Biogenic amines and bacterial spoilage in Plant-Based grill sausage alternatives

Vegan and vegetarian diets are increasing in popularity. Consequently, the supply and demand of plant-based meat alternatives has increased steadily over the past few years. However, scientific research on spoilage processes for such products is still inadequate as compared to research on traditional meat products. In traditional meat products, biogenic amines are prominent spoilage markers and potential sources of food toxicity, especially for people sensitive to biogenic amines. Plant-based meat alternatives are manufactured to mimic the taste, look, texture, and nutritional value of meat, and they have a protein-rich basis. It is therefore hypothesized that biogenic amines could be markers for spoilage in such products as well. Further analysis of their presence and concentrations and comparison to conventional meat products is necessary. If biogenic amines are lower in plant-based meat alternatives, these products are possibly better suited for consumption by people with biogenic amine sensitivities. A simple and rapid extraction method, followed by HILIC-MS/MS separation and detection was therefore developed as a first step and validated for nine biogenic amines in plant-based meat alternatives. This method showed a strong linear correlation between amine concentration and detector response, high accuracy, and precision (< 12 %), as well as high sensitivity, as proven by the lowest limits of quantification (i.e., the lowest concentration within the calibration model) of 1 mg/kg for all analytes, which also compares well with other methods. Subsequently, as part of a pilot spoilage study, the method was applied to one vegetarian and nine vegan grill sausage alternatives during a period of 32 days of open-package storage at refrigerator temperature. Correlations with the results of microbiological testing of the same samples, as well as with the storage time were investigated. However, the results of the correlation analysis showed that biogenic amines are not suitable as spoilage indicators for plant-based meat alternatives, as almost no increase in biogenic amines was identified during the spoilage study for all the samples investigated. Differences in the microbiota of conventional meat products versus plant-based meat alternatives, as well as possibly lower concentrations of free amino acids, are proposed as reasons for biogenic amines not being similarly prevalent, and consequently, not being suitable spoilage markers in plant-based meat alternatives. However, as spoilage of the analyzed products was evident, both via sensory assessment and appearance of mold growth, further targeted and non-targeted research on potential spoilage markers for plant-based meat alternatives is required in the future.