Birch Sap Research Articles

Tibetan Birchbark Manuscripts in the Serindian Collection of the IOM, RAS: Restoration and Identification

The article presents the Tibetan birchbark manuscripts kept in the Serindian collection of the IOM, RAS. The five birchbark manuscripts exhibit common codicological and paleographic characteristics, and the texts within them demonstrate a functional congruence, primarily associated with the rituals of consecration and empowerment. The objective of the conservation efforts was to flatten the birchbark fragments to both identify and preserve the inscribed texts. The fragments were sufficiently moistened in the birch sap as a plasticizer instead of regular water, given that it is a natural substance inherent to birch bark. The birch sap for conservation was hand-harvested from an ecologically pristine area. The soaking process in warm birch sap softened the fragments, and they were also cleansed of surface impurities. Damaged areas of the birchbark fragments were reinforced using Japanese conservation paper. For subsequent use and preservation, the fragments were stored in envelopes made of high-quality Melinex polyester film. Owing to the restoration work, five Tibetan birchbark manuscripts were described and transliterated.

Preliminary quality/ price analysis for some Betula products

Species from Betula genus have been proven to have bioactive features, including anti-inflammatory, anti- carcinogenic and anti-rheumatic properties. They are either used for therapeutic or pharmacological purposes. There are a variety of types of products, from the well-known sap to tinctures or extracts, having different flavors, for a wider range of preferences. Thus, the purpose of this study was to compare the quality of liquid products produced from birch sap, from various companies and harvested naturally, in relation to the price of each product. This study required a thorough monitoring of prices over a period of several months, as well as qualitative and quantitative analyses. For the investigation of these indices, 6 types of products were used. The price rise research was conducted between November 2023 and January 2024, with 11 samples drawn from each type. All these tests reveal a link between the price of a product and its quality; thus, the more expensive products have a greater amount of sugar, which shows that the products have been preserved well.

Qualitative Changes in Birch Sap after Freezing and Thawing

In this study, the qualitative changes in raw birch sap after freezing and thawing were determined. Ten-liter bottles and one-ton plastic containers with six replications were used for the freezing of birch sap and thawing of frozen sap. During and after the thawing, the physical and physical–chemical properties of the sap were measured. According to the results, as the ice melts, the concentration of acids and other soluble substances in the sap decreases, but changes in qualitative indicators indicate the beginning of fermentation processes through color changes and pH as the temperature of the melting sap becomes positive. As a result, to freeze raw sap in large-volume containers, it is necessary to develop fast thawing technology using auxiliary means—circulation, external energy sources, and mechanical ice crushing.

Physicochemical, antioxidant activity, and sensory characteristics of mead produced with Hibiscus sabdariffa and Betula pendula (Birch sap)

Nowadays, consumers' preference for low-alcoholic beverages with health-promoting bioactive constituents is rapidly increasing. Thus, there is an increasing search for bioactive ingredients to enhance the nutritional values and related health benefits of beverages such as mead. Hibiscus sabdariffa (HS) and Betula pendula (Birch sap) are plant materials rich in bioactive constituents that offer beneficial functions, including antioxidant and anti-inflammatory properties. Therefore, the study aimed to use HS and birch sap to produce a low-alcohol mead with improved bioactive constituents, sensory qualities, and antioxidant activity. Before fermentation (20 ± 1 °C, 21 days), honey-must (25%) was supplemented with HS brew (8, 19, 22, or 25%). The findings showed that the addition of HS extract had no negative effect on fermentation dynamics, as evidenced by a general decline in extract (%Brix) and simultaneous release of alcohol in both the control and HS-supplemented meads. HS meads had significantly lower alcohol content (3.22 ± 0.04–5.58 ± 0.04) than control meads (36.32 ± 0.04–7.17 ± 0.04). Also, the addition of HS and birch sap enhanced the bioactive elements and antioxidant activity of HS mead compared to the control meads. HS mead (HSC) had the highest (p < 0.05) total phenolic content (134.38 ± 0.83 mg QAE/L), total flavonoid content (117.88 ± 0.150 mg RE/L), and 2,2-Diphenyl-1-picrylhydrazyl antioxidant activity (65.83 ± 0.62%) among all the samples studied. Mead augmented with 1.8 L (HSC) was generally preferred by sensory panellists with an overall acceptability score of 7.67 ± 0.77. The results suggest that the addition of birch sap and HS will not change the fermentation kinetics but will improve the bioactive constituents and health-promoting benefits of the mead.

