Changes In Physicochemical Parameters Research Articles

Distribution of protoporphyrin IX during Prorocentrum donghaiense blooms and its relationship with particle-attached and free-living bacterial communities

Particle-attached (PA) and free-living (FL) bacterial communities are essential for nutrient cycles and metabolite production and serve as a food source in aquatic systems. However, our understanding of how biotic factors influence community interactions, co-occurrence patterns, and niche occupancy remains limited. This study investigated the influence of protoporphyrin IX (PPIX) on bacteria with different lifestyles during Prorocentrum donghaiense bloom. The findings revealed that PPIX distribution responded variably to changes in physicochemical parameters induced by red tide bloom. Large-sized or particle-attached (PA) phytoplankton (cell size >3 μm) were identified as the primary contributors to environmental PPIX, while small-sized plankton or free-living (FL) microorganisms (<3 μm) contributed less. In red tide-affected areas, PPIX and its derivatives were significantly more abundant than in non-red tide areas, indicating an increased demand for porphyrins by plankton during red tides. Additionally, the red tide also significantly influenced the preference of bacterial lineages for PA or FL lifestyles, highlighting a close interaction between bacteria with different lifestyles and PPIX levels. This study quantitatively analyzed the distribution of PPIX across different cell sizes in red tide and non-red tide marine environments, providing insights into microbial interactions and dynamics in changing ecosystems and offering a reference for using PPIX to predict red tide ecological disasters.

The influence of storage conditions on the dynamics of physicochemical markers of champignon (Agaricus bisporus) quality

Agaricus bisporus are the most common cultivated mushrooms. Champignons are a source of chitin, glycogen and minerals, and also have attractive organoleptic properties. Physicochemical and organoleptic characteristics of fresh Agaricus bisporus undergo significant changes during storage due to moisture transpiration, respiration and oxidative processes. The purpose of this work was to study the influence of storage conditions of cultivated champignons with unstained cap epithelium on the dynamics of their physicochemical parameters, as well as its relationship with changes in organoleptic parameters. The mushrooms were stored in refrigerated chambers at a constant temperature of +2 °C and +6 °C in polypropylene trays placed in bags made of biaxially oriented polypropylene (BOPP) perforated film and polyethylene (PE) film without perforation. Under all storage conditions studied, the nature of the dynamics of physicochemical parameters was close to linear (with the exception of the humidity of fruiting bodies when stored in PE film) — the calculated values of the Pearson correlation coefficient ranged from 0.67 to 0.97. Using two-factor analysis of variance, the influence of both packaging material and storage temperature on the dynamics of soluble solids content and mushroom tissue density was confirmed. When stored in PE film without perforation, a more intense negative dynamics of these criteria was observed compared to storage in perforated BOPP film. The identified difference is explained by the fact that in packaging made of PE film without perforation, conditions for anaerobic respiration were formed by the end of storage — the oxygen content decreased from 20.5% to 1.5–2.5%, which also contributed to the activation of decay processes. With increasing storage temperature, a more intense change in physicochemical parameters was observed, which was associated with an increase in metabolic rate. The relationship between the dynamics of all studied physicochemical quality markers and the dynamics of sensory assessments (with the exception of the marker "content of soluble solids" when stored in a perforated BOPP film at a temperature of 2 °C) has been statistically confirmed. Based on the results of the studies, the applicability of the criteria “humidity of fruiting bodies”, “content of soluble dry substances” and “density of fungal tissue” as markers for assessing the quality of cultivated Agaricus bisporus was confirmed.

