Food Chemistry
Dara Rezakhani; Abdolmajid Mirzaalian Dastjerdi; Somaye Rastegar
Abstract
The sapodilla fruit has a limited shelf life due to its perishability and rapid moisture loss. The application of edible coatings has attracted much interest because they are effective in prolonging the shelf life of fruits. This study aims to evaluate the effectiveness of an edible coating made from ...
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The sapodilla fruit has a limited shelf life due to its perishability and rapid moisture loss. The application of edible coatings has attracted much interest because they are effective in prolonging the shelf life of fruits. This study aims to evaluate the effectiveness of an edible coating made from xanthan gum (XG) (0.1% and 0.2%) combined with oleic acid (Ol) (1%) in prolonging the shelf life of sapodilla fruit at 8 ± 1 οc and a relative humidity (RH) of 85-90%. Weight loss was significantly reduced in the treated fruits, with the minimum weight loss observed in the Xan 0.2% + Ol treatment. Except for the Ol treatment, the other treatments showed a higher level of firmness compared to the control. At the end of the experiment, the treatments significantly reduced fruit respiration. The treated fruits also showed significantly increased antioxidant capacity and higher levels of ascorbic acid compared to the control. The lowest TSS (22.8%) level was noted in the Xan 0.2 + Ol treatment. Moreover, the results showed that fruit treated with Xan 0.1% + Ol coating exhibited higher activity in the superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) enzymes compared to the fruit treated with Xan 0.2 + Ol coating and the control samples. In general, fruits treated with Xan 0.2 + Ol and Xan 0.1% + Ol demonstrated the highest overall quality compared to the control and other treatments. Therefore, the application of these treatments is recommended for maintaining the quality of sapodilla fruit.
Food Engineering
Hassan Sabbaghi
Abstract
Introduction: Doughnuts are fried foods that absorb significant amounts of oil, and commercial doughnuts made from wheat flour typically contain 24 to 26 percent oil. The use of additives, especially hydrocolloid compounds, in reducing the oil uptake in doughnuts is a practical method because there is ...
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Introduction: Doughnuts are fried foods that absorb significant amounts of oil, and commercial doughnuts made from wheat flour typically contain 24 to 26 percent oil. The use of additives, especially hydrocolloid compounds, in reducing the oil uptake in doughnuts is a practical method because there is no need to make changes in the industrial design of the equipment. Usually, the level of these compounds used to achieve the desired properties in food systems is less than 2% dry basis. When these compounds are added to the dough, they form a gel as soon as possible, which has a high water holding capacity in contact with hot oil, and this will be effective in maintaining and controlling the moisture content of the product and preventing oil penetration. Controlling moisture outflow from the product reduces the rate of moisture migration and compounds from the food into the frying oil, and subsequent peroxidation reactions in the oil consumed are reduced, thus increasing the useful life of the oil. Therefore, in this study, the effect of xanthan gum and carboxymethylcellulose on doughnut quality characteristics was studied. Materials and Methods: For this purpose, in the formulation of doughnut dough, xanthan gums, carboxymethylcellulose and a combination of these two gums (50:50) were used at the rate of 0.5, 1 and 1.5 percent based on the weight of the dry matter of the dough. The doughnut dough was prepared and molded. The fermentation was carried out for 30 minutes under similar industrial conditions (40°C and 40% humidity). Then the frying process at 180°C, icing and packaging were performed, respectively. The moisture content of the dough and doughnuts, the oil uptake of doughnut, density, color and the porosity ratio of the samples were measured. Also, the qualitative characteristics of shelf life, including soft tissue assessment, non-absorption of icing and non-growth of mold were investigated within 14 days. Statistical analysis was performed in a completely randomized design (p<0.05). Results and Discussion: The results showed that, the moisture content of the samples always increased with elevating the percentage of hydrocolloid compounds. Oil absorption decreased with increasing gum percentage and the lowest oil content was observed in the samples containing xanthan gum. Unlike xanthan, the density decreased and the volume increased with elevating the percentage of carboxymethylcellulose gum. Therefore, the highest porosity and softness of the tissue were found in samples containing carboxymethylcellulose. The brightness parameter (L*) was higher in samples containing xanthan, which could be due to the higher moisture content. The red parameter (a*) was also higher in the samples containing xanthan, which due to the higher compression of the product, a relatively more red pigment was observed with increasing xanthan level. The yellowness parameter (b*) in xanthan-containing samples was lower due to reduced oil absorption. The intensity of the color changes (dE) decreased as the percentage of gums increased. Non-absorption of icing was less in hard sample containing xanthan, which could be due to xanthan's competition with gluten in suction of surface water. Mold growth was not observed for any treatment. Overall, the best additive ratio of xanthan gum was 0.5% in terms of reduced oil absorption. Also, the use of carboxymethylcellulose at the level of 0.5% alone could improve the softening of the product texture and made the doughnut with larger volume. Simultaneous use of xanthan gum and carboxymethylcellulose showed behavior under effect of xanthan gum.In general, xanthan gum was more effective than carboxymethylcellulose gum in reducing oil uptake and moisture retention at test levels. Xanthan has shown the greatest reduction in oil absorption due to its thermal gelling and thickening properties, as it has a high capacity for water retention when product is in contact with hot oil. Since the xanthan gum is inexpensive, its effects on product volume can be further investigated in research work, along with bulking agents or other hydrocolloid compounds.