Exploring the potential of white birch sap: A natural alternative to traditional skin whitening agents with reduced side effects

Common tyrosinase (TYR) inhibitors used in cosmetics, such as hydroquinone, kojic acid, and arbutin, can cause side effects including erythema, skin peeling, and dryness. Therefore, the development of natural whitening agents that offer excellent permeability, minimal irritation, and high safety has become a primary focus in the field of TYR inhibitors. In this study, we demonstrate that White birch sap (WBS), within a safe concentration range, effectively reduces TYR activity and melanin content in both B16F10 mouse melanoma cells and zebrafish larvae. Importantly, WBS exhibits minimal irritation to neutrophils in fluorescent zebrafish and does not affect the behavior of adult zebrafish. Furthermore, WBS downregulates the gene expression levels of microphthalmia-associated transcription factor, TYR, tyrosinase-related protein-1, and tyrosinase-related protein-2 in B16F10 cells. In conclusion, our research confirms that WBS, a naturally derived substance, offers high safety and mild effects, making it a promising candidate for a skin-whitening agent.

The influence of raw materials on the biochemical profile of distillates

This study focuses on exploring novel ingredients for the production of safe, high-quality alcoholic beverages and enhancing the processes involved in fermenting beverages. These efforts aim to support local community development initiatives targeting food security, food sovereignty, and small businesses. The article presents the technology for producing distillates from vegetative raw materials, integrating digital technologies for quality control across all manufacturing stages. Distillates were obtained using the “Minispirtzavod Simpl 2018 set “Authentic” equipment, featuring remote control capabilities and a built-in Wi-Fi module. The quality of distillates derived from various vegetable raw materials, including grapes, apples, wheat, and birch sap, was evaluated through organoleptic analysis, assessing appearance, aroma, and taste. Gas chromatography was employed to determine the content of ethyl alcohol, furfural, methyl alcohol, aldehydes, ethers, and fusel alcohol in the distillates. The resulting distillates contained 40.9% to 43.5% vol.% ethanol and exhibited distinct aromatic profiles and flavors based on the vegetative raw material used. This diversity offers opportunities to expand the range of alcoholic products available.

Cancer patients’ behaviors and attitudes toward natural health products

BackgroundNatural health products (NHPs), including vitamins, minerals, and herbal supplements, are the most common complementary and alternative medicine (CAM) among cancer patients. Our survey determined the attitudes and behaviors of cancer patients toward natural complementary therapies that should be considered to implement an integrative approach in the future.MethodsOur survey was conducted in four hospitals in Belgium. Questionnaires were posted online from October 2020 to October 2021 for cancer patients. Descriptive statistics were used to analyze the data. A χ2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\chi ^{2}$$\\end{document} test was applied to study the type of NHP consumed according to diagnosis time. Fischer’s exact test compared patients who had changed their consumption since diagnosis and those who had not.ResultsOut of 349 questionnaires collected, only 59 met all inclusion criteria. 83.1 % of the patients agreed that conventional medicine (CM) could benefit from complementary therapies, but they did not estimate (72.3 % of the patients) that those latter are more effective than conventional medicine. More than half of the patients used five or more NHPs. The most frequent NHPs consumed daily were vitamins (64.4 %), followed by other products (i.e., probiotics, gemmotherapy, birch sap and omega 3/6) (42.4 %) and herbs (40.7 %). Almost all patients started taking NHPs before their cancer diagnosis, but 72.7 % have changed their consumption significantly (p = 0.009) since their diagnosis. Boosting the immune system (79.7 %) and limiting conventional treatment side effects (76.9 %) were the most common reasons for NHPs’ use. 74.4 % of the patients did not take complementary therapies to delay or avoid conventional treatment.ConclusionsThe combination and high diversity of NHPs consumption highlight the importance of educating patients and healthcare providers (HCPs) about the risk of drug interactions associated with these natural products. Most cancer patients are more interested in using this non-mainstream medicine to complement their conventional treatment than as an alternative. Knowing the patients' reasons and understanding patients’ attitudes toward NHPs will be essential for HCPs to address NHPs’ use.

