Effect Of Long-term Storage Research Articles

Antimycotic effects of synthetic fungicides and plant extracts on Aspergillus flavus

Aspergillus flavus contaminates the seeds of cowpea (Vigna unguiculata) and produces mycotoxins. This study was carried out to proffer solutions to the infection caused by A. flavus on cowpea seeds. The in vitro trial was set up using two rates (50 and 100%) of each potential control agent (mancozeb, COPMET (Copper-I-oxide + metalaxyl), and aqueous extracts of Eucalyptus and neem) and a control (0%). The botanical extracts and pesticides inhibited the fungus growth significantly (P≤0.05) at different times. Both concentrations of mancozeb gave 100% inhibition of the fungus at 24–168 hours after incubation (HAI). At 24 HAI, Eucalyptus extract (50 and 100%) completely inhibited the fungus growth similar to mancozeb. Eucalyptus extract was more effective than neem extract and COPMET throughout. Though the extracts of both botanicals inhibited the growth of A. flavus at 168 HAI, Eucalyptus (83.8-89.2%) was more potent than neem (20.3–28.4%). At 48-168 HAI, both concentrations of neem extract and COPMET had similar effect on the fungus. The early stage of the antimycotic intervention is critical to the control of the fungus. This can be achieved by dressing cowpea seeds with mancozeb or Eucalyptus. However, due to the high cost and toxicity of synthetic chemicals, Eucalyptus extract could be used as an alternative for management of the fungus or incorporated into integrated disease management programmes for A. flavus. Research on the effects of long-term storage of cowpea using these botanicals is highly admonished.

Evaluation of long-term cryostorage on sperm function and fertility of brown-marbled grouper (Epinephelus fuscoguttatus)

Cryopreservation of fish semen is a valuable technique for reproductive management in aquaculture. The aim of this study was to evaluate the effect of long-term storage in liquid nitrogen on post-thaw sperm functional parameters of brown-marbled grouper (Epinephelus fuscoguttatus). Samples were cryopreserved in a simple freezing medium (10 % DMSO + 0.3 M Glucose), sperm quality parameters were assessed at different storage periods (one month, one year, 2 years and 3 years). Our results indicated that cryostorage periods had a significant effect on the quality of frozen-thawed spermatozoa. Compared with fresh semen, cryopreserved sample was characterized by an overall decline in motility, viability, mitochondrial membrane potential (MMP), ATP content and increased level of lipid peroxidation with the storage time going on. For the analyzed quality parameters, there were no significant differences in storage time cryopreserved over one month. After 3 years of storage, frozen sperm still showed relatively high total motility, viability and MMP (all over 80 %), yielding acceptable fertilizing capacity close to that of fresh sperm. Therefore, it can be concluded that brown-marbled grouper sperm could be effectively cryopreserved for at least 3 years. The results of this study would be helpful to optimize gamete management in routine hatchery practices.

Effect of Long Term Storage of Soil Sample on Some Chemical Properties of Vertisol and Andosol at Kulumsa Agricultural Sub Centers

The present study was conducted at the Kulumsa Soil and Plant Analysis Laboratory, Ethiopia from January 2021 to January 2022 to identify the appropriate storage duration of soil samples and recommend good storage materials for soil laboratories. The effects of soil sample storage on the pH, TN (%), OC (%), and available phosphorus were studied for 12 months. The highest and lowest concentrations of pH, TN (%), OC (%), and available phosphorus at the Kulumsa site were: 6.29 and 5.82; 0.17 and 0.12%; 2.93 and 1.70%; 22.53 and 10.88 respectively. At the Arsi Robe site, the highest and lowest concentrations of pH, TN (%), OC (%), and available phosphorus were 6.54 and 5.97, 0.16 and 0.12%, 3.02 and 1.00%, and 19.09 and 10.39 respectively. The highest and lowest concentrations of pH, TN (%), OC (%), and available phosphorus (mg kg1) at the Dera site were 9.14 and 8.47; 0.11, 0.07%; 4.36, 1.04%; and 111.85 and 75.37 respectively. Soil samples were stored in three storage containers with replications. The storage materials a card box with a plastic bag and a polyethylene bottle have not made any significant difference in the results of a soil sample stored under laboratory. A card box with a plastic bag was the appropriate material for soil sample storage for long-term analysis. However, based on the cost effectiveness and availability of the material to be purchased for the soil storage condition, the polyethylene plastic bag was the best option for soil sample storage under laboratory conditions.

