JWSS - Journal of Water and Soil Science

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The antifungal effect of sodium diacetate on inhibiting the growth of some bread spoiling molds was examined both in culture media and in flat bread “In situ”. In the first step, the antifungal effect of different concentrations of sodium diacetate: 0, 1000, 2000, 3000, 4000, and 5000 ppm were examined against Aspergillus sp., Aspergillus niger, Rhizopus sp., and Penicillium sp.

The results indicated that as the concentration of sodium diacetate increased, the mold growth decreased. At 5000 ppm the mold growth was inhibited up to fifth day (the last day of experiment). Based on these results, the antifungal effect of different concentrations of sodium diacetate was evaluated in bread “In situ”. In this stage Aspergillus sp. was selected as the indicator mold. The results indicated that if 3000 ppm of sodium diacetate is used, not only mold growth is inhibited but bread staling can also be prevented. This concentration of sodium diacetate does not have any harmful effect on texture and flavour, and can increase bread shelf life up to four days. Higher concentrations of sodium diacetate can inhibit mold growth completely, but have negative effects on texture and flavour. Therefore, 3000 ppm of sodium diacetate is recommended for increasing bread shelf life.

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The quality of Iranian breads has intensively decreased during recent years due to socio-economic factors and poor quality of flour. The purpose of this study is to investigate the effects of mono- and diglycerides and ascorbic acid as improvers on Iranian bread (Taftoon) quality. Three wheat type flours (Ghods, Mahdavi and Roshan wheat varieties produced in Isfahan region) were used. The effects of ascorbic acid at three levels (20, 40 and 60 ppm flour basis) and esters of mono- and diglycerides at three levels (0.5, 1.0 and 1.5 percent) on the dough baking and bread quality were measured. The Taftoon bread was baked in a semi-traditional oven.

 Loaves of bread were scored after baking and also on the first and second days of storage at room temperature. Analysis of variances indicated that ascorbic acid and mono- and diglycerides have significant effects on the improvement of the rheological properties of dough. However, ascorbic acid had higher effects than mono- and diglycerides. The results of the tests showed that dough resistance to mixing and tensile stress increased with addition of the improvers. Both improvers used in this experiment have an anti-stabling effect on bread. However, the ascorbic acid effect is much less than that of mono- and diglyceride. The low concentration of 0.5 percent of mono- and diglyceride and 60 ppm of ascorbic acid with flours of moderate protein contents (10-11%) resulted in good quality Taftoon bread with good organoleptic and tearing qualities after two days.

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The variation and path coefficient analysis of bread-making quality traits have been studied for 145 genotypes of breeding lines, cultivars and landrace varieties of wheat (Triticum aestivum L.). Bread-making quality traits of genotypes was evaluated indirectly by protein percentage, SDS and Zeleny sedimentation tests, hardness index, test weight, bread volume, grain moisture, and water absorption percentage. Hardness index, Zeleny and SDS sedimentation tests had the highest coefficient of variability (13.51%, 11.83% and 11.03%, respectively). Factor analysis for the genotypes, based on qualitative traits revealed two factors, which explain 98.23% of total variation and were named grain protein index and bread volume factors. The result of correlation analysis indicated positive and significant relationship between protein percentage, SDS sedimentation test and other bread-making quality traits. On the first and second steps of stepwise regression analysis, protein percentage was the most effective trait in explaining different qualitative trait variations. Path analysis also showed the direct and significant effects of protein percentage, Zeleny sedimentation volume, grain moisture and water absorption percentage, and bread volume on SDS sedimentation test. According to cluster analysis based on qualitative traits, the cultivars and landrace varieties, from the view poit of protein quality and quantity, had the highest potential among other groups (generally breading lines).

