جستجوی مقالات مرتبط با کلیدواژه "tomato paste" در نشریات گروه "پزشکی"

This study aimed to compare the storage stability of tomato paste packaging of cans and a container with the brand name of "Robby" during 6 weeks. Four cans of tomato paste were prepared from brand A. Sample 1 was covered with the plastic lid after opening. Sample 2 was transferred into a container with the brand name of "Robby". Tomato paste of cans 3 and 4 were contaminated with Aspergillus flavus spore ssuspension (t 2×106spore/ml) and homogenized in a sterile container. Subsequently, an equal amount of contaminated tomato paste was transferred into the original can (sample 3) and the "Robby" container (sample 4). Samples were stored in a refrigerator at 4°C for 6 weeks. Samples 1 and sample 2 were evaluated regarding acidity, Brix, pH, vitamin C, as well as total bacteria, mold, and yeast count. However, samples 3 and 4 only were analyzed in terms of total bacteria, mold, and yeast count with two replications. All the experiments were individually repeated on another tomato paste with a different brand name. Ethics code: 395833   After the second week, there was a 62% decrease and a 4% increase in vitamin C and Brix levels in the tomato paste in the can. However, the reduction in vitamin C level (5%) and the Brix changes were not significant in the "Robby" container. The gradual increase of acidity was observed in both treatments. Nevertheless, there was an increase in the acidity of the tomato paste kept in the can (28%) and "Robby" container (22%) at the end of the sixth week (P<0.05). The "Robby" container had no significant effect on pH and microbial groups (P> 0.05). The "Robby" container definitely provides better conditions for preserving the chemical properties of tomato paste than common means of tomato paste storage.

This paper is concerned with rheological behavior of tomato paste from the view point of viscoelasticity and time dependant properties in order to design various units of tomato paste production line. Rheological behavior of tomato paste is determined at Spindle Brookfield viscometer. Experiments were carried out and determined that time dependant category of the samples show thixotropic behavior. Both stress overshoot and step strain tests emphasized the viscoelastic property of the sample, therefore the appropriate model were obtained to define the viscoelastic and time dependent behavior. This work exhibited one model which consisted of time dependent and viscoelastic rheological behavior of tomato paste. The results of the model are compared with experimental data which indicated good correlations between model result and experimental data. The experimental results showed that tomato paste behaves as a non-Newtonian semifluid which follows power law model.