Effect of Long-Term Storage in Light and Dark at Room Temperature on Physicochemical Characteristics of Some Vegetable Oils

Effect of Long-Term Storage in Light and Dark at Room Temperature on Physicochemical Characteristics of Some Vegetable Oils

Effect of Long-Term Storage on Glucosinolate and S-Methyl-L-Cysteine Sulfoxide Hydrolysis in Cabbage (Brassica Oleracea VAR. Capitata)

Effect of Long-Term Storage on Glucosinolate and S-Methyl-L-Cysteine Sulfoxide Hydrolysis in Cabbage (Brassica Oleracea VAR. Capitata)

Effect of long-term natural aging on the tensile and fracture properties of aluminum alloy AA2219-T87 parent and weldments at room and cryogenic temperatures

Aluminum alloy (AA2219) is widely used for the fabrication of earth storable and cryogenic propellant tanks. To ensure flight safety, it is important to understand the effect of long-term storage on the mechanical properties, which are dependent on the microstructure. Therefore, the present work is carried out to understand the effect of long term (11 years) ambient storage on the tensile and fracture properties of AA2219-T87 in parent material and weld joint. The tensile test results of naturally aged AA2219-T87 material for 11 years in both parent and weldments indicate an increase in tensile strength at room and cryogenic (77 and 20 K) temperatures. STEM-HAADF and TEM analysis revealed the presence of well-oriented densely populated CuAl2 precipitates (plate-like θ’ and θ” precipitates). The changes in mechanical and fracture properties were understood from the quantification of precipitate distribution, that can be attributed to the natural aging phenomenon taking place at ambient conditions, during the extended period of storage. Here, we report the mechanism towards understanding the increase in strength of AA2219-T87, by the growth of the finer θ” precipitates during natural aging. Since tensile (RT, 77 K, and 20 K) and fracture properties (RT) of welds have improved, with no significant reduction in ductility, long-term naturally aged (up to 11 years) fabricated products of AA2219-T87 are flightworthy.

ROLE OF THE ANTIOXIDANT IN FUNCTIONING OF THE AGING MECHANISMS ON THE EXAMPLE OF BARLEY

Introduction. Despite close attention to the process of seed aging, there is still no unambiguous answer to questions about the mechanisms of aging. The solution of these issues is due to both economic needs and the need to store plant genetic resources. Aim. The aim was to study the effect of long-term storage of seeds of different barley varieties, previously differentiated by tolerance to seed aging, on the state of the antioxidant system enzymes. Methods. The studies were carried out on three varieties of barley (Hordeum vulgare L.) Rosava, Selena Star and Trudivnik which had been stored under non-specialized laboratory conditions in paper envelopes for 8 years. The seed viability was assessed by germination energy and germinating ability according to the state standards. The direct test was supplemented with a cytogenetic study: an anatelophase test. The condition of the antioxidant system was characterized by an electrophoretic method for studying nonspecific peroxidase and superoxide dismutase in germinated shoots. The number of multiple forms of enzymes, their relative electrophoretic mobility and specific gravity (share) in percent in the total spectrum were determined. Enzymatic activity was assessed by the area of the peaks of the corresponding multiple forms on the densitograms. Results. In terms of tolerance to long-term storage in direct and cytogenetic tests, the varieties were arranged as follows: Trudivnik > Rosava > Selena Star. It has been shown that the viability of seeds after storage is closely related to the activity of peroxidase and superoxide dismutase: more tolerant varieties are characterized by the stability of the total activity of peroxidase and superoxide dismutase. Conclusion. The specific activity of the medium-mobile peroxidase fraction and low- and medium-mobile SOD fractions plays a leading role in determining the viability of seeds during long-term storage.

Retrogradation in radiation-synthesized cassava starch/acrylic acid super water absorbent and its effect on gel stability

The effects of long-term storage and retrogradation on the stability of the gel properties of radiation-synthesized super water absorbents (SWA) made from cassava starch and acrylic acid were explored in this study. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) analyses were used to explore the retrogradation phenomenon. TEM and scanning area electron diffraction (SAED) images revealed the presence of starch nanocrystallites and increase of crystalline state in SWA matrix after 24 months storage. FT-IR peak ratios and enthalpy changes in DSC analysis also confirmed retrogradation of aged SWA samples. However, no sharp peak was observed in XRD diffractograms which is mainly due to the nanostarches present in the SWA. The most critical property affected by starch retrogradation in SWA is the degree of swelling. The degree of swelling of SWA was greatly reduced from 148 to 30 g/g while the gel fraction remained stable after 24 mos. The aged SWA samples with low degree of swelling due to retrogradation returned to their high and stable soil water content after 15 d in unsterile pure garden soil. Despite being exposed to high energy gamma radiation of starch with acrylic acid to form SWA, wherein possible oxidation and chemical modification of starch may take place, retrogradation can still occur. Lowering the storage temperature evidently suppressed the effect of starch retrogradation in SWA. Suppression of starch retrogradation in the optimized SWA is crucial to prolong its marketable life.

