Root tissue strength and storage losses of sugar beet varieties as affected by N application and irrigation

There is some evidence that sugar beet root tissue strength affects damage susceptibility and storage losses. This study aimed at analyzing the effect of N application and of irrigation on tissue strength of sugar beet varieties, on root composition, and on root tip breakage and storage losses. For this purpose, field trials in six replicates with three sugar beet varieties were carried out with three N doses in The Netherlands and Belgium in 2018 and 2019, alternatively with three irrigation treatments in Sweden in 2018 and 2019. Results show a low impact of N application and irrigation on puncture resistance, tissue firmness and compressive strength of the roots, while varieties differed always stronger and significantly. Cell wall composition (pectin, hemicellulose, cellulose, lignin) did not differ markedly in roots from different environments (sites, years) and varieties, giving no explanation for differences in tissue strength. However, the percentage of cell wall material (AIR, marc) and of dry matter were higher in roots with higher tissue strength. Root tip breakage and sugar losses during storage tended to be lower when root compressive strength of varieties was higher. Hence, root tissue strength could serve as an indirect selection criterion for reduced damage susceptibility and improved storability of sugar beet varieties.

Catch crop cultivation – A contribution to the EU Green Deal

The strategies for the future direction of agriculture in the EU and in Germany increasingly focus on climate and environmental protection. Catch crop cultivation may play a role in protecting soil, climate, water, and biodiversity. Data from a farm survey on sugar beet production in Germany between 2010 and 2019 were evaluated regarding the development of catch crop cultivation in connection with other production factors. The question was whether the cultivation of catch crops would support the intended environmental goals. It was investigated whether (1) fewer herbicides were used and (2) less nitrogen fertilizer was applied on fields with catch crops in comparison to fields without catch crops. The proportion of fields with catch crops before sugar beets has risen since greening was introduced as part of the EU’s common agricultural policy. Pesticide and nitrogen fertilizer applications were higher on fields with catch crops than on fields without. As these are results from a survey, it remains open why the use of herbicides and fertilizer in sugar beet cultivation is higher with than without catch crops. However, the results show that an increase in catch crop cultivation does not automatically have positive effects on the environment and climate. Sugar beet cultivation in practice should be further optimized in a targeted manner, so that greater benefits regarding environmental protection can be realized.

Virus Yellows in sugar beet – possibilities to achieve virus resistance

Virus yellows in sugar beet is caused by different virus species. Monitoring has shown that Beet yellows virus (BYV), Beet mild yellowing virus (BMYV), Beet chlorosis virus (BChV) are common and widespread, while Beet mosaic virus (BtMV) is less prevalent. The green peach aphid (Myzus persicae) is considered the main vector of these viruses. Sugar beet varieties with resistance or tolerance traits are currently not available to practical growers, therefore it is imperative to support breeding efforts with improved strategies to achieve virus resistance. For this purpose, a field test was established in which yield differences between susceptible and tolerant varieties can be generated by a 3% inoculation with BMYV-carrying aphids. A greenhouse bioassay has also been developed to distinguish susceptible and tolerant genotypes following BYV infection. Both assays pave the way for future use of natural resources such as wild forms and other breeding material to screen for virus resistance. In addition, molecular biology approaches are used to identify plant susceptibility factors of the plant-virus interaction, which will be knocked out via modern precision breeding methods to generate recessive virus resistance. Consequently, genotypes with naturally occurring mutations in the appropriate factors can be used for crossbreeding processes into elite breeding material.

Reduction of ammonia emissions and use of carbonatation vapors in sugar factories

Due to international agreements, there is a requirement to reduce ammonia emissions in beet sugar factories and to comply with the specified limit values. After looking at the sources of ammonia emissions in sugar factories, various ways of reducing these emissions are shown. In case of carbonatation exhaust gases in addition to reducing emissions, there is also the option of extracting heat from the exhaust gases and using it for technological purposes, which reduces the total energy consumption.

Das integrierte Sortenprüfsystem Zuckerrübe – Wachsen mit den Herausforderungen

Die Wertprüfungen beim Bundessortenamt (BSA) vor der Zulassung und die weitere Testung der zugelassenen Sorten über den Koordinierungsausschuss am Institut für Zuckerrübenforschung (IfZ) und die regionalen Arbeitsgemeinschaften bilden das integrierte Sortenprüfsystem Zuckerrübe. Durch die enge Zusammenarbeit von BSA, IfZ, Zuckerwirtschaft und Züchtungsunternehmen können kurzfristig flexible Lösungen für neue Fragestellungen erarbeitet und Zulassungen von Sorten mit innovativen Eigenschaften beim BSA ermöglicht werden. Der Schlüssel zur erfolgreichen Nutzung der Sortenleistung im Zuckerrübenanbau ist die neutrale Bewertung und Beratung auf Basis valider Versuchsergebnisse mit hoher Schätzgenauigkeit. Die hohe Qualität und der Umfang der Sortenversuche sind dafür entscheidende Voraussetzungen und im integrierten Sortenprüfsystem bei Zuckerrüben beispielhaft gelöst. Eine Feststellung der Identität von in Deutschland zugelassenen Sorten im Saatgutverkehr ist sichergestellt. Bei Sorten, die in anderen EU-Ländern zugelassen wurden, ist dies jedoch nur mit erheblicher Zeitverzögerung möglich und eine sichere Identifizierung ist deutlich erschwert.

