Maryam Farahmand; Mohammad Taghi Golmakani; Asgar Farahnaki; Gholam Reza Mesbahi
Abstract
Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate ...
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Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate and its polyphenols. Pomegranate fruit has valuable compounds with functional and medicinal effects like antioxidant, anticancer, and anti-atherosclerotic effects. Storage of juice concentrate can have a dramatic impact on physicochemical quality. The bioactive compounds and antioxidant activity in fruit juice products are influenced by many external factors like different storage temperatures. Knowledge of the rheological behaviour of juice products is essential for product development, design and evaluation of process equipment like pumps and piping. Pomegranate concentrate is so susceptible to the condition of storage, which results in a reduction in consumer acceptability and quality losses. Accordingly, the industrial concentrate stores frozen (-20 °C) which has a lot of costs to the producer. The objectives of this study were to evaluate the degradation visual color, the rheological characteristics of pomegranate juice concentrates, the stability of phytochemicals, the antioxidant activity, and the haze formation of reconstituted pomegranate juice concentrate during storage at different temperatures to determine the best storage conditions to reduce the quality losses and solving the problem about high cost of storage.
Materials and methods: The concentrated pomegranate (Punica granatum (L.) cv. Rabab) juice used in this study supplied from Narni (Green farm, Neyriz, Iran) factory. The pomegranate juice concentrate was poured into falcons for measuring physicochemical attributes, and micro tubes for determination of antioxidant activities. Then the samples were divided into four parts and stored equally in four different temperatures (-20, 4, 20, and 35 °C). The control samples were stored at -80 °C as fresh sample for the storage period (140 days). Folin-Ciocalteu reagent and 2,2-diphenyl-1-picrylhydrazyl radical (DPPHº) were supplied from Sigma-Aldrich Company (St. Louis, MO, USA). All other chemicals were of analytical grade and purchased from Merck Company (Darmstadt, Germany). The total soluble solid (TSS) was determined with a digital refractometer (Carl Zeiss, Germany). Total insoluble solid was measured by centrifugation at (5,000 × g) according to the IFFJP method 60, using a high speed centrifuge (Ibarz et al., 2011). The haze formation of reconstituted juice was determined by “settling” in a glass tube for 3 hour at room temperature. Color measurements of the juice samples were carried out using a HunterLab (CHROMA METER CR-400/410, KONICA MINOLTA, Japan) after dilution. The rheological characteristics of the pomegranate juice concentrate stored in different temperatures were studied by using a computer controlled rotational viscometer. Sample compartment was monitored at a constant temperature (25°C) using a water bath/circulator, while TSS was 65 °Brix. The viscosity measurements, was carried out According to the methods described by Cárdenas et al., (1997), using a Brookfield cone and plate viscometer (DVII pro Brook field, USA) between the shear rate of 0.5–200 (1/s). Total phenolic content of samples was measured according to the Folin-Ciocalteu colorimetric method (Sun et al., 2007). Total flavonoid content in juices was determined via a spectrophotometer according to the method of Chang et al. (2002). Radical scavenging activities of the samples were measured by using DPPHº as described by Mazidi et al., (2012). The ferrous ion reducing antioxidant power (FRAP) of the samples was measured calorimetrically according to the method by Fawole and Opara (2013). All analyses were performed by the Statistical Analysis System (SAS) software V 9.1 (SAS Institute, Inc., Cary, NC, USA). By using the analysis of variance (ANOVA), the differences among means were determined for significance at P< 0.05.
Results and discussion: The industrial pomegranate juice concentrate stored at (-20, 4, 20, and 35 °C) for 20 weeks, and some physicochemical properties like the second turbidity, CIE Lab color parameters, the rheological properties, the bioactive component (total phenolic and flavonoid contents), and antioxidant properties (FRAP and DPPH) investigated in order to determine the best condition of storage. The second turbidity was obvious among the samples stored at 35 °C in the last fourth weeks. Although there were no significant differences among L* value of the samples stored at -20, 4, and 20 °C, a* and b* value of the samples stored at -20 and 4 °C had the same reduction trend for 14 weeks. Even though the control samples had shear thinning behavior, the samples showed a dilatant behaviour after storage. Antioxidant activities measured via DPPH and FRAP sowed reduction with increasing time and temperature. Flavonoid content increased by increasing time and temperature. In conclusion, storage at 4 °C for 14 weeks was the best storage condition to keep the quality and reduce the costs.
Mohsen Gavahian; Reza Farhoosh; Asgar Farahnaki; Katayoun Javidnia; Fakhri Shahidi
Abstract
As traditional extraction methods like Hydrodistillation (HD) and steamdistillation (SD) have long extraction times, some novel extraction methods like microwave-assisted hydrodistillation (MAHD) and ohmic-assisted hydrodistillation (OAHD) are recently introduced. In this study, essential oils of Mentha ...