Food Technology
Mohammad Ali Hesarinejad; Atefeh Arefkhani; Ali Rafe; Fatemeh Javidi; Alireza Sadeghian
Abstract
Introduction: Improving the texture and sensory properties of Iranian white cheese by reducing fat content is one of the most important issues that are considered both technologically and economically. Meanwhile, controlling the amount of water absorption in cheese usually causes textural problems in ...
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Introduction: Improving the texture and sensory properties of Iranian white cheese by reducing fat content is one of the most important issues that are considered both technologically and economically. Meanwhile, controlling the amount of water absorption in cheese usually causes textural problems in cheese, including the softness of the cheese texture. Therefore, this problem will be solved if the amount of water absorption in the cheese can be controlled in such a way that the resulting cheese texture does not change and even its quality improves. Currently, the demand for the use of compounds or methods to achieve this goal is increasing. Hydrocolloids are compounds that, due to their inherent nature in absorbing water and creating a mouth-feel like fat, can have a special effect on fat replacement. Therefore, creating a suitable formula in the composition of hydrocolloids can complement the qualitative improvement of cheese texture. Basil seed gum (BSG) is a native hydrocolloid that has shown good stability and emulsifier properties, making it a potential functional ingredient in the food industry. Xanthan gum (XG) is also used in food as a thickener and stabilizer, and also can acts as a gelling agent along with other gums. In this study, by creating a suitable formulation in the use of these hydrocolloids, an attempt is made to improve the texture and sensory properties of cheese. Materials and methods: The effect of different concentrations of mixed-hydrocolloids based on XG/BSG, and Guar gum (GG)/BSG on the textural attributes of Iranian white cheese was investigated. Four cheese treatments (without hydrocolloids or with 0.25, 0.5, or 0.75 g/kg of milk) were produced to study the effects of hydrocolloid content on the textural properties of the product. Cheese samples were analyzed with respect to physicochemical, color, sensory characteristics, textural properties, and microstructure. Results and discussion: The results showed that the higher concentration of hydrocolloids from 0 to 0.075% used, the higher the increasein the moisture content of cheese samples. The results also showed that samples containing GG had higher moisture content than samples containing XG, which is probably due to the higher water absorption capacity of GG than XG. Increasing the concentration of hydrocolloids reduces the fat in the sample, which is due to the absorption and retention of more water in the cheese due to the hydrophilic properties of hydrocolloids. Samples containing GG had a lower fat content than samples containing XG. As the concentration of hydrocolloids increased, lightness increased, indicating the effect of hydrocolloids on the increase in whey cavities. The results also showed more lightness of XG samples than GG samples. Samples containing XG were more rigid, possibly confirming that this hydrocolloid has a greater effect than a mixture containing GG in the strength of the cheese and the effect of the GG is merely thickenning. With the increase in the concentration of BSG/XG (from 0.025 to 0.075%), the hardness increased from 260.96 to 364.23 g. The springiness of all samples also ranged from 0.99 to 1 mm, indicating good reversible behavior. It was found that the formula containing BSG/XG at a concentration of 0.50% had the highest overall acceptance after the sample containing BSG/XG at a concentration of 0.075%. Samples containing gum had low sensory evaluation results, possibly due to high moisture content, and were reported to be undesirable. In terms of taste, the samples did not differ significantly from each other. According to the results of textural analysis and sensory evaluation, the formula containing BSG/XG at 0.075% concentration, due to having the highest score of sensory evaluation and desirable textural characteristics, was selected as the optimal sample. In the microstructure of the desired cheese sample, the location of the whey serum has been determined. By adding hydrocolloid to the cheese, the protein matrix opens. When the sample was prepared for SEM analysis, the moisture was removed. Therefore, the effect of hydrated hydrocolloid was observed in the form of cavities. This structure has enough space to trap water and form a suitable gel.
Battol Attar; Seyedeh Zahra Seyed Alangi; Sara Jorjani
Abstract
Introduction: Value-added products, referring to the fact that a raw commodity or commodities are transformed into a processed product through use of materials and technology, may have different appearances, textures, tastes and smells than their raw material. Fried product is one of the most popular ...
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Introduction: Value-added products, referring to the fact that a raw commodity or commodities are transformed into a processed product through use of materials and technology, may have different appearances, textures, tastes and smells than their raw material. Fried product is one of the most popular ready to eat foods all around the world. They have excellent sensory qualities due to their appealing flavor and texture. Products such as shrimp usually coated with breading before frying to induce additional sensory and quality attributes. The process of battering and breading provides special functions in food products, including improved appearance of the products, increased texture crispness, reduced oil uptake during the frying process and increased the shelf life of the coated products.
