THE QUALITY PARAMETERS OF TOMATO PASTE STORED IN CONTAINERS ROBBY IN COMPARISON WITH CONVENTIONAL WAYS OF COLD STORAGE

Abstract

Food containers, especially those used for cooked and processed food, should comply with certain standards to increase the shelf life of food products. Tomato paste is the most popular processed food due to the presence of such functional compounds as lycopene, β-carotene, ascorbic acid, and phenolics. In this regard, the present study compares the quality of products stored for 56 days in the new container Robby (invented to keep tomato paste in) and in conventional containers (industrially manufactured or homemade). This study was a full factorial design experiment with 48 experimental treatments involving 3 different containers, 2 types of tomato paste (homemade and industrially manufactured), 2 different producers for each type of tomato paste, 2 refrigeration environments (an isolated laboratory refrigerator and a refrigerator used in a dormitory with normal household conditions), and 2 replicates. Chemical and microbial tests were performed using precise methods. The chemical tests included determining the acidity, measuring vitamin C and total soluble solids, salt content, concentrations of aflatoxins B1, B2, G1, and G2, and the findings were compared at the end of the storage period. All microbial tests were carried out by the pour plate method. The total viable cells were counted on Plate Count Agar (PCA) after incubation at 30°C for 24 h. Acid-resistant bacteria and mould/yeast were counted, respectively, on de Man, Rogosa and Sharpe agar (MRS) and DRBC after incubation at 30°C for 3–5 days. To analyse the data, three‑way analysis of variance (ANOVA) and paired t-test were applied, using the SPSS20 software. At the end of the study period, the least and the worst contaminated homemade samples were examined for aflatoxin. As to the industrial samples, the type of a container had a significant effect on the total microbial count, yeast and mould count, LAB and vitamin C concentration. The same results (except those concerning vitamin C) have been obtained for the homemade samples. Compared with conventional means of cold storage of tomato paste, using Robby containers results in the least change in the microbial and chemical quality of tomato paste, preserves more vitamin C in the product, hinders the secondary contamination and microbial growth. Also, proliferation of microorganisms in homemade tomato paste during refrigeration can be well controlled when this container is used