DETERMINATION OF TOTAL NITROGEN IN BARLEY AND MALT BY COMBUSTION METHOD—COLLABORATIVE TRIAL

A combustion method, relying on the Dumas principle, for the determination of total nitrogen in barley and malt, has been collaboratively tested by the Analysis Committee of the European Brewery Convention. Repeatability, r₉₅, and reproducibility, R₉₅, values were 0.063 and 0.116% of dry matter, respectively, for samples with nitrogen contents in the range 1.23 to 1.86% N of dry matter. There was no significant difference between these values for barley and malt. The Analysis Committee approved the adoption of the combustion method for inclusion in Analytica EBC as an alternative method.     

Effect of Iron on the Color of Barley and Other Cereal Porridges

ABSTRACT: Iron added as ferrous sulfate at 500 mg*kg⁻¹ to rice, oats, whole grain wheat, or proanthocyanidin-free barley porridge caused significant changes in the Hunter "L", "a", and "b" values but the visual appearance of these porridges remained satisfactory. Porridge made with normal barley flour fortified with 500 mg*kg⁻¹ of iron developed an unappealing gray color with ferrous sulfate, ferrous fumarate, or electrolytic iron, 3 salts differing in solubility. At 100 and 250 mg*kg⁻¹ of iron, the discoloration of normal barley porridge was less pronounced, but still objectionable. When fortified with 50 mg*kg⁻¹ of iron, normal barley porridge had a slight color change but was not noticeably gray. Thus barley-containing foods can be fortified with a soluble iron compound at the level of iron used in enriched flour and similar cereal-grain foods for the general population without developing an unattractive color.     

Variation in Malting Quality and Heat Resistance in the Malting Barley Variety “Alexis”

In earlier studies concerning vigour, where subsamples are heat‐treated before germination there was found heat‐sensitive as well as heat‐resistant barley samples. The vigour model developed by Ellis and Roberts and further developed at Carlsberg, could only describe the heat‐sensitive barleys. Seventeen samples of the “Alexis” variety grown widely in Europe were collected from the EBC trials in 1994 in order to see if heat resistance in barley was influenced by different growing conditions. We found both heat‐sensitive samples following the vigour model as well as pronounced heat‐resistant samples, but these were not divided according to growing conditions. The germination curves dependent on heat treatment and germination time were evaluated by Principal Component Analysis (PCA). Heat‐resistant barley samples could be differentiated from heat‐sensitive samples already after ½ h of heat treatment at 68°C (12% moisture) and after 3 days of germination. The barley samples were analysed with regard to malting quality. The PCA evaluation of the data divided the samples according to growing location, mainly due to differences in protein and β‐glucan. However, the malting analyses could not describe the differences in heat resistance and sensitivity of the barleys. The biochemical background of the heat resistance found is discussed on the basis of literature. Our findings should give an experimental basis for exploiting a biochemical principle for heat resistance, which is formed during grain filling and consumed during storage and germination.     

Biologically active secondary metabolites of barley. IV. Hordenine production by different barley lines

Forty-three lines of barley, including ancestral (wild), landraces, Middle Eastern lines, and modern cultivars, were grown under two different sets of environmental conditions. Hordenine production in barley roots was determined at the one-leaf stage by HPLC analysis and, in two lines only, over a period of 35 days. Forty-two of the 43 lines produced significant amounts of hordenine, although there was no variation among groups. Middle Eastern lines had the highest production with 327 µg/g on a dry weight basis. Production was, however, determined more by environmental conditions during growth than by genetic factors. Hordenine production was up to seven times higher in plants grown under lower light intensities.     

Soil Apparent Electrical Conductivity (EC<Subscript>a</Subscript>) as a Means of Monitoring Changesin Soil Inorganic N on Heterogeneous Morainic Soils in SE Norway During Two Growing Seasons

An efficient method to monitor changes in soil inorganic N content during crop growth would be a useful means to guide N fertilization to ensure high yields and low N losses to the environment. In this study, soil apparent electrical conductivity (EC_a) measured by the widely used conductivity meter EM38 was tested as an indirect measurement of available N in spring barley during two cropping seasons at two sites with morainic loam in SE Norway. The experiment was constructed to maximize soil variation. In spite of the ȁ8noiseȁ9 caused by the soil heterogeneity, concentrations of inorganic N (cN_inorg) or NO₃-N were most strongly correlated with EC_a in both years and at both locations (with one exception). The measurements of EC_a reflected well the temporal variation in inorganic N content (N_inorg), and a ranking of the treatments based on EC_a fitted very well with a ranking based on N_inorg at the first three sampling times after fertilizing. The best subset of sensor variables (i.e. variables which can be measured ȁ8on-the-goȁ9 by sensor techniques in the field) described 27–69% (average 47%) of the variation in topsoil cN_inorg. When expanding the regression models to include pH as well, the degree of explanation increased significantly. In conclusion, the method of using EC_a appears to be quite robust in terms of detecting relative differences in cN_inorg, whereas a determination of absolute levels of cN_inorg with the method is unreliable.     

