Storage Time Research Articles

Effect of Parking Time on the Microstructure and Properties of 7050 Aluminum Alloy

The duration of the parking time between quenching and artificial aging can affect the final mechanical and corrosion properties of the material after artificial aging, etc. At present, there are fewer studies on the parking time before artificial aging, and this paper investigates the influence of the parking time before artificial aging on the microstructure and properties of 7050 aluminum alloy. The results show that: with the prolongation of the parking time, the proportion of HAGBs of the alloy is gradually increased through EBSD analysis, the dislocations are mainly concentrated in HAGBs and areas with dense GBs, the precipitated phase of the alloy continuously precipitates and grows at the GBs, the alloy’s hardness shows a trend of stabilization and then decreasing, and the corrosion resistance is stabilized and then deteriorated quickly with the prolongation of the parking time. The alloy has stabilized comprehensive performance when the storage time does not exceed 6 h, with microhardness of 132.2 HV, the Ecorr of −0.991 V and −1.007 V, the Icorr of 6.14×10−8 A·cm−2 and 4.16×10−7 A·cm−2.

The effect of rosemary, ginger, or garlic on microbial shelf life and sensory acceptability of nutritionally enriched cassava-based pancake (Kabalagala)

Iron and vitamin A contents of Cassava-based pancake (Kabalagala), a delicacy among children in northern Uganda have recently been improved through the addition of biofortified iron-rich beans and orange-fleshed sweet potato. The nutritionally improved product (NIK) was designed as a strategy to address iron and vitamin A deficiencies which are endemic challenges among children in Uganda. However, the NIK had a lower microbial shelf life (24 hours) than the original product (72 hours). The objective of this study was to investigate the potential of the spices; rosemary, ginger, and garlic to improve the microbial shelf life of the NIK. Each of the spices was used individually to prepare NIK at a rate of 0.5, 0.75, and 1%. The resultant products were evaluated for counts of total microbial load, Enterobacteriaceae, lactic acid bacteria, yeasts and molds as well as consumer sensory acceptability during storage at ambient temperature. Results of One-way Analysis of Variance (ANOVA) showed that all the spices exhibited potency against the microbial groups investigated only when included in the NIK at 0.75% or 1% (p<0.05). The microbial shelf life of the NIK based on total microbial count increased from 24 to 72 hours depending on the spice type and concentration. The spice, 1% ginger resulted in Enterobacteriaceae and yeast and molds counts within acceptable microbial threshold for the entire storage time (72 hours) with a maximum load of 3.41 and 2.82 log10 CFU/g, respectively. The NIK containing ginger or garlic at 0.75 or 1%, was more accepted and the extent of acceptability increased with storage time (p<0.05). Based on the overall acceptability, the consumer acceptability varied from 1% garlic > 0.75% garlic > 1% ginger > 0.75% ginger > 0.5% ginger in decreasing order. Spearman's correlation analysis revealed a strong association between the sensory parameters examined (appearance, aroma, texture, taste) and the overall acceptability of the products (p<0.05). The magnitude of association between appearance, aroma, texture, taste and overall acceptability varied between 0.396-0.703, 0.504-0.679, 0.452-0.589, and 0.498-0.698, respectively. This study has demonstrated that ginger or garlic when applied at 0.75-1% improves microbial shelf life of NIK concomitant with better consumer sensory acceptability. Therefore, ginger or garlic can be applied at 0.75-1% to produce microbiologically and sensorially acceptable NIK for use to improve intake of vitamin A and iron among children in Uganda.

Multi-Faceted Analysis of Phase-Change Composite Intended for Autonomous Buildings

This paper presents the long-term, holistic results of research into an innovative heat accumulator based on an organic phase-change material in the form of a mixture of aliphatic alkanes, molecular silica sieves, carbon recyclate and epoxy and cement matrices. The research included chemical testing of vacuum soaking of molecular silica sieves with a liquid phase-change material. The results proved an improvement in the heat storage efficiency of the heat accumulators due to the addition of carbon recyclate by 28%, while increasing the heat storage time by 134 min, and a reduction in PCM leakage due to the use of molecular silica sieves. In addition to its cognitive scientific value, another research objective of the work achieved was to obtain response functions in the form of approximating polynomials. They provide a useful, validated and verified tool to predict the physical and chemical characteristics of heat accumulators with different contents of individual components. As part of the ongoing research, technical problems related to leak-proofing assurance and matrix selection for organic phase-change materials were also solved. The solution presented is in line with the issues of efficient use of renewable energy, low-carbon and energy-efficient circular economy.

