Ratio Of Organic Acids Research Articles

The quality of snaplage from an early ripening corn hybrid with biological inoculant and chemical preservatives

The article presents the results of experiments on studying the preservative effect of various additives in the production of snaplage from early-ripening corn hybrids in the conditions of the Central region of the Russian Federation. After opening the containers with feed, its quality indicators were assessed by the content and ratio of organic acids, the degree of acidification, the content of ammonia nitrogen, the preservation of sugars and essential nutrients. In physiological experiments on Romanov wethers, the digestibility of nutrients was determined. It was found that in all variants, the acidity of the feed was optimal (pH 4.2 and below), which excluded the development of undesirable microbiota. At the same time, in the snaplage with chemical preservatives, acidification occurred due to formic and propionic acids introduced with the preparations and (partially) due to the fermentation of sugars. The results of the physiological experiment showed that the digestibility of dry matter of snaplage from the early-ripening hybrid corn Emelin was high (over 70.2%) in all variants, which also affected the energy value (over 11 MJ NE). Thus, for high-moisture snaplage from early-ripening corn hybrids in the Central region of Russia, it is possible to use both chemical preservatives based on organic acids and biological inoculants intended for the preservation of wet flattened grain, containing active strains of lactic acid bacteria.

Integrating organic fertilization and soil tillage techniques to enhance the nutritional attributes of “Royal” grapes (Vitis vinifera L. cv.)

AbstractIn the context of global efforts to improve food quality against the backdrop of climate change and increasing demands for food, this study sought to investigate the influence of tillage and fertilization methods on essential nutritional components. Thus, this extensive investigation into the variability of organic acid, sugar, and vitamin content within berries over the years 2020 to 2022 shows the critical influence of agricultural practices on the nutritional quality of grape. Our findings revealed significant fluctuations in the levels of various organic acids, with oxalic and propionic acids seeing a notable increase in 2022, while tartaric, citric, and maleic acids decreased. Similarly, a significant rise in sucrose, glucose, and fructose levels was documented by 2022, alongside a variable trend in vitamin content. The PCA results revealed a clear impact of tillage and organic amendments on the biochemical composition of Royal grapes. Heatmap findings confirmed the results obtained from PCA and showed that certain treatments resulted in high organic acid content, while others resulted in high sugar content. However, disc harrow and olive blackwater 2021 followed by disc harrow and Antep radish 2021 and no‐tillage broccoli 2020 were the best treatments with a balanced distribution of organic acids, soluble sugars, and vitamins among all treatments. On the other hand, chisel and olive blackwater '20 was the treatment with the lowest ratio of organic acids, sugars, and vitamins, followed by chisel and Antep radish 2020. These results show that the concentration of organic acids, soluble sugars, and vitamins in grapes is more affected by the tillage method than the type of organic fertilizer used. To sum up, our study holds valuable implications for viticulture and agriculture at large, highlighting the potential to tailor farming practices for enhanced nutritional outcomes. Such advancements not only promise to elevate the quality of agricultural produce but also contribute to the broader objective of achieving food security and nutritional adequacy, thus offering a roadmap for future research and practice in sustainable agriculture and viticulture.

Regulation of organic acid and hydrogen production by NADH/NAD+ ratio in Synechocystis sp. PCC 6803.

Cyanobacteria serve as useful hosts in the production of substances to support a low-carbon society. Specifically, the unicellular cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis 6803) can produce organic acids, such as acetate, lactate, and succinate, as well as hydrogen, under dark, anaerobic conditions. The efficient production of these compounds appears to be closely linked to the regulation of intracellular redox balance. Notably, alterations in intracellular redox balance have been believed to influence the production of organic acids and hydrogen. To achieve these alterations, genetic manipulations involved overexpressing malate dehydrogenase (MDH), knocking out d-lactate dehydrogenase (DDH), or knocking out acetate kinase (AK), which subsequently modified the quantities and ratios of organic acids and hydrogen under dark, anaerobic conditions. Furthermore, the mutants generated displayed changes in the oxidation of reducing powers and the nicotinamide adenine dinucleotide hydrogen (NADH)/NAD+ ratio when compared to the parental wild-type strain. These findings strongly suggest that intracellular redox balance, especially the NADH/NAD+ ratio, plays a pivotal role in the production of organic acids and hydrogen in Synechocystis 6803.