Structural and functional characterization of exopolysaccharide from Leuconostoc citreum BH10 discovered in birch sap

In this study, Leuconostoc citreum BH10, an endophytic strain, was isolated from aseptically collected xylem sap of birch for the first time, and its exopolysaccharide (LCEPS) production was up to 46.31 g/L in glucan producing medium. The produced LCEPS was purified to obtain two water-soluble fractions, named as LCEPS-1 and LCEPS-2, respectively. The major fraction LCEPS-1 was characterized to be comprised of glucose with average molecular weight of 6.34 × 106 Da. The structure of LCEPS-1 was investigated by spectroscopy analysis, which revealed that LCEPS-1 was identified with containing 90.45 % α-(1,6) linkages in the main chains and 9.55 % α-(1,3) branch linkages. The scanning electron microscope results demonstrated that the dried LCEPS-1 appeared porous surface overlaid with an irregular glittering. The water solubility index (WSI) and water holding capacity (WHC) of LCEPS-1 were 88.02 ± 1.69 % and 241.43 ± 6.38 %, respectively. Besides, it exhibited high thermal stability as well as fine antioxidant activities. Taken together, the results indicated that LCEPS-1 could have good potentiality to be applied in fields of foods, cosmetics, nutraceuticals and pharmaceutical industries as the natural agent.

Effect of Birch Sap as Solvent and Source of Bioactive Compounds in Casein and Gelatine Films.

Birch sap consists of a natural water-based solution with valuable compounds such as minerals, sugars, organic acids and phenolic compounds that can be used advantageously in the preparation of edible films. In this study, gelatine- and casein-based films were prepared using birch sap as biopolymer solvent and source of bioactive compounds with the aim of developing new bioactive materials for food packaging. The physical, mechanical, barrier, antioxidant and iron-chelating properties of the obtained films were investigated. Birch sap enhanced the mechanical properties of the films by increasing puncture strength and flexibility, as well as their ultraviolet-visible light barrier properties. In addition, the presence of bioactive compounds endowed the birch sap films with an antioxidant capacity of almost 90% and an iron-chelating capacity of 40-50% with respect to the control films. Finally, to test these films as food packaging material, a photosensitive curcumin solution was packed and exposed to ultraviolet light. Tested films were able to protect curcumin against photodegradation, and the presence of bioactive compounds inside the birch-sap-enriched materials offered an additional 10% photoprotective effect compared to control films. Results showed the potential of birch sap as an environmentally friendly biopolymer solvent and plasticizer that can improve the mechanical and photoprotective properties of the prepared materials.

The modeling of changes in the specific activity of tritium in plants

Birch juice is a drink made of birch sap of medium-sized wild trees at the springtime. It is popular especially in northern Europe and Asia on territories with occasionally waterlogged permeable soils. However, some of these areas coincide with highest tritium leakage ever recorded (Kyshtym, Chernobyl and Fukushima). Robust analyses on tritium levels (scintillation method) in the birch sap were carried out in location with a constant load of tritiated water between 2003 and 2016. Sampling the birch sap was carried out annually in season (usually from the final week of February to the first-week of April. Sampling of birch sap was usually has been carried out during the period when the daytime air temperature was within +(5–8) °C minimum for 3 days. During this period, began intensive sap flow. Data obtained is put in relation to air temperature and humidity in order to contribute to the understanding basic mechanisms of tritium intake via birch. Findings confirmed that tritium easily penetrates via water into any organism and it can accumulate there for much longer than its half-decay times. It was firstly revealed that it is possible to predict the concentration of this dangerous pollutant in the birch sap based on the temperature and humidity dynamics. And with continuous input of tritium into the environment, the concentration of tritium in free water increases polynomial. The specific tritium activity values due to the gradient of tritium concentration in the atmosphere-plant-ground system of the change in temperature and humidity. For the organization of monitoring and control, the possibility of radioecological safety for the affected areas was determined

