Determination of Changes in Physicochemical and Microbiological Properties of Tomato Paste Exposed to Different Gases of Cold Plasma Technique

This study aimed to reveal the effect of cold plasma application using different gases and mixtures on some physicochemical and microbiological properties of tomato paste. For this purpose, applications were performed in different gases and times, and the effect of each application was examined separately. As a result of the study, the pH values of the samples varied between 3.77 and 4.87, and the aw values between 0.718 and 0.819. When the color values were examined, it was determined that the L* value varied between 22.42 - 32.48, the a* value varied between 23.59 - 30.18 and the b* value varied between 12.16 - 19.52 (P<0.05). In addition to this, when the samples were evaluated microbiologically, TMAB counts varied between 3.02 - 5.42 log cfu/g, TPAB values ranged between 1.80 - 3.37 log cfu/g, total mold counts were between 3.08 - 5.67 log cfu/g, total yeast counts were between 3.13-5.42 and osmophilic yeast counts were between 1.74 - 3.49 log cfu/g. Lycopene values of samples in the study were in the range of 15.30 - 23.42 mg/100g DM. When the data obtained from the study are evaluated as a whole, it is thought that cold plasma application has positive effects on the shelf life and quality of tomato paste. In the research where two different gases and mixtures of these gases were used, oxygen gas application showed the most effect on the physicochemical and microbiological properties of the samples (P<0.05). Mixture and argon gas applications followed this effect, and prolonging the application period also increased the effect. When the data obtained from the study are evaluated as a whole, it has been revealed that cold plasma application delays the mold problem, which is one of the most critical problems in industrially produced tomato paste, extends the shelf life, and slows down the negative changes in physicochemical quality values due to storage.