Optimization of apple fruit flavor by MdVHP1-2 via modulation of soluble sugar and organic acid accumulation

For fleshy fruits, the content and ratio of organic acids and soluble sugars are key factors for their flavor. Therefore, a better understanding of soluble sugar and organic acid accumulation in vacuoles is essential to the improvement of fruit quality. Vacuolar-type inorganic pyrophosphatase (V-PPase) has been found in various plants with crucial functions based on the hydrolysis of PPi. However, the effects of V-PPase on the soluble sugar and organic acid accumulation in apple fruit remain unclear. In this study, MdVHP1-2, a V-PPase protein in the vacuolar membrane, was identified. The results showed a positive correlation between the expression of MdVHP1-2 and the sugar/acid ratio during ripening of apple fruits. A series of transgenic analyses showed that overexpression of MdVHP1-2 significantly elevated the contents of soluble sugars and organic acids as well as the sugar/acid ratio in apple fruits and calli. Additionally, transient interference induced by MdVHP1-2 expression inhibited the accumulation of soluble sugars and organic acids in apple fruits. In summary, this study provides insight into the mechanisms by which MdVHP1-2 modulates fruit flavor through mediation of soluble sugar and organic acid accumulation, thereby facilitating improvement of the overall quality of apple and other fruits.

The use of corn hybrid ROSS 195 for silage production in Central Non-Black Earth Region

Relevance. This article presents the results of assessing the biochemical parameters and aerobic stability of silage prepared from the domestic early ripening corn hybrid Ross 195 (FAO 180) in the phase of milky-wax ripeness of the grain. Green mass was carried out during harvesting at Barybino LLC in August 2021.Methods. Ensiling was carried out in laboratory conditions of the Federal Williams Research Center of Forage Production & Agroecology in four variants of treatments with various preservatives in three replications of each.Results. Quality indicators were monitored after 30 and 60 days of conservation. Seven days after opening the containers during outdoor storage in silage variants with the addition of biological inoculants, a slight decrease in the concentration of lactic acid and an increase in acetic acid were determined. In silage with chemical preservative, the acid content remained at the same level. The results of assessing the dynamics of silage heating during outdoor storage allow us to conclude that the aerobic stability of the feed with biological inoculants is sufficient, versus control. At the same time, best preservation (over a period of up to 135 hours) the best aerobic stability of silage was obtained with chemical preservative, which was characterized by higher quality indicators in terms of the level of active acidity (pH 4.0–4.1), ammonia content (0.0055–0.0078%) and sugar, and the quantity and ratio of organic acids remained at the level determined at opening.

METABOLIC ACTIVITY OF LACTIC ACID BACTERIAL STRAINS AFTER THEIR INTRODUCTION INTO ALFALFA HAYLAGE

Objective. Study the metabolic activity of strains of lactic acid bacterial strains after their introduction into alfalfa haylage as a component of preservatives. Methods. Microbiological (determining the number of microorganisms, obtaining antibiotic-resistant mutants of bacterial strains), zootechnical (pH level, accumulation and ratio of organic acids in the fermentation process), statistical. Results. Lactobacillus plantarum KT-L18/1str, L. plantarum 32str strains introduced into the haylage substrate are stored in the feed in an active state for a long time and at day 30 of fermentation take a dominant position among native lactic acid bacteria, retaining 80 % of the acid-forming capacity and antagonistic activity against Staphylococcus aureus. The best results of the action of the studied lactic acid bacteria (LAB) after introduction into alfalfa haylage were obtained when the mass was dry-cured to a moisture content of 60–61 %, while the share of lactic acid in the total amount of organic acids formed in the experimental variants of the haylage ranged from 85.5 % to 89.3 % versus the control, where the share of lactic acid reached only 42 %. Increasing the degree of feed acidification in experimental variants at a given alfalfa moisture content ensured a decrease in the butyric acid content to 1.12–1.7 % versus 26.3 % in the control variant. Treatment of alfalfa haylage dry-cured to a moisture content of 38–39 % with strains of lactic acid bacteria did not affect the increase in the proportion of lactic acid. Conclusion. The use of probiotic L. plantarum KT-L18/1str and L. plantarum 32str made it possible to establish their competitiveness and metabolic activity in the process of alfalfa haylage preparation. The use of LAB probiotic strains for alfalfa haylage preparation improved fermentation processes, in particular, when dry matter content was at the level of 39–40 %.

