The application prospects of Nisin in functional foods

Nisin, as a natural, safe, and highly effective antimicrobial peptide, its application prospects in the field of functional foods are continuously expanding with in-depth exploration of its properties. Its advantages and potential application scenarios are mainly reflected in the following aspects:

First, its core value in clean-label and natural preservative functional foods is increasingly prominent. As consumers' demand for "natural" and "simplified" food ingredients upgrades, the use of traditional chemical preservatives is gradually restricted. Nisin, as a polypeptide substance produced by the fermentation of Streptococcus lactis, is not only approved as a food additive by most countries worldwide (e.g., EU number E234) but also conforms to the "clean label" trend, which can be directly labeled as a "natural antimicrobial agent." In functional foods, it can specifically inhibit Gram-positive pathogenic bacteria (such as Listeria and Staphylococcus aureus) and spoilage bacteria, and is particularly suitable for perishable functional formulas such as high-protein, low-fat, and low-sugar products. For example, in functional yogurt added with probiotics, nisin can reduce the intensity of heat treatment, which not only protects the activity of probiotics but also delays acidification caused by miscellaneous bacterial contamination; in high-protein meal replacement bars, it can inhibit the growth of molds and bacilli, extend the product shelf life, and at the same time, does not affect the functional properties of proteins.

Second, synergizing with functional ingredients to expand product functional dimensions is an important application direction. Nisin's antimicrobial mechanism (such as destroying cell membranes and interfering with metabolism) enables it to complement a variety of functional ingredients. For example, in functional beverages rich in plant polyphenols (such as tea polyphenols and curcumin), Nisin can enhance the antimicrobial activity of polyphenols—polyphenols work by inhibiting bacterial enzyme activity, while its pore-forming effect can promote polyphenols to enter bacterial cells. The two synergistically improve the inhibitory effect on food pathogenic bacteria while retaining the antioxidant function of polyphenols. In addition, in functional bread added with dietary fiber, nisin can combine with the colloidal network of dietary fiber to slowly release antimicrobial activity, which not only solves the problem of local spoilage caused by uneven moisture distribution in high-fiber foods but also does not affect the prebiotic effect of dietary fiber in the intestines.

Third, its potential for precise application in special dietary functional foods is huge. Functional foods for specific groups of people (such as infant complementary foods, elderly nutritional preparations, and sports nutrition supplements) have stricter requirements for safety and functionality, and Nisin's natural properties make it an ideal choice. For example, infant complementary foods need to strictly control microbial risks. Nisin can replace some chemical preservatives to ensure product safety under low heat treatment conditions, while avoiding damage to functional ingredients such as DHA and nucleotides added in complementary foods; in sports nutrition protein bars, nisin can inhibit the reproduction of protein-decomposing bacteria, reduce amino acid oxidation, and cooperate with branched-chain amino acids (such as L-leucine) in the product, which is more conducive to muscle repair after exercise.

In addition, technological innovation has promoted the diversification of its application forms. Through technologies such as microcapsule embedding and nanocomposites, the stability and targeting of nisin can be further optimized. For example, encapsulating Nisin with chitosan-sodium alginate microcapsules makes it not easy to degrade in acidic functional beverages (such as fruit juices containing vitamin C) and only releases when entering the intestines, which not only exerts the preservative effect but also helps inhibit harmful intestinal bacteria, forming a synergistic prebiotic effect with probiotics in the product; compounding Nisin with functional polysaccharides (such as chitosan) to make edible films for wrapping functional snacks (such as nuts and freeze-dried fruits) can block oxygen and moisture, slowly release antimicrobial components, extend the product shelf life, and endow the packaging with "degradable" environmental attributes, which is in line with the "health + sustainability" development concept of functional foods.

However, attention should be paid to the limitation of nisin's antimicrobial spectrum (mainly targeting Gram-positive bacteria). In practical applications, it often needs to be compounded with other natural preservatives (such as lysozyme and plant essential oils) to expand the antimicrobial range. In general, relying on its naturalness, safety, and functional synergy, nisin has irreplaceable potential in the preservation, functional enhancement, and quality improvement of functional foods. With the maturity of related technologies, its application scenarios will further extend to subdivided functional fields.