The diversity among the species Tetragenococcus halophilus including new isolates from a lupine seed fermentation

Background Tetragenococcus (T.) halophilus can be isolated from a variety of fermented foods, such as soy sauce, different soy pastes, salted fish sauce and from cheese brine or degraded sugar beet thick juice. This species contributes by the formation of short chain acids to the flavor of the product. Recently, T. halophilus has been identified as a dominant species in a seasoning sauce fermentation based on koji made with lupine seeds. Results In this study we characterized six strains of T. halophilus isolated from lupine moromi fermentations in terms of their adaptation towards this fermentation environment, salt tolerance and production of biogenic amines. Phylogenic and genomic analysis revealed three distinctive lineages within the species T. halophilus with no relation to their isolation source, besides the lineage of T. halophilus subsp. flandriensis. All isolated strains from lupine moromi belong to one lineage in that any of the type strains are absent. The strains form lupine moromi could not convincingly be assigned to one of the current subspecies. Taken together with strain specific differences in the carbohydrate metabolism (arabinose, mannitol, melibiose, gluconate, galactonate) and amino acid degradation pathways such as arginine deiminase pathway (ADI) and the agmatine deiminase pathway (AgDI) the biodiversity in the species of T. halophilus is greater than expected. Among the new strains, some strains have a favorable combination of traits wanted in a starter culture. Conclusions Our study characterized T. halophilus strains that were isolated from lupine fermentation. The lupine moromi environment appears to select strains with specific traits as all of the strains are phylogenetically closely related, which potentially can be used as a starter culture for lupine moromi. We also found that the strains can be clearly distinguished phylogenetically and phenotypically from the type strains of both subspecies T. halophilus subsp. halophilus and T. halophilus subsp. flandriensis.

INFLUENCE OF SULPHITATION TREATMENT ON TECHNOLOGICAL AND MICROBIOLOGICAL INDICATORS OF THICK JUICE DURING ITS LONG-TERM STORAGE UNDER CONDITIONS OF SUGAR FACTORY

Для увеличения производительности сахарного завода без существенных финансовых затрат можно использовать технологическую схему вывода сиропа на длительное хранение с последующей его переработкой в межсезонье. Одним из недостатков такой технологической схемы является риск микробиологической обсемененности сиропа, для снижения которой отечественные исследователи предлагают обработку электромагнитными полями. Однако, на наш взгляд, обработка сиропа сульфитсодержащими реагентами более безопасна и менее энергоемка. Проведены лабораторные исследования, направленные на снижение микробиологической обсемененности сиропа при выводе его на хранение. Объектом исследований был полученный в лабораторных условиях концентрированный сироп с содержанием сухих веществ 67%, который делили на три образца по 300 мл каждый. Контрольный образец сиропа оставляли без обработки, образец 1 обрабатывали сернистым ангидридом до рН 7,3–7,5, образец 2 – раствором бисульфита натрия в количестве 0,01% к массе образца. После этого все три образца подвергали подщелачиванию 1 н раствором NaOH до pH 9,15 и хранили в течение 100 сут при комнатной температуре. По окончанию срока хранения в образцах сиропа определяли микробиологические показатели и содержание редуцирующих веществ. Установлено, что предварительная обработка сиропа, направляемого на длительное хранение, сульфитсодержащими реагентами способствует достаточно эффективному снижению количества мезофильных аэробных и факультативно-анаэробных микроорганизмов и плесеней. Наибольший эффект снижения наблюдается при обработке сиропа сернистым ангидридом: на 69% снижается показатель микробиальной обсемененности и на 58% количество плесеней по сравнению с необработанным сиропом. При обработке сиропа бисульфитом натрия снижение составило 31 и 33% соответственно. Степень предотвращения накопления редуцирующих веществ при обработке сиропа сернистым ангидридом составила 18,8%, а при обработке бисульфитом натрия – 11,5%. Снижение микробиальной обсемененности сиропа при выводе его на длительное хранение будет способствовать снижению потерь сахарозы. To increase the productivity of the sugar factory without significant financial costs, you can use a technological scheme for the withdrawal of thick juice for long-term storage with its subsequent processing in the off-season. One of the disadvantages of such a technological scheme is the risk of microbiological contamination of the thick juice, to reduce which domestic researchers offer treatment with electromagnetic fields. However, in our opinion, the treatment of thick juice with sulfite-containing reagents is safer and less energy intensive. Laboratory studies aimed at reducing the microbiological contamination of the thick juiceduring its storage were carried out. The object of research was a concentrated thick juice obtained under laboratory conditions with a dry matter content of 67%, which was divided into three samples of 300 ml each. The control sample of the thick juice was left untreated, sample 1 was treated with sulfur dioxide to a pH of 7,3–7,5, sample 2 – with a solution of sodium bisulfite in an amount of 0.01% by weight of the sample. After that, all three samples were alkalized with 1 n NaOH solution to pH 9,15 and stored for 100 days at room temperature. At the end of the shelf life, microbiological parameters and the content of reducing substances were determined in the thick juice samples. It was found that the pretreatment of thick juice sent for long-term storage with sulfite-containing reagents contributes to a sufficiently effective reduction in the number of mesophilic aerobic and facultative anaerobic microorganisms and molds. The greatest reduction effect is observed when the thick juice is treated with sulfurous anhydride: the indicator of microbial contamination is reduced by 69% and the number of molds is reduced by 58% compared to untreated thick juice. When treating the syrup with sodium bisulfite, the reduction was 31 and 33% respectively. The degree of prevention of the accumulation of reducing substances when treating the thick juice with sulfur dioxide was 18,8%, and when treating with sodium bisulfite – 11,5%. Reducing the microbial contamination of the thick juicewhen it is taken out for long-term storage will help to reduce the loss of sucrose.