Single-photon Level Quantum Memory in an Isotopically Pure 143Nd3+:Y7LiF4 Crystal

In an isotopically pure 143Nd3+:Y7LiF4 crystal we demonstrate an optical quantum memory on a single photon level using the atomic frequency comb memory protocol. Using weakened laser pulses we demonstrate storage efficiency of 6.5% with the storage time of ~60 ns and signal to noise ratio of around 3.

Bio‐yoghurt enriched with Spirulina‐encapsulated pomegranate peel: Impact on some metabolomics, antioxidative, textural and colour properties

As an innovative bio‐dairy product, yoghurt was enriched with Spirulina‐encapsulated aqueous/hydroalcoholic extracts of pomegranate peel (PP). Some metabolomics, antioxidative, textural and colour properties of bio‐yoghurt samples were investigated. The samples with Spirulina (YM) and PP (YPA) had the highest lactic, citric and uric acid. The aroma profile of the samples was affected encapsulation process and storage time. The values on day 1 and day 21 were 17.84–17.04 mg/kg for acetaldehyde, 0.98–0.90 mg/kg for diacetyl and 54.42–46.65 mg/kg for acetoin. The sample with encapsulated PP aqueous extract (YEPA) had the highest TPC (2.97 mg GAE/g), and the sample with PP aqueous extract (YPA) had the highest antioxidant capacity (0.36 mg TE/g). The present study describes that bio‐yoghurt enriched with Spirulina‐encapsulated PP could be considered a good alternative for consumers demanding functional dairy products and a holistic approach to a circular bioeconomy.

Effect of Seed Storage Duration and Methods on Growth and Yield of Basil Variety

The experiment was conducted at Wondogenet Agricultural Research Center to determine the effect of seed storage period and methods on the growth and yield of basil. Basil seeds stored in three storage methods (Plastic jar, Polypropylene, and Cotton bags) for six storage periods (initial period, one, three, six, nine, and twelve months) were used to evaluate the impact of the treatments on the yield and performance in the field. The field experiment was arranged by using RCBD design with three replications. The data were taken at the 90% physiological maturity stage. The results showed a significant difference between the treatments. The results indicated that the interaction effects of basil seed storage time and methods had a significant (P&amp;lt;0.05) effect on Primary Branch Number, Plant Height, Umbrella length, Dry, and Fresh biomass. The umbrella number of the storage methods had an accelerating trend with raising storage duration to 3 months storage, after that it shows a declining trend with raising storage time. The two storage methods plastic jar and bag maintained the seed in good condition for 3 months further, storage of the seed leads to the shortest plant and umbrella length. The highest dry biomass was recorded at 3 months stored seed in a plastic bag which was not significantly different from 3 months stored seed in a plastic jar. Basil dry biomass for the jar stored seed ranged from 0.85 to 3.33, 0.91 to 3.42 ton/ha for plastic bag whereas for the cotton bag, it ranged from 0.6 to 2.26 ton/ha. In general, seeds stored for three months had shown better growth and yield.

Effects of Different Na+ Concentrations on cAMP-Dependent Protein Kinase Activity in Postmortem Meat

cAMP-dependent protein kinase (PKA) activity regulates protein phosphorylation, with Na+ playing a crucial role in PKA activity. The aim of this study was to investigate the effects of different Na+ concentrations on PKA activity and protein phosphorylation level in postmortem muscle. The study consisted of two experiments: (1) NaCl of 0, 20, 100, 200 and 400 mM was added to a muscle homogenate incubation model to analyze the effect of Na+ concentration on PKA activity, and (2) the same concentrations were added to pure PKA in vitro incubation models at 4 °C to verify the effect of Na+ on PKA activity. The PKA activity of the muscle homogenate model increased with storage time in groups with different Na+ concentrations. High concentrations of Na+ inhibited sarcoplasmic protein phosphorylation. The PKA activity at 24 h of storage and the sarcoplasmic protein phosphorylation level at 12 h of storage in the group with 200 mM Na+ was lower than that of the other groups. After 1 h incubation, the PKA activity of samples in the 200 mM Na+ group was inhibited and lower than that in the other Na+ groups in the in vitro incubation model. These results suggest that the Na+ concentration at 200 mM could better inhibit PKA activity. This study provided valuable insights for enhancing curing efficiency and improving meat quality.

