Zhaleh Sadat Ladjvardi; Mohammad Saeid Yarmand; Zahra Emam-Djomeh; Amir Niasari-Nasalji
Abstract
Introduction: In recent decays, consumers have more information about foods. Vegetables, crops and other natural food with high nutritional value replace hazardous substances. In this study, the effects of locust bean gum and xanthan gum with β-glucan were investigated in camel synbiotic yogurt ...
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Introduction: In recent decays, consumers have more information about foods. Vegetables, crops and other natural food with high nutritional value replace hazardous substances. In this study, the effects of locust bean gum and xanthan gum with β-glucan were investigated in camel synbiotic yogurt functional. Locust bean gum (LBG) has about 88% of galactose and mannose, 4% other polysaccharides, 6% protein, 1% cellulose and 1% the ashes (Nasirpour, 2013; Hansen, 1993).Xanthan gum is an extracellular polysaccharide produced by Compestris Xanthomonas in aerobic fermentation process. Xanthan reactions synergies with guar and LBG, so the low concentrations in the presence of LBG viscosity increase (Ramirez-Figueroa et al., 2002).In this study, the oats β-glucan inoculated with probiotic bacteria to camel milk for production of functional synbiotic yogurt was employed. The camel milk has high nutritional value such as insulin-like substance, less lactose, immuno-globulins and lactoferrin, antioxidants and antimicrobial agents and other nutrients (ladjevardi et al., 2015; Niasari Naslaji et al., 2011). Synbiotic dairy product made from combinations of probiotic bacteria with prebiotics agent (β-glucan). About 108- 107 cfu/mL of live bacteria should be in the final products (Faraj et al., 2012). β-glucan is an indigestible carbohydrate complicated (Theuwissen & Mensink, 2008) with very high nutritional properties, including improved intestinal activity (fibers), lowering uric acid blood, stimulating the immune system (Xue et al., 2013; Chao et al., 2013). Materials and Methods: At first, camel milk (from Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Iran) was standardized by centrifugation (Universal 320, Hettich, Tuttlingen, Germany) to 1.9% fat content. Then xanthan gum and locust bean gum (1:1) were added in three level 0.1, 0.2 and 0.3%. β-glucan (extracted from oats as described by Moura et al. (2011() in 1.5, 2 and 2.5% levels was added to milk. Camel milk was homogenized with ultra-turrax blender (T25, IKA, Staufen, Germany) in speed 9000 r.p.m. Then, the milk sample was pasteurized for 15 min at 75±1 °C. Samples were prepared by adding yogurt starter culture (1.5%) containing probiotic microorganisms (ABY1, Cristian Hansen, Hørsholm, Denmark) at 42 °C. The mixtures were redistributed into 50 mL sterile plastic cups, incubated at 42 °C until their pH decreased to 4.6, they cooled and stored at 4±1 °C ( Mazloomi et al. 2011). Determination of water-holding Capacity (WHC)5 g of yogurt was centrifuged (Mikro 220R, Hettich, Tuttlingen, Germany) at 4500 r.p.m. for 30 min at 10°C. After centrifugation, the supernatant was removed and the pellet was collected and weighed. Microbial Analyses1 g of yogurt with 9 mL of normal saline (a solution of 0.9 % (w/v) NaCl ( Merck, Darmstadt, Germany)) was mixed and diluted to a concentration of 106 and 107, and then 1 mL of each dilution was repeated in 2 plate containing the MRS-Agar (Merck, Darmstadt, Germany) with 0.15% Bovin-Bile (Sigma-Aldrich, Louis, MO, USA). Bacteria were counted by the pour plate technique. The plates in duplicates were incubated anaerobically at 37 °C for 72 h, after this period, colonies were counted (Mishra and Mishra 2012). Statistical AnalysisThe response surface methodology (RSM) and ANOVA (p<0.05) were used for data analysis using Design Expert 8 (Version 8.0.7.1, Minneapolis, MN, U.S.A) software. The experiment was designed according to central composite design (CCD). All experiments and measurements were conducted in triplicate, mean value ±sd are reported. Result and discussionWater-Holding Capacity (WHC)Changes of xanthan gum, LBG, β-glucan and time storage have a significant effect on the WHC. Increasing the percentage of LBG, xanthan gum and the percentage of β-glucan significantly increased the WHC. Time storage reduced the WHC similar results of Ladjevardi et al. (2015) and Sahan et al. (2008).According ANOVA table, the products had maximum water holding capacity at the highest percentage of LBG and xanthan gum. The percentage of xanthan gum and β-glucan increased water holding capacity. These factors (LBG and xanthan gum, xanthan gum and β-glucan) have a synergistic effect on each other mutually.Xanthan gum and LBG showed interaction effect with time storage on changes in WHC including maximum water retention in the sample tissue, the high percentage of gums and the early days of production. Viability of probiotic bacteriaViability of probiotic bacteria significantly increased when used from high percentage of β-glucan (as a prebiotic agent) in synbiotic yogurt. This change was related to increasing food for probiotic bacteria (Kearney et al., 2011). According to the results mentioned a good environment for the growth and activity of the microorganisms (ladjevardi et al., 2015). The unfavorable conditions in production of synbiotic yogurt, was time duration. During storage, the number of probiotic bacteria that are present in the product is reduced Xanthan gum and LBG have no significant effect on viability of probiotic bacteriaXanthan gum and time storage have interaction effect on the viability of probiotics bacteria. As expected, the best conditions for probiotic bacteria to maintain a high percentage of xanthan gum was at the early days of the sample production ((Norton and Lacroix, 1990; Sanderson, 1990).According to the results, it was found that gums such as xanthan gum and LBG showed similar results to those of El-Salamt et al. (1996) and Hematyar et al. (2012) and had adverse influence on the growth and activity of beneficial bacteria.
