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Showing 4 results for mazaheritehrani


Volume 17, Issue 104 (October 2020)
Abstract

Kaymak or Sarshir, a traditional dairy product, is served in Iranian breakfast. The aim of this study was to investigate the fatty acids profile, physicochemical properties (texture, color, pH, acidity, the content of dry matter, fat and protein) and organoleptic aspects of Gilanvand and Dalirankaymaks in comparison to the heavy cream. To study more closely the texture and appearance differences of these products, scanning electron microscope (SEM) images were also prepared. The obtained results showed that the contents of fat and dry matter in heavy cream were higher than the kaymaks; however, Gilanvandkaymak had the highest protein content, acidity, and b*-value. Based on the study of the fatty acids profile, palmitic acid and cis-oleic acid were recognized as the most dominated saturated and unsaturated fatty acids, respectively. Microstructural analysis of SEM revealed that the structure of the protein in the fat field was compact, irregular and abundant in Gilanvandkaymak which influenced the product properties. The hardness, gumminess, and adhesiveness of the heavy cream were highest in comparison to the kaymaks. The Gilamvandkaymak obtained higher scores in evaluating the taste and total acceptance. In conclusion, it can be mentioned that the Gilamvandkaymak will have high potential in marketability by considering its higher protein content as well as total acceptance.

Volume 18, Issue 115 (September 2021)
Abstract

The high levels of tomato production as well as its perishability, make the development of research on processing and improving the quality of existing products more evident. The aim of this study was to assess the effect of whole tomato heating treatment by steam on the physicochemical and structural properties of produced tomamto paste with different degree of Brix (°Br). The fresh tomatoes was washed with water followed by exposing to steam and the tomamto paste with different °Br (18-26) produced through hot breaking approach. The results showed that the color indexes, precentage of precipitation weight ratio, acidity, viscosity, consistency and microstructure of final products were significantly influenced by steam preheating. The color indexes of *a and b* and precentage of precipitation weight ratio were negatively affected by steam preheating. The reason behind these observation is increasing the efficiency of heating process in hot breaking stage reulted in lycopene destruction. On the other hand, the viscosity and consistency of tomato paste were meaningfully increased. The images of scanning electron microscopy revealed that the steam preheating brought about solube pectin to migrate from cell wall, forming an amorph structure. Considering the acceptble range of color indexes as well as profound improvment in rheological characteristics of produced tomamto paste, in can be concluded that applying preheating treatment by steam would be of efficeint procedure in tomato paste production.
 

Volume 18, Issue 116 (October 2021)
Abstract

In this study, the effect of low methoxyl pectin addition oi the three levels including 0.2, 0.4 and 0.6% on the structural properties of cream with 45% fat globules was investigated. Structural study of the dispersed phase was performed using particle size distribution method and the morphological properties evaluated by optical microscopic images. The results show the effectiveness of low methoxyl pectin on the size distribution of fat globules in the cream. The mean volume-surface of ​​fat globules in pectin-free cream increased from 2.28 to 4.65 μm in the sample with 0.6% low methoxyl pectin. Optical microscopic images demonstrated the morphological of fat globules change from spherical and solitary to the agglomerated form. On the other hand, increasing of low methoxyl pectin levels caused to increase the irregularity of particles size distribution in the images obtained from microscopic observation. Fractal dimension was calculated as an indicator for complexity quantification based on microscopic images. An increase in fractal parameter observed with increasing levels of low methoxyl pectin in the cream. On the other hand, a relationship with high coefficient of determination was observed between the changes in particle size and fractal dimension.

Volume 19, Issue 125 (July 2022)
Abstract

Paste, as one of the main tomato products, has always been of great importance in the food. About 5% (w/w) of the entering the factories, despite their high nutritional and technological value, is discarded as waste. This study aimed to investigate the effect of adding different levels of tomato peel and calcium chloride and replacing the homogenization process with the colloidal mill on the properties of tomato paste through response surface methodology (RSM). The results of this study showed that the use of tomato peel caused a significant increase in the amount of total solids, water-insoluble solids, fiber, consistency and precipitate weight ratio (p <0.05). Applying a three-step homogenization process with a colloidal mill improved the viscosity of the product due to its effect on the properties of suspended particles of the paste matrix, including a significant size reduction, change in particle size distribution and increase surface area. Calcium chloride significantly increased the consistency of the product by reacting with the pectin in the paste and forming a gel network. Microscopic analysis of the samples showed that by increasing the number of homogenization steps from one to three and adding the tomato peel, the matrix uniformity increased and a dense structure was obtained. Creating new peaks and changing the peaks’ intensity at the ATR-FTIR spectrum confirmed the binding of calcium chloride and the fiber distribution in the paste network. The results of this study showed that tomato peel can be used as a consistency-enhancing compound in tomato paste and not only prevent the discarding of a large part of this valuable compound, but also create good added value for the food industry.

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