Nutritional Supplementation of Yogurt with Jerusalem Artichoke Tubers: Organic Acid Profiles and Quality Parameters.

Jerusalem artichoke (Helianthus tuberosus L.), also called wild sunflower, belongs to the Asteraceae family and is cultivated widely across the temperate zone for its nutritious tuber, which is used as a root vegetable. In this study, the Jerusalem artichoke (JA) was used as a supplementary additive for producing a functional yogurt, with enhanced health benefits and improving the microbiological, rheological, and sensorial quality characteristics of the product. The effects of the three different concentrations (1%, 2%, and 3%, w/w) of JA on the physicochemical properties, bacterial counts, sensorial properties, and organic acid profiles of yogurts were determined after 1, 7, 14, and 21 days of storage at ±4 °C. The results obtained revealed that with the addition of different concentrations of JA the overall parameters were statistically significant (p < 0.01 and p < 0.05) except for apparent viscosity, Streptococcus thermophilus, yeast and mold count, pyruvic ratios, and scores of flavor. Similarly, some parameters (fat ratio, yeast and mold count, concentrations of propionic, acetic, pyruvic, orotic, and lactic acids, and scores of appearance, consistency, and odor) changed depending on the storage time, while some did not show any changes regarding storage time. There was a relationship found between the concentration of JA and organic acid ratio (except for pyruvic acid) concentration in the yogurt samples. In conclusion, the research revealed the effect of JA in yogurt production as a thickener, flavor enhancer, prebiotic agent, and source of organic acids and bioactive compounds. The results indicate that JA has a good potential for enhancing the nutritional and physicochemical properties of the studied yogurt.

Консервирование бобовых трав и бобово-злаковых травосмесей с новым биологическим препаратом

The results of testing a domestic experimental biological additive on perennial legume grasses are pre-sented in this article. High-quality silage was obtained with new preparation on active acidity, content and ratio of organic acids, ammonia, parameters of nutrient losses. The optimal dose of application was de-termined: at ensiling the basic types of legumes — 80 ml/t, for forage galega — 100 ml/t. Under scientific and production conditions the experimental biological additive was used for ensiling alfalfa-gramineous grass mixture, that was non-ensiling raw material. The enzyme-bacterial additive Acidphast NC GOLD, produced by ''Lallemand'' Company, and the Finnish chemical preparation AIV 3 PLUS were used as the controls. The high quality of silage with a new additive was revealed on the basic organoleptic and bio-chemical parameters in comparison to feed, prepared with biological additive Acidphast NC GOLD. Then the nutritional value of obtained silage in each variant was determined in physiological experiments at feeding Romanov`s rams-valukhi when used as the only feed with addition of mineral supplements. A higher digestibility of crude fiber and fat in feeds with biological additives was found. The energy nutri-tional value of the silage with the experimental additive was 9.6 MJ metabolizable energy per 1 kg of dry matter versus 9.5 and 9.4 in feeds, prepared with Acidphast NC GOLD and chemical preservative AIV 3 PLUS respectively. Our investigations proved the high effectiveness of the experimental sample of new enzyme-bacterial additive at preservation of different species of legume grasses.

