Characterization and comparison of flavors in fresh and aged fermented peppers: Impact of different varieties.

The flavor profiles of fresh and aged fermented peppers obtained from four varieties were thoroughly compared in this study. A total of 385 volatile compounds in fermented pepper samples were detected by flavoromics (two-dimensional gas chromatography-time-of-flight mass spectrometry). As fermentation progressed, both the number and the total concentration of volatile compounds changed, with esters, alcohols, acids, terpenoids, sulfur compounds, and funans increasing, whereas hydrocarbons and benzenes decreased. In contrast to the fresh fermented peppers, the aged fermented samples exhibited lower values of pH, total sugars, and capsaicinoids but higher contents of organic acids and free amino acids. Furthermore, the specific differences and characteristic aroma substances among aged fermented peppers were unveiled by multivariate statistical analysis. Overall, 64 volatiles were screened as differential compounds. In addition, Huanggongjiao samples possessed the most abundant differential volatiles and compounds with odor activity values > 1, which were flavored with fruity, floral, and slightly phenolic odors. Correlation analysis demonstrated that the levels of 23 key aroma compounds (e.g., ethyl 2-methylbutyrate, 1-butanol, and ethyl valerate) showed a significantly positive correlation with Asp, Glu and 5 organic acids. By contrast, there is a negative association between the pH value and total sugar. Overall, aging contributed significantly to the flavor attributes of fermented peppers.

A novel organic acids-targeted colorimetric sensor array for the rapid discrimination of origins of Baijiu with three main aroma types.

Given the severe problem of Baijiu authenticity, it is essential to discriminate Baijiu from different origins quickly and effectively. As organic acids (OAs) are the most dominant taste-imparting substances in Baijiu, we proposed a simple, fast, and effective OAs-targeted colorimetric sensor array based on the colorimetric reaction of 4-aminophenol (AP)/4-amino-3-chlorophenol (ACP) under oxidation of Cu(NO3)2 for the rapid discrimination of origins of Baijiu with three main aroma types. Hydrogen ions ionized from OAs induced the protonation of the amino group, which blocked the colorimetric reaction, and the different levels of OAs in Baijiu enabled the array to discriminate different origins of Baijiu. The array was implemented to analyze 10 simple OAs and 16 mixed OAs and further for the discrimination of 42 Baijius with an accuracy of 98%. This method provided an efficient research strategy for a basis for rapid quality analysis of Baijiu.

High acidity of bracatinga honeydew honey: A new regulatory limit proposal.

The free acidity of bracatinga honeydew honey (BHH) was monthly monitored over short-term storage (four months) until all the samples exceeded 50 mEq kg-1 - the maximum value allowed by the international regulatory honey standards. In addition, BHH quality was also investigated through moisture content, water activity, electrical conductivity, pH, 5-hydroxymethylfurfural, and aliphatic organic acids (AOA) analyses. According to our results, most of the parameters investigated presented significant differences during the short storage period studied; however, the quality parameters (except acidity) did not exceed the limits established by the international regulatory honey standards. Therefore, the high free acidity observed in the BHH samples did not affect its quality. Moreover, the total AOA concentration decreased as the free acidity increased, indicating that the high acidity is not related to postharvest fermentation. Since all BHH samples exceeded the established limit of 50 mEq kg-1 after four months of storage (up to 62.7 mEq kg-1), this data corroborates that this type of honey does not comply with the regulatory honey standards, which represents an obstacle to its commercialization. Therefore, our data reinforce the need for a future reassessment of the international regulatory honey standards regarding the free acidity limit for BHH. In this sense, taking together all the studies developed by our research group since 2014, a new free acidity value of 65 mEq kg-1 is proposed, which may discourage fraud practices and negative impacts on the BHH beekeeping chain.

Improving liming mode for remediation of Cd-contaminated acidic paddy soils: Identifying the optimal soil pH, model and efficacies.