N. Rohova, O. Volodko, Ya. bychkov DEPENDENCE OF LACTOBACILLI ACTIVITY ON THE CONCENTRATION OF SUGAR IN THE SUBSTRATE

The purpose of the article was to extend the shelf life of birch sap and the time of its processing by pre-fermentation of birch sap with pure crops Lactobacillus casei ssp. alactosus. The disadvantage of the existing method of production of birch sap is that the newly collected birch sap must be immediately sent for processing, because short-term storage for no more than 24 hours is allowed only in chilled rooms at a temperature of 0 to 5 0C and a relative humidity of not more than 75 %. In case of violation of these conditions, turbidity of the juice appears, acidity increases and spontaneous fermentation of the juice begins, which has significant flaws. The sugar content in birch sap is relatively low. Since the fluctuations in the sugar content of fresh juice are quite significant, it was necessary to identify the activity of its costs during the fermentation process. Research methodology. The activity of lactobacilli was determined by measuring the loss of dry soluble substances in the juice during fermentation and the accumulation of titrated acids in terms of lactic acid. Results. Fluctuations in sugars depending on weather conditions and place of cultivation range from 0.5 to 0.9 %. The final product of sugar fermentation with lactobacilli, as already noted, is mainly lactic acid and other substances (acetic acid, ethyl alcohol, carbon dioxide, dextrin, mannitol) in small quantities. The term fermentation of birch sap to the desired lactic acid content can be adjusted by adding a certain amount of sugar to it. According to the derived regression equations, it is possible to predict on which day and at what concentration in the juice the desired acidity will be. The concentration of titrated acids in terms of lactic acid changed during the entire fermentation period, which occurred in rectilinear dependence, which is confirmed by the correlation coefficients Conclusions. To activate lactic fermentation with a small amount of sugar, it should be added to freshly harvested birch sap.

Investigation and modelling of the electrical charging effect in birch wood above the fibre saturation point (FSP)

Abstract Wood moisture content (MC) has a significant impact on all electrical properties of wood. Regarding the development of the (so-called polarization-type) wood moisture meter with the electrical charging effect for monitoring and controlling the wood drying process, it is of interest to expand the theoretical background of this type of novel wood moisture meter by means of modelling. Two mediums were selected for modelling – raw birch wood and, as a reference medium, birch liquid sap – into which two symmetrical carbon fibre measuring electrodes were inserted. In both mediums, direct current and alternating current were passed between electrodes at different electrode potentials. The electrical field and electrical response of the current-affected mediums were then measured and modelled in the time domain and frequency domain. The numerical results of modelling are comparable both in the time domain and frequency domain (i.e. if E = 1.8V, then Cs = 0.5 mF and C1,int = 0.7 mF). The concept of energetic chargeability (CHA(W)) of wood was defined and compared to conventional chargeability as defined by C. Schlumberger in 1913. Empirical dependencies of CHA(W) on electrode potential and primary energy W1 transmitted through the wood (sap) medium were found. In the frequency domain, frequency dependencies were found to distinguish between adsorption processes and mixed kinetics ranges in birch sap and in raw birch wood.

Экологические особенности накопления радионуклидов компонентами наземных экосистем зоны отчуждения

