Regulation by Nisin Enhances Storage Quality of Pre-Packaged Fermented Soybean Whey-Based Tofu: Food Safety, Texture and Flavour

Abstract

To systematically investigate the effects of nisin on the storage quality of pre-packaged fermented soybean whey-based tofu, an evaluation of physicochemical indices, biogenic amine accumulation, sensory attributes and flavour profiles were performed. The results demonstrated that he addition of nisin strongly retard the increase of the total viable count (TVC), the total volatile basic nitrogen (TVB-N) and malondialdehyde (MDA), and also inhibited the decrease of the water-holding capacity and sensory scores. Biogenic amine analysis revealed that nisin effectively inhibited the accumulation of histamine, tyramine and total biogenic amines by 40–60%. Overall, nisin treatment at 2.0% had the best preservation effect on tofu. Consequently, 1.0% nisin was identified as the most suitable concentration for subsequent trials, considering market acceptance and economic viability. Electronic nose and GC-IMS/GC-MS analyses further confirmed that nisin suppressed off-flavour compounds (e.g., isovaleric acid, 3-methylbutanal) while retaining key aroma contributors (ethyl butyrate, (E)-2-hexenal). Principal component analysis and orthogonal partial least squares discriminant analysis further highlighted nisin’s role in stabilising volatile profiles, mainly decreasing sulphide and ammonia derivatives. These findings underscore nisin’s potential as a natural preservative to enhance the shelf life and quality of fermented soybean products, offering a scientific basis for its application in traditional food preservation.

Keywords: Nisin, Fermented soybean whey-based tofu, Storage Quality, Biogenic Amines, Flavour