Dough Maturity Research Articles

Доцільність використання продуктів переробки безалкалоїдного люпину для підвищення харчової і біологічної цінності хлібобулочних виробів

Improving of the nutritive and biological value of food products by enriching them with plant functional components is the most urgent task of the world science. Solving of a problem of full, ecological protein nutrition becomes especially important in the conditions of technogenic pollution of the environment by heavy metals and radionuclides as a result of the Chernobyl accident. One way of solving this problem is a search and use of new plant protein sources to create dietary, therapeutic and prophylactic products with radioprotective and enterosorption properties that could successfully compete with soy bean proteins that have been widely used for decades. The purpose of the research is to substantiate the expediency and perspective of the use of the processing products of non-alkaloid lupin on the basis of theoretical and experimental researches, for improving the food and biological value of bakery products. The Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine has conducted researches on the study of the feasibility and effectiveness of the use of a narrow-leaved lupin flour in the technology of bread production with wheat flour of own breeding varieties in order to increase its nutritional and biological values by changing the structural and mechanical properties of the dough by increasing a water absorption capacity, an agility of dough formation, reduction of its dilution. These researches have helped to establish that the proposed introduction of a narrow-leaved lupin flour to the recipe had effected on the main indicators of the gluten state – elasticity, tensile strength, moisture-keeping ability (hydration). The series of experiments and determinations were conducted with Brabender's pharinograph and “Chopin” alveograph for the study of the structural and mechanical properties of the dough with the addition of the narrow-leaf lupin flour. The author of the article has studied the chemical composition and technological properties of processing products of lupin, studied the basic regularities of their changes in the processes of technological preparation. A flour mixture of a narrow-leaved lupin with wheat flour was tested while baking and it is determined that along with the increased activity of proteolytic enzymes, lupin flour has a high content of non-volatile organic acids. The regularities of lupin flour impact on the most important parameters of the technological process and the quality of bread were determined in the article. It was established that in terms of appropriate structural and mechanical properties of dough and the desired increase of biological value of bread, a lupin flour dosing is optimal up to 6% in the total wheat flour weight. A 3% dose provides the best effect when bread volume increased to 910–1010 ml with a total baking estimate – 7,0–8,1 with the use of 7.0 points for scoring under control. A further increase of lupin flour dose to 9–15% in wheat flour has reduced a power of a flour mixture and increased the formation time of stable dough and this fact allows recommending the specified dose of lupine flour for use in semi-finished biscuit technology. The influence of flour from seeds of a narrow-leaved lupin and flour from its malt on the structural-mechanical properties of the dough has been investigated. It is established that the application of 9–15% of the lupin into the dough increases its water absorption capacity by 2.0–10.0%, increases the viscosity, strengthens the gluten. The increase in the viscosity of the dough delays the development of fluidity deformation, which leads to a decrease in its deliquescence. This structure is characterized by low elastic deformation, this fact leads to a decrease in the volume of dough and finished products. The influence of the narrow-leaf lupin flour on the course of microbiological and biochemical processes in the dough has been established. Due to the high activity of the enzyme complex, 3% of the lupin flour activates the hydrolysis of starch and proteins in the dough, increases the accumulation of sugars and water-soluble nitrogen, which results in accelerating the rate of gas formation, reducing the duration of dough maturation. The flour of the narrow-leaf lupin enriches the bread not only with protein (balanced by the amino acid composition) but also with the biologically active substances: pectin, fiber, pentosans, organic acids, tocopherol, mineral elements; this fact increases the level of maintenance of daily needs of human organism in these substances and spreads the possibility of such bread as a functional food product.