Liming has been widely taken to remediate Cd-contaminated acidic paddy soils, whereas liming mode involving in the relevant optimal soil pH, model and efficacies remain unclear. Both soil and field liming experiments were conducted to improve liming mode for precise remediation of Cd-contaminated acidic paddy soils. Soil batch liming experiments indicated soil DTPA-Cd and CaCl2-Cd were piecewise linearly correlated to soil pH with nodes of 6.8-8.0, and decreased respectively by 15.3%37.7% and 80.7%93.8% (P < 0.05) when soil pH raised over the nodes, indicating an appropriate target soil pH 7.0 for liming. Stepwise linear regression revealed that liming ratio (LR, kg ha-1) could be estimated from soil basal pH (pH0) and the interval to the target soil pH (ΔpH), as [LR=exp(1.10 ×ΔpH+0.61 ×pH0-4.98), R2 = 0.97, n = 42, P < 0.01]. The model exhibited high prediction accuracy (95.2%), low mean estimation error (-0.02) and root mean square error (0.20). Field liming experiment indicated liming to target pH decreased respectively soil CaCl2-Cd by 95.2-98.0% and rice grain Cd by 59.8-80.6% (P < 0.01), whereas uninfluenced rice grain yield. Correlation analysis and structural equation models (SEM) demonstrated that great reduction in Cd phytoavailability was mainly attributed to the transformation of soil water-soluble and exchangeable Cd to carbonate-bound Cd and Fe/Mn oxides-bound Cd and reduced Cd in iron plaque as increasing soil pH. However, rice grain Cd of 50% samples met national food safety standards limit of China (0.2 mg kg-1) due to the high soil Cd level (0.8 mg kg-1). In conclusion, liming to target soil pH 7.0 could be considered as a precise and effective remediation mode for Cd-contaminated acidic paddy soils and complementary practices should be implemented for severe pollution. Our results could provide novel insights on precise liming remediation of Cd-contaminated acidic paddy soils.

Factors controlling accumulation and bioavailability of selenium in paddy soils: A case study in Luxi County, China.

Selenium (Se) accumulation in rice (Oryza sativa L.) has become a major global concern. Se offers multiple health benefits in humans; however, its inadequate or excessive intake can be harmful. Therefore, determining the factors driving Se abundance and bioavailability in paddy soils is essential to ensure the safety of human Se intake. This study investigated the accumulation, bioavailability, and distribution of Se in 820 paddy soil and rice grain samples from Luxi County, China to assess how soil properties (soil organic matter [SOM], cation exchange capacity [CEC], and pH), geographical factors (parent materials, elevation, and mean annual precipitation [MAP] and temperature [MAT]), and essential micronutrients (copper [Cu], zinc [Zn], and manganese [Mn]) govern Se accumulation and bioavailability in paddy soils. Results showed that the average soil Se content was 0.36 mg kg-1, which was higher than that in China (0.29 mg kg-1). Alternatively, the average rice grain Se content was 0.032 mg kg-1, which was lower than the minimum allowable content in Se-rich rice grains (0.04 mg kg-1). Five studied parent materials all had a significant effect on soil Se content but had little effect on Se bioavailability (p < 0.05). CEC, elevation, and SOM, as well as the soil contents of Cu, Zn, and Mn were positively correlated with soil Se content, but pH, MAP, and MAT were negatively correlated. Correspondingly, Se bioavailability was negatively correlated with SOM and soil Zn content, but positively correlated with MAP and grain contents of Cu, Zn, and Mn. Furthermore, partial least squares path analysis revealed the interactive impacts of the influencing factors on Se accumulation and bioavailability in soils. On this basis, prediction models were established to predict Se accumulation and bioavailability in paddy soils, thereby providing theoretical support for developing efficient control measures to meet Se challenges in agriculture.

Non-thermal treatments of strawberry pulp: The relationship between quality attributes and microstructure.

The relationship between quality attributes and microstructure in strawberry pulp after pasteurization (PS), ultrasound (US), electron beam irradiation (EB), and high pressure (HP) treatments was investigated. The results showed that US treatment decreased the viscosity to the lowest by 80.15% and increased the a* value, cloudy stability, and contents of titratable acid, total soluble solid, organic acids, total phenols, total flavonoids, and total anthocyanins (TAC), as well as its antioxidant capacity, due to the decrease in particle size, the destruction of microstructure, and the release of intracellular compounds. US and EB treatments could maintain the volatile compounds. The greatest deterioration in TAC and volatile compound content was found in the pulp treated with PS and HP treatments. HP treatment was beneficial to the enhancement of apparent viscosity, organic acids, and soluble sugar. These results provided insights into the enhancement of quality attributes in strawberry pulp due to the microstructure change.