The studies were carried out 30 years after the Chernobyl accident on the lands of the former land use subject to natural successional changes. The patterns of the lateral distribution of 137Cs, 90Sr, 241Am in the upper 20-cm soil layer of various biogeocenoses, including those depending on the height fluctuations of the relief, have been studied. The values of the coefficient of variation (V) of the content of radionuclides in the upper soil layer decrease with the time that has passed since the accident. The highest value of the coefficient of variation (75.2 %) was obtained for 90Sr in the soil in the pine forest. The influence of various soil conditions on the entry of radionuclides into birch sap, cap mushrooms, and meadow grasses was studied. Despite the significant excess of the density of soil contamination with 137Cs of all the studied communities (up to 9.1 times), its volumetric activity in the juice is significantly lower than 90Sr, which indicates a lower availability of 137Cs compared to 90Sr. Dynamic processes of accumulation of radionuclides during the entire period of the movement of sap are studied. With increase in extent of moistening of the soil, accumulation of radionuclides in mushrooms tends to decrease. At the same time differences between types is established that connected with feeding habits of mushroom and variability of microclimatic conditions. The effect of soil moisture content, the ratio of 137Cs mobility forms in the soil on the biological availability of the radionuclide by meadow grasses was studied. A decrease in the specific activity of radionuclides in the plant components of ecosystems was found as the phytocenoses moved away from the epicenter of the accident at an identical density of soil contamination. A relationship has been established between the accumulation of radionuclides and the agrochemical parameters of the soil: maintenance of humus, absorption capacity, cation exchange capacity, hydrolytic acidity, content of exchange phosphorus, concentration of mobile calcium, magnesium and potassium on post-agrogenic lands. The analysis of the soil-to-plant transfer factors (Cf) and aggregated transfer factors (Tag), the discrimination coefficient (DF) of 137Cs by a chemical analog element (potassium) was carried out. Species features of plants associated with the transport of K+ - Cs+ cations make significant adjustments to the mechanisms of 137Cs accumulation. Attention is drawn to the significant increase in the concentration of 90Sr in all components in recent years.

Enzymatically Hydrolysed Common Buckwheat (Fagopyrum esculentum M.) as a Fermentable Source of Oligosaccharides and Sugars

Common buckwheat (Fagopyrum esculentum M.) is highly rich in starches and polysaccharides. Nowadays, the use of common buckwheat in brewing processes and functional product development is gaining popularity as it is gluten-free and therefore suitable for those suffering from coeliac disease. Moreover, enzyme-assisted extraction for common buckwheat releases these oligosaccharides as well as bioactive substances, which can be further used for developing new products. This research aims to compare different enzymatic hydrolysis methods and their effect on roasted common buckwheat flour. The degradation of buckwheat flour using these hydrolytic enzymes was captured using SEM. Oligosaccharide and sugar molecular mass distributions were identified using HPLC-SEC. The extract with the highest fermentable monomeric sugar content was further fermented with ancient lactic acid bacteria starters: Tibetan kefir grains and birch sap. Ferment extracts were analyzed for antimicrobial activity against ten different pathogenic bacteria. The results indicated that the incorporation of enzymes into the extraction process lead to the release of a wide variety of DP3-DP4. Furthermore, the successful fermentation of these extracts with ancient starters revealed promising antimicrobial activity against nine different pathogenic bacteria, including E. coli and L. monocytogenes. In general, common buckwheat is a suitable ingredient for developing beverages and products with high value and has high potential in pharmaceutical applications.

The Biochemical Alteration of Enzymatically Hydrolysed and Spontaneously Fermented Oat Flour and Its Impact on Pathogenic Bacteria.

Avena sativa (A. sativa) oats have recently made a comeback as suitable alternative raw materials for dairy substitutes due to their functional properties. Amylolytic and cellulolytic enzyme-assisted modifications of oats produce new products that are more appealing to consumers. However, the biochemical and functional alteration of products and extracts requires careful selection of raw materials, enzyme cocktails, and technological aspects. This study compares the biochemical composition of different A. sativa enzyme-assisted water extracts and evaluates their microbial growth using spontaneous fermentation and the antimicrobial properties of the ferment extracts. Fibre content, total phenolic content, and antioxidant activity were evaluated using traditional methodologies. The degradation of A. sativa flour was captured using scanning electron microscopy (SEM); moreover, sugar and oligosaccharide alteration were identified using HPLC and HPLC-SEC after INFOGEST in vitro digestion (IVD). Additionally, taste differentiation was performed using an electronic tongue with principal component analysis. The oat liquid extracts were continuously fermented using two ancient fermentation starters, birch sap and Tibetan kefir grains. Both starters contain lactic acid bacteria (LAB), which has major potential for use in bio-preservation. In fermented extracts, antimicrobial properties against Gram-positive Staphylococcus aureus and group A streptococci as well as Gram-negative opportunistic bacteria such as Escherichia coli and Pseudomonas aeruginosa were also determined. SEM images confirmed the successful incorporation of enzymes into the oat flour. The results indicate that using enzyme-assisted extraction significantly increased TPC and antioxidant activity in both the extract and residues. Additionally, carbohydrates with a molecular mass (MM) of over 70,000 kDa were reduced to 7000 kDa and lower after the incorporation of amylolytic and cellulolytic enzymes. The MM impacted the variation in microbial fermentation, which demonstrated favourable antimicrobial properties. The results demonstrated promising applications for developing functional products and components using bioprocessing as an innovative tool.