СПОСОБЫ КОРРЕКТИРОВКИ СВОЙСТВ СЫРЬЯ И КАЧЕСТВА ХЛЕБА ИЗ ПШЕНИЧНОЙ МУКИ

The analysis of effective factors of physical nature used for the intensification of biotechnological processes is conducted. The treatment of water obtained as the result of ultrasound exposure is considered as one of these factors. The gas production rate, technological effectiveness of dough fermentation, intensity of acid accumulation at the process of maturation of experimental and control samples are defined. The period of yeast growth moderation is significantly decreased in experimental samples, and at the end of the process their total amount is higher then the control sample has. In 3 hours of fermentation there are 8-10 % more yeast cells in experimental samples of dough rather then in its control samples (margin of error is 0.12·106-0.15·106). The increase of volume of control samples is pointed out. This is because when the dough of control sample is risen by 100 ml, the 1150 СО2 is precipitated in the sample, which is mixed with treated water, 722.2 ml of CO2. The use of treated water contributes both the acceleration of the dough maturation and improvement of the technological efficiency of the fermentation process. As a result, the bread, prepared using the treated water, has a high consumer advantages. The mathematical processing of the received experimental data shows that the treated water has a significant impact on the specific volume and porosity of bread baked from wheat flour. Based on the conducted experiment it’s specified that the use of treated water facilitates faster swelling of starch grains and proteins, as a result of which right after the dough kneading the osmotic and adsorption moisture content increases and before cutting the monoadsorption stratum size increases. The increase in the moisture content in a bread crumb with the treated water, particularly the monoadsorption stratum, hampers with aggregation of its structure elements, which slows down the bread firming processes.

Study of the fractional composition of sugars of the secondary products of potato processing

The chemical composition of secondary products of potato processing (SPPP) shows that they contain a complex of substances that will allow to level the production process parameters of yeast semi-finished products at the stage of the yeast medium pre-activation or yeast dough maturation. The object of the research were solutions of SPPP, pre-crushed, frozen and dried. The aim of the research was to determine the fractional composition of SPPP by a spectropolarimetric method. In determining the fractional composition, optically active substances were in optically inactive solution. Therefore, the concentration of components in a solution of a mixture of optically active substances can be found if rotation constants and the total number of components in the mixture are known. The values of rotation constants of optically active potato carbohydrates at different wavelengths λi were found from experimental data of measuring the rotation angle of the polarization plane when radiation passes through the standard carbohydrate solutions with different known concentrations. In this case, the system of five linear equations, linking the rotation angles φλi of the polarization plane of the solution with unknown concentrations Ci and specific optical activities [αλ] of potato carbohydrates at different wavelengths λi, took the form of expressions (1) and (2). To solve systems of linear equations (1) and (2), the Gaussian elimination method with pivoting, which greatly reduces the effect of computational error in the computer calculation was used. Studies have shown that pre-freezing of SPPP increases the amount of reducing sugars by 3-4 times.

Використання борошна з пшениці ваксі в технології кексів на дріжджах

In this article, based on the analysis of cakes production features and waxy wheat flour (amylose-free) technological properties, shown the practicability of its use in the preparation of these products made from yeast dough. It has been determined the influence of waxy wheat flour mass fraction and method of its introduction on the course of the yeast cakes production technological process, namely, gas formation, acid accumulation and raising power of cakes' semi-products, the specific volume of the dough. The obtained results show that the addition of amylose-free flour in the recipe is accompanied by an intensification of the process of alcoholic and lactic acid fermentation, the formation of more loosened structure of sourdough and dough during their maturation, as evidenced by the improvement of their raising power and an increase in the specific volume. Comparative characteristics of methods for introduction flour with modified carbohydrate composition shows that the use of a mixture of baking and amylose-free flour promotes greater intensification of the sourdough fermentation process and by adding the maximum amount of waxy wheat flour in dough kneading - more rapid maturation of dough. It is shown that the use of amylose-free flour will allow to intensify fermentation of cakes' semi-products and to reduce the duration of the yeast cakes production process.

Nitrogen fertilization and maturity influence the phenolic concentration of wheat grain (Triticum aestivum)

AbstractThis work investigated the influence of N fertilization and grain maturity on total phenolic concentration (TPC) of wheat caryopses. A pot experiment was conducted, using soft spring wheat (Triticum aestivum cv. Thasos) which was treated with four different amounts of nitrogen (0.25–2.00 g N pot−1) and harvested at three different development stages (medium milk stage, late milk stage, and dough maturity). Phenolic compounds were extracted and analyzed as total phenolic concentration in three discrete fractions: free soluble, conjugated soluble and insoluble bound forms. TPC of free phenolic compounds rose with increasing N supply while TPC of conjugated soluble phenolics decreased at the same time. Insoluble phenolics were less affected by N treatment. Total phenolic concentration also changed with the development stage of caryopses and reached a peak at the late milk stage.

