Changes In Physiological Properties Research Articles

Transcriptome Analysis on the Quality of Epimedium koreanum in Different Soil Moisture Conditions at Harvesting Stage.

Epimedium koreanum is a traditional Chinese tonic herb. Its main medicinal components are secondary metabolites such as flavonoids and flavonol glycosides, but the biosynthetic mechanism is still unclear. Moisture conditions are a key environmental factor affecting E. koreanum medicinal components during harvesting. Different stages of E. koreanum under natural conditions after rainfall were selected to study changes in physiological properties, herb quality, and transcriptome. Malondialdehyde (MDA) content increased significantly in the D3 stage after rainfall, and protective enzyme levels also rose. Additionally, the flavonol glycoside content was relatively high. We sequenced the transcriptomes of D1, D3, and D9 (R) and identified differentially expressed genes (DEGs) related to flavonoid synthesis. This analysis allowed us to predict the roadmap and key genes involved in flavonoid biosynthesis for E. koreanum. These results suggest that the E. koreanum quality can be enhanced by natural drought conditions in the soil after precipitation during harvest. The harvesting period of E. koreanum is optimal when soil moisture naturally dries to a relative water content of 26% after precipitation. These conditions help E. koreanum tolerate a certain level of water scarcity, resulting in increased expression of flavonoid-related genes and ultimately enhancing the quality of the herb.

Simultaneously enhancement in the assimilation of microalgal nitrogen and the accumulation of carbohydrate by Debaryomyces hansenii

Microalgae-based techniques are considered an alternative to traditional activated sludge processes for removing nitrogen from wastewater. Bacteria consortia have been broadly conducted as one of the most important partners. However, fungal effects on the removal of nutrients and changes in physiological properties of microalgae, and their impact mechanisms remain unclear. The current work demonstrates that, adding fungi increased the nitrogen assimilation of microalgae and the generation of carbohydrates compared to pure microalgal cultivation. The NH4+-N removal efficiency was 95.0% within 48 h using the microalgae-fungi system. At 48 h, total sugars (glucose, xylose, and arabinose) accounted for 24.2 ± 4.2% per dry weight in the microalgae-fungi group. Gene ontology (GO) enrichment analysis revealed that, among various processes, phosphorylation and carbohydrate metabolic processes were more prominent. Gene encoding the key enzymes of glycolysis, pyruvate kinase, and phosphofructokinase were significantly up-regulated. Overall, for the first time, this study provides new insights into the art of microalgae-fungi consortia for producing value-added metabolites.

Effects of basilar-membrane lesions on dynamic responses of the middle ear

Background Numerical simulations can reflect the changes in physiological properties caused by various factors in the cochlea. Aims/Objective To analyze the influence of lesions of the basilar membrane (BM) on the dynamic response of the middle ear. Method Based on healthy human ear CT scan images, use PATRAN software to build a three-dimensional finite element model of the human ear, then apply NASTRAN software to conduct analysis of solid-fluid coupled frequency response. The influence of lesions in the BM on the dynamic response of the middle ear is simulated through the method of numerical simulation. Result Through comparing experimental data and the frequency-response curve of displacement of BM and stapes, the validity of the model in this paper was verified. Conclusion Regarding sclerosis in BM, the most obvious decline of displacement and velocity exists in the range of 800–10,000Hz and 800–2000Hz frequency, respectively. The higher degree of sclerosis, the more obvious decline becomes. The maximal decline of hearing can reach from 6.2 dB to 9.1 dB. Regarding added mass in BM, the most obvious decline of displacement exists in the range of 600–1000Hz frequency, and the maximal decline of hearing can reach 4.0 dB. There is no obvious decline in velocity.

Polymer-Modified Liposomes for Drug Delivery: From Fundamentals to Applications.

Liposomes are highly advantageous platforms for drug delivery. To improve the colloidal stability and avoid rapid uptake by the mononuclear phagocytic system of conventional liposomes while controlling the release of encapsulated agents, modification of liposomes with well-designed polymers to modulate the physiological, particularly the interfacial properties of the drug carriers, has been intensively investigated. Briefly, polymers are incorporated into liposomes mainly using “grafting” or “coating”, defined according to the configuration of polymers at the surface. Polymer-modified liposomes preserve the advantages of liposomes as drug-delivery carriers and possess specific functionality from the polymers, such as long circulation, precise targeting, and stimulus-responsiveness, thereby resulting in improved pharmacokinetics, biodistribution, toxicity, and therapeutic efficacy. In this review, we summarize the progress in polymer-modified liposomes for drug delivery, focusing on the change in physiological properties of liposomes and factors influencing the overall therapeutic efficacy.