Environmental and agronomic factors that impact the regional identity of Cascade and Mosaic® hops grown in the Pacific Northwest.

BACKGROUND: Regional identity is a well-established concept of economic interest that has been identified as a source of unique quality traits of various agricultural products originating from a specific region. In the context of hops, the exploration of regional identity is still at a very early stage despite an increasing global demand for specialized aroma hops to enable more product diversity, especially in the growing craft beer industry. Thus, we conducted a large-scale investigation characterizing the growing environments of Cascade and Mosaic® hops at 39 field locations throughout two important valleys in the Pacific Northwest region of the United States to identify factors that significantly impact hop characteristics and to better understand how these impact hop regional identity. RESULTS: The Willamette Valley (Oregon) and the Yakima Valley (Washington) have distinctly different soil characteristics, soil chemistry, and climate. In turn, growers in these two regions apply unique agronomic practices in response to these differences. This investigation also revealed significant subregional differences in growing environment within each of these two valleys. Multivariate statistics, correlation, and regression analysis identified a number of environmental and agronomic factors like soil pH, the concentration of zinc, sulfur, and manganese in the soil, and the amount of applied zinc fertilization, which exhibited strong positive or negative correlations with specific hop quality traits depending on the hop variety, primarily in Oregon. CONCLUSION: This study provides new insights into understanding hop regional identity and represents an important step towards fully utilizing this effect. © 2023 Society of Chemical Industry.

Integrated untargeted metabolome, full-length sequencing, and transcriptome analyses reveal insights into the fruit quality at different harvest times of Chaenomeles speciosa.

Chaenomeles speciosa fruit is a homologous medicine and food plant with a long history of multiple uses. It could be harvested near maturity and last for a long time. However, the optimal harvest strategy of Chaenomeles speciosa for various uses is currently unavailable. Here, untargeted metabolome at different harvest times during maturation was investigated for the first time, and 896 metabolites, including sugars, organic acids, amino acids, and phenylpropanoids, were identified. Optimal harvesting methods were proposed for different purposes. During the early maturation stages (before 105 days after full bloom), Ch. speciosa fruit could be harvested as Chinesemedicine. Whereas as snacks and food, Ch. speciosa fruit might be harvested at late maturity (after 120 days after full bloom). In addition, the overall network was revealed by integrating full-length Iso-seq and transcriptomics (RNA-seq) to investigate the association between quality-associated metabolites and Chaenomeles speciosa fruit gene expression during maturation. A few putative genes were captured via screening, dissecting and correlation analysis with the quality-associated metabolites (including d-glucose, catechin, gallocatechin, and succinic acid). Overall, in addition to providing a harvesting strategy for food and medicine, we also investigated the metabolism and gene expression pattern of Chaenomeles speciosa fruit during maturation. This comprehensive data and analyses laid the foundation for further investigating potential regulatory mechanisms during harvest and provided a new possibility for its development and utilization.

A Review of the Efficacy of Ultraviolet C Irradiation for Decontamination of Pathogenic and Spoilage Microorganisms in Fruit Juices.

Ultraviolet C (UV-C, 200-280 nm) light has germicidal properties that inactivate a wide range of pathogenic and spoilage microorganisms. UV-C has been extensively studied as an alternative to thermal decontamination of fruit juices. Recent studies suggest that the efficacy of UV-C irradiation in reducing microorganisms in fruit juices is greatly dependent on the characteristics of the target microorganisms, juice matrices, and parameters of the UV-C treatment procedure, such as equipment and processing. Based on evidence from recent studies, this review describes how the characteristics of target microorganisms (e.g., type of microorganism/strain, acid adaptation, physiological states, single/composite inoculum, spore, etc.) and fruit juice matrices (e.g., UV absorbance, UV transmittance, turbidity, soluble solid content, pH, color, etc.) affect the efficacy of UV-C. We also discuss the influences on UV-C treatment efficacy of parameters, including UV-C light source, reactor conditions (e.g., continuous/batch, size, thickness, volume, diameter, outer case, configuration/arrangement), pumping/flow system conditions (e.g., sample flow rate and pattern, sample residence time, number of cycles), homogenization conditions (e.g., continuous flow/recirculation, stirring, mixing), and cleaning capability of the reactor. The collective facts indicate the immense potential of UV-C irradiation in the fruit juice industry. Existing drawbacks need to be addressed in future studies before the technique is applicable at the industrial scale.

