Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

By purchasing malting barley the quality is evaluated according to standards, techniques, laboratory methods and qualitative indicators, which are set by norm. Evaluation of quality of barleycorn as a material for producing malt is used for setting the price, observing changes of the quality during storing etc. There were evaluated qualitative indicators of 13 sorts of malting barley, which were bought by company ZZN Pelhřimov between 2010-2014 from farmers, agricaltural cooperatives and companies and also self-employed farmers from the region Vysočina. These sorts were represented by different number of samples in connection with bought-up amount and number of supplies of each sort. Weighted averages were counted from results. Average figures of results of analysis were compared with the national average. Research institute of brewer´s and orchardist a.s. in Brno deals with monitoring of quality of malting barley in the Czech Republic and it evaluates annually ca. 500 harvest samples which were received by producers from all regions in the Czech Republic. The quality of malting barley showed a big variability in all parameters across all types and also in particular years. Malting quality is influenced by many factors especially by course of weather in each particular year. Limiting parameter of quality by purchasing malting barley was N- substances content in barleycorn. Germination capacity seems to be the most stable from all parameters. Lower figures of germination capacity were found only by winter types in connection with longer period of ripening after harvest.

This diploma thesis is focused on studies of changing of protein profile during barley malting. Substantial part of this work is devoted to the proteomics identification of barley proteins which change during malting and so become more stationary and they influence quality of beer (haze and foam in beer). For this experiment was used barley variety Jersey. In the theoretical part of this thesis there is information about beer, manufacturing of beer with description of important commodities for manufacturing of beer and information about barley malting and information about malting process. Next there is description of methods for separation of proteins (1D gel electrophoresis and 2D gel electrophoresis), MALDI TOF/TOF mass spectrometry and this use for the analysis and identification of proteins, the use of matrices and ways of the sample preparation. In the experimental part of this thesis there was carried out the optimisation of the dosage of sample for 1D gel electrophoresis and the optimisation of staining. The 15 % TRIS-HCl gel was the best, this gel was stained by Commassie Brilliant Blue G-250. For illustration of changes was made 2D gel electrophoresis. With help of method peptide mass fingerprinting and MS/MS protein of barley – protein Z, -amylase subtilisin inhibitor, -amylase a peroxidase were identificated. The analysis of barley extract intact proteins was carried out, this analysis was focused on changes of important barley protein LTP 1.

The theses presents results of experiments with spring barley started in years 2017 and 2018. The experiments were put into practice at Mr Jiří Nepovím's (BSc) place in Opatovice near Světlá nad Sázavou. Laudis 550 was used as the experimental variety of spring barley and the objective of the experiment was to observe the increasing amount of nitrogen and its effect on the resulting quantity and quality. The experimental amounts of nitrogen were set to 60 kg.ha-1, 75 kg.ha-1, 90 kg.ha-1, 105 kg.ha-1 and 120 kg.ha-1. With the increasing amount of nitrogen the crop increased of 0,2 - 0,4 t.ha-1. The share of nitrogen substances in grain increased of 0,2-0,5 %.

