QUALITY LOSS of DOUBLE CONCENTRATED TOMATO PASTE: EVOLUTION of the MICROBIAL FLORA and MAIN ANALYTICAL PARAMETERS DURING STORAGE AT DIFFERENT TEMPERATURES

Abstract

This study deals with nonsterile canning of double concentrate tomatoes (30° Brix) stored for 210 days at three different temperatures (4, 10 and 25C) in 200 kg drums. the evolving analytical composition (soluble solids, total solids, glucose, fructose, pH, total acidity, volatile acidity, citric acid, malic acid, succinic acid, hydroxymethylfurfural (HMF) and color parameters) that the product underwent during storage was dependent both on storage temperature and on different aerobic levels within the drum (top and bottom sections). the microbial profile (yeast, lactic acid bacilli and molds) was correlated with many important metabolites (D‐ and L‐lactic acids, ethanol, acetic acid and diacetyl). the results indicate that the increase of these substances is dependent both on storage temperature as well as the oxygen tension within the drums. Taken all together, the analytical findings offer a great help in evaluating the quality of semifinished tomatoes. We also found that lactic bacteria grow rapidly at 25C and after 15 days their number from both sampling areas in the drums (i.e., 10 cm below the sample surface and 15 cm above the bottom of each drum) is already greater than 105 cfu/ml. At 10C, 30 days were needed to reach such a cell concentration, and after 45 days the level reaches 107‐108 cfu/ml. By contrast, at 4C there were differences between top and bottom sampling areas. In the top area, 105 cfu/ml was reached after 60 days, while for the bottom area this was reached after 120 days. Regarding yeast at 25C.

The Extension of the Shelf Life of Ready-to-Serve Pizza by a Combination of Modified Atmosphere Packaging and Refrigeration

“…The work of Eliot et al (1998) on shredded mozzarella cheese under modified atmosphere also indicated that initial psychrotrophic count 4.36 log cfu/g increased to 7.00 log cfu/g after 3 weeks of storage. The results match with the findings of Villari et al (1994) who observed that the psychrotrophic organisms were less numerous when stored in high CO 2 atmospheres in case of refrigerated pizza. Finally, the counts of anaerobic spore formers were also low (< 3 log cfu/g) and show increasing trend in all pizza samples with anaerobic conditions and slight decrease in air packed pizza samples throughout the entire storage period (Fig.…”

“…The results also confirm the earlier findings of Alves et al (1996);Fedio et al (1994); Eliot et al (1998);Alam (2004), who while working on MAP of mozzarella cheese observed that CO 2 had bactericidal effect Of the facultative anaerobic bacterial species, LAB constituted part of the natural microflora of baked pizza samples stored in air and under MAP (Fig. 1b) probably originating from pizza ingredients such as cheese (Eliot et al, 1998) and tomato paste (Villari et al, 1994). Coliforms also found in the pizza samples but to a lesser degree may be due to cross contamination and their contribution is significant only for samples stored under aerobic conditions (Fig.…”

Quality attributes of processed tomato products: A review

“…Wiese and Dalmossa (32) also reported increases in organic acids (lactic acid, malic acid, citric acid, and pyrocarboxylic acid) after processing of tomato juice. Villari et al (33), however, reported decreases in organic acids with increased storage time and temperature of tomato paste. They also reported a decrease in pH and increase in the acidity during storage of tomato juice.…”

“…Wiese and Dalmasso (32) reported significant increase in the hue angle of tomato juice after processing and storage, indicating loss of red color. Color retention in tomato products is better at lower temperature (33,34). The main cause of carotenoid degradation in foods is oxidation.…”

Lycopene in Tomatoes: Chemical and Physical Properties Affected by Food Processing

“…Wiese and Dalmasso (1994) reported an increase in the hue angle of tomato juice after processing and storage, indicating a loss of red color. The color retention in tomato products is better at lower temperatures (Sherkat and Luh, 1976;Villari et al, 1994).…”