Bogyós és más gyümölcs nyersanyagok hamisításáról

We studied organoleptic, physical, chemical parameters, and nutrient composition of strawberry, raspberry, and melon powders and identified their profile of organic acids and mineral composition produced by a Russian company. It was found that the color and flavor ranges of the studied materials were uncharacteristic of the initial raw materials. The actual protein and lipids levels did not correspond to the ones declared by the manufacturer in the labeling, and were uncharacteristic of the processed raw materials. In all powder samples the sugars were represented by sucrose in 80-97%. This high level of sucrose content indicated the addition of 40.4-52.3% white sugar. The amount and ratio of organic acids did not correspond to the profile of natural raw materials. Thus, the strawberry powder lacked oxalic and tartaric acids, the raspberry raw material lacked malic acid, and the melon material – citric acid. The strawberry powder above the detection limit did not contain such essential macro- and microelements as Ca, Mg, B, Co, the amount of Si, Fe, K was at trace level. The raspberry powder was devoid of detectable amount of Co and K, and B, Ca, Cu, Mg, Mn, Si important for plant life were present in residual amounts. The “obligatory” amount of K, Fe, Ca, Co, Cu, Mg, Mn were absent in the melon powder, which did not correspond to the fundamental laws of the plant physiology. The results obtained allowed to conclude about misinformation and qualitative adulteration of the materials. Currently, there are practically no studies aimed at determining quality and chemical composition of fruit and berry powders in order to identify adulteration, though this type of survey would be great practical interest both for producers and consumers.

The effect of inorganic acids on reducing iron impurities during iron-rich laterite ore leaching

The Recovery of nickel from lateritic ores as the main oxide resources has been always debated. Since it consists of 1.74% Ni, 0.14% Co and 40.8% Fe, co-dissolution of iron occurred by using common lixiviation like sulfuric acid. Therefore, some leaching agents should be sought due to promoting a high dissolution of nickel/cobalt and a negligible iron recovery. This research investigates the effect of using organic acids such as gluconic, lactic and citric acid along with sulfuric acid on recoveries of Ni/Co from an iron-rich laterite ore. The results showed that adding sulfuric acid to the optimal combined ratio of the organic acids (gluconic: lactic: citric= 1: 2: 3) to obtain the combined ratio of 6 : 1: 2: 3 (sulfuric: gluconic: lactic: citric acid), simultaneously increasing the temperature from 60 to 90 °C, and increasing the final combined concentration of the acids from 3.5 M to 5 M, significantly increased nickel and cobalt recoveries by 80.4 and 68.7%, respectively, and slightly increased iron extraction by 5.05% all when compared to using the optimal combined ratio of organic acids. The use of 5 M sulfuric acid alone as a leaching agent, at 90 ° C, resulted in an 81.11% increase in iron dissolution than the 6: 1: 2: 3 combination. The results obtained indicated that the reaction rate was controlled by the chemical reaction, and the activation energies of 42.71 kJ/mol for nickel and 84.57 kJ/mol for cobalt were consistent with this conclusion.

Научные аспекты разработки идентификационных критериев дистиллятов из фруктового сырья

Introduction. Beverages based on fruit distillates belong to elite alcoholic drinks. As a result, there is a high risk of counterfeit. Controlled indicators do not allow identifying distillates by the type of raw material. The research objective was to develop scientifically based identification criteria for fruit distillates. 
 Study objects and methods. The research featured ten fruits and their distillates. It involved three schemes of pre-distillation processing: pulp fermentation, juice fermentation, and pulp fermentation with subsequent maceration. The biochemical composition of raw materials was assessed by the HPLC analysis of mass concentration of sugars, titratable acids, pH, mono- and disaccharides, free organic acids and amino acids, as well as by the sugar-acid index. The concentration of higher alcohols in the distillates was determined using gas chromatography.
 Results and discussion. The research revealed significant differences in the biochemical composition of raw materials, which made it possible to divide it into groups depending on the methods of pre-distillation processing. The groups can be identified by the ratio of the concentrations of the main higher alcohols: 1-propanol to the sum of isobutanol and isoamylol. The revealed differences were caused by the peculiarities of the ratio of organic acids and amino acids. For the distillates of Cornelian cherry, black currant, cherry-plum, plum, cherry, and apricot, the ratio of 1-propanol to the sum of isobutanol and isoamylol was within the following ranges: 0.02–0.06, 0.08–0.10, 0.30–0.35, 0.47–0.51, 0.55–0.65, and 0.69–0.92, respectively. The method of preparing raw materials for distillation did not affect the values of the identification indicator.
 Conclusion. The ratio of 1-propanol to the sum of isobutanol and isoamylol could serve as an indicator for the identification of distillates of Cornelian cherries, black currant, cherry-plum, plum, cherry, and apricot. However, it proved useless for distillates of pears, raspberries, tangerines, and mulberries, since its values were within comparable limits. Therefore, the research requires a GC-MS analysis to determine the concentration and ratios of other specific volatile components in other raw materials.