Maize lipids play a pivotal role in the fumonisin accumulation

The role of lipids in maize –Fusarium verticillioides interaction and fumonisin production in natural field conditions were investigated. In 2010, ten maize hybrids were grown in fields located in 3 districts in Northern Italy and sampled at 4 growing stages, from early dough to full ripe. Chemical composition, fungal incidence and free and hidden fumonisin contamination were determined in all grain samples. All the hybrids considered within this study showed a strong fungal incidence, withFusarium sectionLiseola as prevalent, already at the early dough maturity and along the ripening period. Fumonisins accumulated over the growing season and reached the maximum level at the full ripe stage; hidden fumonisins were found significant in all the considered samples (~57% of the free form at harvest). Hybrid H9 showed more than 50% of kernels infected byAspergillus flavus and no hidden fumonisins were detected. This finding stresses the relevance of monitoring both free and total fumonisins for a comprehensive assessment of consumer exposure to mycotoxins. Previous studies showed a positive correlation between the content of linoleic acid and fumonisin accumulation into maize kernels infected withFusarium sectionLiseola. Hence, an untargeted and targeted lipid analysis of maize kernels along the growing season and at harvest was performed. Results suggested a significant involvement of lipid composition of maize kernels in fungal infection and toxin accumulation. Specifically, mass spectrometry data pinpointed that at least 4 lipid entities might differentiate high-contaminated from low-contaminated samples when the cut-off of 2,000 μg/kg of fumonisins was selected. Among them, the oxylipin 9-HODE and three sphingolipids were identified. These results suggest that sphingolipid and oxylipin metabolism in maize kernels interferes withF. verticillioides growth and fumonisin production in plants growing in field.

Research of functional animal proteins influence on food systems’ viscosity

The influence of functional animal proteins on flour-water suspension’s viscosity and effective viscosity of unleavened dough was researched. The objects of studies were: wheat premium flour with gluten content about 30% and functional animal proteins Skanpro T-95, Gitpro D and Helios-11, unleavened wheat dough ( humidity about 56% ) with the addition of FAP , flour mixtures for molded product Veselka ( humidity about 12% ) with the addition of FAP (1.5% by weight of flour). Research of effective viscosity of unleavened dough was conducted on a rotary viscometer. The viscosity of flour-water suspensions was studied by standard method on Amilograph test. Research of effective viscosity was conducted after 20 and 180 min of maturation. Viscosity of samples with FAP addition decreased after 180 minutes of dough maturation due to enzymatic processes. It was found when additives content increased from 1 to 2%, dough’s viscosity enhanced. After dough maturation during 180 minutes Helios had the similar effect on viscosity as Skanpro. It was found that flour-water gelatinization began a few minutes before when we add FAP, this phenomena can be explained by the fact that proteins begin to swell at a slightly lower temperature than starch, so start of gelatinization moved. It was proven that adding of FAP Skanpro and Helios to the weak wheat flour increased effective viscosity of dough. Recommended content of additives is in the range of 1-2% by weight of flour. Bakery products, made from this flour, had good organoleptic, structural and mechanical properties that met the requirements of regulatory documents

Healthiness and fungus composition of barley roots under organic, integrated and conventional farming systems

The researched material was healthiness of roots and fungus composition of spring barley cultivated under organic, integrated and conventional farming systems. The studies were carried out in 1998-2001 on experimental fields in Osiny near Puławy, south-eastern Poland. In the emergence stage the roots health status was the lowest in organic system however in the end of vegetation season, in dough maturity stage the most disease symptoms were stated in conventional system. The mycological analyses revealed the occurrence of two important pathogens: <i>Bipolaris sorokiniana</i> and <i>Fusarium</i> spp. Despite of root healthiness macroscopic analyses showed their lower health status in organic system only in emergence stage and the most quantity of plants with disease symptoms in dough maturity stage were observed in conventional system, but pathogens like <i>Bipolaris sorokiniana</i> and <i>Fusarium</i> spp. were mostly isolated in organic system in both phases. It can suggest that disease symptoms in conventional system can be caused by different than fungus factors. The lowest percent of mentioned pathogens was stated in integrated system. It is worth to notice that organic conditions could be favourable to <i>Gliocladium roseum</i>. Because of growing interest in ecology, giving up of using pesticides and more and more popular biological disease control, these fungi of <i>Gliocladium</i> genus be used in this system due to their antagonistic properties.