Assessing EPO stability in urine and comparing recombinant EPO detectability in matched urine, venous serum, and capillary serum following a controlled epoetin alfa administration.

The instability of erythropoietin receptor agonists (ERAs, i.e., EPO) in urine presents a challenge to their detectability in doping control samples; however, this issue is not often seen in blood (serum) samples. With the anti-doping field beginning to transition into alternative blood collection technologies, it is important to understand recombinant EPO (rEPO) detectability in serum samples collected from one such capillary collection device, the Tasso+ SST. Twelve individuals were administered a single, 40 IU/kg dose of rEPO (epoetin alfa, EPOGEN®). Following administration, matched urine, venous serum, and capillary serum samples were concurrently collected. Urine aliquots were subject to various storage times and temperatures mimicking shipping conditions of doping control urine samples to assess EPO stability, while other urine aliquots, venous serum, and capillary serum aliquots were frozen until analysis to understand rEPO detectability across all three matrices. EPO and rEPO instability was identified in urine collected from 8 of 12 participants, especially in aliquots stored at room temperature and 37°C. In some of these unstable samples, rEPO was still detectable, while in others, no recombinant nor endogenous EPO was detectable and would have resulted in negative sample reports. Analyzing the concurrently collected urine, venous, and capillary serum samples, rEPO detectability was identical across the three matrices. In most cases, rEPO was detectable for at least 168 h post-administration. Noting greater stability in blood compared with urine, it is recommended that anti-doping authorities utilize this novel capillary serum collection technology to improve overall ERA detectability in doping control samples.

Numerical Investigation of Heat Transfer Characteristics of Trapezoidal Fin Phase Change Thermal Energy Storage Unit

Abstract: In order to enhance the heat transfer performance of a phase change thermal energy storage unit, the effects of trapezoidal fins of different sizes and arrangement modes were studied by numerical simulation in the heat storage and release processes. The optimal enhancement solution was obtained by comparing the temperature distribution, instantaneous liquid-phase ratio, solid–liquid phase diagram and comprehensive heat storage and release performance of the thermal energy storage unit under different fin sizes. During the heat storage process, the results show that when the ratio of the length of the upper and lower base of the trapezoid h1/h2 is 1:9, the heat storage time is shortened by 9.03% and 18.21% compared with h1/h2 = 3:7 and 5:5, respectively. During the heat release process, the optimal heat transfer effect is achieved when h1/h2 = 5:5. To further improve the heat transfer effects, the energy storage unit is placed upside down; then, the least time is achieved when h1/h2 = 2:8. When heat storage and release are considered together, the energy storage unit with h1/h2 = 2:8 takes the shortest time to melt in upright placement and then to solidify in upside-down placement.

Metagenomics Analysis of Microbiota in Raw Chicken Stored at Different Temperature over Storage Time in Chennai

Metagenomics Analysis of Microbiota in Raw Chicken Stored at Different Temperature over Storage Time in Chennai

Development of sensory tools for green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) and changes in quality attributes during shelf-life storage.

Green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) herbal tea is popular due to its health-promoting properties. Information on its characteristic sensory profile is scarce and sensory tools to define product variation are needed. The storage conditions and time during its shelf-life are hypothesized to affect the product quality. Production batches from two producers spanning 5 years (n = 57) were analyzed using descriptive sensory analysis. Primary attributes (>30 median intensity; 100% occurrence frequency) included 'hay/dried grass', 'cooked oats', 'tobacco', 'honey' and 'caramel' aromas, and astringent mouthfeel. 'Cooked vegetables', 'green grass', 'stewed fruit', 'rooibos-woody', 'marmalade' and 'cardboard' aromas, sweet taste and bitter taste were secondary attributes (10-20 median intensity; 100% occurrence frequency). The same flavor attributes were present, except for sweet-associated and fruity notes. A sensory lexicon and sensory wheels for aroma and palate attributes were constructed from the data. The shelf-life stability of green rooibos was evaluated in moisture-impermeable (pouches) and moisture-permeable (sachets) packaging at 25 and 40 °C at 60% relative humidity over 24 weeks. Green rooibos samples stored in pouches at 4 °C were also evaluated. Storage in sachets led to moisture uptake (~10 g (100 g)-1 dry basis) and an increase in water activity (>0.6), causing degradation of chlorophyll and dihydrochalcones. Changes in color and sensory profile (decreased vegetal, cereal and cardboard aromas and increased sweet-associated and fruity aromas) were evident and more pronounced at the higher storage temperature. Storage at ≤25 °C in moisture-impermeable packaging material is recommended for green rooibos herbal tea. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Flexible bistable polymer stabilised cholesteric texture light shutter display