КАЧЕСТВО СЕНАЖА ИЗ ЛЮЦЕРНЫ, ПРИГОТОВЛЕННОГО С ИСПОЛЬЗОВАНИЕМ БИОКОНСЕРВАНТА «ГРИНГРАС 3×3»

The aim of the research is to improve the quality and nutritional value of the alfalfa haylage applying the «Green-grass 3×3» biopreservative with herbage. Current biological preparations contain live cultures of specially selected lactic, propionic acids, and sporogenous bacillus, a complex of amino acids, enzymes, vitamins and minor nutrient elements. Preparation use with herbage during haylage leads to intensification the lactic acid fermentation, im-provement of ratio of organic acids, increase the content of nutrients and ensuring their reliable safety during stor-age. The research was carried out at the milk production complex of «Radna» LLC in the Samara region. The re-search was provided involving Holstein and Ayrshire breeds. The haylage was fed to cows in the amount of 24 kg as part of a balanced feed mixture in accordance with the casein diet. As a result of applying a bio-preservative with herbage, the content of organic acids in the ready made feeds increased by 0.54%, including lactic acid – by 0.80%. The dry weight increased by 4.6%, available energy – by 37.4%, energy feed units – by 9.1%, digestible protein – by 13.8%, crude fiber – by 0.9%. Feeding the cows haylage with a bioconservative increased the meta-bolic processes in the tripe of animals. Ciliata weight in the ruminal fluid of Holstein cows increased by 29.0%, Ayr-shire – by 25.8%, number of bacteria, respectively, by 26.5 and 27.5%. As a result, the content of total nitrogen in-creased by 15.0-15.1%, protein nitrogen – by 40.4-42.9%, and ammonia, on the contrary, decreased by 40.0-40.6%. The content of volatile fatty acids decreased by 12.6-16.2%, while the proportion of acetic acid increased by 7.73-8.71%. All this had a positive effect on the digestibility of nutrients by the animals of the experimental groups. The digestibility of the dry weight of the feed increased, respectively, by 4.14-4.57%, and its components – by 4.23-6.97%.

Carbon isotope ratio of organic acids in sake and wine by solid-phase extraction combined with LC/IRMS.

We developed an analytical procedure for determining the δ13C values of organic acids in sake and wine using solid-phase extraction combined with liquid chromatography/isotope ratio mass spectrometry (LC/IRMS). First, the solid-phase extraction (SPE) procedure was performed and various tests were conducted to extract organic acids from alcoholic beverages using the simulated sake sample. Under the optimal SPE procedure, high recovery rates (96-118%) and good accuracies (≤ 0.7‰) were thus achieved for the simulated sake and wine samples. Next, we determined the δ13C of organic acid (tartaric acid, malic acid, lactic acid, succinic acid) in 9 sake and 11 wine samples. Finally, the δ13C values of lactic acid in nine sake samples suggested that lactic acid had been added during the brewing process. The high correlation between the δ13C values of tartaric acid and malic acid in 11 wine samples was consistent with their common source, grapes. This analytical method may help to identify when organic acids have been added to sake and wine and to elucidate the process of organic acid production therein. Graphical abstract.

Modification of Moth Bean Starch Using Mixture of Organic Acids under Dry Heating

Moth bean (Vigna aconitifolia) starch is modified in its dry state (110 °C for 8 h, 14% moisture) using various ratios of organic acids (citric acid and stearic acid) in solvent free (solid–solid) reaction mode. Apparent amylose content is observed to increase in organic acid treated starches. Modified starches show lower swelling power than native starch. Scanning electron micrographs display rough granules surface for treated starches. Crystalline polymorphic pattern of moth bean starch is unaffected by organic acid treatment and dry heating. However, relative crystallinity increases after dry modification. Pasting properties indicate reduction following hydrolysis and loss of granular strength. Resistant starch (RS) content increases as an effect of the modification. This novel modification provides different functionality as compared to aqueous protocols and also provides a clean alternative to replace acid hydrolysis process with concentrated mineral acids.