Enzyme production by soilborne fungal strains of Aspergillus niger isolated from different localities affected by mining

The research focused on the enzyme production/activity of sixteen Aspergillus niger strains isolated from different localities. The soils vary mainly in their pH value, which ranges from an ultra-acidic (< 3.5) to a very strongly alkaline (> 9.0) environment. Contamination caused by several centuries of mining activities at old mining sites persists at all the localities. The concentrations of toxic elements, such as As, Sb, Zn, Cu and Pb, very often exceed the common limit values. Presence of toxic elements in contaminated sites may affect microscopic fungi and cause changes of their physiology, including the production of different metabolites, such as enzymes. Production of esterase, cellulase, lipase and protease was investigated. Changes in physiological properties, such as the growth and enzymatic activity of the sixteen A. niger wild type strains, were determined. Esterase, cellulase and lipase activity was not determined in the sixteen strains tested. Considerable differences were recorded in the size of the colonies also within strains cultivated on the same nutrient medium. The control strain from locality Gabčíkovo formed the smallest colonies when tracking LA, EA and PA compared with the other strains. Lipase production was determined for several strains at different intensities and was highest in the strain isolated from the uncontaminated locality Gabčíkovo. The enzymatic activity of the other strains isolated from contaminated sites was very low. The achieved results confirmed the direct influence of environmental factors on the physiological properties of the studied strains of Aspergillus niger.

Rapid and Efficient Determination of Relative Water Contents of Crop Leaves Using Electrical Impedance Spectroscopy in Vegetative Growth Stage

Crop water stress is a deficiency in plants in water supply when the transpiration rate becomes higher than the water absorption capacity. The stress may be detected by a reduction in soil water content, or by the change in physiological properties of the crop. The leaf water content (LWC) is commonly used to assess the water status of plants, which is one of the indicators of crop water stress. In this work, the leaf relative water contents of four different crops: canola, wheat, soybeans, and corn—all in vegetative growth stage—were determined by a noninvasive tool called, electrical impedance spectroscopy (EIS). Using a frequency range of 5–15 kHz, a strong correlation between leaf water contents and leaf impedances was obtained using multiple linear regression. The trained dataset was validated by analysis of variance tests. Regression results were obtained using the least square method. The optimized regression model coefficients for different crops were proposed by selecting features using the wrapper backward elimination method. Multi-collinearity among the features was considered and individual T-tests were made in the feature selection. A maximum correlation coefficient (R) of 0.99 was obtained for canola compared to the other crops; the corresponding coefficient of determination (R2) of 0.98, an adjusted R2 of 0.93, and root mean square error (rmse) of 0.30% were obtained for 36 features. Therefore, the results show that the proposed technique using EIS can be used to develop a low-cost and effective tool for determining the leaf water contents rapidly and efficiently in multiple crops.

Effects of ethylene and 1-methylcyclopropene treatments on physiological changes and ripening-related gene expression of ‘Mopan’ persimmon fruit during storage

Abstract ‘Mopan’ persimmon (Diospyros kaki L. cv. Mopan) is an economically important persimmon cultivar that is widely grown in northern China areas. Expanded understanding of postharvest fruit physiological changes and the role that ethylene plays will enhance the efficiency of fruit storage and marketing. Treatments with ethylene and 1-MCP on ‘Mopan’ persimmons showed opposite effects on softening, color, total soluble solid (TSS), total and soluble tannin contents, ethylene production and respiration rate during fruit storage. Ethylene and 1-MCP treatments also affected the expression of five ethylene signaling genes DkCTR1, DkETR1, DkETR2, DkERF22 and DkERF19, three de-astringent related genes DkADH1, DkPDC1 and DkPDC2, and four cell wall-hydrolyzing enzyme genes DkPG1, DkXTH2, DkPME1 and Dkβ-GAL1 during fruit storage. High correlations were observed between ethylene signal pathway genes, physiological characters and ripening related gene expression. The results indicate that ethylene greatly accelerate fruit ripening, and the ripening process can be inhibited by 1-MCP treatment both on physiological and molecular levels. The application of 1-MCP delayed seven to ten days on fruit ripening compared to controls. The overall information obtained from this study demonstrates that ethylene plays the critical roles in postharvest ripening, gene expressions and physiological property changes of ‘Mopan’ persimmon fruit during storage. The suppression of ethylene activity by 1-MCP provides the industry with an applicable technology to improve postharvest processing and ‘Mopan’ persimmon fruit value.

