which share similar structural characteristics. The establishment and application of widely accepted TTC values would benefit consumers, industry and regulators. By avoiding unnecessary toxicity testing and safety evaluations when human intakes are below such a threshold, application of the TTC approach would focus limited resources of time, cost, animal use and expertise on the testing and evaluation of substances with the greatest potential to pose risks to human health and thereby contribute to a reduction in the use of animals. An Expert Group of the European branch of the International Life Sciences Institute-ILSI Europe-has examined the TTC principle for its wider applicability in food safety evaluation. The Expert Group examined metabolism and accumulation, structural alerts, endocrine disrupting chemicals and specific endpoints, such as neurotoxicity, teratogenicity, developmental toxicity, allergenicity and immunotoxicity, and determined whether such properties or endpoints had to be taken into consideration specifically in a step-wise approach. The Expert Group concluded that the TTC principle can be applied for low concentrations in food of chemicals that lack toxicity data, provided that there is a sound intake estimate. The use of a decision tree to apply the TTC principle is proposed, and this paper describes the step-wise process in detail. Proteins, heavy metals and polyhalogenated-dibenzodioxins and related compounds were excluded from this approach. When assessing a chemical, a review of prior knowledge and context of use should always precede the use of the TTC decision tree. The initial step is the identification and evaluation of possible genotoxic and/or high potency carcinogens. Following this step, non-genotoxic substances are evaluated in a sequence of steps related to the concerns that would be associated with increasing intakes. For organophosphates a TTC of 18microg per person per day (0.3 microg/kg bw/day) is proposed, and when the compound is not an OP, the TTC values for the Cramer structural classes III, II and I, with their respective TTC levels (e.g. 1800, 540 and 90 microg per person per day; or 30, 9 and 1.5 microg/kg bw /day), would be applied sequentially. All other endpoints or properties were shown to have a distribution of no observed effect levels (NOELs) similar to the distribution of NOELs for general toxicity endpoints in Cramer classes I, II and III. The document was discussed with a wider audience during a workshop held in March 2003 (see list of workshop participants).

Structure-Based Thresholds of Toxicological Concern (TTC): Guidance for Application to Substances Present at Low Levels in the Diet

Recently, insects have received increased attention as an important source of sustainable raw materials for animal feed, especially in fish, poultry, and swine. In particular, the most promising species are represented by the black soldier fly (Hermetia illucens, HI), the yellow mealworm (Tenebrio molitor, TM), and the common house fly (Musca domestica, MD). Although rapid development is expected, insects remain underutilized in the animal feed industry mainly due to technical, financial, and regulatory barriers. In addition, few works have analyzed consumer and stakeholder points of view towards the use of insects as animal feed. In this article, we summarize the main findings of this body of research and provide a discussion of consumer studies regarding the consumption of animals fed with insects. Our review suggests that consumer acceptance will not be a barrier towards the development of this novel protein industry. Furthermore, we conclude that it will be of interest to understand whether the use of this more sustainable feed source might increase consumer willingness to pay for animal products fed with insects and whether the overall acceptability, from a sensory point of view, will be perceived better than conventional products. Finally, the main challenges of the feed farming industry are addressed.

https://www.mdpi.com/2076-2615/9/4/119/pdf

The Potential Role of Insects as Feed: A Multi-Perspective Review.

Background Fish and other seafoods are highly perishable food products due basically to microbiological growth and lipid oxidation, which are known to be the principal causes of quality deterioration of such products. Therefore, offering safe and high quality seafoods combined with consumers' desire for natural products free from chemical preservatives creates real challenging problems. In the recent past, there has been extensive focus on antioxidant and antimicrobial effects of natural preservatives such as essential oils (EOs), as effective alternative to synthetic additives, in order to enhance oxidative and microbial stability of foods and extend their shelf life. Scope and approach In this review, the main spoilage mechanisms of fish and seafood products and the most common techniques used to preserve quality and extend shelf life of such products are first discussed. The chemistry and modes of action of some selected EOs are then briefly presented. The antioxidative and antimicrobial activities of some common EOs, either alone or in combination with other preservative systems, in fish and other seafoods are reviewed. Finally the limitations and the future trends are shown. Key findings and conclusions Several EOs have shown i) great antimicrobial activities versus many spoilage and pathogenic microorganisms, and ii) remarkable antioxidant powers against lipid oxidation in fish and other seafoods during processing or storage. However, much more works are still required in order to better understand the exact mechanism of action of EOs or their main components, the effective dose, and the best combination strategy.

Essential oils for antimicrobial and antioxidant applications in fish and other seafood products

Consumer demand for minimally processed seafood that retains its sensory and nutritional properties after handling and storage is increasing. Nevertheless, quality loss in seafood occurs immediately after death, during processing and storage, and is associated with enzymatic, microbiological, and chemical reactions. To maintain the quality, several synthetic additives (preservatives) are promising for preventing the changes in texture and color, development of unpleasant flavor and rancid odor, and loss of nutrients of seafood during storage at low temperature. However, the use of these preservatives has been linked to potential health hazards. In this regard, natural preservatives with excellent antioxidant and antimicrobial properties have been extensively searched and implemented as safe alternatives in seafood processing, with the sole purpose of extending shelf-life. Natural preservatives commonly used include plants extracts, chitosan and chitooligosaccharide, bacteriocins, bioactive peptides, and essential oils, among others. This review provides updated information about the production, mode of action, applications, and limitations of these natural preservatives in seafood preservation.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1541-4337.12390

