Ghazaleh Abdollahi Moghaddam Masouleh; Leila Nateghi; Kian Pahlevan Afshari
Abstract
One of the most widely used methods for sanitizing and reducing the microbial load of fruit juices is thermal pasteurization, which damages bioactive pigments such as anthocyanins. This study was conducted to evaluate the possibility of pasteurization of grape juice by ultrasound (at ...
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One of the most widely used methods for sanitizing and reducing the microbial load of fruit juices is thermal pasteurization, which damages bioactive pigments such as anthocyanins. This study was conducted to evaluate the possibility of pasteurization of grape juice by ultrasound (at powers 10, 105, and 200 W, temperatures 0, 30, and 60 °C, and times 2, 6, and 10 min) and to compare the microbial load and color properties by thermal pasteurization (pasteurization at 90 °C for 30 sec). According to the results, the number of color components (a*, b*, and L*) and the total count of microorganisms in pasteurized grape juice decreased significantly (p≤0.05) as the power, temperature, and time increased. Optimal conditions for simultaneous pasteurization by ultrasound to achieve the minimum microbial load and the maximum number of color components with 90.196% desirability were predicted at a power of 113 watts, a temperature of 60 °C, and a time of 8.850 min. The microbial load of pasteurized grape juice by ultrasound was 0 (CFU/ml), and the number of color components was L*= 18.8021, a*= 37.8406, and b*=27.2104. The results indicated that the pigments of grape juice could be preserved and the same safety in terms of microbial load reduction could be achieved through pasteurization by ultrasound.
Amir Hossein Elhami Rad; Atefeh Ghorbani; Leila Nateghi; Mohammad Hossein Haddad Khodaparast; Fatemeh Zarei
Abstract
In this study, the structure and physicochemical properties of mucilage extracted from Malva flowers were investigated. The mucilage suspension contains large particles with low polydispersity showing low stability due to low zeta potential. The morphology of particles indicates polyhedral ...
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In this study, the structure and physicochemical properties of mucilage extracted from Malva flowers were investigated. The mucilage suspension contains large particles with low polydispersity showing low stability due to low zeta potential. The morphology of particles indicates polyhedral monodisperse particles. The predominantly present element is potassium and the most important functional group by FTIR is carboxylate at the wavelength of 1623cm-1 and 1407 cm-1, pyranose vibratory ring at 1256cm-1, and 1062cm-1, and Beta configuration at 780 cm-1 and 618 cm-1. Results of NMR also suggested the presence of sugars in the mucilage. Its low enthalpy (193.27J/g) is due to the presence of ordered granules. Also, a high glass transfer temperature (95.4°C) indicates a high crystallization rate thus a stable structure and heat–resistant granules.
Leila Nateghi
Abstract
Date syrup is healthy food for consumers especially people with diabetes because of its minerals, high amount of natural sugars such as fructose and glucose, and low percentage of sucrose. The objective of this study was to evaluate the effect of sugar replacement with date syrup on ...
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Date syrup is healthy food for consumers especially people with diabetes because of its minerals, high amount of natural sugars such as fructose and glucose, and low percentage of sucrose. The objective of this study was to evaluate the effect of sugar replacement with date syrup on the physicochemical and sensory properties of quince jam. Date syrup at concentrations of 0 (control), 25, 50, 75, and 100% w/w was used in place of sucrose in the formulation of quince jam. As the concentration of date syrup increased, pH, Brix, viscosity, and calories decreased and acidity increased. With increasing concentration of date syrup, L* index decreased significantly (p≤0.05). The results of the sensory evaluation showed that the replacement of sugar with 50% of date syrup resulted in improved sensory properties as compared to control, however at higher concentrations it caused dark color and sour taste in the product. The sample containing 100% date syrup had the lowest calorie and the highest protein content as compared to other treatments, so it could be desirable in terms of nutritional and health properties. The addition of date syrup in place of sugar up to 50% improved the sensory properties of quince jam when compared to control, therefore it was selected as the superior treatment for sensory and health properties
Shima Moazzezi; Amir Hossein Elhamirad; Leila Nateghi; Mohammad Hossein Haddad Khodaparast; Fatemeh Zarei
Abstract
Food products could be exposed to heat treatments during manufacture, storage, and distribution chains which can affect the rheological properties of hydrocolloid solutions. Viscosity is an important factor for quality evaluation in many food products. In the current study marshmallow ...
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Food products could be exposed to heat treatments during manufacture, storage, and distribution chains which can affect the rheological properties of hydrocolloid solutions. Viscosity is an important factor for quality evaluation in many food products. In the current study marshmallow seed mucilage, as a potential new source of hydrocolloid, was prepared at concentrations of 4, 6, and 8 % (w/v) and subjected to heat treatments at 30, 55, and 80 °C. Afterward, time-independent rheological behaviors of examined concentrations were assessed by using a rheometer. The findings revolved around that marshmallow seed mucilage showed a pseudoplastic behavior (n<1) as well as in the power low model. In the mentioned model the consistency coefficient (K) of all analyzed concentrations significantly has been increased at different temperatures (p≤0.01). Also, the flow behavior index value changed from 0.5092 to 0.7934 and showed a significant decrease at higher temperatures (55 and 80 °C) and also as a result of increasing in concentration. The concentrations of 4 % and 8% showed the highest temperature-dependency of consistency coefficient and flow index, respectively. In contrast, the lowest temperature dependency of consistency coefficient and flow index were detected at 6 and 4 % mucilage solution, respectively. At low concentrations, Bingham and at high concentrations Casson models, in addition, Hershel-Bulkley model best fitted with the mucilage solution.