Algal diversity and its relationship with seasonal variation of water quality in Gajedi Lake, Rupandehi District (Nepal)

The current study focuses on the algal diversity of Gajedi Lake in different seasons in connection to the lake's water quality indicators. Algae and water samples were collected from eight peripheral sites of the lake in summer, rainy, and winter seasons in 2021. The water temperature, conductivity, total dissolved solids, hardness, alkalinity, phosphorus, free CO2, and dissolved oxygen were recorded as high during the summer season while water pH was high during the rainy season. Altogether 93 species of algae were reported under 52 genera, 30 families, 7 classes and 6 phyla in this study. The largest phylum was Bacillariophyta (44.08%) followed by Chlorophyta (17.20%), Euglenozoa (10.97%), Cyanobacteria (12.90%), Charophyta (10.75%) and Miozoa (1.07%). The Shannon-Weiner diversity index indicated high abundance during the summer season, with more evenly distributed algal species. More algal species were recorded in the winter season. Trachelomonas, Navicula, and Nitzschia were dominant genera during summer; Anagostidinema, Desmodesmus, and Pinnularia were dominant during rainy; and Trachelomonas, Tetradesmus, and Gomphonema were dominant during winter. The redundancy analysis ordination showed that the algal composition varied along with the seasonal changes in physico-chemical parameters. Temperature, pH, and conductivity were thus identified as significant factors influencing species richness.

New insights into the relationship between optical response and physicochemical properties in apple flesh: Hyperspectral microscope imaging technology

Hyperspectral microscope imaging (HMI) technique was employed to assess the changes in physicochemical parameters and microstructure of ‘Golden Delicious’ apples flesh during storage. Four regions of interest (ROIs), including whole-cell ROI, intercellular space ROI, cytoplasm ROI, and cell wall ROI were investigated to assess their relationships with physicochemical parameters. Different ROIs presented similar vibrational profiles, but with slight differences in spectral intensity, especially in the range of 800–1000 nm. Spectral angle mapper (SAM) was applied to the HMI of apple tissues at different storage stages to clearly show the structural changes of parenchyma cells, while principal component analysis (PCA) could highlight the distribution of sugars, water and pigments in apple flesh at the cellular scale. Simultaneously with the degradation of acid-soluble pectin (ASP), middle lamella dissolution and increased intercellular space were observed using SEM and TEM. Single feature variables were used to construct linear models based on pearson correlation analysis, with R2 of 0.96 for moisture at 982 nm, 0.85 for water-soluble pectin (WSP) at 420 nm, 0.82 for L* at 946 nm, 0.77 for soluble solids content (SSC) at 484 nm, and 0.66 for firmness at 490 nm. This work demonstrated the great potential of HMI technology as a fast, accurate and efficient solution for assessing the quality of ‘Golden Delicious’ apples.

Effect of NaCl replacement on physicochemical and sensory properties of the traditional cured coppa

This study aimed to reduce sodium content in pork coppa without affecting consumer acceptance. NaCl reduction, partial replacement with KCl, and reduction in salting process time were evaluated. Six treatments were performed: Standard - 100% NaCl with a 2-day salting process and a 5-day re-salting process; T1 - a mixture of 70% NaCl/30% KCl; T2, T3, T4 - mixtures of 85% NaCl/15% KCl; T5 - 100% NaCl. T1 to T5 applied a 2-day salting process and a 2-day re-salting process. All treatments complied with Brazilian sodium guidelines. No statistically significant difference in consumer acceptance was observed. A reduction of 4 days in salting and re-salting processes maintained sensory characteristics and reduced sodium content by 50%. Even with reduced salt content, no changes in physicochemical parameters or effects on product preservation and microbiological quality were observed. NaCl reduction and replacement up to 30% KCl did not affect coppa characteristics or acceptance.

Changes in physicochemical parameters of the alpine/mountain stream influenced by summer flash flood in Tatra Mountains (Western Carpathians)

taChanges to the physicochemical parameters of water in alpine/mountain streams can provide evidence of ongoing natural and anthropogenic processes in their catchment. In this study, we analysed a mountain stream (Javorinka) on the north-eastern side of the Tatra Mountains (Western Carpathians), which is minimally influenced by human activity. The stream was monitored weekly for 5 years (2017–2021) and evaluated for its seasonal variations in physicochemical parameters. These seasonal variations were influenced by the large summer flash flood in July 2018. We hypothesise that floods are essential for the oligotrophic profile of alpine/mountain streams. To support this idea, our main objective was to compare the seasonal trends of the main physicochemical parameters in the stream before and after floods or periods of high flow. We found evidence to support our hypothesis. For example, there was a significant decrease in the chemical consumption of oxygen and ammonia, and, conversely, an increase in the ratio of saturated oxygen and nitrate concentrations. Stream bed erosion also resulted in increased phosphates (over the next 2 years) and high enrichment of the water by dissolved solids in the spring. Interestingly outside of the main objectives, we observed a significant decrease in sulphates, especially in the summer and autumn of 2020 and 2021, which may be related to suppressed emissions due to the restriction of the COVID-19 lockdown. The observed trends and their changes therefore support the idea that alpine/mountain streams are excellent indicators of ongoing environmental processes, and that occasional summer flash floods support the oligotrophic profile of the stream system.