Effects of distribution of sugars and organic acids on the taste of strawberries.

The concentrations of sugars and organic acids as well as the total soluble solid (TSS) in different parts of the strawberry fruit were characterized. The data were used to create simulated fruit juice jellies, in order to clarify how the sugar and organic acid levels affect the taste. Such an approach eliminates the influence of external factors such as size, color, and texture when using real fruits in sensory evaluations. Further, the use of a jelly allowed us to simulate the concentration differences between various parts of the fruit. In the strawberry fruit, the sugar content is higher in the apex than in the peduncle; however, the level of organic acids is the same throughout. It was revealed that the sweetness and sourness in the apex and peduncle could be sufficiently recognized by humans as tastes. Also, a layered jelly sample replicating the sugar and acid distribution in real strawberry was perceived as less sweet and more sour, compared to a homogeneous one with the same overall composition. The likely reason is that the sourness in the peduncle is accentuated by the low TSS level, which decreases the TSS/total organic acid ratio that affects the sweetness/sour perceptions. Based on these results, factors for the appropriate sensory evaluation of fresh fruits in general were considered. Specifically, the distribution of sugars and organic acids in the fruit should be analyzed first, and bite‐sized parts with concentrations close to the average provide the most accurate evaluation results.

TRENDS OF MICROBIOLOGICAL PROCESSES IN PRESERVED CORN ROLLED GRAIN UNDER THE INFLUENCE OF BACILLUS SUBTILIS

Objective. To study the trends of microbiological processes, changes in the level of acidity and the ratio of accumulated organic acids in preserved corn rolled grain due to the influence of selected strains of Bacillus subtilis, promising for the creation of biological preservatives on their basis.
 Methods. Microbiological, zootechnical.
 Results. Grain processing with suspensions of the test strains of B. subtilis promotes the intensive development of epiphytic lactic acid bacteria in feed at day 15 of preservation, with subsequent gradual decrease at day 30 and 70 of the experiment. The number of lactic acid bacteria at day 14 after opening samples of preserved corn rolled grain is a tenfold higher than in the control variant (without the additional application of microorganisms). The dynamics of yeast growth in the feed due to the effect of the test strains of B. subtilis is characterized by their intensive development at day 15 with a gradual decrease in the number in all variants at day 30 and 70 of preservation. The number of moulds in the control variant exceeds the maximum allowable level (up to 5×104 CFU per 1 g feed) and is 2×105 at day 7 and 6.2×105 at day 14 after opening and access of air to the thickness of the preserved mass. In experimental variants, the number of moulds is smaller compared with the control both in the process of preservation and after opening the feed. The optimum pH and the ratio of organic acids at day 14 after opening has been registered in the rolled grain treated with B. subtilis B1, B. subtilis B6y and B. subtilis 44-p.
 Conclusion. The use of selected B. subtilis strains to preserve moist corn rolled grain promotes the establishment of the optimum level of acidity of the feed and the ratio of organic acids, inhibition of the development of undesirable microorganisms.

DYNAMICS OF POPULATIONS OF MICROORGANISMS IN CANNED CRIMPED GRAIN MAIZE WHEN IMPACT STRAINS OF LACTIC ACID BACTERIA

The dynamics of the development of microorganisms, changes in the level of acidity andthe ratio of the accumulated organic acids in canned by flattening the grain of corn wasinvestigated under the influence of strains of lactic acid bacteria (LAB), perspective for creationbiology preservatives.Application of the studied bacterial strains for canning rolled grain corn leads to theestablishment of optimal acidity of the feed and the ratio of organic acids, the inhibition of thegrowth and development of undesirable microorganisms. Introduction at the grain withsuspensions of the studied strains of LAB provides the maximum number of epiphytic lactic acidbacteria in the feed on the 15th day of canning with a further gradual reduction at 30th and 70htdays of the experiment. The number of lactic acid bacteria on 7th and 14th day after the openedsamples of canned rolled grain corn much higher than in the control variant (withoutprocessing).Dynamics of yeast growth in the feed under the influence of the investigated strainsof LAB characterized by their rapid development for 15th days with a gradual decline in theirnumbers in all variants at 30th and 70th days of conservation. The least number of yeasts isobserved on 14th day after the opening and air access in rolled grain treated with strains L.plantarum L32 and L. plantarum L18/1.