Principles of juice purification

The raw juice as obtained by juice extraction of sugar beet cossettes contains dissolved and insoluble impurities (nonsugars) which need to be removed as much as possible to enable a cost-effective production of the wanted quality of white crystal sugar. The most commonly used purification approach of beet raw juice is the so-called classical liming process. The aim and principles of the different successive process steps in juice purification will be outlined in this paper. The purification principles comprise several chemical-physical reactions of particular nonsugars in the juice which are initiated at first by the addition of milk of lime to the raw juice in preliming and main liming. Through injection of the carbon dioxide produced in the lime kiln in the 1st carbonatation calcium ions precipitate as calcium carbonate, which is then used as filter aid to remove by sedimentation and/or filtration the formed slurry. The remaining surplus of lime salts are finally removed in the 2nd carbonatation which after filtration results in a clear thin juice.

Current perspective and future research directions on defecation clarification for the manufacture of raw sugar

Juice clarification is integral to the sugar-manufacturing process and determines the quality of clarified juice which is subsequently processed to produce sugar. Clarification performance is defined largely by turbidity of the clarified juice, but the presence of soluble impurities, colour and colour precursors, polysaccharides and proteins influence heat-transfer performance of evaporators and evaporating crystallizers, the crystallisation performance in evaporating crystallizers and the achievable yield and quality of sugar. The conventional defecation process is inadequate to remove these nonsucrose impurities, and the gradual worldwide transition to green-cane harvesting is introducing greater levels of impurities into the cane supply. As a result, the clarification station is now having to deal with not only the endogenous impurities (e.g. stalk impurities) but also the trash (leaves and tops) impurities. This paper reviews work that has been conducted over the years to remove these impurities and presents future research directions that should improve clarification performance. Examples of future research directions include development of multi-functional nanoparticles to significantly improve impurity removal; processing strategies to enhance precipitation of proteins and polysaccharides; and ballasting and adsorbent agents.

Chemistry and microbiology in sugar extraction

The stability of the sucrose molecule and the firmness of the tissue structure in the cossettes are of major concern when optimizing the operating conditions for the extraction system. For a given extraction system the retention time is more or less fixed, but the actual pH values and temperatures to be set across the system largely determine the extent to which both sugar gets lost by hydrolysis and the cossette structure deteriorates, particularly by dissolution of pectin. Furthermore, potential sugar loss by microbial infection in the extraction system needs to be controlled too. The influence of the pH value and temperature on these undesirable chemical and microbial reactions will be outlined in this paper, including the consequences for the subsequent processing steps. It can be concluded that the recommended optimal pH values and temperatures for operating the extraction system are a compromise between good and bad.

Steam drying markedly increases the solubility of feruloylated arabinan-rich pectic polysaccharide in sugar beet pulp

Three sugar beet pulp samples, which were dried by different methods (drum-dried, steam-dried, and shelf-dried), were prepared and hot water extractions (90 °C, 6 h) were performed to compare the pectic polysaccharide yield. The steam-dried pulp yielded 34.1 g of pectic polysaccharides per 100 g of dry matter. This represented about twice the yield of the other techniques, with a recovery of about 60% of the estimated amount contained in the raw material. The pectic polysaccharide obtained from the steam-dried pulp by hot water extraction and dialysis contained larger amount of arabinose (32.4 g/ 100 g solids) as constituent sugars than that of commercial beet pectin. The weight-average molecular mass was 175 kDa, which was lower than that of commercial beet pectin (538 kDa) and most of the extracted feruloyl group were bound to this polysaccharide. These characteristics were similar to those of pectic polysaccharides obtained previously by autoclave extraction from wet beet pulp. It was presumed that the pectic polysaccharides contained in sugar beet pulp were partially hydrolyzed and solubilized under pressurized and high temperature conditions (0.25–0.3 MPa, 150–180 °C) during steam drying, making them easier to extract. Using steam-dried pulp as a raw material, feruloylated arabinan-rich pectic polysaccharides can be efficiently obtained by hot water extraction under non-pressurized conditions without acid addition.

Operation of a six-effect evaporator station with a deficit in the vapour balance

During the operation of a six-effect evaporator station the vapour balance is subject of interfering incidents such as changing technological states of the process or surrounding conditions (ambient temperature e.g.) This article analyses and compares possible methods of managing the operation i.e. reaction to these incidents. In particular, methods of stabilizing the vapour balance by supplying water or thin juice to individual effects of the evaporator station and bypassing the vapours between effects are compared. The best way of reacting to the overload of the evaporator station seems to be the bypass of vapour from an effect of higher parameters to an effect of lower parameters. This method creates a much faster reaction of the evaporator station to excessive bleeding of vapour than supply of water or thin juice, which need to mix with the juice in the vessels. Feeding water to the thin juice tank or to one of the effects of the evaporator station to compensate excessive vapour consumption can be an acceptable solution in case of prolonged increase in vapour consumption from the evaporator station due to e.g. a significant decrease in ambient temperature.