Comparative Study of Ripening Related Gene Expression and Postharvest Physiological Changes between Astringent and Nonastringent Persimmon Cultivars

‘Mopan’ persimmon (Diospyros kaki Thunb.) is a traditional astringent cultivar of persimmon and ‘Yoho’ persimmon (D. kaki) is a newly introduced Japanese nonastringent type of cultivar in northern China. Studies were conducted to investigate the physiological changes and expression of ripening-related genes in the postharvest process at different periods under the effects of endogenous ethylene in both cultivars. Persimmons were harvested and stored under room temperature for 20 days. An analysis of physiological changes showed significant differences between the two cultivars. Total soluble solids declined in ‘Mopan’ fruit, whereas those in ‘Yoho’ fruit increased during storage. Firmness, color, index of absorbance difference, total and soluble tannin contents, ethylene production, and respiration rates showed the same trend, but these values vary by cultivar. ‘Mopan’ fruit softened rapidly after harvest and attained edible quality in 20 days, with an increased rate of softening accompanied by increased expression of ripening-related genes. In contract, ‘Yoho’ fruit softening occurred slowly and did not soften even after 20 days, with minimal accumulation of the ripening-related genes. The information obtained from this study demonstrates that cell wall-hydrolyzing enzymes, the de-astringent process, and endogenous ethylene have critical roles in postharvest ripening, gene expression, and physiological property changes of ‘Mopan’ and ‘Yoho’ persimmon fruit during storage.

Study of the cell wall components produced during different ripening stages through thermogravimetric analysis

Fruit softening during ripening is mainly a consequence of the solubilization and depolymerization of cell wall components mediated by the action of a complex set of enzymes and proteins. In the present work, we performed a comparative study of the changes in physiological properties and cell wall-associated polysaccharide contents during different developmental stages of strawberry fruit (Fragaria × ananassa Duch. cultivar Camarosa) using thermogravimetry (TG) combined with Fourier transform infrared and physiological analyses. The Camarosa cultivar showed a decline in the fruit firmness, based on the TGA curves was demonstrated the degradation of the cell wall polymers. Additionally, the TG analysis showed that the dry sample derived from the green stage fruit had the greatest thermal stability, most likely due to the increase in inter-chain hydrogen bonding within the cell wall, while the sample derived from the ripe stage fruit had the least thermal stability. Finally, the existence of a correlation between fruit firmness and mass loss at specific temperatures, that provides a basis for a model for understanding the changes within the cell wall in F. × ananassa during fruit ripening.

The ratio of single-turnover to multiple-turnover fluorescence varies predictably with growth rate and cellular chlorophyll in the green alga Dunaliella tertiolecta.

Marine phytoplankton experience a wide range of nutrient and light conditions in nature and respond to these conditions through changes in growth rate, chlorophyll concentration, and other physiological properties. Chlorophyll fluorescence is a non-invasive and efficient tool for characterizing changes in these physiological properties. In particular, the introduction of fast repetition rate fluorometry (FRRf) into studies of phytoplankton physiology has enabled detailed studies of photosynthetic components and kinetics. One property retrieved with an FRRf is the 'single-turnover' maximum fluorescence (FmST) when the primary electron acceptor, Qa, is reduced but the plastoquinone (PQ) pool is oxidized. A second retrieved property is the 'multiple-turnover' fluorescence (FMT) when both Qa and PQ are reduced. Here, variations in FmST and FMT were measured in the green alga Dunaliella tertiolecta grown under nitrate-limited, light-limited, and replete conditions. The ratio of FmST to FMT (ST/MT) showed a consistent relationship with cellular chlorophyll in D. tertiolecta across all growth conditions. However, the ST/MT ratio decreased with growth rate under nitrate-limited conditions but increased with growth rate under light-limited conditions. In addition, cells from light-limited conditions showed a high accumulation of Qb-nonreducing centers, while cells from nitrate-limited conditions showed little to none. We propose that these findings reflect differences in the reduction and oxidation rates of plastoquinone due to the unique impacts of light and nitrate limitation on the stoichiometry of light-harvesting components and downstream electron acceptors.