The influence of different land uses on the chemical and physicochemical properties of typical chernozem in the Kursk region

The article presents the results of a study of the influence of different land uses on the chemical and physicochemical properties of typical chernozem. Objects of study: typical chernozem on carbonate loess-like loam (HaplicChernozem, Loamic, Pachic). Research has shown that the extensive use of typical chernozem is accompanied by its active dehumusification, a decrease in metabolic capacity, hydrolytic acidity, as well as the amount of exchangeable bases, however, when it is transferred to a fallow, more favorable conditions for the humus formation process begin to be created, resulting in soil properties begin to recover, which is manifested in an increase in the content of organic carbon, total nitrogen and a change in physicochemical parameters, closely related to the humus content. Keywords: TYPICAL CHERNOZEM, PHYSICAL AND CHEMICAL PROPERTIES OF CHERNOZEM, LAND USE, HUMUS, NITROGEN, ORGANIC CARBON

Integrated plankton and trace metal analysis as indicators of organic pollution threats from carp-cultured ponds to adjacent ecosystems: Implications for sustainability

Stawy Milickie (Milicz Ponds) is a natural reserve that has a great ecological importance as a Ramsar site and economic importance as one of the largest carp breeding centres in Europe. Continuous anthropogenic pressure on these large ecosystems can lead to a high disturbance on its natural ecology and sustainability. Phytoplankton, one of the most important indicators of any anthropogenic load, especially organic pollution have been studied in the present study. This is the first work ever from Milicz ponds, wherein the diversity, community structure and seasonal variability of phytoplankton with respect to changes in physicochemical parameters and trace metals have been studied. Periodic samples of water and phytoplankton were collected from four selected ponds of various sizes from October 2018 to September 2019. Of the four selected ponds one was unused for carp cultivation. The study reports the presence of 147 phytoplankton species in nine distinct taxonomic groups. The Genera based Algal pollution index indicated presence of organic pollution in both noncultured pond and carp-cultured pond. The heavy metals detected in the concentration order of Cd>Mn>Fe>Zn>Cu>Pb remained much higher than the safe limits of freshwater aquaculture ponds. The probable sources of these pollutants were identified as artificial feed used in the cultivation of carp and inundation from the river basin. This study emphasizes the urgent need for continuous qualitative and quantitative assessment and monitoring of water parameters, including plankton, in these ponds. This study highlights how the structure of microplankton communities, in conjunction with heavy metal analysis, serves as indicators of the spread of organic pollution in non-cultivated aquaculture environments. It strongly advocates for implementing sustainable measures to safeguard this vital ecosystem.

Phytoplanktonig Studies in River Hooghly

The river Hooghly flowing through Calcutta and Howrah has a high degree of pollutants. Present study revealed the sources of pollution with phytoplanktonic abundance in the stream. Samples were collected from 5 sites near Howrah and Calcutta from June 1985 to May 1986. Members of Bluegreen algae, Bacillariophyceae and Chlorophyceae were found during the study. Changes in physicochemical parameters due to pollution were observed. Several parameters were responsible directly and indirectly which occurred in Phytoplankton, population. A correlation between biological examination and chemical examination of river water has been made.

A Study of the Micellar Formation of N-Alkyl Betaine Ethyl Ester Chlorides Based on the Physicochemical Properties of Their Aqueous Solutions.