Dans un marché en permanente progression et pour répondre aux besoins des brasseurs en malt de qualité, la maîtrise du procédé de maltage est indispensable. La qualité du malt est fortement dépendante des conditions opératoires, en particulier des conditions de trempe, mais également de la qualité de la matière première : l'orge. Dans cette étude, nous avons établi des modèles polynomiaux qui mettent en relation les conditions opératoires et la qualité du malt. Ces modèles ont été couplés à nos algorithmes génétiques et nous ont permis de déterminer les conditions optimales de maltage, soit pour atteindre une qualité ciblée de malt (friabilité), soit pour permettre un maltage à faible teneur en eau (pour réduire la consommation en eau et maîtriser les coûts environnementaux de production) tout en conservant une qualité acceptable de malt. Cependant, la variabilité de la matière première est un facteur limitant de notre approche. Les modèles établis sont en effet très sensibles à l'espèce d'orge (printemps, hiver) ou encore à la variété d'orge utilisée. Les modèles sont surtout très dépendants de l'année de récolte. Les variations observées sur les propriétés d'une année de récolte à une autre sont mal caractérisées et ne sont donc pas intégrées dans nos modèles. Elles empêchent ainsi de capitaliser l'information expérimentale au cours du temps. Certaines propriétés structurelles de l'orge (porosité, dureté) ont été envisagées comme nouveaux facteurs pour mieux caractériser la matière première mais ils n'ont pas permis d'expliquer les variations observés en malterie.Afin de caractériser la matière première, 394 échantillons d'orge issus de 3 années de récolte différentes 2009-2010-2011 ont été analysés par spectroscopie MIR. Les analyses ACP ont confirmé l'effet notable des années de récolte, des espèces, des variétés voire des lieux de culture sur les propriétés de l'orge. Une régression PLS a permis, pour certaines années et pour certaines espèces, de prédire les teneurs en protéines et en béta-glucanes de l'orge à partir des spectres MIR. Cependant, ces résultats, pourtant prometteurs, se heurtent toujours à la variabilité. Ces nouveaux modèles PLS peuvent toutefois être exploités pour mettre en place des stratégies de pilotage du procédé de maltage à partir de mesures spectroscopiques MIR / In a continuously growing market and in order to meet the needs of Brewers in high quality malt, control of the malting process is a great challenge. Malt quality is highly dependent on the malting process operating conditions, especially on the steeping conditions, but also the quality of the raw material: barley. In this study, we established polynomial models that relate the operating conditions and the malt quality. These models have been coupled with our genetic algorithms to determine the optimal steeping conditions, either to obtain a targeted quality of malt (friability), or to allow a malting at low water content while maintaining acceptable quality of malt (to reduce water consumption and control the environmental costs of malt production). However, the variability of the raw material is a limiting factor for our approach. Established models are very sensitive to the species (spring and winter barley) or to the barley variety. The models are especially highly dependent on the crop year. Variations on the properties of a crop from one to another year are poorly characterized and are not incorporated in our models. They thus prevent us to capitalize experimental information over time. Some structural properties of barley (porosity, hardness) were considered as new factors to better characterize barley but they did not explain the observed variations.To characterize barley, 394 samples from 3 years of different crops 2009-2010-2011 were analysed by MIR spectroscopy. ACP analyses have confirmed the significant effect of the crop-years, species, varieties and sometimes of places of harvest on the properties of barley. A PLS regression allowed, for some years and for some species, to predict content of protein and beta-glucans of barley using MIR spectra. These results thus still face product variability, however, these new PLS models are very promising and could be exploited to implement control strategies in malting process using MIR spectroscopic measurements