제과제빵기계의 열전달 해석

본 논문의 목적은 제과제빵기계인 다기능 도우 컨디셔너의 열전달 해석에 있다. 도우 컨디셔너는 제과제빵의 원료인 생지(dough)를 숙성시키는 중요한 기계로서 사용량이 증가하고 있다. 새로운 형태의 다기능 도우 컨디셔너를 제작하기 위하여 자동 설계프로그램인 Solidworks를 활용하여 설계하였으며 이를 근거로 3차원 유한요소 해석코드인 ANSYS를 활용하여 열전달 해석을 수행하였다. 해석결과로서 다기능 도우 컨디셔너의 내부온도와 열유속을 구하였으며 이 결과는 다기능 도우 컨디셔너의 제작에 활용되었다. This research aims to do heat transfer analysis on multi-functional dough conditioner. The dough conditioner is a key bakery machine for the maturation of dough which is raw material of bakery and also it's amount of used has been increased. Solidworks which is one of automatic design programs is applied to design in order to manufacture the multi-functional dough conditioner, and ANSYS which is a three dimensional finite element analysis code is used for the heat transfer analysis. Inside temperatures and heat fluxes are obtained as the results of heat transfer analysis and the results are contributed significantly in manufacturing the multi-functional dough conditioner.

Impact of fungicides and other preparations for seed treatment and different cultivation techniques on seed contamination of winter wheat (Triticum aestivum L. emend. Fiori et Paol.)

Contamination of cereal crops and their products could be a result of inappropriate cultivation techniques as well as disregarding usual agro-technical measures like the seed treatment with fungicides. The aim of the study was to determine the impact of pre-sowing seed treatment on wheat seed infection and contamination of produced grains from the field trial at the Biotechnical faculty (BF) and contamination of crop samples from Slovene farms with conventional and organic type of production. In our laboratory we performed grain incubation on agar with various disinfectants before sowing the grain on the field. We found that seed treatment with fungicides Maxim 050 FS and Vitavax 200-FF had significantly improved the health status (2% infected grains) compared to untreated processed seed (25% infected grains). The effectiveness of both tested fungicides was significantly better (2% infected grains) compared to the Agrostemin and Fitolife preparations, which are allowed in organic farming (15% infected grains). Compared to the untreated seed, treating the seeds with both fungicides and the Agrostemin preparation reduced visible ear contamination with fusariosis during the time of dough maturity. With incubation of grain from our field experiment with different seed treatments, the positive effect of fungicides on the health status of grain yield was confirmed (27% infected grains), compared to sowing of seed that was not treated with disinfectants (34% infected grains). When compared to the control group a positive effect of wheat seed treatment with disinfectants used in organic farming was determined. Furthermore, seed treatment with fungicides had a greater influence on improving the health status of produced grain, compared to the above mentioned preparations allowed in organic farming (29% infected grains). The effect of seed treatment on the health status of the grain was the greatest when using the Vitavax 200-FF fungicide. The percentage of infected grains in laboratory incubation of produced wheat grain on agar, sampled from eight Slovenian farms, ranged from 1.5 to 19.5%. Contamination of sampled grain from organic production (7% infected grains) was comparable with infection of grain from the conventional farming (8.4% infected grains), where the infection ranged from 1.5% to 19.5%.

Effects of chemical additives and ensiling time on whole plant wheat silage microbial profiles inferred by phenotypic and 16S ribosomal DNA analyses

The objectives of this study were to test the effects of various chemical additives, and ensiling time periods on microbial profiles of whole plant wheat silage (WPWS). WPWS was harvested at dough maturation stage, and ensiled with sodium chloride (T), sodium bicarbonate (N), sucrose (S), or urea (U) at 1% dry matter (DM) (w/w). Each WPWS treatment (i.e. T, N, S, and U) was ensiled in 1dm(3) duplicate anaerobic jars for 7, 14, 28, 35, 42, 49, and 56days. The highest lactic acid concentration was detected for U (5.9% DM) compared to the control (0.5% DM) at day 56. Similarly, the highest ammonia concentration was observed for U (9.3% DM) compared to the control; T, N, and S treatments averaged 2.4% DM. A higher lactic acid bacteria (LAB) count was observed between days 14 and 56 for all treatments relative to control WPWS, which averaged 6.7 and 5.6 c.f.u./g of fresh material, respectively. The highest quality silage was observed for N and U treated WPWS, with an absence of yeasts and molds from days 7 to 49. Identification of bacterial isolates at days 7 and 56 from each individual silage treatment was performed based on phenotypic (biochemical tests), and molecular (16S rDNA partial gene sequence) methods. 16S rDNA sequence results identified U7 and N56 isolates as Enterococcus faecium, and demonstrated positive galactose, ribose, lactose, maltose, mannitol, mannose, sucrose, and trehalose fermenting characteristics. In addition, most isolates exhibited growth potential in 6.5% NaCl. Overall sequence alignment results supported phenotypic identification, and indicated that U and N treated WPWS were LAB (Enterococcus) dominant compared to the control (non-LAB).