Effects of Long-Term Storage on the Quality of Palm Oil Biodiesel and Canola Oil Biodiesel

Effective storage of biodiesel has proven to be a challenge, which the Indonesian government has invested billions of Indonesian rupiahs (IDR) in to overcome. It is thus important to investigate how different storage methods can affect the quality of biodiesel. The purpose of this study was to determine how storage at room temperature in the dark affects the quality of palm oil biodiesel (POB) and canola oil biodiesel (COB). POB and COB were stored in closed containers at 22 °C in the dark for 12 months. The results showed that POB was more significantly damaged than COB. This study found increases of density (POB by 51.52 kg/m3 and COB by 17.52 kg/m3), kinematic viscosity (POB by 0.67 mm2/s and COB by 0.32 mm2/s), acid value (POB by 0.27 mg-KOH/g and COB by 0.25 mg-KOH/g), total glycerol (POB by 0.58%-mass and COB by 0.60%-mass), and peroxide value (POB by 48 meq-O2/kg and COB by 54 meq-O2/kg), whereas there were decreases in fatty acid methyl esters (POB by 7.11%-mass and COB by 9.36%-mass). Gas chromatography-mass spectrometry results for POB and COB showed decreases in 9-octadecenoic acid methyl ester and 9,12-octadecadienoic acid (Z,Z)-methyl ester, and increases in 9-octadecenoic acid and 9,12-octadecadienoic acid (Z,Z). Fourier transform infrared spectroscopy (FTIR) results revealed the presence of methyl ester functional groups. The storage of biodiesel in a closed container at 22 °C in the dark can minimize biodiesel oxidation, as evidenced by the findings of this study, namely, the insignificant formation of ketone and aldehyde groups in the biodiesel oxidation process during storage, based on the results of FTIR.

Alterations in the Physicochemical Properties and Antioxidant Activity during Aging of Stored Raw Garlic.

Garlic, a once-a-year crop, is mass-produced in a single event. Most of the garlic harvested during the year, unless consumed or processed immediately, should be stored. Stored raw garlic (SRG) can be used to make black garlic (BG) via aging, and storage may affect the properties and quality of the BG compared with the use of raw garlic that has not been stored. This study was performed to identify the effect of long-term storage of raw garlic on the quality of BG products. SRG was aged for 21 days at 40–86 °C for BG production. Moisture content and pH gradually decreased with the aging period. Total phenolic, total flavonoid, and fructose contents were significantly increased during the aging period. Compared with non-stored raw garlic (NSRG), alliin and S-allylcysteine (SAC) contents were 1.7-fold and 5.9-fold higher in SRG, respectively, and γ-glutamyl-S-allylcysteine (γ-GSAC) content was 2.8-fold lower in SRG. The contents of alliin and γ-GSAC reduced as the aging period of SRG and NSRG progressed. However, the SAC content of NSRG increased with aging, but the SAC content of SRG decreased or increased slightly with extended aging. The antioxidant activity was also higher in BG made from NSRG rather than SRG. These results show that the SAC content is relatively low in BG manufactured from SRG compared with NSRG. Our findings suggest that it is necessary to establish an aging method suitable for SRG in BG production with high SAC content, a representative indicator of BG.

Differential response of softneck and hardneck garlic ecotypes to quality attributes for long-term storage