ABSTRACT Bistable cholesteric liquid crystal displays meet various needs such as energy saving, long image storage time, and no backlight; however, their dense polymer network affects the electro-optical performance. In this work, polymer-stabilised cholesteric texture (PSCT) films with polymer spacer columns were prepared by two-step polymerisation using photomask. The effects of crosslinker content and mask polymerisation time on the morphology of the polymer spacer columns and the optoelectronic properties of the PSCT films were investigated. The results suggested that the film showed bistable performance and the formation of polymer spacer columns helped to optimize the contrast ratio of the sample without sacrificing response time. The cyclic experiment indicated that the optimized bistable PSCT film showed good stability. The adhesion strength of the PSCT film to the substrate was essentially the same as that of commercial PDLC. The simple operability and reusability of the process method make it a practical solution for the preparation of bistable PSCT films.

Optimization of parameters affecting the recovery in the analysis of polycyclic aromatic hydrocarbons in natural waters by HPLC-fluorescence

To improve the recovery percentages in the analysis of PAH (polycyclic aromatic hydrocarbons) in natural waters, parameters such as standard stability, filtration, storage time and matrix effect were optimized for five PAH by HPLC-FD. For aqueous standards, with the addition of 10% acetonitrile, good linearity was found for naphthalene, acenaphthene, anthracene, pyrene, and chrysene curves up to the second day of standards preparation. In filtration, the best results were obtained using the AP10 and Nylon filters with 10% acetonitrile, with recovery ranges of 98-72% and 93-56%, respectively. In contrast, lower values were obtained with cellulose filters in a polyethylene holder without the addition of 10% acetonitrile with recoveries of 52-0%. A 23 factorial design established, for natural water, that the most important factors were: storage time for naphthalene and acenaphthene, with area losses at 48 hours and the use of organic solvent for anthracene, pyrene and chrysene, with area gain for 20 % acetonitrile. For liquid-liquid extraction in standards, recoveries of 62-45% were found in aqueous matrix without acetonitrile and 98-35% with 20% acetonitrile + 2.5% NaCl, at 24 hours of preparation.

Clinical Practice of Pre-Assembling and Storing of Extracorporeal Membrane Oxygenation Systems

According to the Extracorporeal Life Support Organization (ELSO) guidelines, pre-assembled and already primed extracorporeal membrane oxygenation (ECMO) systems can be safely stored for up to 30 days under specific conditions. This study gives a detailed overview of existing pre-assembly practices. An anonymous online survey was conducted among chief perfusionists at German ECMO centers. Forty-four of a total of 83 ECMO centers (53%) completed the survey. Thirty-three percent do not preassemble ECMO systems. Seventy-seven percent (n = 34) reported having preassembled ECMO systems readily available (30% dry preassembly/20% wet preassembly/27% wet preassembly with circulation). Half of the participating centers (50%) reported having a standard operating procedure (SOP) and the majority (57%) of chief perfusionists expressed a need for an evidence-based SOP. A maximum storage time for wet preassembled ECMO systems is established in 88% of departments. On average, wet preassembled systems are discarded after 20 days, which is below the ELSO’s safe limit of 30 days. Overall, this survey reveals a heterogeneous approach regarding the practice of provisioning preassembled ECMO systems. The demand for an evidence-based SOP for the preassembly and storing of ECMO systems becomes evident, necessitating the determination of hygienic standards, regular training, and a reliable maximum storage period.

Effect of the storage process on quality characteristics of hemp-enriched "tsoureki" a rich-dough baked Greek product.