In this study, a series of four surface-active compounds-N-alkyl betaine ethyl ester chlorides, CnBetC2Cl-were synthesized and characterized in aqueous solutions. As with other alkyl betaines, these amphiphiles can be practically used, for example, as co-surfactants and/or solubility enhancers acting according to hydrotropic or micellar mechanisms, depending on the alkyl chain length in the amine. We focused on the representatives of the medium alkyl chain length (C6-C12) to find the dependence between the alkyl chain length in N-alkyl betaine ethyl ester chlorides and the surface, volumetric, acoustic, and viscometric properties of their solutions. Ethyl esters, the derivatives of amino acids, were chosen to increase functionality and take advantage of possible hydrolysis in solutions at higher pH, which is also a key parameter in biodegradability. The micellization parameters were calculated based on the physicochemical characteristics. We focused our interest on the ester with a dodecyl substituent since we can compare and discuss its properties with some other C12 representatives that are available in literature. Surprisingly, its micellization characteristic is almost temperature-independent in the investigated temperature range, t = (15-45) °C. Particularly interesting are the results of dynamic light scattering (DLS), which show that the changes in physicochemical parameters of the C12 homolog around the CMC are caused by the two types of micelles of different sizes present in solutions.

Response of phytoplankton composition to environmental stressors under humidification in three alpine lakes on the Qinghai-Tibet Plateau, China.

Owning to their extreme environmental conditions, lakes on the Qinghai-Tibet Plateau have typically displayed a simplistic food web structure, rendering them more vulnerable to climate change compared to lakes in plains. Phytoplankton, undergoing a changing aquatic environment, play a crucial role in the material cycle and energy flow of the food chain, particularly important for the unique fish species of the Tibetan Plateau. To identify the changing environment indexes and determine the response of phytoplankton composition to the environment change in alpine lakes, three lakes-Lake Qinghai, Lake Keluke and Lake Tuosu-were selected as study areas. Seasonal sampling surveys were conducted in spring and summer annually from 2018 to 2020. Our findings revealed there were significant changes in physicochemical parameters and phytoplankton in the three lakes. Bacillariophyta was the predominant phytoplankton in Lake Qinghai from 2018 to 2020, with the genera Synedra sp., Navicula sp., Cymbella sp. and Achnanthidium sp. predominated alternately. Lake Keluke alternated between being dominated by Bacillariophyta and cyanobacteria during the same period. Dolichospermum sp., a cyanobacteria, was prevalent in the summer of 2018 and 2019 and in the spring of 2020. In Lake Tuosu, Bacillariophyta was the predominant phytoplankton from 2018 to 2020, except in the summer of 2019, which was dominated by cyanobacteria. Synedra sp., Oscillatoria sp., Pseudoanabaena sp., Chromulina sp. and Achnanthidium sp. appeared successively as the dominant genera. Analysis revealed that all three lakes exhibited higher phytoplankton abundance in 2018 that in 2019 and 2020. Concurrently, they experienced higher average temperatures in 2018 than in the subsequent years. The cyanobacteria, Bacillariophyta, Chlorophyta and overall phytoplankton increased with temperature and decreased with salinity and NH4-N. Besides, the ratios of cyanobacteria, and the ratios of Bacillariophyta accounted in total phytoplankton increased with temperature. These findings suggest that cyanobacteria and phytoplankton abundance, especially Bacillariophyta, may have an increase tendency in the three alpine lakes under warm and wet climate.

Dynamic changes of physicochemical parameters, antioxidant activity, organic acids, polyphenols, and volatile components in prune vinegar during fermentation

To investigate the quality variations of prune vinegar during fermentation, multivariate statistical analysis (MSA) was used in conjunction with high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The results showed that the pH decreased slightly, there was a rapid decline in sugar content, and a gradual increase in total acid content, which achieved stabilization at 3.68 g/100 mL. The content of organic acid increased, while the total phenol content decreased. The total flavonoid content did not change significantly. Furthermore, the antioxidant capacity initially decreased and then increased. Prune vinegar contains important phenolics such as rutin, resveratrol, salicylic acid, trans-ferulic acid, and (+)-catechin. In addition, the flavor of prune fruit vinegar underwent changes during the fermentation process. During the fermentation of fruit vinegar, large quantities of 2,3-butanediol, glacial acetic acid, nonanoic acid, ethyl acetate, ethyl heptanoate, ethyl caproate, and linalool were produced. These compounds give prune vinegar its distinctive fruity and floral aroma. This study provided a comprehensive framework for the efficient processing of prunes and a strategy for enhancing the quality characteristics of prune vinegar or other fermented products.