Oxalate contents in green juice prepared using either a high-speed blender or a masticating juicer

Green vegetables are very beneficial for health, but sometimes it is not understood that some vegetables also contain anti-nutrients. For example, oxalic acid can be found in some green vegetables, such as spinach. Oxalic acid can be absorbed from food and as it is a toxin it has to be removed from the body via the kidneys. Under certain conditions, oxalate can combine with calcium in the kidneys forming stones which can lead to impaired kidney function. This study aims to compare two techniques for making vegetable juice, using a high-speed blender or a masticating juicer. The content of oxalic acid, calcium, pH and titratable acidity (TA) was measured in both juices. Total oxalic acid was measured using HPLC, calcium content was analyzed using a Coupled Plasma Optical Emission Spectrophotometer. Dry matter, pH and TA were measured based on AOAC methods. The highest total oxalate (OA) was found in juice made using a masticating juicer of 7638.27 mg OA/100 g dry weight. The highest calcium content was found in the fiber fraction or in the remaining juice using the masticating juicer technique, which was 10.04 mg/100 g juice. Meanwhile, the TA value of the thick juice produced by the high speed blender was not significantly different from the runny juice produced by the masticating juicer. The smoothie-like green juice prepared using a high-speed blender was healthier as the soluble and insoluble oxalate extracted in the juice was lower than in the clear juice prepared using a masticating juicer.