English

The changes in physiological properties and leaf ultrastructures caused by early nitrogen application for potatoes under drought stress were explored. Potato variety Chuanyu117 was used to conduct a controlled experiment in a sand medium. Nutrient solution treatments (0.84, 1.26, 1.68 and 2.10) were administered, followed by severe drought, moderate drought, and normal (control) water treatments (45, 60, and 75% of soil saturation moisture capacity) in the seedling stage of potatoes. Early additional nitrogen application maintained chlorophyll content in potato leaves under drought stress and increased activities of protective enzymes in the plants. Severe and moderate drought stress treatments resulted in the smallest reductions in chlorophyll content compared with the control and largest increases in POD and CAT activities. Under the same water conditions, potato with high nitrogen treatment (1.68 g N L-1) had significantly higher net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and intercellular CO2 concentration (Ci) than other nitrogen treatment levels; the highest levels of these photosynthetic parameters were obtained under the normal water condition. As drought stress increased, the degree of damage to chloroplasts and mitochondria in potato leaves gradually increased and the number of starch grains increased; however, with increases in the nitrogen application level, the degree of damage to chloroplasts and mitochondria gradually decreased. Early additional nitrogen application had mitigative effects on the damage to cellular structures of potato leaves under drought stress and could improve gas exchange and increase absorption and utilization of light energy in potato leaves. Further, the adaptive capacity of photosynthetic structures in potato leaves increased, leading to greater drought resistance in potato. However, with increases in the nitrogen levels, drought resistance of potato showed an initially increasing trend that decreased subsequently, suggesting that over-application of nitrogen reduced drought resistance in potato. &nbsp; Key words: Early nitrogen application, drought stress, physiological properties, photosynthetic parameters, ultrastructure.

Investigations on the Timing of Fruit Infection by Fungal Pathogens Causing Fruit Rot of Deciduous Holly.

Fruit rot of deciduous holly is an emerging fungal disease that is affecting plant production across midwestern and eastern U.S. nurseries. To determine the growth stage(s) of host susceptibility to infection by the major pathogens associated with the disease, Alternaria alternata and Diaporthe ilicicola, and minor pathogens such as Colletotrichum fioriniae and Epicoccum nigrum, we conducted two sets of experiments over two consecutive seasons. In the first case we monitored the presence of the pathogens as well as disease progression in a commercial nursery under natural conditions by collecting plant tissues from the flower bud stage until fruit maturity. The target pathogens were consistently isolated from asymptomatic samples at all stages of fruit development and from symptomatic samples at fruit maturity across the 2 years of collection. A significant increase in fungal isolation frequency, primarily species of Alternaria and Colletotrichum, was observed right after flowering, but fruit rot symptoms only developed on mature fruit. In the second case we artificially inoculated containerized plants maintained outdoor at our research farm with individual or combined pathogens at different fruit developmental stages, and we assessed disease incidence on mature fruit to determine the time of host susceptibility to infection and, indirectly, whether pathogens in the fungal complex carry out latent infections. D. ilicicola could cause latent infection on deciduous holly fruit when inoculated at the full bloom and petal fall stages, and all inoculations made on wounded mature fruit resulted in fruit rot. These findings suggest that flowering represents a critical period to manage D. ilicicola infections and that mature fruit should be protected from any injury to avoid disease. In both experiments a negative correlation between disease incidence and temperature was found; however, the decrease in temperature also coincided with fruit ripening. The effects of temperature and changes in physiological properties of the fruit during maturation on disease development should be further investigated to fully interpret these findings.

Desensitizing mouse cardiac troponin C to calcium converts slow muscle towards a fast muscle phenotype.

The Ca2+ -desensitizing D73N mutation in slow skeletal/cardiac troponin C caused dilatated cardiomyopathy in mice, but the consequences of this mutation in skeletal muscle were not known. The D73N mutation led to a rightward shift in the force versus pCa (-log [Ca]) relationship in slow-twitch mouse fibres. The D73N mutation led to a rightward shift in the force-stimulation frequency relationship and reduced fatigue resistance of mouse soleus muscle. The D73N mutation led to reduced cross-sectional area of slow-twitch fibres in mouse soleus muscle without affecting fibre type composition of the muscle. The D73N mutation resulted in significantly shorter times to peak force and to relaxation during isometric twitches and tetani in mouse soleus muscle. The D73N mutation led to major changes in physiological properties of mouse soleus muscle, converting slow muscle toward a fast muscle phenotype. The missense mutation, D73N, in mouse cardiac troponin C has a profound impact on cardiac function, mediated by a decreased myofilament Ca2+ sensitivity. Mammalian cardiac muscle and slow skeletal muscle normally share expression of the same troponin C isoform. Therefore, the objective of this study was to determine the consequences of the D73N mutation in skeletal muscle, as a potential mechanism that contributes to the morbidity associated with heart failure or other conditions in which Ca2+ sensitivity might be altered. Effects of the D73N mutation on physiological properties of mouse soleus muscle, in which slow-twitch fibres are prevalent, were examined. The mutation resulted in a rightward shift of the force-stimulation frequency relationship, and significantly faster kinetics of isometric twitches and tetani in isolated soleus muscle. Furthermore, soleus muscles from D73N mice underwent a significantly greater reduction in force during a fatigue test. The mutation significantly reduced slow fibre mean cross-sectional area without affecting soleus fibre type composition. The effects of the mutation on Ca2+ sensitivity of force development in soleus skinned slow and fast fibres were also examined. As expected, the D73N mutation did not affect the Ca2+ sensitivity of force development in fast fibres but resulted in substantially decreased Ca2+ sensitivity in slow fibres. The results demonstrate that a point mutation in a single constituent of myofilaments (slow/cardiac troponin C) led to major changes in physiological properties of skeletal muscle and converted slow muscle toward a fast muscle phenotype with reduced fatigue resistance and Ca2+ sensitivity of force generation.