Assessment of the efficacy of decontamination treatments against Salmonella enterica subsp. enterica serovar Thompson on strawberries at different storage conditions

The risk of outbreaks associated with strawberries consumption has led to the evaluation of different antimicrobial strategies. The effect of disinfectants, i.e. chlorine (100 and 200 mg L−1), peracetic acid (40 and 80 mg L−1), lactic acid and hydrogen peroxide (2.5 and 5%), on strawberries contaminated with Salmonella enterica subsp. enterica serovar Thompson during 2 min and stored at different times at two temperatures (20 and 4 °C) was studied. Likewise, the influence of disinfectants on the physicochemical quality of fruits was addressed. The efficacy of 100 mg L−1 chlorine or 40 mg L−1 peracetic acid decreased as storage time at 20 °C increased. Most of the physicochemical parameters were not affected by the treatments, except for 5% hydrogen peroxide, which caused discoloration of the strawberries. 2.5% lactic acid treatment was selected for the evaluation of its antimicrobial effect on strawberries stored at 4 °C for 6 d after treatment. This treatment achieved an efficient reduction of S. Thompson which was maintained over time, while for the case of mesophilic bacteria and yeasts and molds, differences with control or water-washed samples were levelled out over time. No changes in physicochemical parameters were observed during the storage time. 2.5% lactic acid is proposed for decontamination of strawberry-derived products.

Impact of deep-fat frying cycles on the physicochemical characteristics of two edible vegetable oils marketed in Algeria

Background: Vegetable oils containing polyunsaturated fatty acids are prone to oxidation when exposed to high-temperature frying processes. Aims: This study aims to follow the changes that occur in frying oil when used to fry potatoes. Material and Methods: The impact of the ratio of potatoes (g) to oil (g) as well as the number of frying cycles on the quality of two commonly marketed oils in Algeria: 100% soybean oil (oil A) and a blend of 60% soybean, 20% sunflower, and 20% corn oil (oil B) was assessed. The quality of these oils throughout repeated frying cycles was monitored by analyzing pH, density, color, moisture, acidity, peroxide value, saponification value, and acid index. Results: The results of the present study revealed that both oils experienced deterioration as the frying cycles were repeated, with more significant degradation observed with the 1/5 ratio of fries to oil compared to the 1/8 ratio. Remarkably, the 100% soybean oil deteriorated more rapidly than the oil blend. Conclusion: Based on the observed changes in physicochemical parameters and chemical indices, the use of frying oils beyond the third cycle significantly compromises their quality and safety. This not only impacts the consumer’s health but also the organoleptic properties of fried foods. Therefore, it is highly recommended to refrain from exceeding this limit to ensure optimal frying practices and protect consumer health. Keywords: Vegetable oils, deep-fat frying, ratio of fries/volume of oil, physical quality, chemical indices.

Investigating the effect of postharvest conditions on the microbial quality and physicochemical characteristics of bee pollen

Considering the scarcity of information on postharvest management of bee pollen, especially its fresh form, this study aims to investigate the effect of storage conditions and duration on the microbial load of fresh and dried pollen, while also considering changes in physicochemical parameters. Specifically, microbiological analyses were applied to record the growth of Mesophilic Total Viable Counts (MTVC), Yeasts & Moulds (Y&M), Enterobacteriaceae (ENT), Lactic Acid Bacteria (LAB), and Escherichia coli. The results showed that fresh pollen can be stored in the freezer (-18 °C) for one year, without exceeding the legislative limits for the studied pathogens, as after storing for 12 months, the mean counts of MTVC, Y&M, ENT, and LAB were 3.93, 4.04, 1.71, and 2.82 log cfu/g, respectively, whereas moisture, protein and lipid content, fatty acid composition, and colour remained unchanged. When fresh pollen was stored at 4 °C, over a six-month period, the MTVC & ENT counts were out of limits, and changes were observed in colour, total lipid content (32.18% decrease), and fatty acid composition (31.68% for C18:2 and 21.56% for C18:3 reduction, 31.5% increase for C18:0). Finally, storing fresh pollen at 25 °C is deemed insufficient for maintaining quality characteristics. Dried pollen demonstrated better results, compared to fresh pollen, maintaining values of microbial load within legislative limits at all storage temperatures, thus making long-term storage easier. The data gathered during this study may form the basis for a guide including proper beekeeping practices and postharvest bee pollen treatment and management, contributing to the optimization of pollen production.