Maryam Zaeri; Simin Asadollahi; Mahnaz Hashemiravan
Abstract
Introduction: Fat substitutes are the compounds that use for providing all or some fat properties, while producing fewer calories than it. It is noteworthy that in confectionary products, carbohydrate-based fat substitutes are more used than other substitutes because of having other technical and economic ...
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Introduction: Fat substitutes are the compounds that use for providing all or some fat properties, while producing fewer calories than it. It is noteworthy that in confectionary products, carbohydrate-based fat substitutes are more used than other substitutes because of having other technical and economic benefits and one of these substitutes is gum. In this regard, in the present research, the effects of locust bean gum and xanthan gum as a fat substitute on the physicochemical, rheological and sensory properties of oil cake were studied.
Materials and Methods: Treatments included: A0 (control), A1 (0.2% (w/w%) xanthan and 0% locust), A2 (0.4% (w/w%) xanthan and 0% locust), A3 (0.6% (w/w%) xanthan and 0% locust) B1 (0.2% (w/w%) locust and 0% Xanthan), B2 (0.4% (w/w%) locust and 0% Xanthan), B3 (0.6% (w/w%) locust and 0% Xanthan), C1 (0.1% (w/w%) locust and 0.2% xanthan), C2 (0.2% (w/w%) locust, and 0.2% xanthan), C3 (0.3% (w/w%) locust, and 0.3% xanthan), D1 (0.4% (w/w%) locust, and 0.2% xanthan) and D2 (0.2% (w/w%) locust and 0.4% xanthan). In order to produce an oil cake, in the first step, the eggs, the sugar and emulsifier in the formulation were completely mixed by mixer with high speed for 3 minutes. In the second step, the oil and water were added to the mixture and mixed by the mixer with high speed. In the third step, flour, vanilla, baking powder, invert syrup and salt were added and mixed for 3 minutes at medium speed. In the fourth step, the dough obtained from the previous stage was poured into the desired molds and cooked in an oven at 175 o C for 30 minutes. Finally, the cakes were packed in polyethylene bags and stored at room temperature. The tests performed on the dough included the density, viscosity and specific weight, as well as tests on the final product included the measurement of moisture, aw, volume, color, fat, height and sensory tests. On the other hand, to evaluate the effect of xanthan gum and locust gum on cake texture, the test of firmness was performed on days 1, 7 and 15. In order to analyze the data obtained from the experiment (except for the instrumental analysis of data on the staling conducted by using a factorial experiment in a completely randomized block design), a completely randomized design with three replications was used and the mean comparisons were conducted by Duncan's multiple range test, at the probability level of α=1% and by SPSS software version 16.
Results and Discussion: According to the results, adding gum at different levels increased the viscosity of the dough samples compared to the control. The reason for the results is that the reaction between the gums and the protein of flour, especially gluten, leads to the strength of the gluten network and the increase in viscosity of the dough. According to the results, with the addition of different levels of gum, the density of dough decreased, some reasons of which can be water absorption and the amount of air bubbles in the dough. According to the results, by increasing gum content, the moisture content of cake samples increased due to the presence of hydroxyl groups in these compounds that form a hydrogen bonding with water, resulting in the stability of the gluten dough network, better preservation of dough water, reduction of the staling and firmness of the product. Also, by increasing the amount of gum, the fat content of the samples decreased. The reason for decreasing the fat in the cake samples containing the gum was to use them in the formulation of produced cakes instead of oil. On the other hand, the height of the cake is directly related to the volume of the samples, so that the height of the cake samples will be decreased by decreasing the volume, which it is consistent with the results obtained in this study. According to the results obtained in this study, when the amount of gum used in the product structure increased, the amount of fat decreased, and gradually the height of the desired cakes also increased. Then, the volume of samples increased by increasing gum content. The reason for increasing in volume of the samples containing gum is increasing the viscosity of the dough, slowing down the gas release rate, maintaining it in the early stages of cooking, and thus retaining CO2 and water vapor in the air cells. According to the results, the addition of gum increased the L * color index compared to the control sample. The reason for the increase of L* color index in gum-based treatments can be attributed to the dark color of gums, and on the other hand, to the reaction of becoming brown in the formulation of cake production. Adding the different gum levels also decreased a* color index. This is due to the moisture content in the crust, the intensity of the Maillard reaction, and the amount of light and bright colored compounds in the cake. According to the results, adding different gum levels decreased the b* color index in the treatments containing it. Also, increasing the levels of xanthan and Locust gum consumption decreased the staling of samples. According to the results, the addition of gums to the treatments increased the sensory scores of flavor due to the presence of aldehyde compounds in xanthan and locust gums. Addition of Locust bean and xanthan gums also increased the sensory score of color. The reason for this result can be attributed to the Maillard reaction. Overall, the addition of different levels of gums increased the total acceptance score of samples compared to the control sample, which can be attributed to the presence of xanthan and locust gums which have the special and proper work properties. Finally, according to the results, D2 treatment was introduced as the best treatment.