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Whey powder, due to its lactose and protein contents, can be used as an important flour improver to decrease the rate of staling. In the present investigation, whey powder was added at 5 levels (zero to 5%, W/W) to the flour of Sangak bread. Bread was baked according to the formula and procedure used by traditional Sangak bakeries. Bread samples were kept at room temperature or under refrigeration for 36 hours. They were then evaluated for staling by a taste panel. They were also subjected to proximate analysis. The dough was examined for farinographic, amylographic, extensographic and fermentographic properties. The data of staling tests including color, texture, flavor and also proximate analysis data were analyzed by ANOVA. Finally, differences among treatments were examined by Ducan’s multiple range procedure. The results indicated that the best treatment was the use of 3% whey powder, as far as staling and texture of bread are concerned. However, the best color of bread was achieved with 5% whey powder so was true of the protein, ash and fat contents. Viscosity, as tested by amylography, and also parameters of farinography reached their highest levels in the dough prepared from flour having 5% whey powder in the formula. The best extensibility was observed with the flours containing 4% whey powder and the highest dough energy was associated with the dough prepared from flour having 5% whey powder. As for the loaf volume, best results were obtained with the dough prepared from flour having 3% whey powder. Overall, it is concluded that the use of 3% whey powder is the best treatment with regard to the delay in the rate of staling, increase in loaf volume, and color appeal of Sangak bread, and rheological properties of the dough.

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Consumption of bread made from flours with high extraction rates is fairly common in western countries and has recently become widespread in Iran. Such breads contain relatively high levels of phytic acid. Phytic acid is present in the aleurone layer of wheat in the form of potassium-magnesium salts. It is carried over to wheat flour and to bread. Phytic acid is known to have chelating properties and to form complexes with bivalent cations (iron, calcium, zinc and so on), thus reducing their bioavailability in humans. In addition, phytate salts can form complexes with proteins, carbohydrates, and fats in the diet, making them unavailable too. In the present study, phytic acid contents of flours ( 3 individual extraction rates and 2 combinations), the dough and two types of popular breads of Khorasan (Lavash & Sangak) made from these flours were determined. The results showed that the flours had, on the average, 570.37 mg phytic acid per 100 g and that the phytic acid contents of breads were, on the average, 347.31 mg/100g. This indicates that the present baking procedures do not have an appreciable effect on the level of phytic acid recovered in bread.

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Bread, the main staple food of Iran, imparts a major portion of energy and protein to urban and rural diets. Due to the use of flour with high extraction rate and improper fermentation of the corresponding dough, traditional breads have a rather high level of phytic acid. This has a detrimental effect on absorption and availability of minerals (Ca, Fe, Zn, Mg, Cr, Cu, etc.), carbohydrates, proteins and lipids, thus leading, for e.g., to iron-deficiency anemia in the present study, flours with different extraction rates (with known phytic acid content) were used for baking “Sangak” and “Lavash” breads and analyzed for phytic acid. Different levels of yeast, times of fermentation and extraction rates of flour were applied in the preparation of breads and their phytic acid levels were then estimated. Based on technological merits and residual phytic acid contents, breads prepared from two types of treatments were selected, their chemical composition, availabilities of iron and lysine as well as organoleptic characteristics were evaluated. Results indicated that under the employed conditions total destruction of phytic acid in “Sangak” and “Lavash” is rather impractical. A considerable reduction in phytic acid was noted: in “Lavash” bread using 2.5% yeast, 4 h of fermentation and a 50-50 blend of flours with 81.0 and 86.5% extraction rates and in “Sangak” bread with similar conditions (except for the flour which was a 50-50 blend of 86.5 & 97.5% extraction rates). Available lysine was similar in both of the selected breads compared to their respective references. Their available iron contents, however, were higher than their corresponding references (P ≤ 0.05 ). No significant differences were observed with regard to organoleptic evaluations of selected breads as compared to their references (P ≤ 0.05 ). Overall, the above-mentioned treatments are recommended for the baking of “Sangak” and “Lavash” breads.