Conventional and innovative extraction technologies to produce food-grade hop extracts: Influence on bitter acids content and volatile organic compounds profile.

Hop extracts represent a natural alternative to synthetic food additives because of their high content of bitter acids and volatile organic compounds (VOCs) with bittering, flavoring, and antimicrobial properties. However, broader uses of hop extracts as natural techno-functional ingredients rely on the identification of sustainable and affordable extraction technologies allowing to diversify the processes and produce extracts characterized by different compositions and, consequently, qualitative properties. Thus, this study is aimed to evaluate and compare the effect of innovative and conventional extraction methods on the bitter acids content and VOCs pattern of food-grade ethanolic hop extracts for food applications. Innovative extractions were carried out by using two ultrasound systems (a laboratory bath [US] and a high-power ultrasound bath [HPUS]), and a high-pressure industrial process (high hydrostatic pressure [HHP]). Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60°C; for ultrasound and conventional methods, the effect of the extraction time was also investigated. Among the extracts, the highest and lowest content of bitter acids was found in CONV 60°C extracts, and HHP and CONV 25°C extracts, respectively. Of the 34 VOCs identified in dry hops, ∼24 compounds were found in US, HPUS and CONV extracts, while only 18 were found in HHP. CONV extractions showed higher selectivity for sesquiterpenes, while US and HPUS showed higher selectivity for esters and monoterpenes. Hierarchical cluster analysis (HCA) and partial least squares-discriminant analysis (PLS-DA) allowed classifying hop extracts based on the extraction methods and also allowed highlighting the technological conditions to produce hop extracts with specific techno-functional and flavoring properties. PRACTICAL APPLICATION: The study showed that different extraction methods can lead to hop products with varying sensory and functional properties. By selecting the right extraction method, companies can produce hop extracts with specific compositions that meet their needs for clean label and sustainable food products, as well as new edible packaging or coatings.

Assessment of potential contamination and acid drainage generation in uranium mining zones of Peña Blanca, Chihuahua, Mexico.

Potential pollution of mining environmental liabilities' locations can be preliminarily and efficiently assessed by the potential generation of acid mine drainage and indices of contamination. This research evaluates the potential pollution by potentially toxic elements at locations with uranium mining liability evidence, using the net acid generation test and determining the background values to estimate acid mine drainage and indices of contamination. Sixty soil samples were collected, and the mineralogy and potentially toxic elements' total contents were determined by x-ray diffraction and optical spectrometry. The findings suggest that the soils related to a specific lithology might not present potential acid mine drainage generation but potential soil and sediment contamination. Future research is recommended on applying leaching tests to identify which potentially toxic elements are effectively being solubilized. Finally, it can be concluded that the study area's potential contamination is relatively low overall.

Physiological and biochemical changes during fruit maturation and ripening in highbush blueberry (Vaccinium corymbosum L.).

The sweetness of blueberry fruit increases over time, as acids are converted to sugars, and full flavor development is formed by harvest. We comprehensively analyzed the changes and correlation in physiological and biochemical characteristics of blueberries at different maturity stages, including texture, quality, taste and energy change. Our analysis revealed that total anthocyanin content increased and firmness decreased as fruit ripened. Percent moisture, titratable acid (TA), chlorophyll and carotenoid content also decreased, while total soluble solids (TSS), pH, TSS/TA ratio, vitamin C, soluble proteins, and ethylene production all increased. Antioxidant enzyme activity gradually increased during ripening but energy-related metabolites decreased. The flavor attributes of sweetness, bitterness, and sourness were readily perceived using an electronic tongue and a total of 76 volatile compounds were detected by GC-MS. In summary, the maturation of blueberries was correlated with increases of anthocyanins, nutrients, antioxidant activity, taste and aroma, but negatively correlated with energy metabolism.