The effect of microbial transglutaminase on probiotic fermented milk produced using a mixture of bovine milk and soy drink

In this study, the effects of microbial transglutaminase (m‐TGs) enzymes on the physicochemical, microbial and sensorial properties of probiotic fermented milk produced using a mixture of bovine milk and soy drink were investigated. Probiotic fermented milk samples were prepared by 3:1 v/v bovine milk, 0.002 w/v soy drink and 0, 0.5, 1, 1.5 U m‐TGs per gram of milk protein. The starter culture used was ABT‐2 1000 I (a mixture of Lactobacillus acidophilus LA‐5, Bifidobacterium animalis subsp. lactis BB‐12 and Streptococcus thermophilus). Viscosity and hardness values increased with increased transglutaminase ratio, whereas syneresis values decreased. All samples had an apparently acceptable number of probiotic bacteria over the storage period. While the minimum and maximum percentage ratios of alcohol components and carbonyl components in total volatile aromatic components of fermented milk samples are 24.75–30.70% (v/v) and 65.66–71.96% (v/v) during storage time, the minimum and maximum percentage ratios of organic acids and esters are 0.56–2.54% (v/v) and 0.73–1.57% (v/v).

Strength characteristics of artificial organic soils stabilized with copolymer stabilizer

Organic soil is known as low strength material, and chemical stabilization is widely used to increase its bearing capacity. However, the use of traditional stabilizer has some limitations. Therefore, stabilization was carried out by using non-traditional stabilizer - Vinyl acetate-ethylene (VAE) copolymer emulsion in this study with the aim to determine its suitability to stabilize soil mixed with organic matter. Two types of artificial organic soil with kaolin: organic acid ratio of 5:5 (K5HA5) and 7:3 (K7HA3) were utilized. Control specimens were tested using pure kaolin. Different percentages of VAE (5%, 7.5%, 10%) were added in order to determine the minimum amount of stabilizer required to achieve a minimum strength increment of a 345 kPa. The strength of samples was determined with automated unconfined compressive test device. Specimens were air cured for 7 days prior to testing. Both K7HA3 with 7.5% VAE and K5HA5 with 10% VAE had achieved the minimum strength increment to be considered as effective stabilization. The strength of the artificial organic soil was found to be increasing with the increment of percentages of VAE used. Hence, it can be concluded that stabilizing mechanism of the artificial organic soils with VAE is not affected by organic matter.

A case study: Using microbial abundance data to mathematically calculate organic acid production by human faecal microbiota within an in vitro batch fermentation

The amount and ratio of organic acids from carbohydrate fermentation by the gut microbiota is dependent upon both the ability of members of the microbiota to exploit undigested dietary carbohydrate and the type of organic acids they have the capability to generate. Additionally, some bacteria feed upon carbohydrate degradation products, as well as organic acids produced by other bacteria, further affecting the overall organic acid profile. Experimentally unentangling these complex trophic food webs is challenging.Here we demonstrate a mathematical model that calculates the organic acid profile resulting from an in vitro human faecal microbial fermentation of kiwifruit cell wall polysaccharides, parameterised with organic acid and microbial abundance data. The model was based on our hypothesis that in conditions of carbohydrate excess, changes in the abundance of members of the microbiota will be reflected in an equivalent change in those organic acids they have the capability to produce. We used microbial abundance data to calculate changes in organic acids over time, and the resulting data was shown to recapitulate the measured organic acid profiles. We also demonstrate here the successful mathematical simulation of the metabolic cross-feeding which occurs upon simulated digestion and fermentation of a fresh whole fruit carbohydrate. We assign the relative propensity of various members of a complex microbial community to generate selected acids within the organic acid profiles. We anticipate this case study to be a starting point for more sophisticated research and clinical tools to investigate and predict the interactions with food, the microbiota and the host.