The selection of suitable garlic ecotypes is necessary for better storage quality to meet domestic and export requirements. For this purpose, ten promising garlic ecotypes, including hardneck and softneck types (Kilis, Mersin, Kahramanmaraş, Araban, Yavuzeli, Taşköprü, Nevşehir, Ankara, Aksaray, and Tokat) were examined to identify superior ecotype/s in terms of storability without detrimental changes for 6 months in warehouse condition. Thus, weight loss, sprouting ratio, and titratable acidity increased, whereas pH and antioxidant capacity decreased in all ecotypes with an increase in storage period. In addition, dissimilar behaviors were detected in SSC, ash, total phenolic, and macro- and micro minerals among ecotypes in relation to the storage period. This study demonstrates that Taşköprü, Tokat, Nevşehir, and Ankara ecotypes presented the best behaviors during storage, which are considered quality attributes and good indicators of predicting storage life. It also highlighted the potential of ecotype selection to prevent unacceptable levels of quality in garlic and the ecotype-dependent effect of long-term storage on quality parameters. Conclusively, it is possible to declare that softneck garlic ecotypes are more durable in the same storage conditions, considering the maintenance of quality attributes and good adaptation to longer storage. Therefore, the intensity of change in quality attributes was found to be crucial for identifying and choosing ecotypes to enhance the storage stability. It also imparts desirable properties for consumer acceptance and various processed garlic-based products.

T-2 and HT-2 toxins in harvested oat grains and their prevalence in whole grain flour during storage

Mycotoxin contamination of food is a constant global concern. There has been a scientific debate in Europe on the validation of accredited detection methods for type A trichothecenes T-2 and HT-2 and the restriction on dangerous concentrations. The issue is of great importance as this type of mycotoxin is frequently found in spring cereals grown in Lithuania. The aim of this study was to optimise and validate a method for the determination of T-2/HT-2 toxin concentrations in oats harvested in 2015–2018 and to observe the changes in the concentrations of both toxins in oat flour during 3- and 6-week storage at different temperatures and increased relative air humidity. All of the oat grain samples (100%) collected in 2015–2018 tested positive for contamination with type A trichothecenes. The highest mean co-contamination by T-2 + HT-2 (260.4 ± 140.9 µg/kg) and the highest concentration (594.6 µg/kg) were determined in 2018 when warm and wet weather conditions prevailed during oat flowering. The effect of long-term storage (6 weeks) on T-2 and HT-2 toxin production manifested itself only when the samples had been stored under cooler conditions (8 °C). The most important factors which impacted the variation of the concentrations of type A trichothecenes in flour were ambient temperature and storage time.

Effect of long-term storage on the quality of cryopreserved sperm of the giant grouper, Epinephelus lanceolatus

The giant grouper, Epinephelus lanceolatus, is one of the most valuable tropical commercial fishes. The asynchronous maturity periods between males and females hampers breeding programs. Sperm cryopreservation for gamete conservation is important for fish reproduction. We evaluated the effects of storage for 1, 3, 4, and 5 years on cryopreserved sperm of the giant grouper, E. lanceolatus, in 10% DMSO as a cryoprotectant with artificial seminal plasma and 300 mM sucrose as a diluent. Sperm motility, cell survival rate, DNA damage, fertilization rate, and hatching rate were investigated in this study. Post-thaw sperm motility peaked after 1 year of storage (63.27 ± 2.87%; p < 0.05), followed by 3 and 4 years (54.50 ± 4.33% and 54.40 ± 0.30%, respectively). Post-thaw sperm motility decreased after 5 years of storage. The cell survival rate after 1 year of storage (91.54 ± 3.02%) was similar to that of fresh sperm (98.12 ± 0.44%). The rate of DNA damage was unaffected by storage but significantly higher than that of fresh sperm. The fertility rate was significantly higher after storage for 1 and 3 years (98.06 ± 0.57% and 93.26 ± 1.73%, respectively). Samples stored for 1 and 3 years also resulted in high hatching rates (95.90 ± 1.53% and 88.73 ± 1.15%, respectively), which tended to decrease with increasing storage duration. Sperm cryopreserved for 4 years were of good quality in terms of motility and cell survival rate. However, storage for longer than 3 years decreased the fertility and hatching rates.

Effect of Long-Term Storage on the Reliability of Blood Biomarkers for Alzheimer's Disease and Neurodegeneration.

Stored blood samples from longitudinal cohort studies may be useful for studying biomarkers of preclinical Alzheimer's disease. This study aimed to determine the reliability of amyloid-β40 and amyloid-β42 (Aβ40, Aβ42), total tau (TTau), and neurofilament light (NfL) concentrations measured in blood samples stored long-term at -80°C. Aβ40, Aβ42, TTau, and NfL were measured in serum and plasma samples from two longitudinal cohort studies. Serum samples had been stored at -80°C for 5 (n = 24), 14 (n = 24), and 20 years (N = 78) and plasma samples had been stored for 16 years (N = 78). Biomarker concentrations were measured in duplicate using a single molecule array assay (Simoa; Quanterix, Billerica, MA). Replicate samples for each sample type and storage length were included. The concentrations of Aβ40, Aβ42, TTau, and NfL were within expected ranges. Some serum TTau concentrations were below the limit of detection. The average intra-assay coefficients of variation (CV) for duplicate measures were 2-7% for all assays except for serum TTau, which were higher (CVs 13% and 17%). Mean differences in original replicate pair Aβ40, Aβ42, and NfL concentrations were slightly greater in samples stored for longer versus shorter time periods. Aβ40, Aβ42, TTau, and NfL can be measured in serum and plasma samples that have been stored up to 20 years at -80°C. Long-term storage may be associated with small increases in the variability of concentrations in samples stored 14 or more years.