Towards sweetness classification of orange cultivars using short-wave NIR spectroscopy.

The global orange industry constantly faces new technical challenges to meet consumer demands for quality fruits. Instead of traditional subjective fruit quality assessment methods, the interest in the horticulture industry has increased in objective, quantitative, and non-destructive assessment methods. Oranges have a thick peel which makes their non-destructive quality assessment challenging. This paper evaluates the potential of short-wave NIR spectroscopy and direct sweetness classification approach for Pakistani cultivars of orange, i.e., Red-Blood, Mosambi, and Succari. The correlation between quality indices, i.e., Brix, titratable acidity (TA), Brix: TA and BrimA (Brix minus acids), sensory assessment of the fruit, and short-wave NIR spectra, is analysed. Mix cultivar oranges are classified as sweet, mixed, and acidic based on short-wave NIR spectra. Short-wave NIR spectral data were obtained using the industry standard F-750 fruit quality meter (310-1100 nm). Reference Brix and TA measurements were taken using standard destructive testing methods. Reference taste labels i.e., sweet, mix, and acidic, were acquired through sensory evaluation of samples. For indirect fruit classification, partial least squares regression models were developed for Brix, TA, Brix: TA, and BrimA estimation with a correlation coefficient of 0.57, 0.73, 0.66, and 0.55, respectively, on independent test data. The ensemble classifier achieved 81.03% accuracy for three classes (sweet, mixed, and acidic) classification on independent test data for direct fruit classification. A good correlation between NIR spectra and sensory assessment is observed as compared to quality indices. A direct classification approach is more suitable for a machine-learning-based orange sweetness classification using NIR spectroscopy than the estimation of quality indices.

Acidic electrolyzed water treatment suppresses Phomopsis longanae Chi-induced the decreased storability and quality properties of fresh longans through modulating energy metabolism.

Longan fruit loses its market value rapidly due to postharvest pathogenic infestation and quality deterioration. Here, we hypothesized that acidic electrolyzed water (AEW) could maintain higher quality of P. longanae-inoculated longans via regulating energy metabolism. Results indicated that AEW reduced fruit disease index and decay incidence. Significantly, AEW treatment retained higher levels of ATP, ADP, and energy charge, and higher activities of Ca2+-ATPase, Mg2+-ATPase, and H+-ATPase in the membranes of plasma, vacuole, and mitochondria, which maintained the structural and functional integrity of cell membrane. Furthermore, indirectly sustaining cell membrane function via AEW treatment could maintain the storability and quality properties of longans, including keeping higher values of color chromaticity (L*, a*, and b*), higher amounts of vitamin C, total soluble solids, sucrose, and total soluble sugars, lower titratable acid and reducing sugar contents. This work elucidated the potential regulation of AEW on the balance of energy metabolism and fruit quality.

Mapping Chini Lake (Pahang, Malaysia) using Sentinel-2 images to determine the effect of acid mine drainage in the pre- to post-COVID-19 restriction period.

Mining activities in the Chini Lake catchment area have been extensive for several years, contributing to acid mine drainage (AMD) events with high concentrations of iron (Fe) and other heavy metals impacting the surface water. However, during the restriction period due to the COVID-19 outbreak, anthropogenic activities have been suspended, which clearly shows a good opportunity for a better environment. Therefore, we aimed to analyze the variation of AMD-associated water pollution in three main zones of the Chini Lake catchment area using Sentinel-2 data for the periods pre-movement control order (MCO), during MCO, and post-MCO from 2019 to 2021. These three zones were chosen due to their proximity to mining areas: zone 1 in the northeastern part, zone 2 in the southeastern part, and zone 3 in the southern part of the Chini Lake area. The acid mine water index (AMWI) was a specific index used to estimate acid mine water. The AMWI values from Sentinel-2 images exhibited that the mean AMWI values in all zones during the MCO period decreased by 14% compared with the pre-MCO period. The spatiotemporal analysis found that the highest polluted zones were recorded in zone 1, followed by zone 3 and zone 2. As compared with during the MCO period, the maximum percentage of increment during post-MCO in all zones was up to 25%. The loosened restriction policy has resulted in more AMD flowing into surface water and increased pollution in Chini Lake. As a whole, our outputs revealed that Sentinel-2 data had a major potential for assessing the AMD-associated pollution of water.