Habib Jahandideh; Masoud Taghizadeh; Mohammad Hossein Hadad Khodaparast; Arash Koocheki
Abstract
Introduction: Nowadays, one of the most important nutritional problems in different societies is the protein mal-nutrition. Since bread is the main food material being consumed in all over the world, bread enrichment using the grains rich in protein such as sesame seeds would be an appropriate alternative. ...
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Introduction: Nowadays, one of the most important nutritional problems in different societies is the protein mal-nutrition. Since bread is the main food material being consumed in all over the world, bread enrichment using the grains rich in protein such as sesame seeds would be an appropriate alternative. However, addition of sesame products such as Tahini meal would cause some technical difficulties such as dough stability, water absorption, dough extension time, etc. in bread manufacturing processes.In this study the effect of addition of xanthan gum to on physical and textural properties of Baguette bread containing tahini meal was investigated.Materials and methods: Wheat flour and tahini meal were supplied from Damghan and Ardakan cities, respectively. They were then refrigerated prior to baking process and different chemical tests were carried out according to standard methods. Protein was measured based on Kejeldahl method. Moisture content as well as ash content were determined using oven method.Raw fat was calculated according to AACC-No. 30-10 and raw fiber was measured using appropriate instrument (Scientific velp-FIWE6 F30530201). Starch determination was carried out using Small universal polarimeter (SUP-Germany). Xanthan gum was purchased from Provisco Ltd. (Switzerland) in food grade quality. Bread yeast (Saccharomyces cerevisiae) was also supplied in dried form. All other chemical enhancers were purchased from Merck Ltd. (Germany). Baguette dough was produced from mixture of wheat and Tahini meal flour based on protein content and the amount of protein in final dough was increased from 10.28% in flour free of tahini meal to 12, 14 and 16% in different treatments. The rest time for all flour samples was fixed at 15 min and the baking process was carried out for 15 min at 300°C. Baked breads were exposed to room temperature for two hours and then were packed using poly-ethylene (PE) film for further tests. Specific volume of bread samples was measured using rapeseed displacement method (AACC, No. 54-30, 2000). Samples porosity was determined using image processing techniques. Samples were cut to 2cm×2cmcubes and an appropriate scanner (Canoscan 8800F, Japan) with 300 pixel resolution was used to acquire the images for further process using Image J(1.6r, 2010). Apparent color for the baguette samples (in terms of CIE ‘L*’- lightness,“a*” - redness and greenness, and “b*”- yellowness and blueness) were also measured using image processing techniques (Image J, 1.6r, 2010).Texture profile analysis (TPA) test was carried out using a texture analyzer (QTS Texture Analyzer, CNS Farnell, Hertfordshire, UK) to study the effect of xanthan gum and tahini meal on parameters such as hardness, gumminess and cohesiveness in all baguette samples.Results and discussion: ANOVA test showed the significant effect of xanthan gum and tahini meal on the porosity of samples. The porosity of samples containing less than 0.5% xanthan gum at all tahini meal levels, was significantly less than control sample.Similar results were obtained in the case of specific volume meaning that the employed treatments have significant effect on bread’s specific volume. Increasing tahini meal from 9.45% to 14.53% caused significant decrease in specific volume. This could be due to the weakness of dough gluten matrix. These results are in agreement with other works reported by other researchers (Paraskevopoulouet al., 2010; Mohammad Idrisset al., 2012; and Guardaet al., 2004). The results obtained for apparent color of bread core also showed the effect of xanthan and tahini meal. The only exception was found in case of a* value when studying the effect of xanthan gum, meaning that xanthan gum has no significant effect of this parameter. In the case of apparent color in bread crust, the studied treatments (xanthan gum and tahini meal) showed significant effect on all color parameters. Different textural properties of baguette samples including hardness, gumminess and cohesiveness were also measured. Conclusion: The results indicated obvious effect of xanthan gum and tahini meal levels on these mentioned parameters. Increasing tahini meal and xanthan gum levels would increase hardness as well as gumminess. However, addition of xanthan gum and tahini meal cause significant decrease in cohesiveness. This could be due to dilution effect of these substances which decrease the concentration of protein matrix existed in flour’s gluten.