Cell wall-related enzymatic activities and transcriptional profiles in four strawberry ( Fragaria x ananassa ) cultivars during fruit development and ripening

Abstract Fruit softening during ripening is mainly a consequence of solubilization and depolymerization of cell wall components mediated by the action of a complex set of enzymes and proteins. In the present work, we performed a comparative study of the changes in physiological properties, cell wall-associated polysaccharide contents and expression of cell wall-related genes during different fruit developmental stages of four strawberry (Fragaria x ananassa Duch.) cultivars (Camarosa, Cristal, Monterey, and Portola). The four cultivars showed different fruit firmness values being Camarosa and Cristal the firmest, Monterey the softest, and Portola with an intermediate value between them. Additionally, in order to obtain a correlation between mRNA transcriptional levels and fruit firmness with physiological properties, we have analyzed the abundance of five mRNAs (FaEXPA2, FaEXPA4, FaXTH1, FaXTH2 and FaPG1). We have found a correlation between fruit firmness and mRNA abundance levels for FaEXPA2, FaEXPA4, FaXTH1 and FaPG1. For these four mRNAs we have observed higher transcript levels in the softest cultivar (Monterey) than in the other two firmer cultivars (Cristal and Camarosa) at the 50% ripe or ripe stage. Finally, the results showed that exist a correlation between cell wall-modifying enzymes, physiological properties and firmness, which would explain the fruit softening process that reduces post-harvest life.

Changes in Polyphenolic Content and Antioxidant Activity of Grapes cv Vranac During Ripening

This study characterised and evaluated the phenolic composition and antioxidant activity of the red wine grape Vranac (Vitis vinifera L.) from the southern Serbian vineyard region during grape ripening. Polyphenol composition at different harvest dates was determined by HPLC-DAD analysis. Antioxidant activity was estimated by DPPH assay. The study demonstrates that the Vranac variety represents important sources of dietary antioxidants. The results show that (+)-catechin, (-)-epicatechin and procyanidin dimer B2 were the most prevalent in the seeds, and quercetin and malvidin glucosides in the grape skins. All grape extracts were shown to have high radical-scavenging activity. Strong correlations between radical-scavenging activity and polyphenols suggest that the phenolic composition of the Vranac variety contributes significantly to the antioxidant capacities of grape extracts. During grape ripening there were significant changes in physiological properties and phenolic content, and it is important to determine optimal harvest time, which will ensure grapes with very good quality parameters (in our study at the 30th day after veraison).

Exercise and gait training in persons with paraplegia and its effect on muscle properties.