青稞挤压糊化粉的研制

以青稞粉为原料,采用双螺杆挤压改性方法加工速食营养粉,研究挤压温度、螺杆转速和物料水分对物料品质的影响规律,并通过二次旋转正交组合实验（响应面实验）,优化营养粉工艺参数.结果表明,物料水分、螺杆转速和挤压温度对于青稞营养粉产品品质影响显著（P＜0.05）.响应面试验得出速食营养粉的较优加工条件：螺杆转速290 r/min,温度165℃和水分含量16.5％.在此优化条件获得青稞预糊化粉的各项指标为：膨化度3.14,吸水指数5.92,容重0.53,碘呈色度5.44.     

Influence of inoculum and climatic factors on the severity of Fusarium head blight in German spring and winter barley

Fusarium head blight (FHB) of small cereals is a disease of global importance with regard to economic losses and mycotoxin contamination harmful to human and animal health. In Germany, FHB is predominantly associated with wheat and F. graminearum is recognised as the major causal agent of the disease, but little is known about FHB of barley. Monitoring of the natural occurrence of FHB on Bavarian barley revealed differences for individual Fusarium spp. in incidence and severity of grain infection between years and between spring and winter barley. Parallel measurement of fungal DNA content in grain and mycotoxin content suggested the importance of F. graminearum in winter barley and of F. langsethiae in spring barley for FHB. The infection success of these two species was associated with certain weather conditions and barley flowering time. Inoculation experiments in the field revealed different effects of five Fusarium spp. on symptom formation, grain yield and mycotoxin production. A significant association between fungal infection of grain and mycotoxin content was observed following natural or artificial infection with the type B trichothecene producer F. culmorum, but not with the type A trichothecene-producing species F. langsethiae and F. sporotrichioides. Trichothecene type A toxin contamination also occurred in the absence of significant damage to grain and did not necessarily promote fungal colonisation.     

The protein properties of germinated naked barley with infrared and hot air-drying and its noodle-making potential

The naked barley was germinated and then carried out with hot air- or infrared drying to explore the physicochemical and functional properties of protein isolated from barley. Moreover, the relationship between protein and the noodles made from wheat and germinated barley flour was evaluated. It was found that germination affected the protein properties, and the protein properties were correlated with the properties of noodles. The content of β-sheet in protein was first increased and then decreased with germination time increased, and the protein had larger emulsification and foaming properties. Besides, the protein isolated from hot air-dried germinated barley had higher gelatinisation enthalpy and secondary structure content. Furthermore, the wheat and germinated barley mixed noodles had increased elasticity and cohesiveness and reduced viscosity and water absorption. The hardness of noodles showed was positively correlated with water absorption capacity, and the extensibility of cooked noodles was positively correlated with the foaming capacity of proteins.     

Physicochemical and structural characteristics of starches from Chinese hull‐less barley cultivars

Fourteen hull‐less barley cultivars, collected from four major cultivated areas in China, were employed to investigate the structural and physicochemical properties of their starches in this study. Relatively wide variations in physicochemical properties of the starches were observed. Amylose content ranged from 23.1% to 30.0%, swelling power and water solubility index ranged from 12.8 to 19.9 g g^?1 and 12.7% to 23.7% respectively. Peak viscosity was from 170 to 346 Rapid Visco Unit (RVU), peak temperature (T_p) of starch gelatinisation was from 55.6 to 61.8 °C and enthalpy of starch retrogradation ranged from 0.3 to 3.1 J g^?1. Weight‐based chain‐length proportions of fa, fb₁, fb₂ and fb₃ in amylopectins ranged from 21.65% to 24.95%, 44.48% to 49.44%, 15.56% to 17.19% and 9.83% to 16.66% respectively. Correlation analyses showed that amylose content was inversely related to pasting parameters and enthalpy of gelatinisation. Pasting properties and amylopectin structures were the most important parameters to differentiate starch properties among different hull‐less barley cultivars in this study. This work will be useful for exploring applications of Chinese hull‐less barley starches in food and non‐food industries.