Changes in Physicochemical Parameters of Soil Along the Villages in Pendhurti Block of Visakhapatnam District, Andhra Pradesh

Soil represents a critical element of plant existence, ranking prominently among the five essential elements. When soil quality declines, it adversely impacts crop productivity. In the present research, the emphasis was placed on conducting a physicochemical analysis of soils in various villages within the Pendhurti block of Visakhapatnam district. In this research, 30 samples of soil were gathered haphazardly from 0 to 15 cm depth across 15 distinct villages.The soil samples gathered underwent analysis in a laboratory to assess their physicochemical parameters. The results revealed that the soil pH exhibited a neutral to slightly alkaline reaction i.e. 6.9 to 8.2 and EC 0.076 to 0.381. The organic-C content was found to be low i.e. (0.12 to 0.59). The Particle density and bulk density were observed to be 2.05 to 2.8 Mg m-3 and 1.33 to 1.57 Mg m-3. The available N in soil was found lowi.e.75.26 to 137.98 kg ha-1, medium to low for K (78.4 to 389.40), and high for P i.e. (22.38 to 151.98 kg ha-1). The available Ca and Mg were recorded to be adequate and S was low to medium (0.21 to 19.6 mg kg-1) and nutrient index values for N, S, Organic-C found to be low, medium for K and high for P. The available micronutrients were reported sufficient (Cu, Zn) to high (Fe, Mn).This analysis emphasizes the need for a greater emphasis on improving soil quality using enhanced practices such as integrated nutrient management and crop rotations, rather than depending solely on monoculture farming.

Консервирование проб сырого молока пищевой добавкой низин (Е-234)

In order to preserve the initial organoleptic, physico-chemical and microbiological parameters, raw milk samples for veterinary and sanitary examination are transported to the laboratory in a chilled form within a short period of time. Preservatives, which eliminate the need to cool samples, affect the initial milk parameters, pose a danger to laboratory workers and change organoleptics. This paper presents data on the effect of the safe food additive nizin (E-234) at a concentration of 0,03 g/0,5 l on the initial organoleptic (taste, color, odor and consistency) and physico-chemical (mass fraction of fat, protein, skimmed milk residue (SOMO), density, titrated acidity) indicators milk stored at room temperature. It was found that nisin slows down the change in physico-chemical parameters due to spoilage, but causes an increase of 0,14 % in the mass fraction of protein, 1,28 kg/ m3 in density, 0,32 % in the mass fraction of SOMO after 24 hours of experiment. Two methods of reducing the concentration of nisin in the samples were tested: heat treatment of milk and dilution of the preservative before each application. Heat treatment had a weak effect, the indicators decreased by an average of 0,04 %, 0,07 %, 0,22 kg/m3 for protein, SOMO and density, respectively. The second method turned out to be simpler and more effective – the true values of protein, SOMO and density indicators were preserved for the first 6–18 hours of sample storage.