Natural Preservatives for Extending the Shelf-Life of Seafood: A Revisit

In 2018, the industrial compound feed production throughout the world was 1103 metric billion tons, which was an increase of 3% compared to 2017. In order to meet the needs of the increasing population, a further increment in compound feed production is necessary. Conventional protein sources are no longer suitable to completely satisfy the increment of feed production in a sustainable way. Insects are one of the most promising options, due to their valuable nutritional features. This paper reviews the state-of-the-art of research on the use of insect meals and oils in aquatic, avian and other animal species diets, focusing mainly on the effects on digestibility, performance and product quality. In general, insect-derived product digestibility is affected by the insect species, the inclusion levels and by the process. Sometimes, the presence of chitin can lead to a decrease in nutrient digestibility. The same considerations are true for animal performance. As far as product quality is concerned, a dramatic effect of insect products has been recorded for the fatty acid profile, with a decrease in valuable n3 fatty acids. Sensory analyses have reported no or slight differences. Insect-derived products seem to be a good alternative to conventional feed sources and can make an important contribution to the sustainable development of the livestock industry.

https://www.mdpi.com/2076-2615/9/4/170/pdf

Animals Fed Insect-Based Diets: State-of-the-Art on Digestibility, Performance and Product Quality

Lipid oxidation is a very complex and important event threatening the quality of foods especially of those containing highly unsaturated fats. Fish are the main source of polyunsaturated fatty acid...

https://www.tandfonline.com/doi/pdf/10.1080/1828051X.2015.1128687

From farm to fork: lipid oxidation in fish products. A review

Soya bean is the main protein source in poultry feed but rising prices make an alternative protein source necessary. Insects, such as the black soldier fly (Hermetia illucens), may be an attractive solution for hens, although little information is available on their effect on egg quality. The present study aims to fill this gap by testing the effect of 100% replacement of soya bean with H. illucens larva meal in the diet of Lohmann Brown Classic laying hens for 21 weeks. At the end of the trial, the eggs were characterized for parameters such as weight, colour, proximate composition of albumen and yolk, and content of carotenoids, tocopherols and cholesterol. The fatty acid profile of yolks was also determined. Hens fed the insect-based diet produced eggs (HIM group) with a higher proportion of yolk than the group fed the soya bean-based diet (SBM group). HIM was associated with redder yolks (red index 5.63 v. 1.36) than SBM. HIM yolks were richer in γ-tocopherol (4.0 against 2.4 mg/kg), lutein (8.6 against 4.9 mg/kg), β-carotene (0.33 against 0.19 mg/kg) and total carotenoids (15 against 10.5 mg/kg) than SBM yolks. The fatty acid composition of HIM yolks was almost identical to that of SBM yolks. Finally, HIM yolks contained 11% less cholesterol than SBM yolks. These results suggest that H. illucens larva meal is a suitable total substitute for soya bean meal in the diet of Lohmann Brown Classic laying hens. A sustainable alternative to the plant protein source therefore seems feasible.

Quality of eggs from Lohmann Brown Classic laying hens fed black soldier fly meal as substitute for soya bean.

Background The aquafeed sector has been replacing conventional dietary ingredients with more economic and eco-friendly ingredients. Insects embody a promising alternative as a result of being highly nutritious and showing traits leading to a circular bioeconomy. Atlantic salmon (Salmo salar L.) at the sea-water stage were fed diets with a partial or complete substitution of fishmeal with meal of Hermetia illucens larvae reared on a media containing Ascophyllum nodosum mixed with organic wastes (60:40). The present study aimed to assess the quality of fillets by characterizing its physico-chemical traits with conventional and innovative methods, such as the proton transfer reaction-time of flight-mass spectrometer technique, allowing the analysis of samples at room temperature. Finally, steamed fillets underwent a consumer test to investigate the liking of consumers and their intention of re-consumption. Results The main findings showed that a complete dietary substitution of fishmeal with H. illucens larvae meal did not impair the physico-chemical quality of A. salmon fillets. Notably, neutral n-3 polyunsaturated fatty acids (PUFA) slightly but significantly increased in the fillets of A. salmon fed H. illucens, also as a result of the additional fish oil present in the diets containing insect. The volatile organic profile was not altered by the different diets. The consumer-liking test revealed that Italian consumers appreciated the tested salmon irrespective of the administered feed. Conclusion Tailoring the insect fatty acid profile by rearing the larvae on a PUFA-rich substrate, coupled with a dietary modulation of the oily source, can successfully maintain or even increase the cardioprotective characteristics of fillets. © 2019 Society of Chemical Industry.

Total replacement of dietary fish meal with black soldier fly (Hermetia illucens) larvae does not impair physical, chemical or volatile composition of farmed Atlantic salmon (Salmo salar L.)

Dietary inclusion of full-fat Hermetia illucens prepupae meal in practical diets for rainbow trout (Oncorhynchus mykiss): Lipid metabolism and fillet quality investigations

Giulia Secci

Papers

From farm to fork: lipid oxidation in fish products. A review

Quality of eggs from Lohmann Brown Classic laying hens fed black soldier fly meal as substitute for soya bean.

Total replacement of dietary fish meal with black soldier fly (Hermetia illucens) larvae does not impair physical, chemical or volatile composition of farmed Atlantic salmon (Salmo salar L.)

Dietary inclusion of full-fat Hermetia illucens prepupae meal in practical diets for rainbow trout (Oncorhynchus mykiss): Lipid metabolism and fillet quality investigations

Barbary partridge meat quality as affected by Hermetia illucens and Tenebrio molitor larva meals in feeds