Food Technology
Amineh Avami; Mostafa Mazaheri Tehrani; Mohebbat Mohebbi; Fatemeh Pourhaji
Abstract
There is a challenge in producing a portion both compatible to ketogenic diet and sufficient satiety. This study investigated the possibility of producing sugar-free chocolate product using increasing total fat and protein. The ingredients were chosen such that they do not contain any source of starch ...
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There is a challenge in producing a portion both compatible to ketogenic diet and sufficient satiety. This study investigated the possibility of producing sugar-free chocolate product using increasing total fat and protein. The ingredients were chosen such that they do not contain any source of starch and sucrose. The cocoa powder was replaced with cocoa butter substitute (CBS) and sodium caseinate at different levels (0, 5 and 10%) along with constant amount of stevia ketogenic powder and soybean hull as sugar substitute. Results showed that cocoa powder substitution significantly (p< 0.05) led to an increase in moisture, water activity, fat and protein and a decrease in ash and carbohydrate amount, respectively. It was also observed that addition of sodium caseinate and CBS made the chocolate softer and to be easily melted (p< 0.05). Sensory analysis showed that samples with high protein and fat content got better scores in overall acceptance (p< 0.05). Also, principle component analysis showed that the first two components could explain about 81% of total variance. Finally, the best composition was determined by considering both TPA, DSC and sensory properties. This sample contained 5% sodium caseinate and 35% CBS. Moreover, total sugar content and calorie amount of this sample was 2.17% and 547.41 kcal, respectively. The peroxide value of optimized sample was 0.5 meq per kg immediately after production and it reached to 1.13 meq per kg after two months. Consuming 100 g of this chocolate can supply 27% of daily calorie of an adult person (assuming 2000 kcal per day for adults). Consuming this 100 g can also supply 17% and 40% of classic and atkins keto diet. These results showed that, the selected sample with 35% CBS and 5% sodium caseinate could be compatible to ketogenic diet but more clinical research should be done in future.
Food Technology
Bahareh Sahraiyan; Fatemeh Pourhaji; Behrooz Alizadeh Behbahani
Abstract
Introduction: Celiac disease leads to the malabsorption of nutrients and damage to intestinal mucosa. High nutritional value is one of the advantages of dairy powders, associated with their high calcium, protein and essential amino acid contents. Research has shown that such powders boost the gluten ...
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Introduction: Celiac disease leads to the malabsorption of nutrients and damage to intestinal mucosa. High nutritional value is one of the advantages of dairy powders, associated with their high calcium, protein and essential amino acid contents. Research has shown that such powders boost the gluten quasi-network by forming interfacial films. They are also able to increase the moisture, improve the organoleptic properties, and retard the staling of gluten-free bakery products. In addition, it has been reported that ultrasonic waves can accelerate the oxidation and increase the aeration, volume, porosity and moisture content of bakery products. They can also reduce the hardness and improve the color of such products, thus resulting in the enhancement of their quality and marketability. Consequently, the aim of this study was to improve the appearance, flavor and texture of the gluten-free cake based on rice, germinated quinoa and potato flour using cheese powder at 0, 3, 6 and 9% and ultrasound intensity of 0, 30 and 70% for 5 min. Material and methods: In this study, cheese powder at 0, 3, 6 and 9% and ultrasound intensity of 0, 30 and 70% for 5 min were used to improve the quality of gluten-free cupcake. Control cake formulation had 70 g rice flour, 15 g germinated quinoa flour, 15 g potato flour, 52 g sugar, 50 g water, 36 g egg, 36 g oil, 12 g invert syrup, 2 g baking powder, 0.2 g vanilla, 1.5 g guar gum and 0.5 g xanthan gum. Moisture, specific volume, firmness, crust and crumb color, sensory properties, porosity and scanning electron microscopy (SEM) (with 100× magnification) were evaluated. To study the effect of processing parameters on color components of gluten-free cupcake, the RGB color space images were converted to L*a*b space. For determination of gluten-free cupcake porosity using image analysis, the color images were first gray scaled and then thresholded using isodata algorithm. The porosity was measured from the ratio of white to the total numbers of pixels. Results were reported as the average of three replications. In order to assess significant differences among samples, a complete randomized design of triplicate analyses of samples was performed using the Mini-Tab17. Turkey’s new multiple range tests were used to study the statistical differences of the means with 95% confidence. Result and discussion: Results revealed that moisture content increased as the cheese powder and ultrasound intensity were elevated. Cheese powder caused the moisture content to increase by boosting the gluten quasi-network and ultrasonic waves brought about this phenomenon by dissociating the polymeric chains of starch molecules and forming hydrogen bonds between water molecules and free hydroxyl groups. The sample containing 6% cheese powder sonicated at 30% intensity had higher specific volume (4/4 Cm3/g) and porosity (31.2%) as well as lower hardness (3.4 and 4.4 N after 2 hours and one week respectively) compared with other samples. Cheese powder, by boosting the gluten quasi-network and improving the dough elastic properties, and ultrasound, through enlarging the air bubbles present in the dough, caused an increase in the porosity, specific volume and softness. The results also indicated that the rise in the cheese powder content up to 6% led to an increase in the L* value (from 44.9 to 53.5) and up to 9% in the a* value (from 2.6 to 8.4) of the gluten-free cupcake crust. On the other hand, the results demonstrated that as the ultrasonic intensity was increased, the L* value of the gluten-free cupcake crumb also increased (from 60.3 to 77.9), while its b* value was reduced (from 17.3 to 7.9). This could be due to the aeration and oxidation acceleration which resulted in the increased whiteness and decreased yellowness of the cake crumb. Finally, the findings of sensory evaluation showed the preference of the samples containing 3 and 6% cheese powder sonicated at 30% intensity (4.2 and 4.4 score). The SEM and binary images of the preferred samples also confirmed the integrity of the internal structure and the gluten quasi-network of these samples, compared with the control.