The association between dietary acid load and odds and severity of irritable bowel syndrome in adults.

No study has been conducted to investigate the association between dietary acid load and irritable bowel syndrome (IBS). So, this cross-sectional study was performed to investigate the association between dietary acid load and odds of IBS, its severity, and IBS subtypes. A sample of 3362 Iranian subjects was selected from health centers in Isfahan province. A validated semi-quantitative food frequency questionnaire (DS-FFQ) was applied to estimate dietary intakes. The dietary acid load was measured using net endogenous acid production (NEAP), dietary acid load (DAL), and potential renal acid load (PRAL) scores. In crude models, the highest compared with the lowest category of the PRAL score was significantly associated with increased odds of IBS severity in participants with BMI ≥ 25 (kg/m2) (OR = 1.54; 95% CI = (1.03-2.32). Also, the results indicated a significant positive association between the PARL and odds of mixed subtype of IBS (OR = 1.74; 95% CI = (1.11-2.74); P trend = 0.02). In propensity score-adjusted model with potential confounders, only a positive association was found between PRAL and odds of mixed subtype of IBS (OR = 1.78; 95% CI = (1.05-3.00); P trend = 0.03). The DAL and NEAP scores tended to show non-significant similar findings. This study indicates that dietary acid load might be associated with odds of mixed type of IBS. However, further research is warranted to infer these findings.

Multivariate Statistical Analysis for Mutual Dependence Assessment of Selected Polyphenols, Organic Acids and Metals in Cool-Climate Wines.

Polyphenols, organic acids and metal ions are an important group of compounds that affect the human health and quality of food and beverage products, including wines. It is known that a specific correlation between these groups exist. While wines coming from the New World and the Old World countries are extensively studied, wines coming from cool-climate countries are rarely discussed in the literature. One of the goals of this study was to determine the elemental composition of the wine samples, which later on, together as polyphenols and organic acids content, was used as input data for chemometric analysis. The multivariate statistical approach was applied in order to find specific correlations between the selected group of compounds in the cool-climate wines and the features that distinguish the most and differ between red and white wines and rosé wines. Moreover, special attention was paid to resveratrol and its correlation with selected wine constituents.

Acid Mine Drainage Effects in the Hydrobiology of Freshwater Streams from Three Mining Areas (SW Portugal): A Statistical Approach.

Aljustrel, Lousal and S. Domingos mines are located in the Iberian Pyrite Belt (IPB), one of the greatest massive sulfide ore deposits worldwide. These mines' surrounding streams are affected by Acid Mine Drainage (AMD). The main purpose of this study was to understand AMD influence in the water quality and diatom behavior. Thus, waters and diatoms were sampled in 6 sites from the 3 selected mines on winter and summer of 2016. The highest concentrations were found in acidic sites: A3 (Aljustrel-Al, Cd, Cu, Fe and Zn (and lowest pH)) and L1 (Lousal-As, Mn, Ca, Mg, SO42- and conductivity). The most abundant diatom species was Pinnularia aljustrelica with 100% of dominance in A3 and S1 acidic sites, which puts in evidence this species adaptation to AMD harsh conditions. Multivariate cluster analysis allowed us to reinforce results from previous studies, where spatial differences were more relevant than seasonal ones. In 12 years (2004-2016), and with many transformations undertaken (re-opening and rehabilitation), there is a conservative behavior in the biological species (diatoms) and physicochemical concentrations (metals, pH and sulfates) from these three mining sites. This type of biogeochemical diagnosis is necessary for the sustainable use of these waters and the prevention of the polluting process, aimed to protect the water ecosystem and its biodiversity.

Rare earth elements - Source and evolution in an aquatic system dominated by mine-Influenced waters.