Study of the microstructure of chitosan aerogel beads prepared by supercritical CO2 drying and the effect of long-term storage

In order to investigate the pore properties and effect of storage time on the microstructure of CO2-dried aerogels, chitosan aerogel beads were obtained from chitosan hydrogels with an initial concentration in the range of 1.5–3.0 wt% through SCCO2 drying and freeze-drying (as a comparison). The SCCO2-dried chitosan aerogels showed a three-dimensional network structure, and had higher BET surface area (200 m2 g−1) and higher crystallinity (0.62/XRD, 0.80/ATR-FTIR) than the freeze-dried aerogels. The stability of the microstructure of the SCCO2-dried chitosan aerogel beads during 10 months was studied. The BET surface area of the aerogel beads at each concentration declined by 30.5% at 2 months, 56.7% at 6 months and 67.2% at 10 months. Accelerated aging tests of the chitosan aerogel beads were carried out to study the effect of humidity on the chitosan aerogel beads. The average diameter of the chitosan aerogel decreased from 2.3 mm to 0.9 mm when stored at 65 °C with 90% relative humidity (RH). In contrast, there was no obvious change during storage at 65 °C with 20% RH. The amount of adsorbed water increased from 4% to 12% at 65 °C with 90% RH for 96 h, and the bound water content of the aerogel beads gradually increased. This study demonstrates that SCCO2-dried chitosan aerogel beads could be better at maintaining their mesoporous structure, and the adsorption of water from the surrounding air had a significant effect on the microstructure and shrinkage of the chitosan aerogel beads.

Effect of long-term storage on viability of buffel grass (Cenchrus ciliaris L.) seeds

Abstract: Prolonged storage of seeds may lead to decreases in seed quality, negatively affecting germination and vigor and preventing the obtaining of a promising stand. Seed quality is a critical factor, and the performance of the lot can be altered by vigor, dormancy and, mainly, by the time and conditions in which the seeds were stored. In the experiment, the physiological quality of seeds 14 genotypes of buffel grass (Cenchrus ciliaris L.) genotypes stored for a period of thirteen years in cold conditions was evaluated. The seeds were subjected to germination induction treatment with potassium nitrate (KNO3) and evaluated to identify seeds with presence and absence of embryos. The seed storage period affected their germination capacity and the use of KNO3 did not increase seed germination. A low number of full seeds was found for genotype 613 (12%). The relative germination percentages did not underestimate the buffel grass seed germination potential, as it is usually calculated, providing an improved distinction between the evaluated genotypes. The use of KNO3 increased the seedling root and shoot weights of some genotypes, as well as the dry matter weight of seedlings, an important characteristic for forage production. The prolonged storage affects the physiological quality of buffel grass seeds. The production of seeds without embryo is a problem found for this species, which affects the final quality of the seed lots produced.

Effect of the physicochemical changes in the antimicrobial durability of green synthesized silver nanoparticles during their long-term storage.