Fatemeh Pourhaji; Farideh Tabatabaei Yazdi; Seyed Ali Mortazavi; Mohebbat Mohebbi; Mostafa Mazaheri Tehrani
Abstract
Introduction: Banana is one of the most consumed fruit in the world and is cultivated almost in all tropical countries. This fruit has a high nutritional value and is a suitable source of energy due to the presence of high amount of starch, sugar, vitamin A and C, potassium, sodium, and magnesium. Banana ...
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Introduction: Banana is one of the most consumed fruit in the world and is cultivated almost in all tropical countries. This fruit has a high nutritional value and is a suitable source of energy due to the presence of high amount of starch, sugar, vitamin A and C, potassium, sodium, and magnesium. Banana is highly vulnerable after harvesting and is subject to the microbial spoilage due to the high moisture content which makes difficult its sales and exports. Therefore, several methods have been used to overcome these problems. Drying and dehydration are methods to extend the shelf life of banana which usually carries out by hot air. This method can prevent some degree of microbial spoilage, but it has some disadvantages such as changing color, taste, flavor and reducing the nutritional value.
Foam-mat drying as a substitute for hot air drying introduces some advantages such as using the microwave energy. In this method, food products are whipped to form stable form and then dehydrated by thermal means. Due to the larger surface area and accelerated moisture transfer from foam, food products can be dried at lower temperature and time by this method of drying. Moreover, the porous structure of dried foam results in a faster rehydration and solubility of dried food samples. Additionally, microwave-assisted drying results in a product with better quality because of faster rate and saving energy.
Materials and methods: The fresh banana was cut into small pieces with a diameter of 1.0 mm after peeling. To prevent the enzymatic browning of samples, blanching was carried out by boiling water (100 °C) for 3 min. After that, the banana cuts were placed in a container containing 10°C water in order to cool. To produce pulps, the homemade Bosch mixer (model w600, CNSM, 30EW, Slovenia) at a speed of 1500 rpm and 1.0 min was used. Then, the pulps were mixed with skim milk at different concentrations (3-6 % w/w) and homogenized by ultra-turrax (IKA® Labortechnik) at 10000 rpm for 5.0 min. Moreover; the prepared xanthan gum was added to the mixture at concentrations of 0.15 and 0.25%. Xanthan gum was prepared by adding 1.0 g gum into 100 mL water and mixing by magnet stirrer. Afterwards, the gum solution was kept overnight at 4 °C for complete hydration. Finally, the sample transferred into the foam-maker device which was connected to a nitrogen gas tank with different flow rate (0.2-2 L min-1). The speed and time were adjusted to 16000 rpm and 5.0 min, respectively. After the producing of banana milk foam and selecting optimum sample based on the lowest density and the highest stability, the drying kinetic of this sample was studied. Then the banana milk foam was dried using microwave (360, 660 and 900 V) in a glass plate with diameter of 3.0 and 5.0 mm. Foam density and stability were determined by the methods of Xian-Zheetal (2010), Stauffer (1999) and Bag et al. (2010). The color of samples was studied by hunterlab. Moisture content also was measured based on the AACC standard method (AACC, 2000). Glass transition temperature also was determined by differential scanning calorimetry (DSC, model OIT-500 Sanaf Electronics Co, Iran).
Results and Discussion: In the present study, foam-mat method and microwave drying were used to reduce the drying damages. Nitrogen gas and xanthan gum also were used respectively to control foam generation and improve the stability of foams. Optimization of the banana milk production was carried out using response surface methodology based on three variables including the rate of nitrogen gas (0.2-2 L min-1), concentration of xanthan gum (0.15-0.25 %) and milk to banana ratio (1:6 and 1:3). Optimization was done based on the highest stability and lowest foam density. The optimum condition was proposed as the nitrogen gas rate of 0.2 L min-1, xanthan gum of 0.22 % and 3% banana which showed the density of 0.39 and the highest stability (0 mL after 1.0 h). After that, the optimum sample was dried by microwave. The effects of three levels of microwave voltage (360, 660 and 900 V) and two diameters (3 and 5 mm) were evaluated for drying of optimum sample. The results showed that the sample dried with diameter of 3 mm and voltage of 900 V had the highest L*, highest glass transition temperature and the lowest moisture content.