Upper extremity strengthening and gait training with orthoses form a major part of inpatient rehabilitation of paraplegic patients in developing countries. This helps to overcome architectural barriers and limited wheelchair accessible environment in the community. To evaluate the changes in physiological properties of the Triceps Brachii muscle following exercise training in individuals with paraplegia. The authors also explored the correlation between muscle property changes and gait parameters using orthoses in paraplegic persons. Twelve subjects with complete paraplegia and neurological level of injury (NLI) from T9 to L1, underwent exercise training for a mean 64.1 ± 4.1 days. Triceps brachii was chosen as the sample muscle. Variables like arm circumference, time to fatigue and mean power frequency (MF) (surface EMG parameter), were recorded at the beginning and the end of training, during a sub-maximal isometric elbow extension. Non-parametric tests were used to assess statistical significance between the two recordings. Additionally, gait parameters like walking speed and distance (with the help of orthoses) were obtained and compared with the above variables, to determine impact of upper extremity strengthening on gait improvements in such patients. Statistically significant changes were noted in bilateral arm circumferences (p= 0.003 bilaterally) and MF drop, expressed as percentage (right p= 0.04, left p= 0.01), indicative of better muscle resilience and adaptation. Significant positive correlation was observed between `time to fatigue' and the orthoses-aided total walking distance (right ρ = 0.65, left ρ = 0.69). Exercise training induces noticeable changes in the muscles of upper extremities favoring better muscle adaptation. Furthermore, positive correlation between `time to fatigue' and (orthotic) aided walking distance highlights the positive impact of strengthening program on gait parameters in paraplegic patients. These findings are important and relevant in developing countries with environmental barriers. Upper extremity strengthening should be included in the rehabilitation of paraplegic patients who are being trained for ambulation with orthoses.

Physiological Tissue Response to Various Ablative Modalities1

Physiological Tissue Response to Various Ablative Modalities1

Changes in the photosynthetic efficiency of winter wheat in response to abiotic stress

Abstract The assessment of heat and drought tolerance is of primary importance in breeding programmes designed to improve heat and drought tolerance in cereals. Three winter wheat varieties grown in controlled growth chambers were exposed to heat (H) and drought (D) stress singly and in combination (H+D). The combined effects of H and D stress were much more severe than those of individual treatments for both physiological and yield parameters during grain filling. The chlorophyll content, effective quantum yield of PSII, net assimilation rate, transpiration, stomatal conductance and intercellular CO2 concentration were greatly reduced by H, D and their interaction. Grain yield decreased to a greater extent (48.3%) in Plainsman V, averaged over the stress treatments, than in Mv Magma (67.8%) and Fatima 2 (53.7%). The least decline was found in grain number, except in Plainsman V. Mv Magma tolerated heat stress better than Fatima 2. In terms of photosynthetic activity, Plainsman V showed better drought tolerance than Mv Magma. The results showed that changes in physiological properties during stress treatment are not always associated with changes in yield parameters, so a combination of methods may be needed to give a more precise picture of the stress tolerance of wheat varieties.

Impact of cold plasma on Citrobacter freundii in apple juice: Inactivation kinetics and mechanisms

Various studies have shown that cold plasma is capable of inactivating microorganisms located on a variety of food surfaces, food packaging materials and process equipment under atmospheric pressure conditions; however, less attention has been paid to the impact of cold plasma on microorganisms in liquid foodstuffs.The present study investigates cold plasma's ability to inactivate Citrobacter freundii in apple juice. Optical emission spectroscopy (OES) and temperature measurements were performed to characterise the plasma source. The plasma-related impact on microbial loads was evaluated by traditional plate count methods, while morphological changes were determined using scanning electron microscopy (SEM). Physiological property changes were obtained through flow cytometric measurements (membrane integrity, esterase activity and membrane potential). In addition, mathematical modelling was performed in order to achieve a reliable prediction of microbial inactivation and to establish the basis for possible industrial implementation.C. freundii loads in apple juice were reduced by about 5 log cycles after a plasma exposure of 480s using argon and 0.1% oxygen plus a subsequent storage time of 24h. The results indicate that a direct contact between bacterial cells and plasma is not necessary for achieving successful inactivation. The plasma-generated compounds in the liquid, such as H2O2 and most likely hydroperoxy radicals, are particularly responsible for microbial inactivation.

Attenuation coefficients and absorbed gamma radiation energy of different varieties of potato, mango and prawn at different storage time and physiological condition

Attenuation coefficients of different varieties of gamma irradiated potato (Kufri Chandramukhi, Kufri Jyoti, and Kufri Sindhuri), mango (Himsagar, Langra, Dashehri and Fazli) and prawn (Tiger prawn and Fresh water prawn) of different storage time and physiological stages were determined. After six months storage attenuation coefficient of Kufri Chandramukhi was decreased by 30.8% with decrease of density and moisture content. Decreasing trend of attenuation coefficient during storage was more prominent (almost 50%) in other two varieties of potato. On the other hand in all four varieties, unripe mango consisted of significantly less (p⩽0.05) attenuation coefficient (around 11–14%) than the ripe one due to changes in physiological properties and density. Different varieties of prawn had different attenuation coefficients due to subtle differences in their proximate composition. Due to having different attenuation coefficients, different food components, even different varieties of same food component absorbed different gamma radiation energy though exposed to same radiation dose.