Investigation of some chemical, antimicrobial and bioactive properties of mint jam

In this study, it was aimed to examine some physical, chemical, microbiological and bioactive properties of jam samples produced from Mint (Mentha longifolia) with (R1) and without colorants (R2) during storage at room temperature and in the dark for 6 months. Water soluble dry matter (brix), titratable acidity, pH, total phenolic matter content, antioxidant activity (determination of DPPH radical scavenging activity and FRAP method) and microbiological (yeast-mold count, total aerobic mesophilic bacteria count, lactic acid bacteria count, coliform bacteria count and osmophilic yeast count) analyzes in jam samples at 0, 2, 4 and 6 months were performed. Additionally, sensory analysis and antimicrobial activity determination at the beginning of storage; At the beginning and end of storage, color, texture (gel strength, rupture strength, brittleness and adhesiveness) and hydroxymethylfurfural (HMF) analyzes were performed. It was determined that brix, pH and titratable acidity values in R1 and R2 samples were similar and there was no significant change with storage. Additionally, microbiological analyzes showed that there was no microbial growth in the jam samples during storage. As a result of sensory evaluation of R1, R2 and a commercial mint jam available from the market, it was found that the presence of colorant did not have a significant effect on sensory acceptance of jams. It was determined that the known antimicrobial activity of mint was lost in mint jam and did not show any inhibition on the tested microorganisms. It was determined that the addition of colorant caused a significant change in all color values, especially the a value (p<0.05). It was observed that there were significant changes in the L and b values of the jams with storage (p<0.05). It was observed that gel strength and brittleness values were similar and there was no significant change with storage. While no difference was observed in terms of HMF content in the jam samples, although it was observed that the HMF content in the jam samples increased with storage, these differences were not statistically significant (p>0.05). It was observed that there was no significant change in total phenolic matter content and antioxidant activity in mint jam samples with storage. Additionally, FRAP and DPPH antioxidant activity values were determined to be compatible with each other. It was observed that the mint jam studied for the first time had bioactive properties, regardless of the addition of colorants, and maintained these properties during 6 months of storage under the specified conditions, and could be consumed without any microbiological deterioration. Keywords: Antioxidant Activity, HMF, Mint, Mint Jam, Phenolic Compounds, Storage