The effects of the storage process on the quality characteristics of a hemp-enriched "tsoureki" (a rich-dough baked Greek product, rich-dough baked product [RDBP]) were investigated. The wheat flour was substituted with defatted hemp flour at selected ratios (0%-50% hemp:wheat flour). The baked products were stored at 25°C and at specific time intervals (0, 1, 4, 7, 10, and 14 days), and their properties were determined, including moisture content, water activity, structure, texture, color, total phenolic content (TPC), and antioxidant activity. Moreover, analyses of phenolic compounds were performed using quadrupole time of flight liquid chromatography-mass spectroscopy, identifying 14 compounds. Both the first-order kinetic model and modified Avrami equation, including the hemp-to-wheat ratio effect in the rate constant, well described the changes in the quality characteristics. The results showed that storage time and hemp incorporation significantly affected the quality of the product. Water activity decreased from 0.901 to 0.859, whereas moisture content decreased from 30.52%-32.33% (0 days) to 26.97%-27.02% w.b. (14 days) with storage time for all hemp additions. Hardness was greatly affected by hemp flour addition and approached 14.72 and 17.85 N after 14 days of storage for 30% and 50% substitutions, respectively. Springiness and cohesiveness decreased with hemp addition and storage time. The color difference of the hemp-enriched products compared to the control sample increased during storage. TPC increased due to the addition of hemp flour, whereas 14 compounds were identified. Based on property correlation, the hemp-enriched RDBP-tsoureki held its high-quality characteristics for 7 days of storage and contained a significant amount of bioactive compounds. PRACTICAL APPLICATION: Industrially produced, defatted hemp is a promising byproduct that can be used to nutritionally enhance baked goods. Modeling results can be used for the prediction of the properties that define product storage ability and also that the hemp-enriched, rich dough-baked Greek "tsoureki" could be produced while maintaining total phenolic content and antioxidant activity during 7 days of storage. These findings are expected to be used in the future in baked goods industry applications to produce goods with an improved nutritional profile.

Fertilization by short-term stored sperm alters DNA methylation patterns at single-base resolution in common carp (Cyprinus carpio) embryos

AbstractSperm after short-term storage in vitro is widely used for artificial fertilization in aquaculture. It has been shown that short-term storage affects sperm motility characteristics, resulting in diminished fertility. However, the detrimental effects of short-term sperm storage on embryos development have remained unexplored in single-base methylome resolution. The main aim of the present study was to investigate DNA methylation in the offspring of common carp (Cyprinus carpio) derived from short-term stored sperm. Sperm were stored in artificial seminal plasma on ice (0–2 °C) for 0, 3 and 6 days in vitro, fertilization was performed using oocytes from a single female, and embryos were collected at the mid-blastula stage. In the DNA methylation study, DNA from both sperm and embryos was extracted and analysed using liquid chromatography with tandem mass spectrometry (LC–MS/MS). Concurrently, DNA methylation levels of embryos in single base were evaluated through whole genome bisulfite sequencing (WGBS). Sperm storage showed negative effects on sperm motility, viability, and DNA integrity, but had no effect on global DNA methylation of spermatozoa and resulting embryos. Results from the WGBS showed that methylation of 3313 differentially methylated regions (DMRs)-target genes was affected in the embryos fertilized with the 6-day-stored sperm, and the identified DMRs were mainly involved in cell adhesion, calcium, mitogen-activated protein kinase and adrenergic signalling, melanogenesis, metabolism and RNA transport. Such results suggest that prolongation of storage time may have certain impacts on embryonic development. These initial results provide valuable information for future consideration of the DNA methylome in embryos generated from short-term stored sperm, which are used for genetic management of broodstock in aquaculture.

A Peel Test Method to Characterize the Decay Law of Prepreg Tape Tack at Different Temperatures.

The tack of prepreg is a key factor affecting the automatic tape laying process. During the manufacturing process of large composite parts, prepreg material may be stored at room temperature for several days, resulting in a decrease in its tack. In this study, a new tack test tool was designed, and the decay rate of prepreg tack at different temperatures was tested. We proposed a prepreg tack decay model, which assumes that the main factor in tack decay is the reduction in resin chain activity during storage. The maximum deviation between the model calculation results and the experimental results of the tack decay rate is 9.7%. This study also proposed a new statistical unit for prepreg tack, which can establish the relationship between the tack of prepreg and its remaining storage time and reduce prepreg management costs.

