Systematic Literature Review of Functional Snacks: Bioactive Properties, Food Technologies, and Consumer Acceptance

Functional foods containing antioxidants and anti-inflammatory compounds are a promising nutritional intervention. However, significant gaps remain in the literature on the development and evaluation of functional snacks for improving health outcomes. This systematic literature review (SLR) aimed to summarize the existing evidence on the development of enriched functional snacks containing bioactive ingredients, with a particular focus on their potential relevance to mental health. The review also examined food technologies, consumer acceptance, current knowledge gaps, and priorities for future research. The SLR was conducted in accordance with the PRISMA guidelines. PubMed, Scopus, and Web of Science were searched for studies on snacks and functional foods published between 2020 and 2025. Original studies evaluating functional snacks and/or bioactive compounds with neuroprotective, anti-inflammatory, or antioxidant properties were included. The initial search yielded 281,118 records. Following screening and quality assessment, 22 articles were selected through a three-author consensus process. Among the included studies, 12/22 focused on product development and antioxidant activity. Three studies included in vivo evaluations, while four included in vitro assessments of anti-inflammatory or antioxidant effects. Technologies such as extrusion, nanoencapsulation, and freeze-drying were employed to protect bioactive compounds and preserve bioactivity. Only two studies included sensory evaluation, with both reporting preliminary evidence of high acceptability. Overall, the SLR revealed limited evidence on functional snacks, particularly regarding their effects on mental health. Significant gaps remain in biological, neuroprotective, and sensory validation. Further studies are needed to establish the efficacy, biological effects, and consumer acceptability of enriched functional snacks, as well as consumer acceptability across diverse, relevant target populations.