Hydrocolloids are used extensively in food technology as thickening and gelling agents, stabilizers, and emulsifiers. In addition, the hydrocolloid coatings are of great interests due to their desirable barrier properties to gas/moisture and good mechanical characteristics. Thus, a variety of foods have been coated with hydrocolloids to prevent moisture loss, preserve texture, and maintain color, consequently extending the product shelf-life. Specifically, the hydrocolloid coatings are often known to reduce the oil uptake of fried foods. The mechanisms of the oil uptake during frying are associated with heat transfer from the frying oil to the food and the migration of water and oil. Various hydrocolloids have been tested as an oil barrier coating material and the effectiveness of hydrophilic and thermo-gelling hydrocolloids in reducing oil uptake during frying has been well reported in previous studies.
Material and Methods: Fresh peeled shrimp (Litopenaeus vannamei) was purchased from Gomishan city, Golestan province, Iran. Xanthan gum was bought from Asia Research Petrochemisry (Iran). White flour, corn flour, breading powder, oil and salt were prepared from the local supermarket. All other chemicals used in this study had analytical grade and were gained from Fluka or Merck companies.
The freezed shrimps were thawed at room temperature before processing. Four different formulations were applied in pre-dusting and battering as following:
Control= without xanthan in pre-dust and batter,
A=2% xanthan in predust,
B=2% xanthan in batter,
C=1% xanthan in predust + 1% xanthan in batter.
The batter formulation was consisted of wheat flour (75%), corn flour (24.5%), salt (0.5%). The dry ingredients were blended for 3 min at speed 2 m/s in a Kenwood Major Classic mixer (Kenwood-BL460) with water (1:1.4 solid to water ratio). In each treatment, firstly, pre-dusting was done and then, battering. Afterwards, it was allowed to drip additional batter for 30 s. For final coating, orange bread crumbs were used (Gols Company). The samples were pre-deep-fried by sunflower oil at 190 °C for 30 s (Fritaurus Professional 3 domestic fryer, Barcelona, Spain). The treatments were cooled to room temperature for 30 min. Then, they were placed in plastic freezer bags (LDPE film, thickness 150 μ) and stored at -18 °C.
Moisture content in the samples was determined in quadruplicate according to the Association of Official Analytical Chemists (AOAC) (2000) method. Fat content of fried products was distinguished using Soxhlet extractions according to the AOAC (2000) method No. 992.15.
Batter pickups (%) were determined as following equation:
Batter pickup (%) = (Weight of coated shrimp–Weight of uncoated shrimp)/(Weight of coated shrimp)×100
Product yield (%) was calculated by weight of the cooked shrimp block/ weight of the raw shrimp block × 100.
Quantitation of fatty acid methyl esters in raw and fried breaded shrimp was carried out by gas chromatography (Unicam-4600) with 30 mm×0.25 mm column (Film Tekness-0.22 μl) and FID detector, using glyceryl tritridecanoate (C13:0) as an internal standard (Sigma, Barcelona, Spain). Fatty acids were expressed as percentage of total fatty acid methyl esters or in absolute content (mg/100 g food).
Fried shrimp coated with the selected formulations was evaluated by a trained sensory panel of 12 members. Each sample was randomly numbered and presented to the panel member. A hedonic panel was also performed by the same panelists, who evaluated aroma, taste, texture, color, appearance and overall acceptability characteristics. A hedonic 5-point scale was used, 1s unusable, 2s dislike, 3s acceptable, 4s like and 5s like very much. All data are reported as mean± standard deviations of triplicate. One-way analysis of variance (ANOVA) was used to compare the means of all evaluated parameters. Differences were considered significant at P
Sepideh Amirabadi; Arash Koocheki; Mohebbat Mohebbi
Abstract
In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture ...
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In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture properties, crumb and crust color were examined. To investigate the effect of gums on the shelf-life, all cakes were stored for sixth days. Results showed that there were a positive correlation between viscosity of batter and cake volume. Both gums improved chiffon cake properties after removing from the oven and during storage. It was found that using 0.1% xanthan gum increased the cake volume, cohesiveness and sensory scores, decreasing firmness and moisture loss during storage of cake.
Nasrin Faraji; Mohammad Alizadeh khaled abad; Asghar Khosrowshahi; Soheila Faraji
Abstract
Heart disease - cardiovascular, cancer and obesity are the main causes of death and there are direct relationship between the consumption of high-fat foods and the incidence of these diseases. Therefore the demand for low-fat food products and probiotics has been dramatically increased. In this study, ...
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Heart disease - cardiovascular, cancer and obesity are the main causes of death and there are direct relationship between the consumption of high-fat foods and the incidence of these diseases. Therefore the demand for low-fat food products and probiotics has been dramatically increased. In this study, the effect of different levels of three hydrocolloids (inulin, chitosan and xanthan) at three levels (1, 2 and 3%) on survival of Lactobacillus acidophilus, physicochemical and sensory properties of yogurt during 15 days of storage was explored using a combined design. Increased levels of inulin and chitosan positively affected La-5 count, apparent viscosity, acidity and sensory scores during storage. Using graphical method of optimizing (overlaid contour plots), optimum ratios were: inulin 93.4%, xanthan 0.6% and chitosan 6%.