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In this study, the effects of quality and quantity of protein in flours with 95% and 70% extraction rates obtained from Mahdavi and Tajan wheat cultivars each baked at two different durations (100 and 75 sec.) and temperatures (210 and 250°C), after wrapping in polyethylene packages with 40µm thickness were investigated. All tests were carried out during 168 hours after packing and at 24h intervals. Results indicated that bread staling was affected by wheat cultivar, flour extraction rate, and storage time. Bread prepared from Tajan flour had lower firmness and staleness than that prepared from Mahdavi. High bran content bread was firmer than that with lower bran content. Organoleptic tests indicated that bread baked with 95% flour and bread baked at high temperatures with short durations were not very acceptable.

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A diallel analysis of eight bread wheat (Ttriticum aestivum L.) cultivars was conducted to determine genetic parameters and the type of genetic control for yield and yield components. The parents and their F1 hybrids were evaluated in a randomized complete block design with 3 replications. General and specific combining ability effects were estimated by the method 2 of the Griffings model I, and the genetic parameters were estimated by the Jinks-Hayman method. According to the analysis of variance, the variances of parents and crosses were significant for all of the traits, except for the fertile tillers per plant in parents and harvest index in crosses. The variance of GCA was significant for almost all of the traits. GCA to SCA ratio indicated a large additive effects for all the traits, except for the number of fertile tillers, grain yield per plant and biological yield. Darab and Chamran cultivars were the excellent general combiners for days to heading. However, Falat for plant height, Arvand for number of fertile tillers, spike length and grain weight per spike, Qods and Arvand for spikeletes per spike, Falat and Arvand for grain yield per plant and Qods and Arvand cultivars for biological yield were the best general combiners. Based upon the Jinks-Hayman method, the average degree of dominance for grain weight per spike, 1000- grain weight, grain yield per plant and biological yield indicated that these traits might be controlled by over dominance effects and other traits by partial dominance. The correlation between Yr and (Wr + Vr) for the flag leaf length, spikeletes per spike, grains per spike and 1000-grain weight indicated that recessive allels enhanced these traits. But dominant allels had their contribution to enhance other traits. The narrow-sense heritability for grain yield per plant (4%) and biological yield (14%) and harvest index (37%) was lower. However, for other traits it was more than 50%. Therefore, it can be inferred that indirect selection of grain yield through selection for yield components such as spikeletes per spike, grains per spike and grain weight per spike with high heritability and correlation with grain yield can be more effective.

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Diallel analysis was used to estimate the combining ability, gene action, gene number, heritabilties and other genetic parameters of a set of wheat genotypes. For this purpose, nine parents and their 36 crosses were evaluated for 9 traits in a randomized complete block design with three replications in 1996. The analysis of variance revealed significant differences among all genotypes for all traits. Estimates of general and specific combining ability mean squares based on Griffing’s Method 2 indicated the importance of additive and non additive effects in the expression of all traits. Alvand and Roshan cultivars for grain yield per plant, Alvand for grain number per main spike and main spike weight, and Alvand and Alamoot for 1000 grain weight were the best combiners, thus use of them is beneficial for these traits. Based on the estimates of average degree of dominance and results of graphical analysis, the gene action for grain number and spikeletes per main spike were partial dominance, while for grain yield per plant, biological yield, plant height, harvest index and 1000 grain weight, overdominance gene actions were observed. Moreover, genotypic correlation coefficients of grain yield per plant with grain number per main spike, 1000 grain weight, grain weight per main spike and main spike weight were positive and significant.

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Bread is widely consumed as a staple food all over the world. The major ingredient of bread is wheat flour which suffers of a couple of shortcomings, such as essential amino acids. To overcome of this problem, a great deal of attention has been made by fortification of bread with different cereal and legume flours. In this study, wheat flour was replaced with 0, 10, 20, 30 and 40% of oat flour to investigate of its effects on dough texture and sensory attributes at room and lower temperatures for 0, 24, 48, 72 h in improved and unimproved breads. Improved formula containing levels of blanched oats, 1.5% fat and 60 ppm ascorbic acid. Addition of oat flour improved bread shelf life. Breads baked with up to 20% oat flour, were considered to be stable along over the time as indicated by sensory evaluation. Samples substituted with 30% and 40% oat flour had the high intensities of bitterness.