The effect of fixed and rotary roasting methods on the oxidative stability of pistachio oil

Today, the demand for vegetable oils has increased. Unsaturated fatty acids in pistachio oil are an important component in promoting the health of the human diet. The purpose of this study was to evaluate the oxidative properties of roasted pistachio oil in two fixed and rotary roasters at 160 °C for 15 min during 0, 3, and 6 months of storage. The heat used has led to the destruction of the oil in the roasted pistachios, and with the increase in the storage time, the peroxide value of the samples increased from 0.06 to 0.57 meq/kg in the fixed method and from 0.03 to 0.07 meq/kg in the rotating method, respectively. Free fatty acids and acid value increased from 0.34 to 1.34 % and 0.69 to 2.68 mg KOH/g in the fixed method and from 0.3 to 1.11 % and 0.6 to 2.20 mg KOH/g in the rotating method as a result of storage time for 6 months and lipolysis reactions. Under the effect of roasting heat, the Maillard reaction products played an important role in the thermal stability of the oil (P<0.05). The roasted samples at zero storage time have the highest inhibitory percentage of DPPH and the lowest IC50 (3.66 % in the fixed method and 6.9 % in the rotary method). In spite of the fact that the changes made during 6 months of storage in both roasting methods are within the standard range, but due to the fact that in the samples of roasted pistachios in the fixed method, the peroxide value increased and the oxidative stability decreased significantly, it is suggested to use the rotary method in roasting of pistachios.

Impact of breath sample collection method and length of storage of breath samples in Tedlar bags on the level of selected volatiles assessed using gas chromatography-ion mobility spectrometry (GC-IMS)

The analysis of volatile organic compounds (VOCs) in exhaled air has attracted the interest of the scientific community because it provides the possibility of monitoring physiological and metabolic processes and non-invasive diagnostics of various diseases. However, this method remains underused in clinical practice as well as in research because of the lack of standardized procedures for the collection, storage and transport of breath samples, which would guarantee good reproducibility and comparability of results. The method of sampling, as well as the storage time of the breath samples in the polymer bags used for sample storage and transport, affect the composition and concentration of VOCs present in the breath samples. The aim of our study was to compare breath samples obtained using two methods with fully disposable equipment: a Haldane sampling tube intended for direct breath collection and breath samples exhaled into a transparent Tedlar bag. The second task was to monitor the stability of selected compounds of real breath samples stored in a Tedlar bag for 6 h. Gas chromatography coupled with ion mobility spectrometry (GC-IMS) implemented in the BreathSpec® device was used to analyse exhaled breath. Our results showed a significant difference in the signal intensity of some volatiles when taking a breath sample with a Haldane tube and a Tedlar bag. Due to its endogenous origin, acetone levels were significantly higher when the Haldane tube sampler was used while elevated levels of 2-propanol and unidentified VOC (designated as VOC 3) in the Tedlar bag samples likely originated from contamination of the Tedlar bags. The VOC stability study revealed compound-specific signal intensity changes of the selected VOCs with storage time in the Tedlar bags, with some volatiles showing increasing signal intensity during storage in Tedlar bags. This limits the use of Tedlar bags only for very limited time and carefully selected purpose. Our results highlight the importance of careful design and implementation of experiments and clinical protocols to obtain relevant and reliable results.

E. Coli inactivation by humidified air barrier discharge plasmas and the chemical stability of amino acids

In this study, we use atmospheric air dielectric barrier discharge (DBD) plasma to inactivate E. coli (E. coli) by changing the air humidity levels. In order to analyze the inactivation process of E. coli during the humidified air DBD plasma treatment, we analyze the byproducts of 12 representational amino acids and compare their chemical stability. The experimental results show that the E. coli surface density (CFU cm−2) on a steel disc decreased significantly when the air humidity was increased from 20% to 60%, and humidified air DBD plasma at 60% humidity is very effective in inactivating E. coli. A consistently potent deactivation effect on E. coli can be seen in plasma afterglow treatment experiments over a storage time of two minutes, indicating that plasma-activated long-lived reactive oxygen and nitrogen species play a crucial role in controlling the E. coli inactivation. Compared to the low humidity (20%) condition, the concentration of reactive species produced by the plasma at high humidity (60%) increased 2-fold for 2-hydroxyterephthalic acid and 5-fold for hydrogen peroxide while ozone production was halved. Amino acid experiments showed that amino acids may be oxidized, hydroxylated and nitroxylated by reactive species. The reduction of amino acids by air DBD plasma was even more pronounced at high air humidity compared to low air humidity. Our analysis indicates that the significant inactivation of E. coli by humified air DBD plasma is related to the chemical instability of amino acids.