Lactic Acid Streptomycin A Z Detection – Accredited Nisin A and Nisin Z Quantification for Global Food Safety and Quality Assurance
Our internationally accredited laboratory provides a specialist lactic acid streptomycin A Z detection service that empowers food manufacturers, dairy processors, bio‑preservative suppliers, regulatory agencies and research institutes worldwide to accurately quantify the two major natural variants of nisin—nisin A and nisin Z—in complex food matrices, fermentation broths and purified additive preparations. Every analysis is performed under the rigorous framework of ISO/IEC 17025, and each report bearing the ILAC mark is unconditionally accepted by regulatory authorities, notified bodies and supply‑chain partners in all major economies. Nisin, the prototypical lantibiotic produced by certain strains of Lactococcus lactis, is the most widely used natural antimicrobial peptide in the food industry, approved as the preservative E 234 in the European Union and generally recognised as safe by the US Food and Drug Administration. The lactic acid streptomycin A Z detection programme employs high‑resolution liquid chromatography–tandem mass spectrometry and validated immunoassay methods to distinguish and quantify nisin A and nisin Z individually, providing the legally robust, defensible data that underpin product‑label verification, compliance with the maximum permitted levels, fermentation‑process optimisation and the authentication of the nisin variant declared on the certificate of analysis.
Product Samples We Regularly Subject to Lactic Acid Streptomycin A Z Detection
The sample‑extraction laboratory, the solid‑phase‑extraction workstations, the high‑performance liquid chromatography systems and the tandem‑mass‑spectrometry platforms in our facility accommodate a wide variety of food, beverage and ingredient matrices. The following categories represent the most frequently tested items:
- Dairy products and cheese – processed cheese, fresh cheese, cheese spreads, cream, yoghurt and dairy‑based desserts where nisin is used to inhibit the outgrowth of the Clostridium spores and to extend the shelf‑life
- Meat and poultry products – cooked sausages, frankfurters, cured hams, canned meat and ready‑to‑eat poultry products that are surface‑treated or incorporated with the nisin preparation to control the Listeria monocytogenes and the other gram‑positive pathogens
- Canned vegetables, soups and sauces – the heat‑treated, low‑acid canned foods where the nisin is added to prevent the flat‑sour spoilage caused by the thermophilic spore‑forming bacteria
- Bakery and the high‑moisture cereal products – the crumpets, the pancakes, the pasta and the ready‑to‑eat cereal products that are susceptible to the rope‑forming Bacillus species
- Beverages and the fruit‑juice products – the fruit juices, the carbonated soft drinks and the alcoholic beverages such as the beer and the wine where the nisin is used to prevent the spoilage by the lactic‑acid bacteria and the other gram‑positive contaminants
- Purified nisin preparations and the fermentation concentrates – the commercial nisin A, the nisin Z and the mixed‑variant powders, the liquid concentrates and the immobilised‑enzyme preparations, tested for the variant identity, the total nisin titre and the absence of the non‑nisin impurities
Liquid Chromatography–Tandem Mass Spectrometry Quantification – Lactic Acid Streptomycin A Z Detection According to the Internal Validated Protocols
- Simultaneous determination of nisin A and nisin Z by the reversed‑phase liquid chromatography with the multiple‑reaction‑monitoring mass spectrometry according to the internal validated protocol: the sample is homogenised, the nisin peptides are extracted with a methanol‑water‑formic acid mixture, and the extract is cleaned by the solid‑phase extraction on a polymeric sorbent. The eluate is evaporated, reconstituted and injected onto a C18 column, and the nisin A and the nisin Z are separated by a gradient of the acetonitrile and the 0.1 % formic acid. The triple‑quadrupole mass spectrometer monitors two or three characteristic precursor‑to‑product‑ion transitions for each variant, and the quantification is performed by the external‑standard method with the matrix‑matched calibration curves prepared from the certified nisin A and nisin Z reference standards. The concentration of each variant in the milligrams per kilogram or the international units per gram is reported, and the sum of the two variants is expressed as the total nisin content. This lactic acid streptomycin A Z detection provides the specific, variant‑resolved quantification that is impossible with the conventional agar‑diffusion bioassay, enabling the food manufacturer to verify that the declared variant composition of the nisin preparation matches the actual content in the finished product.
- Determination of the total nisin activity by the enzyme‑linked immunosorbent assay and the correlation with the LC‑MS/MS data: a commercial polyclonal or monoclonal anti‑nisin antibody that recognises both the nisin A and the nisin Z is used in a competitive ELISA format, and the total‑nisin‑immunoreactivity in the international units per gram is measured. The ELISA result is correlated with the sum of the nisin A and the nisin Z concentrations that were determined by the LC‑MS/MS, and the conversion factor between the mass‑based and the activity‑based units is established for the specific product matrix, providing the rapid, high‑throughput screening method for the routine quality control.
- Verification of the nisin structural integrity and the detection of the degradation products: the high‑resolution mass spectrometry is used to confirm the intact mass and the amino‑acid sequence of the nisin A and the nisin Z extracted from the product, and the dehydrated, the oxidised and the deamidated degradation products are identified, providing the evidence that the nisin has not been inactivated during the thermal processing and the storage.
- Stability and the homogeneity testing of the nisin in the batch and the finished product: the samples are taken from the multiple locations within a mixing vessel or a production lot, and the nisin A and the nisin Z concentrations are measured, providing the data that the manufacturer uses to demonstrate the uniformity of the nisin distribution and to set the validated mixing time and the sampling plan.
- Compliance testing against the international regulatory limits – the EU E 234 and the Codex Alimentarius maximum levels: the measured total nisin concentration is compared with the maximum permitted level for the specific food category – for example, 12.5 mg/kg in the cheese and the processed cheese, 10 mg/kg in the meat products and 5 mg/kg in the soups and the sauces – and the pass‑or‑fail verdict is reported on the certificate of analysis, providing the essential data for the export‑certification and the regulatory‑inspection clearance.
Report Acceptance and Global Regulatory Compliance
All analyses performed within our lactic acid streptomycin A Z detection service are executed under the fully accredited scope of our ISO/IEC 17025 quality management system. Each test report that carries the ILAC mark is therefore automatically recognised by regulatory authorities, notified bodies, customs offices and supply‑chain partners in all major economies. For food manufacturers, dairy processors, nisin‑additive suppliers and food‑safety testing agencies anywhere in the world, the report constitutes legally robust, internationally accepted evidence that the nisin A and the nisin Z concentrations, the total nisin activity and the compliance with the regulatory maximum levels have been determined in accordance with the internal validated methods and the customer‑specified requirements. The documentation can be directly used to support the EU food‑additive compliance, the FDA generally recognised as safe notification, the issue of inspection certificates according to EN 10204 or equivalent national standards, and the resolution of commercial and technical disputes concerning the identity, the purity and the quantity of the nisin variant that is present in any food or ingredient product.