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In order to determine the effects of emulsifiers (Lecithin, E471 and E472) and their levels (0, 0.25, 0.5, 0.75 and 1%) and also addition of fungal α-amylase (0, 5, 10 and 20 g/100 kg flour) on bread staling, a completely randomized experiment with factorial design and 3 replications was conducted. Bread staling was determined after 0, 24, 48 and 72 hours of storage. Correlation between variables was analyzed by simple and multivariate regression. Results indicated that addition of emulsifiers reduced the firmness of bread. E472 had the most and E471 had the least effect on bread firmness after 72 hours of storage. Addition of α-amylase reduced the bread firmness and this effect was less pronounced after 72 hours of storage. Correlation between variables based on the development of a model showed that in the first day of bread production, optimal levels of emulsifiers were 1%, 0.25% and 0.5% for Lecithin, E471 and E472, respectively. In case of simultaneous application of emulsifiers and enzyme, the optimal level of enzyme was 5 g/100 kg flour.

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Inheritance of physiologicaly related salt tolerance traits including Na⁺ and K⁺ contents, K⁺/Na⁺ ratio of young leaves and biological yield (BY) in six basic generations (P₁, P₂, F₁, F₂, Bc₁ and Bc₂) and their reciprocal crosses derived from crosses between Kharchia × Niknejad and Shorawaki × Niknejad were studied in sand culture under high salinity treatment (EC = 22.5 dS m^-1). Generation means analysis indicated that a simple genetic model (including additive and dominance effects) is sufficient for Na⁺ and BY in Kharchia × Niknejad cross and for Na⁺, K⁺/Na⁺ ratio and BY in Shorawaki × Niknejad cross but, for other traits digenic interactions (additive × additive and dominance × dominance) were important parameters in the expression of salt tolerance of the various generations. Dominance genetic effects were predominant genetic components in most of the models. Weighted generation variances analysis suggested that dominance variance component was more important for Na⁺ and K⁺ content in both crosses. This result was confirmed by significant differences between back cross generations. Results also showed negligible dominance for K⁺/Na⁺ ratio in both crosses, multidirectional dominance for BY in Kharchia × Niknejad cross and absence of dominance gene action in Shorawaki × Niknejad. Kharchia × Niknejad cross showed, in general, more genetic variation, broad-and narrow sense heritabilities than Shorawaki × Niknejad cross, indicating the important role of primary differences between parents. These results revealed that recurrent selection followed by pedigree breeding or a selective diallel mating system may prove useful in improving salinity tolerance of wheat plants. The involvement of dominance × dominance interactions for some traits indicates that it is necessary to postpone selection for salt tolerance of wheat to advanced generations, when sufficient epistatic interactions have become fixed.

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Effect of semihydrogenated vegetable oil (shortening) and sodium stearoyl lactylate (SSL) on retarding Barbari bread staling was investigated in this study. Three levels of 2, 3 and 4 percent shortening and SSL in two levels of 0.5 and 1 percent of flour were used in this research. Treatments included control sample (without shortening and SSL), bread with only shortening, bread with only SSL, and bread with 0.5 percent SSL and 3 percent shortening. Organoleptic properties and staling factors of the samples were determined. The data was statistically analyzed by complete randomized design and means comparison was done by Duncan’s multiple range test (5% level). The results showed that the breads containing SSL and shortening were significantly different in organoleptic properties, and samples with 0.5 SSL and 3 percent shortening had the highest quality. The results of staling test showed that samples with 0.5 percent SSL and 3% shortening had the lowest staling rates.