Effect of packaging and storage of RTS beverage from Garcinia cambogia

The present investigation was envisioned to develop RTS from the fruits of Garcinia cambogia. Garciniais a popular perennial tree categorized under spice and condiment, distributed in the world's tropics. Currently, Garciniais gaining attention and is considered a functional food because of its antioxidant, anti-inflammatory, anti-obesity, and antimicrobial properties. The RTS was pale yellow with a natural fruit flavour and acceptable in taste. Among the treatments T1 (Fresh Garciniaand Jaggery) scores maximum in organoleptic and nutrient evaluation. The developed RTS was stored for 3 months and the changes in physico-chemical parameters were observed. The initial titrable acidity was 0.32 percent. While storing acidity was found to be increased at both ambient and refrigerated temperatures with the decrease in pH. The initial TSS of the prepared RTS was150 Brix. The minimum loss of ascorbic acid was observed in refrigeration storage during the storage period. The sample stored at refrigeration temperature and packed in PET bottles had a lesser percentage of nutrient loss than glass bottles. The total antioxidant activity was around 44.81 percent. An increase in reducing sugar was observed during the storage. The non-enzymatic browning and clarity of the beverage were also influenced by the storage days. A notable reduction in the tannin content of RTS was observed throughout the storage period. There was a slight increase in microbial load during storage. The mean scores of sensorial evaluations of stored GarciniaRTS drinks decreased gradually during the storage period.

Algal Diversity and its Relationship with Seasonal Variation of Water Quality in Gajedi Lake, Rupandehi District, Nepal

The current study focuses on the algal diversity of Gajedi Lake in different seasons in connection to the lake's water quality indicators. Algae and water samples were collected from eight peripheral sites of the lake in summer, rainy, and winter seasons in 2021. The water temperature, conductivity, total dissolved solids, hardness, alkalinity, phosphorus, free CO&lt;sub&gt;2&lt;/sub&gt;, and dissolved oxygen were recorded as high during the summer season while water pH was high during the rainy season. Altogether 93 species of algae were reported under 52 genera, 30 families, 7 classes and 6 phyla in this study. The largest phylum was &lt;i&gt;Bacillariophyta &lt;/i&gt;(44.08&amp;#37;) followed by &lt;i&gt;Chlorophyta &lt;/i&gt;(17.20&amp;#37;), &lt;i&gt;Euglenozoa &lt;/i&gt;(10.97&amp;#37;), &lt;i&gt;Cyanobacteria &lt;/i&gt;(12.90&amp;#37;), &lt;i&gt;Charophyta&lt;/i&gt; (10.75&amp;#37;) and &lt;i&gt;Miozoa &lt;/i&gt;(1.07&amp;#37;). The Shannon-Weiner diversity index indicated high abundance during the summer season, with more evenly distributed algal species. More algal species were recorded in the winter season. &lt;i&gt;Trachelomonas, Navicula&lt;/i&gt;, and &lt;i&gt;Nitzschia &lt;/i&gt;were dominant genera during summer; &lt;i&gt;Anagostidinema, Desmodesmus&lt;/i&gt;, and &lt;i&gt;Pinnularia&lt;/i&gt; were dominant during rainy; and &lt;i&gt;Trachelomonas, Tetradesmus&lt;/i&gt;, and &lt;i&gt;Gomphonema &lt;/i&gt;were dominant during winter. The redundancy analysis ordination showed that the algal composition varied along with the seasonal changes in physico-chemical parameters. Temperature, pH, and conductivity were thus identified as significant factors influencing species richness.

Clustering of organoleptic quality evaluations of red and white wines by physicochemical parameters using statistica software

Organoleptic evaluations in a ten-point scale of wine experts and experimental physicochemical parameters of red (1599 samples) and white (4898 samples) wines of Portuguese manufacturers were analyzed using STATIS-TICA sofware. Methods of agglomerative and iterative ( k -means algorithm) clustering revealed the grouping of similar wine samples into three, four and six clusters depending on the Euclidean distance of association. The quantitative filling of clusters with samples of bad wines (grades 3 and 4), normal wines (grades 5 and 6) and good wines (grades 7, 8, 9) was established. Neural network (MLP) and discriminant analyzes (DA) were performed; algorithms of classification trees (CT), support vector machines (SVM), naive Bayesian classification (NBC) and nearest neighbors (kNN) were involved. The best performance was demonstrated by neural network models. Multilayer perceptorons classifiers were trained: for red wines - MLP 11-7-3, MLP 11-13-4, MLP 11-14-6; for white wines - MLP 11-9-3, MLP 11-5-4, MLP 11-9-6. The properties of wines, whose contribution to the separating power of classifiers is decisive, are revealed. The ranges of changes in physicochemical parameters in three clusters of red and white wines for bad, normal and good wines were given.