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As traditional extraction methods like Hydrodistillation (HD) and steamdistillation (SD) have long extraction times, some novel extraction methods like microwave-assisted hydrodistillation (MAHD) and ohmic-assisted hydrodistillation (OAHD) are recently introduced. In this study, essential oils of Mentha piperita were extracted by OAHD and MAHD and the results were compared with those of the SD and HD to clarify if these novel procedures have significant effect on antioxidant activities of extracted essential oils. The results showed that OAHD and MAHD are able to reduce extraction time (up to 72%) and also required electrical energy. Furthermore, all extracted essential oils were shown to have approximately same physical properties (relative density and visual color) and antioxidant activity using DPPH and β-carotene bleaching methods. The findings of this study revealed the applicability of using mint essential oil obtained by MAHD and OAHD as a natural antioxidant in food and pharmaceutical products.
Mohsen Gavahian; Reza Farhoosh; Asgar Farahnaki; Katayoun Javidnia; Fakhri Shahidi
Abstract
Ohmic-assisted hydrodistillation (OAHD) is an advanced hydrodistillation (HD) technique utilizing ohmic heating process and could be considered as a novel method for the extraction of essential oils. Long extraction time is one of the major problems with traditional methods. OAHD of essential oils from ...
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Ohmic-assisted hydrodistillation (OAHD) is an advanced hydrodistillation (HD) technique utilizing ohmic heating process and could be considered as a novel method for the extraction of essential oils. Long extraction time is one of the major problems with traditional methods. OAHD of essential oils from the aerial parts of peppermint was studied and the results were compared with those of the conventional HD. The results showed that OAHD method had the extraction time of 19.71 min while this value was about 55.88 for HD. Scanning electron micrographs of mint leaves showed a sudden eruption of essential oil glands for OAHD samples. GC- MS analysis did not indicate any noticeable changes in the compounds of the essential oils obtained by OAHD in comparison with HD. The results introduced OAHD as a green technology.
Sara Hoseinpoor; Mohammad Hadi Eskandari; Gholam Reza Mesbahi; Shahram Shekarforoush; Asgar Farahnaki
Abstract
Nitrite is responsible for some characteristics of cured meat products such as color, flavor and suppressing
the outgrowth and production of toxin from Clostridium botulinum. Despite all of its desired properties, nitrite is
responsible for the formation of carcinogenic N-nitrosamine. In this study, ...
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Nitrite is responsible for some characteristics of cured meat products such as color, flavor and suppressing
the outgrowth and production of toxin from Clostridium botulinum. Despite all of its desired properties, nitrite is
responsible for the formation of carcinogenic N-nitrosamine. In this study, nitrite-free and low-nitrite meat
curing systems were developed to eliminate or reduce nitrite from meat products. Thirteen different formulations
were made including standard frankfurter ingredients with or without nitrite in combination with cochineal and
paprika as natural coloring agents. For example, control sample was with 120 mg/kg nitrite, low-nitrite sample
was contained 40 mg/kg nitrite and some samples were without nitrite. The samples were stored at 4 oC for eight
weeks. During the storage, color changes (L*, a*, b*) were determined and evaluated. Also, the produced
samples were exposed to natural and artificial light and their color stability were compared. In addition, the
colors of samples were evaluated by trained panelists. The results showed that the sample with 40 mg/kg nitrite
and 0.002 % cochineal, the sample contained 40 mg/kg nitrite and 1 mg/kg paprika and the sample without
nitrite and contained 0.015 % cochineal had no significant different color (p
Hassan Afshari Jooybari; Asgar Farahnaki; Mahsa Majzoobi; Gholam Reza Mesbahi; Mehrdad Niakosari
Abstract
Mazafati date is a wet and semi-dried date fruit type with dark red to black color that has premier quality. Because of its high moisture content, date fruits of this variety are very perishable at room temperature and therefore must be refrigerated during storage. In this study, effect of air temperature ...
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Mazafati date is a wet and semi-dried date fruit type with dark red to black color that has premier quality. Because of its high moisture content, date fruits of this variety are very perishable at room temperature and therefore must be refrigerated during storage. In this study, effect of air temperature (50, 60, 70, 80 and 90 ˚C) and air flow rate (1, 1.5 and 2 m/s) in hot air drying of Mazafati date were investigated. The results showed that for all samples, drying occurred at the falling rate stage of drying and the main factor affecting the drying rate was air temperature. Air flow rate did not have significant effect on drying rate. Overall, it was concluded that moisture of Mazafati dates can be reduced by cabinet drying and therefore using drying process, the need for their cold storage can be eliminated.
Sara Hoseinpoor; Behnaz Layegh; Asgar Farahnaki; Gholam Reza Mesbahi; Mahsa Majzoobi; Nazanin Darabzadeh
Abstract
Pectin is used as a gelling, texturizing and emulsifying agent in many foods. Sugar beet pulp is a good source of pectin, however due to its low molecular weight and poor gelling characteristic its uses in food industry are limited. In this research, pectin extracted from sugar beet pulp was cross-linked ...
