Pulsed Light Processing of Sword Prawn Powder: Effects on Tropomyosin-Related Indicators, Biological Response Endpoints, and Appearance Quality

Abstract

Pulsed light (PL) is an emerging non-thermal processing technology with potential to modify food proteins while limiting bulk heating. In this study, sword prawn (Parapenaeopsis hardwickii) powder was used as an application-relevant shrimp-derived ingredient matrix to evaluate the effects of PL treatment on tropomyosin (TM)-related indicators, biological response endpoints, and appearance quality. PL-treated powder was first screened by SDS-PAGE, anti-tropomyosin western blotting, and enzyme-linked immunosorbent assay (ELISA). Based on the in vitro results, self-made sword prawn powder treated for 0, 90, and 240 s was further evaluated in BALB/c mice using an IgE-mediated food allergy model and a delayed-type hypersensitivity-related model. Appearance-related changes were assessed by color parameters and browning index. PL treatment induced treatment-time-dependent shifts in TM-related indicators, including reduced ELISA-measured crustacean tropomyosin levels and attenuated TM-related western blot signals. In the biological models, the longer treatment condition was associated with altered immunoglobulin-related indicators, cytokine responses, intestinal injury-related features, and footpad swelling relative to the untreated control. However, longer PL treatment also caused greater browning and color change. These findings indicate that PL processing altered TM-related indicators and biological response endpoints in sword prawn powder, but the treatment effect was accompanied by an appearance-related trade-off. The study supports a multi-level evaluation framework for non-thermal processing of shrimp-derived powder ingredients.