Acid mine drainage (AMD), formed by the instability of sulfides, typically generates acidity and releases potentially toxic elements and sulfate to the environment, among other pollutants. An example is the group of rare earth elements (REE) that may have high toxic behavior. This toxicity leads to degradation of soils, water reservoirs and rivers, promoting serious risks for the ecosystems. So, the main goal of the present work is to study the hydrochemical properties of a system with mine-influenced waters during the rainy season, focusing on the origin, evolution/behavior, and concentration of REE. The study area is the São Domingos mining complex, located in one of the largest metallogenetic provinces in the world (Iberian Pyrite Belt), known by the evidences of AMD contamination. The obtained results reveal extraordinarily low pH (0.4), high electrical conductivity, reaching 26,200 µS/cm, and high values of sulfate and acidity. Regarding the REE, the determined concentration exceeded that observed in normal pH of neutral freshwaters by 2-3 times the order of magnitude. The results revealed that Y and Ce are distinguished in practically all sampled sites, due to its higher concentrations, with maximum values of 221.8 and 166.9 µg/L. In general, the concentrations increase as the water pH decreases. The statistical analysis indicates that REE elements may have a common origin, mutual dependence, and similar behavior during transport with typical AMD elements and composition of host rocks. Most samples show enrichment in middle REE (MREE) (Gdn/Lun), like the classic signature of AMD. In turn, colloids and AMD-precipitates may be participating in the incorporation of these elements. Therefore, due to potential risk of impacts on ecosystems, REE are a topic of relevant interest for future studies in order to assist monitoring processes and help government decisions related to water quality management.

Impact of Different Storage Regimes on the Levels of Physicochemical Characteristics, Especially Free Acidity in Talh (Acacia gerrardii Benth.) Honey.

This study investigates how storage conditions (temperature and duration) may affect the physicochemical parameters, especially free acidity (FA), of Talh honey originating from Acacia gerrardii that have naturally high FA levels. Fresh Talh honey samples were kept at 0, 25, 35, and 45 °C, and analyzed monthly over a period of eight months. The Talh honey was monofloral with 69% A. gerrardii pollen content. The free acidity (FA) of freshly harvested Talh honey samples was higher (93 ± 0.3 meq/kg) than that of standard limits (≤50 meq/kg) and remained stable at 0 °C throughout the storage period. A significantly increase in FA started to occur after storage for 6 months at 25 °C (103 ± 0.2 meq/kg), 2 months at 35 °C (108 ± 0.3 meq/kg), and 1 month at 45 °C (112 ± 0.3 meq/kg). After 8 months of storage, the highest FA level was recorded at 45 °C (159 ± 0.5 meq/kg), followed by 127 ± 0.3 meq/kg at 35 °C, 105 ± 0.2 meq/kg at 25 °C, and 94 ± 0.3 meq/kg at 0 °C. It was found that 0 °C was an appropriate temperature for storing honey for long time. The electrical conductivity (EC) of fresh Talh samples (1.46 ± 0.0 mS/cm) was above the accepted limit (≤0.8 mS/cm), which was slightly increased (non-significant) throughout the storage period under all the storage temperatures. Hydroxymethylfurfural (HMF), diastase activity (DN), and reducing sugars (RSs) showed normal levels only at 0 °C and 25 °C throughout the storage period. However, HMF exceeded the standard limits after the first month at 45 °C (127 ± 9.6 mg/kg) and after the second month at 35 °C (90 ± 23.5 mg/kg), DA decreased below standard limits after the second month (5 ± 1 DN) under 45 °C and after the seventh month under 35 °C (7 ± 2 DN, and RSs decreased below 60% after 2 months under 45 °C and after 6 months at 35 °C. The physicochemical parameters (moisture content, pH, color, and sucrose) were the least affected and were within the standard range throughout the storage period under all the storage temperatures. The levels of FA and EC in fresh Talh samples were higher than the acceptable limits. The moisture content, pH, color, and sucrose content were not affected by storage conditions and remained within the acceptable limits. HMF, DA, and RSs were significantly affected by storage conditions only at 35 and 45 °C. The storage of honey at low temperatures (0 and 25 °C) for up to eight months presented the least amount of changes in the honey, and the honey was unchanged from its fresh status. Honey storage at 35 and 45 °C resulted in significant changes. It is recommended that Talh honey, which normally has high acidity levels, should be stored at temperatures not exceeding 25 °C.