PhD (Food Science) / Department of Food Science and Technology / Finger millet (FM) [Eleusine coracana] is an underutilised cereal grain used as a food source in South Africa. Increased research interest in FM has span over the years owing to its unique nutritional and bioactive composition. Following the recent interest in natural curative substances over their synthetic counterparts in the treatment of food dependent diseases, FM has shown potential nutraceutical effects. Some important health effects like antidiabetic, antioxidative, anti-inflammatory and antimicrobial properties have been reported in recent trials with FM. In view of the increasing utilisation and application of FM in the region of Thulamela Municipality, Vhembe District of South Africa, two common indigenous FM varieties (brown and dark brown) were obtained and analysed for their physicochemical properties, levels of minerals, phytic acid, phenolic compounds and antioxidant activities. For this process, malted non-alcoholic beverages were produced and analysed for their physicochemical properties, levels of phenolic compounds, and total phenolics and antioxidant activities. FM grains were soaked, germinated and kilned at an interval of 24 h for 96 h, using sorghum as an external reference. Mineral composition of the FM and sorghum samples were analysed using an inductively coupled plasma atomic emission spectroscopy (ICP-AES) and mass spectroscopy (ICP-MS), and atomic absorption spectrometer (AAS). Identification and quantification of phenolic compounds were performed using ultra-performance liquid chromatography mass spectrometer (UPLC-MS). All experiments were performed in triplicate except for the UPLC-MS analysis of the malted non-alcoholic beverages that was done in duplicate. Data were analysed by one way analysis of variance, and the mean values were separated by Duncan’s multiple comparison test using SPSS version 24.0. Data showed that the FM varieties were rich in macro- and micro- or trace elements. The macro-elements calcium, magnesium, potassium, phosphorus and sulphur were found in high amounts ranging from 1597.37 mg/ kg – 6775.03 mg/ kg; iron, zinc, strontium and silicon were found in significant amounts in the range 21.47 mg/ kg – 55.67 iii mg/ kg, copper and boron were found in low amounts (2.2 mg/ kg – 7.7 mg/ kg), along with selenium and cobalt (0.02 mg/ kg – 0.05 mg/ kg). Heavy metals, barium and aluminium were found in the FM varieties. Varietal difference was found to play an important role in the mineral content of the grains during malting. Malting for 24 h reduced mineral content except for sodium. Beyond 48 h of malting, mineral content increased, particularly, for 96 h in FM grain malt. Significant (p < 0.05) increases in the mineral content of FM varieties were noted at 48 h and 96 h of malting. Increase occurred at 72 h of malting for potassium, iron and boron. Malting did not have any effect on the manganese content of the dark brown FM; however, it increased the manganese content at 48 h of malting for brown FM. Malting for 96 h significantly (p < 0.05) reduced sodium content. Consecutive decrease in phytic acid content of the grains was not recorded with durations in malting time. Although statistically significant differences (p < 0.05) were observed, malting did not result in too much change in the physicochemical properties of the grains. Several flavonoids, catechin, epicatechin, quercetin, taxifolin, and hesperitin were isolated, whilst protocatechuic acid was the only phenolic acid detected in the unmalted and malted FM. Increases in catechin, epicatechin and protocatechuic acid were observed for 72 and 96 h malt of brown FM with similar observations recorded for sorghum. Complete loss of taxifolin, catechin, and hesperitin were noted with malting time. FM grains exhibited 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2՛-azinobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging action and iron reducing activities. Increased iron reducing activity alongside ABTS radical scavenging activity was recorded with malting time. A fermentation-time dependent decrease in the pH of the non-alcoholic beverages, with a corresponding increase in sugar content were recorded. A similar decrease was also recorded for the viscosities of the beverages. The FM malt beverages were found to contain a higher amount of citric acid compared to the sorghum malt beverage. A decrease in the citric acid content with fermentation time was noted in the grain malt beverages fermented with Lactobacillus fermentum, particularly for the iv FM beverage. The phenolic compounds detected in the FM malt beverages fermented with the grain microbial flora and Lactobacillus fermentum were protocatechuic acid, catechin and epicatechin. Taxifolin and kaempferol along with the earlier mentioned compounds were detected in the sorghum malt beverage. Catechin was found in higher amount compared to other phenolic compounds in the FM and sorghum malt beverages. FM malt beverages were found to contain a higher amount of total phenolics compared to the beverage prepared from sorghum malt. Fermentation with the grains’ microbial flora and L. fermentum resulted in reduced total phenolics of FM and sorghum malt beverages, particularly after 24 h of fermentation. A fermentation-time dependent decrease in total phenolics of FM beverages fermented with L. fermentum was noted. Fermentation within 24 - 48 h using the grain microbial flora showed higher total individual phenolic compounds for the dark brown FM and sorghum, compared to other fermentation periods. Fermentation of the beverages for 24 h retained a higher amount of the total phenolics compared to other fermentation periods, especially for the L. fermentum beverages. Reduced total phenolic content and antioxidant activity of the beverages were noted at 24 h of fermentation for the two microbial sources. Significant (p < 0.05) increases in total phenolics were observed within 72 – 96 h of fermentation of the brown FM malt beverage with the grains’ microbial flora. Fermentation for 72 h and 96 h with L. fermentum increased the total phenolic content of the brown FM. Increase in total flavonoid content (TFC) of brown FM malt beverage was noted at 72 h fermentation for both microbial sources. Unlike with L. fermentum, no significant (p > 0.05) change in TFC was observed for the dark brown FM beverage after 24 h fermentation with the grains’ microbial flora. Beverages exhibited DPPH, ABTS radical scavenging action and iron reducing activities, which were significantly (p < 0.05) reduced at 96 h fermentation for both microbial sources. The 24 h fermented beverage retained a higher amount of total phenolic and flavonoid contents, and had higher antioxidant activity compared to other fermentation periods for both microbial sources. The study shows that FM is a rich source of essential minerals and v phenolic compounds, and demonstrates that 72 to 96 h of malting has a positive effect on minerals and certain phenolic compounds over the 48 h malting period widely used for preparation of FM malt. The presence of hesperitin in FM grain was established. A new method was developed for the production of FM non-alcoholic beverage with measurable amounts of health-promoting compounds. An ideal fermentation period (24 h) for FM malt non-alcoholic beverage production with enhanced health-promoting compounds, using Lactobacillus fermentum was demonstrated. Fermentation limit (96 h) for production of FM malt beverage using either the grain microbial flora or L. fermentum was confirmed. These findings provide a rationale for increased utilisation of FM as a functional food grain, and its use as malt in production of non-alcoholic beverage for health promotion and wellness. / NRF