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Pectin is used as a gelling, texturizing and emulsifying agent in many foods. Sugar beet pulp is a good source of pectin, however due to its low molecular weight and poor gelling characteristic its uses in food industry are limited. In this research, pectin extracted from sugar beet pulp was cross-linked by phosphorus oxycholride at pH 11 to improve it functional properties. Rheological tests carried out revealed that modified pectin had a higher viscosity and greater intrinsic viscosity and molecular weight than native pectin confirming the cross-linking of pectin polymers. Ketchup sauces formulated using modified and native pectins were compared with the control sample without pectin. The results showed that the sample containing modified pectin had a higher consistency and a lower syneresis value compared to the native pectin.
Keywords: Pectin, Sugar beet pulp, Cross-linking, Viscosity, Functional properties
Mahsa Majzoobi; Gholam Reza Mesbahi; Farnaz Sariri; Asgar Farahnaki; Jalal Jamalian
Abstract
The main aim of this study was to improve the bread quality and to postpone its staling. Therefore, sugar beet pulp powder was added to Barbari bread dough formulation at five levels of 1, 3, 5 and 10% (w/w, flour basis). Then the properties of dough and the resulting bread were studied. The results ...
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The main aim of this study was to improve the bread quality and to postpone its staling. Therefore, sugar beet pulp powder was added to Barbari bread dough formulation at five levels of 1, 3, 5 and 10% (w/w, flour basis). Then the properties of dough and the resulting bread were studied. The results showed that with increasing the sugar beet pulp powder, the water absorption of the dough and the fiber content of the bread increased while, bread density and hardness decreased. The electro-micrographs of the bread crumb containing sugar beet pulp powder indicated the improved texture which can delay bread staling. Sensory evaluation of the samples revealed that the bread made with up to 5% sugar beet pulp powder had the highest general acceptability. However, higher levels of sugar beet pulp powder had diverse effects on bread color which would reduce general acceptability of the samples. It was concluded that sugar beet pulp powder can improve the quality of bread and delay its staling.
Keywords: Sugar beet pulp, Dietary fiber, Bread staling, Bread texture
Hassan Afshari Jooybari; Asgar Farahnaki
Abstract
Color and appearance are among the first parameters perceived by consumers to judge the quality of foods. L*a*b* are used to report foods’ colors quantitatively. In this study the use of digital imaging and Photoshop software was evaluated for measurement of L*, a* and b* color parameters. The results ...
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Color and appearance are among the first parameters perceived by consumers to judge the quality of foods. L*a*b* are used to report foods’ colors quantitatively. In this study the use of digital imaging and Photoshop software was evaluated for measurement of L*, a* and b* color parameters. The results showed that L*, a*, and b* values from Hunter colorimeter and the digital imaging method had a good correlation with R2 more than 0.95, but the values from digital imaging method can be used only to monitor the trend of color changes and the actual numbers of digital imaging L*, a* and b* obtained by digital imaging do not have the same value as the L*, a* and b* given by a Hunter colorimeter. Using two equations for the three parameters the values obtained from digital imaging method can be successfully converted to Hunter Lab color corresponding parameters. The color change of Mazafati date during accelerated ripening using acetic acid solutions was monitored by the proposed method. L*, a*, and b* of the samples all decreased over the ripening.
Key words: Colorimetry, Photoshop software, Digital imaging, Mazafati date
Gholam Reza Mesbahi; Ali Asghar Zomorodian; Mojtaba Dadashzadeh; Asgar Farahnaki
Abstract
In recent years immense interest has been focused on the use of solar dryers especially when taking into consideration economical and ecological aspects and increasing in fuel costs. The aim of this study was to compare the qualitative factors of raisins made by five different drying methods. At the ...
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In recent years immense interest has been focused on the use of solar dryers especially when taking into consideration economical and ecological aspects and increasing in fuel costs. The aim of this study was to compare the qualitative factors of raisins made by five different drying methods. At the first step, pretreatments were applied to grapes (Var. Sultanas) and then the grapes were dried by five methods, including open-sun drying, shade drying, drying by industrial cabinet dryer and two different modes of solar drying namely mixed and indirect type. The shortest drying time was obtained with industrial cabinet drying, but mixed and indirect solar drying were more effective than open-sun drying and shade drying. Moisture content, acidity, sensory properties (color, texture, flavor and overall acceptance) and microbial level of the produced raisins were determined and compared. The texture of the raisin samples was evaluated by texture analyzer device as well. The color of the samples was measured and analyzed by a novel digital imaging method for measuring color of foods.The results indicated that the solar dryers were not only able to produce raisins similar to other drying methods but also the raisins produced by these dryers were in some qualitative factors (consumers overall acceptance and color) better than the other raisins.
Keywords: Raisin, Grape, Drying, Solar dryer, cabinet dryer.