It is generally recognized that the stability of nanoparticles (NPs) has a great impact on their potential biological applications. Despite this, very few studies have investigated the change in toxicity of NPs over time but none has studied the periodic physicochemical changes contributing to it. To address this, we analyzed the effects of long-term storage on the physicochemical changes of green synthesized silver nanoparticles (AgNPs) that directly influences their antimicrobial durability. Light-induced slow synthesis of AgNPs was carried out using Saraca asoca aqueous leaf extract. The synthesis was optimized with respect to parameters known to play a major role in the long-term stability of AgNPs: pH, temperature, light exposure time, AgNO3 concentration, extract proportion in the reaction mixture and storage conditions. Freshly synthesized AgNPs were characterized and then stored under optimized conditions. UV-vis spectrophotometry, AAS, conventional TEM and HR-TEM along with EDX spectroscopy were used at regular intervals to test the physicochemical properties that influence their long-term stability. Broth dilution assay was used to test antimicrobial activity of AgNPs against Escherichia coli and Staphylococcus aureus. Under dark storage conditions at room temperature, the AgNPs exhibited excellent stability with very good dispersity, throughout the study period of 18 months, despite the particles undergoing physicochemical changes in largescale. AgNPs exhibited sufficient antimicrobial activity against both strains tested. Due to the stronger stabilizing effect of the extract, we observed the lowest inhibition of E. coli and S. aureus by the freshly synthesized and 15 day old AgNPs; however, the inhibition rate escalated after a month and the highest rate of inhibition was observed with the particles between 2 months to 6 months of storage. After 6 months, we observed the particles losing their antimicrobial potential gradually, that lasted throughout the rest of our study period. This observation was in accord with the physicochemical changes that AgNPs were undergoing with time. By deepening our understanding of the changes in the physicochemical properties of green synthesized AgNPs over time, this study contributes to the development of more effective, durable, and potent AgNPs.

Effect of long-term storage and harvest site on the fatty acid profiles, mineral and antioxidant properties of selected edible Scottish seaweeds

The limited understanding of the effect of pre-and post-harvest techniques still hinders the full exploitation of seaweed. Here, the effect of harvest site, long term storage and species on the elemental composition, fatty acid profile, lipid content, and antioxidant properties were determined in eight intertidal seaweed species common to Scotland, harvested for potential food application and stored for up to 128 weeks. Result showed that the most significant variation was due to species, with no statistical link found for the combined interaction effect of both storage duration and harvest site in most cases, except for the antioxidant parameters and some selected elements, which was limited to some seaweed species. Overall, our result showed that the chemical profiles of the seaweed species studied were remarkably consistent and unaffected by long term storage. Thus, suggesting that seaweeds sampled from Scotland could be a valuable resource for the development of functional foods.

Analyzing the effect of storage conditions on anammox recovery performance from the perspectives of time, temperature and biomass form

In this study, the effects of different storage conditions, such as temperature, storage time and biomass form, on the properties of anaerobic ammonia oxidation (anammox) were investigated along with the identification of the process mechanism. The results showed that the influence of storage time on anammox properties was stronger than that of storage temperature and biomass form. Also, the anammox recovery activity at 15 °C was better than that at 4 °C, and the anammox recovery activity of immobilized filler was better than that of anammox granular sludge (AnGS). Although cryogenic storage severely damaged anammox activity, lower loss of extracellular polymeric substances maintained the AnGS structure. The maximum recovery of specific anammox activity at 15 °C for the immobilized filler was observed to be 109%. In addition, intermittent substrate supplementation weakened the adverse effect of long-term storage on anammox activity, and was conducive to maintaining stable flora composition and promoting regeneration of anammox bacteria (AnAOB). High-throughput sequencing analysis showed that starvation resulted in increased community diversity, and the functional bacteria Candidatus Brocadia was observed to be more tolerant to starvation than Candidatus Kuenenia. Finally, principal component analysis was used to explain the complex relationship between process performance and preservation conditions. Based on the results of this work, it is recommended to preserve AnAOB in the form of immobilized filler at 15 °C and supplement substrate intermittently during long term storage. This study provides an economical and robust strategy for the short-term and long-term preservation of AnAOB.

Effects of Long-Term Storage on Radical Scavenging Properties and Phenolic Content of Kombucha from Black Tea.

Kombucha is a fermented beverage. Its consumption has significantly increased during the last decades due to its perceived beneficial effects. For this reason, it has become a highly commercialized drink that is produced industrially. However, kombucha is still also a homemade beverage, and the parameters which, besides its organoleptic characteristics, define the duration of its potential beneficial properties over time, are poorly known. Therefore, this study aimed to determine the effect of 9-month storage at 4 °C with 30-day sampling on the pH, total phenolic, and flavonoid contents, free radical scavenging properties of kombucha fermented from black tea. Our results highlighted that, after four months, the phenolic content decreased significantly from the initial value of 234.1 ± 1.4 µg GAE mL−1 to 202.9 ± 2.1 µg GAE mL−1, as well its antioxidant capacity tested by two in vitro models, DPPH, and ABTS assays. Concomitantly, the pH value increased from 2.82 to 3.16. The novel findings of this pilot study revealed that kombucha from sugared black tea can be stored at refrigerator temperature for four months. After this period the antioxidant properties of kombucha are no longer retained.