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Showing 4 results for امین لاری


Volume 14, Issue 70 (0-0)
Abstract



Volume 15, Issue 80 (10-2018)
Abstract

In food products packed in hot filling mode, the use of probiotic bacteria is very limited due to thermal sensitivity. The microencapsulation of probiotic bacteria is suggested as a suitable method for reducing thermal damage. Dual layer extrusion using high molecular weight hydrocolloids, such as zedo gum, can prevent thermal damage. In this research, microencapsulation by two layers extrusion method was performed on Lactobacillus rhamnosus. The first layer was sodium alginate and the second was zedo gum at 0.2, 0.4, 0.6, 0.8%., was used. Microencapsulation was followed by light microscopy, texture and color analysis. Thermal stability, acid and salt stability, acid production tests and the growth of microencapsulated bacteria during storage conditions in MRS medium were investigated. The results showed that 0.8% zedo gum used as the second layer could significantly change the outer layer diameter. However, the increase of zedo concentration did not increase the hardness component. Only at 0.2% zedo gum had a significant difference with the rest (p<0.05). At 0.6% and 0.8% zedo gum increase in gumminess component wasobserved. At 72 ° C, the number of microencapsulated bacteria remained stable for 10 minutes, and at the 5th minute their count was about 5 log CFU‌/‌ml higher than free bacteria (p <0.05). The amount of acid production was lower and bacterial growth in the microencapsulated bacteria was slower than free bacteria. The microencapsulated bacteria had microbial survival of 2 log CFU/ml more than free bacteria the of 15% (pH = 1.5).

Volume 18, Issue 119 (january 2021)
Abstract

In the present study, the effect of chemical refining process on the oxidative stability of Bene kernel oil during 32 hours of thermal process at 170 ° C was investigated. Examination of fatty acid structure showed that the amount of trans fatty acid was very small after the thermal process. The trend of changes in tocopherol and polyphenolic compounds during the heating process was different from other studies. The rate of tocopherol changes increased at the end of the thermal process in crude, degummed and neutralized oils and decreased in bleached and deodorized oils. The reason for the increase in tocopherols was related to their regeneration process. Also, the amount of polyphenolic compounds after the thermal process compared to the zero moment was largely in line with tocopherol changes. The reason for the increase in phenolic compounds was related to the breakdown of these compounds and their becoming simpler compounds. Examination of oxidation stability tests (conjugated diene vlue and p-anisidine value) also showed that crude kernel oil was the most stable sample, followed by degummed, neutralized, deodorized and bleached oils, respectively. The reason that the decolorization step caused the lowest oxidative stability in Bene kernel oil can be attributed to the greatest reduction in the amount of tocopherol compounds in this oil sample compared to the zero moment. Also, the trend of changes in antioxidant activity was largely consistent with changes in antioxidant compounds.

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