Impact of fungicides and other preparations for seed treatment and different cultivation techniques on seed contamination of winter wheat (Triticum aestivum L. emend. Fiori et Paol.)

Contamination of cereal crops and their products could be a result of inappropriate cultivation techniques as well as disregarding usual agro-technical measures like the seed treatment with fungicides. The aim of the study was to determine the impact of pre-sowing seed treatment on wheat seed infection and contamination of produced grains from the field trial at the Biotechnical faculty (BF) and contamination of crop samples from Slovene farms with conventional and organic type of production. In our laboratory we performed grain incubation on agar with various disinfectants before sowing the grain on the field. We found that seed treatment with fungicides Maxim 050 FS and Vitavax 200-FF had significantly improved the health status (2% infected grains) compared to untreated processed seed (25% infected grains). The effectiveness of both tested fungicides was significantly better (2% infected grains) compared to the Agrostemin and Fitolife preparations, which are allowed in organic farming (15% infected grains). Compared to the untreated seed, treating the seeds with both fungicides and the Agrostemin preparation reduced visible ear contamination with fusariosis during the time of dough maturity. With incubation of grain from our field experiment with different seed treatments, the positive effect of fungicides on the health status of grain yield was confirmed (27% infected grains), compared to sowing of seed that was not treated with disinfectants (34% infected grains). When compared to the control group a positive effect of wheat seed treatment with disinfectants used in organic farming was determined. Furthermore, seed treatment with fungicides had a greater influence on improving the health status of produced grain, compared to the above mentioned preparations allowed in organic farming (29% infected grains). The effect of seed treatment on the health status of the grain was the greatest when using the Vitavax 200-FF fungicide. The percentage of infected grains in laboratory incubation of produced wheat grain on agar, sampled from eight Slovenian farms, ranged from 1.5 to 19.5%. Contamination of sampled grain from organic production (7% infected grains) was comparable with infection of grain from the conventional farming (8.4% infected grains), where the infection ranged from 1.5% to 19.5%.

Desiccation, postharvest maturity and seed aging of tall oat-grass

The objectives of this work were to determine whether and at which seed physiological maturity stage the diquat desiccant affects the tall oat-grass (Arrhenatherum elatius) seed quality and yield, as well as the proper storage period between harvest and sowing. Diquat desiccation was evaluated in applications during milk or dough seed maturation stages. Seeds conventionally produced and stored under traditional storage conditions were used for the analyses. Seed samples were drawn every 30th day after harvest (DAH). After the 240th DAH, samples were drawn every 90th day up the to 690th DAH. The highest yield were obtained by desiccation applied at the beginning of the seed dough stage, with a satisfactory seed quality. Both final germination and seedling growth parameters achieved their maximum values between 180th and 240th DAH. Oat-grass seeds preserved satisfactory level of final germination (75%) up to 420th DAH. The application of diquat desiccant at the beginning of seed dough maturity stage can be a good solution for seed production of tall oat-grass. Early spring is the best sowing period for freshly harvested seeds of tall oat-grass regarding germination and seedling growth.

Relationships between Stomatal Conductance and Yield Components in Spring Durum Wheat under Mediterranean Conditions

The objective of this study was to determine relationships between stomatal conductance and yield components. Field trials were conducted at Field Crops Department Research Area, Agricultural Faculty, University of Cukurova during the 2000-2001 growing season in a completely randomized blocks design with three replications. The measurements of stomatal conductance (gs) were made at three stages (early milk, late milk and early dough maturity). Stomatal conductance showed statistically differences among genotypes. Genotypes showed differences for all agronomical traits assessed. Stomatal conductance had positive correlations with grain yield, grain numbers per spike, spike yield, and spike length at early stage. Results are discussed in terms of the possibilities of gs to be a criteria in wheat breeding at Cukurova Region.

