Introduction and methodology
In recent years, the search for alternatives to fishmeal (FM) and soybean meal (SBM) has highlighted several promising ingredients, including single-cell proteins (SCPs), algae and microalgae, and insect meals, which can support feed efficiency, fish welfare, and health (Serra et al., 2024). However, their high cost may slow adoption in a sector where feed accounts for 30-60% of total production costs (Mulazzani et al., 2021). In this context, processed animal proteins (PAPs) obtained from livestock by-products, particularly poultry- and porcine-derived PAPs, represent a potentially scalable and circular solution. These ingredients can offer a competitive alternative to FM and SBM in terms of growth performance and cost (Wilkinson & Young, 2020). However, less is known about how consumers perceive them. Although insect PAPs have been widely studied, poultry and porcine PAPs remain under-researched in consumer studies. To fill this gap, the present study examines consumer attitudes toward farmed fish fed diets containing poultry and porcine PAPs, using insect-derived PAPs as a point of comparison. Specifically, it addresses the following research questions: (i) what perceptions act as barriers to consumers' willingness to consume fish raised on PAP-based diets?; (ii) to what extent are consumers willing to pay (WTP) a premium for fish raised on PAP-based diets?; (iii) and does the provision of sustainability-related information influence that WTP?
The analysis is based on an online panel survey of 1,502 consumers living in Italy, selected through stratified sampling by gender, age, and region of residence. First, respondents' perceived naturalness of the wild fish diet was assessed using a multiple-choice question to contextualize their subsequent answers. Next, perceptions of conventional ingredients (FM and SBM) and PAPs were then elicited through open-ended questions and examined using sentiment analysis. Responses were classified as positive, negative, or neutral with an Italian-language model based on the pysentimiento Python library. WTC for fish reared on PAP-based diets and its main barriers were measured using seven-point Likert-scale statements covering four dimensions that emerged from the literature as having a direct effect: disgust, social norms, comparison with conventionally fed fish, and perceived product safety. These items were analyzed using a random forest (RF) classifier, with WTC as the outcome variable and the barriers as predictors. As an ensemble classification method that combines multiple decision trees, RF is well-suited for modeling consumers' WTC and identifying the relative importance of the barriers that shape their decisions. WTP was measured on a percentage scale with a midpoint for no price difference, and values above or below indicating a premium or a discount. Finally, to test the role of information, respondents were shown a short objective text on the sustainability of PAP-based feeds, and WTP was elicited again using the same scale. Changes in WTP were evaluated through a paired pre-post design using the Wilcoxon signed-rank test.
Results and discussion
Results show that 83% of consumers could identify at least one possible component of the natural diet of fish. Plant-based organisms (59%), fish of other species (41%), and insects (31%) were perceived as more closely aligned with the diet of wild fish, whereas small terrestrial animals, such as mammals and reptiles (16%), were considered less likely to be part of it. Sentiment analysis revealed predominantly neutral attitudes toward FM and SBM. By contrast, insect, poultry, and porcine PAPs elicited polarized reactions in about half of the sample (43-49%). Among respondents expressing either positive or negative sentiment, insect PAPs were evaluated more favorably (59% positive), whereas poultry PAPs (69% negative) and especially porcine PAPs (75% negative) elicited more unfavorable responses. The three RF models achieved accuracies ranging from 65% to 69% and showed that the main barriers to WTC differed by ingredient. Disgust emerged as the most influential predictor in the model for insect PAPs, while perceived product safety was the leading concern for both poultry and porcine PAPs. For these two ingredients, the item concerning the perceived naturalness of the raw material emerged as the second most important limiting factor. In terms of WTP, 60% of respondents were not willing to pay either more or less for fish fed PAPs, although the tendency leaned toward discount requests. Acceptance was highest for fish fed insect PAPs (positive WTP: 17%; negative WTP: 23%), whereas fish fed poultry or porcine PAPs were more often associated with lower WTP (positive WTP: 10%; negative WTP: 30% for both). The role of additional sustainability information was statistically significant (p < 0.0001), increasing the share of respondents willing to pay a premium for fish fed insect (22%), poultry (19%), and porcine (18%) PAPs, while slightly reducing negative WTP to 21%, 23%, and 26%, respectively.
Ingredients perceived as more consistent with fish's natural diet tended to elicit more favorable reactions. FM and SBM attracted limited controversy, while PAPs, especially poultry and porcine sources, polarized respondents more strongly. Within the PAP category, insect stood out as the most accepted option. They were associated with more favorable sentiment and consistently showed the highest WTP. Proximity to fish's natural diet may foster acceptance, even though disgust remains an important barrier, consistent with previous research on indirect entomophagy (Niimi et al., 2025). By contrast, reluctance toward poultry and porcine PAPs appears to be driven primarily by perceived safety concerns, possibly reflecting the legacy of past concerns surrounding TSEs, as well as the unnaturalness of the practice. The idea emerging from the results is that insect PAPs are more accepted than the other two, possibly because they may be perceived as more natural. Although the positive effect of the information treatment indicates that targeted communication emphasizing the sustainability of PAP-based feeds could help foster consumer acceptance, future studies should focus on the role of perceived naturalness in the acceptance of these circular solutions.
Acknowledgment
The study is part of the project "Aquainnova 2.0: nuovi mangimi per l'acquacoltura sostenibile e circolare" (CUP: J68H230008200001).
References
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