Соні та антропогенні пастки: особливості трапляння

The author has identified and described regular cases of falling of forest dormice into PET bottles that the locals exhibit to collect birch sap. Such bottles often remain attached to trees for a long time and are not removed after the season from the side of the sap. Various animals fall into them, among which dormice are regularly observed. The author’s experience of working with bottles for catching insects, which are filled with a special attractive and at the same time fixing solution based on wine or beer, with the addition of vinegar, salt and glycerine, is described. In such traps, also fixed on trees, the occurrence of dormice was twice as common as in the first case.

Комплексная оценка сырьевых ресурсов березняков

The research is aimed at a comprehensive assessment of the forest site resources deposited in a birch blueberry forest. The relevance of the work is based on the increasing interest of countries and regions in the diversity of forest ecosystem resources. A material and financial assessment of the major types of resources of the forest site with a birch stand is given for the first time. The stand composition is as follows: birch, 65 %; spruce, 21 %; aspen, 8 %; alder, 3%; elm, 2 %; and maple, 1 %. The stand is described by the following parameters: the relative density – 0.6; the quality class – II; and the growing stock – 344 m3/ha. Food and medicinal resources, wood and forest chemical raw materials, honey plants and birch sap, and household products were taken into account in the comprehensive assessment. The composition and reserves of the forest site reserves were assessed on the 10 m2 circular survey plots in accordance with the patent no. RU 2084129 C1 “Seedling Growth Registering Method”. The commercial species reserves of edible, technical and medicinal plants were estimated using the mowing method; berries – by a single collection during the ripening period. The sap production of the birch forests was determined empirically, based on the stand parameters. The prices for all types of resources were used as of 2019. It is shown that the cost of timber on the forest site is about 15 % (200,840 rub/ha) of the total cost of the other recorded types of resources, i.e. totally 2,643 rub/ha in terms of one year. The stock is dominated by firewood – over 36 %; the share of industrial wood is 34 %. The sap productivity of the birch forest is more than 12 ths L/ha per season. With an average birch sap cost of 20 rub/L, the income from the sale of seasonal sap volume per 1 ha can be more than 257 ths rub. By-products account for the largest share of revenue, ranging from 70 to 85 % depending on the season of the year. The share of edible and medicinal plants is about 10 %. The total income from the sale of the recorded types of resources of this forest site is estimated to be 1.2 mln rub/ha. The most important feature of this kind of resources is their ability to regenerate themselves without human participation. The main types of resources in the birch forest can be used annually during the entire period of reforestation. The obtained results can be used when drafting an agreement on the lease and a project for the development of a forest site where integrated utilization of forest resources or their individual types is assumed. For citation: Gryazkin A.V., Tran Trung Thanh, Vu Van Hung, Prokof’yev A.N., Hoang Minh An. Integrated Assessment of Raw Material Resources of Birch Forests. Lesnoy Zhurnal [Russian Forestry Journal], 2022, no. 1, pp. 23–35. DOI: 10.37482/0536-1036-2022-1-23-35