Semicarbazide Formation in Flour and Bread

Azodicarbonamide, an approved food additive, is commonly used as a flour additive and dough conditioner in the United States and Canada. A number of researchers have clearly established a link between the use of azodicarbonamide and semicarbazide contamination in commercial bread products. However, all of these studies have primarily focused on the final baked product and have not extensively investigated the processing and conditions that affect the final semicarbazide levels. In this study, a previously developed method for measuring free semicarbazide in bread was applied to dough samples during the mixing and kneading process. Additionally, flour and bread samples were spiked with biurea or azodicarbonamide to help elucidate semicarbazide formation pathways. The results showed that semicarbazide was not formed as a byproduct of azodicarbonamide decomposition to biurea, which occurs upon the addition of water. Indeed, semicarbazide was not detected after room temperature or elevated temperature dough maturation, but only after baking. It was concluded that although azodicarbonamide is the initial starting material, semicarbazide formation in bread occurs through a stable intermediate, biurea.

The effect of different additives on the fermentation quality, aerobic stability and in vitro digestibility of pea/wheat bi‐crop silages containing contrasting pea to wheat ratios

Studies were conducted to compare the effects of using two microbial inoculants, a sulphite salt‐based additive, formic acid and quebracho tannins, on the fermentation quality, nutritive value and aerobic stability of pea/wheat bi‐crop silages. Spring peas (Pisum sativum var. Magnus) and spring wheat (Triticum aestivum var. Axona) were drilled together at rates that gave high (HP/W; 3:1) or low (LP/W; 1:3) pea to wheat ratios. The peas and wheat were harvested at the yellow wrinkled pods and late milk/early dough maturity stage, respectively, and conserved in 1·5‐kg polyethylene bag, laboratory silos. The bi‐crops were conserved without treatment (control) or treated with either of two lactic acid bacteria‐based inoculants [Lactobacillus buchneri; applied at 105 colony‐forming units (CFU) g–1 fresh weight (FW) or Lactobacillus plantarum (applied at 106 CFU g–1 FW)], sulphite salts (applied at the rate of 1 ml sulphite solution kg–1 FW), quebracho tannins (applied at 16 g kg–1 FW) and formic acid (applied at 2·5 g kg–1 FW). Six replicates were made for each treatment, and the silos were opened after 112 days of ensilage. The level of peas in the bi‐crop influenced the effectiveness of the additives. With the exception of sulphite salts, all the additives significantly reduced the soluble nitrogen (N) and ammonia‐N concentrations of all the silages. The ratio of lactic acid to acetic acid was generally lower in the LP/W silages than in the HP/W silages, and the additive treatments only increased the in vitro digestible organic matter in dry matter of the LP/W silages. Of all the additives evaluated, formic acid resulted in the least aerobic spoilage in HP/W bi‐crop silages. However, in the LP/W bi‐crops, additive treatment was not necessary for ensuring aerobic stability.

Wet separation of wheat flours into starch and gluten fractions: the combined effects of water to flour ratio–dough maturation time and the effects of flour aging and ascorbic acid addition

AbstractThe process of making a dough, allowing time for maturation, dispersing the dough in water and wet sieving/washing to obtain a protein fraction and starch milk was studied using response surface methodology by changing the water to flour ratio in dough making (400–710 g kg−1), maturation time (45–660 s) and the type of flour. Two grades of bread wheat flour and durum clear flour were studied. The effects of aging at ambient temperature for up to 29 days and the addition of ascorbic acid at 100 or 500 mg kg−1 flour on separation behaviour were also studied for freshly milled high‐grade (65% extraction) bread wheat flours at constant maturation time, 600 s, and at optimum farinograph water absorption value. The quantities and dry matter contents of the protein fraction and starch milk were measured; a sample of starch milk was centrifuged to obtain decantate, tailings and prime starch fractions, and the dry matter contents of each were determined. All the dried samples were also analysed for protein content. The fractional recoveries of dry matter and protein in the protein fraction, prime starch, tailings and decantate were calculated for each experiment. The acid values of flour oils were also determined on some aged flour samples. The results indicated superior separation characteristics in high‐grade wheat flour compared with lower‐grade flours. The water to flour ratio was more influential than maturation time within the range studied. Contrary to the initial expectation, no statistically significant effect of flour aging was observed in the studies with no additive, and ascorbic acid addition was not found to improve the wet separation behaviour, the separation behaviour becoming even worse at the 100 mg kg−1 level. Acid value showed a slight increase with time.© 2002 Society of Chemical Industry