INFLUENCE OF THIN JUICE SULFITATION TREATMENT ON ITS VISCOSITY AND EVAPORATION EFFICIENCY

Описан механизм влияния вязкости на процессы выпаривания очищенного сока и кристаллизации сахарозы. Исследовано влияние сульфитационной обработки очищенного по типовой схеме сока II сатурации на его кинематическую и динамическую вязкость и эффективность выпаривания. Для эксперимента очищенный сок II сатурации со значением рН 9,2 делили на две равные части. Одну часть оставляли в неизменном виде – контрольный образец, другую подвергали сульфитационной обработке до рН 8,8 – опытный образец. В обоих образцах определяли кинематическую вязкость с последующим пересчетом в динамическую вязкость. Эффективность сульфитационной обработки определяли по степени снижения динамической вязкости в образце обработанного сока II сатурации и содержанию сухих веществ в образцах сиропа, полученных после выпаривания контрольного и опытного образцов сока в течение 90 мин на глицериновой бане, нагретой до 120°С. Установлено, что сульфитационная обработка очищенного сока II сатурации обеспечивает снижение его динамической вязкости на 6,27%, а при его последующем выпаривании – повышает содержание сухих веществ в сиропе на 4,0% по сравнению с контрольным образцом. Высказано предположение, что сульфитационная обработка очищенного сока целесообразна для повышения качества – снижения цветности и конкурентоспособности продукции за счет снижения расхода условного топлива на получение готового продукта. The mechanism of influence of viscosity on the processes of evaporation of purified juice and crystallization of sucrose is described. The influence of sulfitation treatment of purified thin juice according to the standard scheme on its kinematic and dynamic viscosity and evaporation efficiency has been studied. For the experiment the purified thin juice with pH value of 9,2 is divided into two equal parts. One part was left unchanged – the control sample, the other was subjected to sulfitation treatment to pH 8,8 – the experimental sample. Kinematic viscosity with subsequent conversion to dynamic viscosity was determined in both samples. The effectiveness of sulfitation treatment is determined by the degree of reduction in the dynamic viscosity in the sample of processed thin juice and the content of dry substances in the thick juice samples obtained after evaporation of the control and experimental samples of juice for 90 minutes in a glycerin bath heated to 120°C. It was found that the sulfitation treatment of purified thin juice provides a decrease in its dynamic viscosity by 6,27%, and during its subsequent evaporation – increases the dry matter content in the thick juice by 4,0% compared to the control sample. The suggestion was made that the sulfitation treatment of purified juice is appropriate for improving the quality – reducing the color and competitiveness of products by reducing the consumption of conventional fuel to obtain the finished product.

Filtration of stored thick juice for the syrup campaign

Extraction of sucrose from sugarbeet for sugar production on an industrial scale can be divided into two distinct types of operations: beet processing (operation of the entire factory) and syrup processing (operation of the sugar house only). During the beet harvesting campaign thick juice is stored in large tanks for subsequent processing in the syrup campaign. It is good practice to filter the thick juice prior to storage for removal of microbes and insolubles. More importantly is filtration of the thick juice during the thick juice campaign for food safety and to remove any solids that have precipitated during storage for sugar quality. This is normally done using a filter aid to ensure filtration to below 5 µm is achieved. The use of a filter aid is not ideal due to health concerns and the risk of causing sugar quality issues if filter aid is carried forward with the syrup. A filtration system designed to operate without the use of a filter aid was therefore trialed at one of the Tereos factories in France. Standard liquor from storage tanks were filtered through 14–25 µm filter material during the 2018 thick juice campaign. Operational and sugar quality results are discussed.

Studies on the storage stability of white beet sugar depending on its quality

Storage stability of white beet sugar is an important factor determining the sugar quality. Due to color formation during storage the sugar color can exceed the quality criteria of the European council directive 2001/111/EC for white sugar. It is not possible to predict the color formation tendency of a white sugar lot at the time of its production. Also the source and the mechanism of color formation during storage are unknown. Color formation in general can be caused by several factors, which can be divided into external influences such as humidity and temperature during storage and internal causes such as contents of ash, polyphenols, mono- and oligosaccharides, and amino compounds. In this work, the effect of the above mentioned factors and the nature of the formed colorants were analyzed. Studies on the color distribution in sugar crystals were carried out and the nonsucrose compounds in the surface film were determined. The syrup film on the crystal surface contains the same compounds and in similar contents as thick juice. A correlation between the changes in the amino acid and monosaccharide content and the color formation was established, which shows that the Maillard reaction is responsible for the color development during storage of sugar.