Rohova N. V. DEVELOPMENT OF TECHNOLOGY OF BUNDED JUICE ON THE BASIS OF FERTILIZED BIRCH JUICE

The purpose of the article is to develop the technology of blended juices based on fermented birch sap. Objectives of the article. The aim of the work was to develop biotechnology of production of fermented birch sap on the basis of preliminary selection of the most effective strains of microorganisms for fermentation, study of therapeutic and prophylactic properties of developed fermented birch sap by establishing the impact of a new product on metabolic processes and metabolic syndrome. determination of biological activity of the developed product against opportunistic pathogens. Research methodology. Different variants of blending ingredient ratios were developed and studied according to a set of organoleptic and physicochemical parameters. The degree of preservation of L-ascorbic acid after heat treatment was determined on model solutions. For this purpose, solutions of lactic acid in concentrations of 0.05 %, 0.1 %, 0.3 %, 0.5 % were prepared in distilled water, and ascorbic acid in concentrations of 0.005 % and 0.010 % was added to them. Organic acids were determined by high performance liquid chromatography in the reverse phase variant by photometric detection on a Waters instrument (USA). Quantitative determination of organic acids was performed according to standard solutions. Results. Freshly harvested birch juice is biologically unstable In the process of collection, it is contaminated with spontaneous microbiota and its shelf life before processing, although dependent on storage temperature, but is usually limited to 2 days. Therefore, it is important to prolong its shelf life by developing biotechnological methods to preserve the therapeutic and prophylactic properties of the original juice. Conclusions.So, modeling the loss of L-ascorbic acid during heat treatment allows us to draw an important conclusion for the technology, namely synthetic ascorbic acid should be added to blended juices based on fermented birch, that is after the fermentation process to establish an acidic environment. In terms of biochemical and microbiological composition, the most valuable can be considered fermented beverages – products of cultivation of mono or associated cultures of microorganisms. This is due to the ability of microorganisms to produce biologically active substances necessary for the normal functioning of the human body. The main difference and advantage of such beverages over conventional blending products is that bioactive substances are not introduced artificially, but are formed naturally during fermentation. If the source product is limited relative to a number of BAS or has a need to improve organoleptic characteristics, it is advisable to blend it with carriers of the desired properties.

Microbial safety and protein composition of birch sap

Consumers’ demand for birch sap, a nutritional juice tapped directly from birch trees, for human consumption is growing. This study aimed to investigate the time- and weather-related variability of the microbiota and protein content in birch sap throughout a complete tapping season, and the effect of birch sap freezing on its shelf life. Birch sap was collected daily during the 2018 season and harvested once a week during three consecutive weeks in 2019. Microbiota and protein content was 0.6–5.7 log(CFU/mL) and 3–60 μg/mL, respectively, with the highest content of both being in the end of the season. Daily temperatures correlated statistically with microbiota counts throughout the tapping season but not with protein concentration. The most prevalent bacteria was the genus Pseudomonas. Freezing birch sap for two weeks reduced the microbiota counts ∼1 log unit but did not affect the shelf life and type of bacteria. Twenty proteins related to plant defence against pathogens and abiotic stress were identified. In conclusion, birch sap harvested in the beginning of the tapping season had a longer shelf life and contained less protein than at the end of the season, which is of importance when developing procedures for microbial safe collection of birch sap and for the collection of sap containing bioactive substances.

Asymbiotic seed germination and in vitro seedling development of Orchis militaris, an endangered orchid in Siberia

BackgroundTerrestrial orchids belonging to the Orchis genus are difficult to propagate and are under great pressure in their natural habitats. Studies regarding the influence of photoperiod and temperature regimes on Orchis militaris germination and morphological changes during immature seed development in vitro are scarce. Our aim was to identify photoperiod, temperature, and different nutrient media requirements for optimization of O. militaris seed germination and vigorous seedling production. ResultsPost-germination morphological changes were recorded with O. militaris seeds collected from 32-day-old fruits, where the percentage of O. militaris seeds without embryo was 38.4%. The highest rate of O. militaris seed germination (82.6%) was obtained on Malmgren modified terrestrial orchid medium (mM), enriched by 5% coconut water, 5% birch sap, and 0.1% AC. Nine percent of seedlings were able to reach the advanced seedling stage (stage 6) after 12 months of maintenance on this medium. In all 3 modified media (Harvais, Knudson С and Malmgren), regeneration was via the production of protocorms and seedlings without callus formation. It was proved that more abundantly vigorous protocorms were formed on the modified Harvais 2 under continuous darkness, while the subculture in Knudson C medium with AC addition could be necessary to stimulate their further development. The regeneration success of the species for in vitro conditions was increased by following its natural seasonal cycle. ConclusionThis study demonstrated an efficient micropropagation system for O. militaris using immature seeds and thus widely opened the perspectives for its conservation in nature. The favorable conditions of seed germination periods for in vitro culture, identified as the definite shift of temperatures and photoperiod regimes intrinsic to the species in nature, could improve seedling survival of this medicinally important orchid.