Accumulation of Iron, Copper, Manganese and Nickel during Maize Grain Maturation

Dynamics of the accumulation of iron, copper, manganese and nickel, as well as their relationships with total ash, crude proteins and total dry matter during maize grain maturation were investigated. The investigation was carried out on normal maize hybrids grown under the same topographical and agrotechnical conditions. The amounts of particular microelements in the fresh grain matter increased significantly up to a late stage of dough maturation. The dynamics of their accumulation correlated positively and significantly with deposition of total dry matter, total ash and crude proteins, and were consistent with biological needs of the maize grain during development. The amounts of microelements expressed on a dry matter basis decreased significantly in a late stage of milky grain maturation. Further fluctuations were not significant. The correlation between particular microelements during grain maturation was positive and significant, as well as the correlation of particular microelements with crude proteins and total ash in the grain dry matter.

Comparison of two Sorghum genotypes for sugar and fiber production

A comparative analysis of the growth and yield performances of two late maturing and productive sweet and fiber sorghums has been conducted, with the perspective of their introduction in temperate Italian climate areas as competitive multi-product crops. Sweet type sorghum `Wray' ( Sorghum bicolor (L.) Moench ssp. bicolor), and the nonsweet type, `H173' (hybrid Sorghum bicolor (L.) Moench× Sorghum docna var. technicum), were grown in a field trial under well-watered conditions in northern Italy (latitude 44°3′N, longitude 11°2′E). During the crop cycle, growth analysis were performed by collecting data from both non-destructive and destructive samplings. Fundamental growth indexes were calculated as a function of accumulated growing degree days (GDD) from sowing. Yield traits were evaluated at soft dough maturity. Sweet and fiber crops reached soft dough maturity after 1250 GDD and did not statistically differ for total and main stem yields. Mean values of 27 and 20 t ha −1 dw, respectively, were detected. The sucrose content was more than three times higher and the cellulose and lignin contents 40–50% lower in `Wray' as compared to `H173', whereas the level of reducing sugars was similar. Both sorghum types can be considered as interesting new crops which might provide an energy production higher than 10 000 kcal m −2, a potential production of around 6000 l ha −1 of ethanol (sweet), and up to 15 t ha −1 of structural polysaccharides (fiber). The rate of leaf formation on the main stem and their final number were similar between the two genotypes. Until the growing differentiation point, one new leaf was visible every 40.5 GDD, thereafter the same growth process required around 123 GDD. During the period of early leaf formation, the fiber type showed a greater tillering ability which positively affected early canopy area and growth parameters. On the other end, the sweet sorghum crop presented enhanced dry matter accumulation capacity after the growing differentiation point as compared to the fiber crop (42.7 and 27.7 g m −2 d −1, respectively). This could be the result of higher leaf thickness and leaf area duration.

Changes of the Methionine Content During Maize Grain Maturation

AbstractThe changes in the amounts of dry matter, total nitrogen and methionine during maturation of normal maize hybrids grown under the same topographical and agrotechnical conditions on two consecutive vegetation years were examined.Total nitrogen was determined by Kjeldahl's method and methionine spectrophotometrically from papain hydrolysate by the method of McCarthy and Sullivan. Analysis of variance was applied to assess the significance of the changes in particular components during grain maturation.A significant increase (p = 0.01) in amounts of the all investigated components in original grain matter up until a late stage of dough maturity in both vegetation years was determined. The increase was mostly expressed by the end of milky maturity. The correlation between these components during maturation is positive and highly significant (p = 0.001). The methionine content in dry matter attained in stage of milky maturation the value being characteristic for mature grain. On a total‐proteins basis, the methionine content is significantly the least (p = 0.01) at the early stage of milky maturation and increases up until dough maturity reaching a value that does not significantly differ from the value in full maturity of grain.