Days Of Storage Period Research Articles

Study on effect on water activity, TBA number and protein of dried chicken meat during storage

The present experiment was envisaged to evaluate the effect of packaging methods and treatments and storage time on protein content, TBA number and water activity of dried chicken meat throughout storage period. Dehydrated chicken meat with sodium nitrite treatment was prepared by high velocity hot air drying at temperature of 55 o C and air velocity of 5.5 m/s. Protein content, TBA number and water activity were determined after 15 days interval during storage of 150 days. Effect of packaging methods and treatments and storage time of dried chicken meat observed significant (P<0.05) in all cases. Protein, TBA number and water activity of vacuum packaged sample were found significantly higher (P<0.05) than conventional packaged and sodium chloride plus sodium nitrite treated chicken meat (treated sample) were detected significantly higher (P<0.05) than sodium chloride treated only (raw sample). Protein content were found decreased both in vacuum as well as conventional packaged sample throughout storage but TBA number and water activity were found increased significantly (P<0.05) during storage in all cases. The dried chicken meat was acceptable at the 150 days of storage period.

Metabolomic profiling highlights oxidative damages in platelet concentrates treated for pathogen inactivation and shows protective role of urate

Research in transfusion medicine is motivated by the desire to deliver the most-compatible and most-efficient blood product to the patient. It is now well accepted that ex vivo platelet concentrates (PCs) experience biochemical alterations and a functional decline known as storage lesions. Photochemical treatments have been introduced to secure PCs against pathogens but are reported to accelerate these lesions. The objective of this study was to investigate metabolic changes in stored PCs treated for pathogen inactivation with the INTERCEPT Blood system (Cerus, Concord, USA). PCs either untreated (uPCs) or INTERCEPT-treated (iPCs) were sampled along the 7-day storage period. First, metabolites were extracted and analyzed using ultra-high pressure liquid chromatography—high resolution mass spectrometry followed by statistical analysis. Secondly, we investigated the role of urate, a major plasma antioxidant, in the platelet function using flow cytometry-based assays. We observed oxidative damages in stored iPCs compared to uPCs, in particular alteration of the purine and the glutathione metabolism. We showed diminution of antioxidant defenses following INTERCEPT treatment such as the conversion of urate to allantoin, only possible in humans under the action of reactive oxygen species (ROS). Functional assays on platelets in absence or in an excess of urate suggest a protective role of urate in PCs. Our results indicate oxidative damages occurring at the metabolic level in stored iPCs. Understanding better the role of antioxidants such as urate in ex vivo PCs would definitively provide new insights to ameliorate the storage conditions and preserve the functionality of platelets.

Influence of preharvest nano calcium applications on postharvest of sweet pepper (Capsicum annum)

Abstract. Amini F, Bayat L, Hosseinkhani S. 2016. Influence of preharvest nano calcium applications on postharvest of sweet pepper (Capsicum annum). Nusantara Bioscience 8: 215-220. The effect of preharvest nano calcium treatment on the quality, physicochemical parameters and antioxidative enzyme activities of sweet pepper fruits were evaluated. For this purpose, sweet pepper plants treated with three concentrations (0, 4 and 8 g/L) of nano calcium in five steps (50, 60, 70, 80 and 90 days after pepper planting). 100 days after pepper planting, fruits were harvested and packaged in plastic bags and stored at 20±3 0C, then total soluble solids, pH, weight loss, carotenoids, electrolyte leakage, lipid peroxidation, titrable acidity, ascorbic acid, chlorophyll, calcium, protein and the activities of total antioxidant enzymes, catalase, and guaiacol peroxidase were evaluated at 0, 7, 14 and 21 days of storage period. Nano calcium treated fruits had lower levels of total soluble solids, pH, weight loss, carotenoids, electrolyte leakage, lipid peroxidation and higher levels of titrable acidity, ascorbic acid, chlorophyll, calcium and protein compared to the control plants. The increase percentage of titrable acidity, ascorbic acid, chlorophyll a, chlorophyll b, total chlorophylls, calcium and protein contents in plants treated with 4 g/L nano calcium and 21 days storage period were calculated 68.86%, 41.89%, 81.17%, 78.57%, 80.81%, 21.46% and 83.30% respectively. The maximum activities of total antioxidant enzymes, catalase and guailcol peroxidase were observed in 21 days control plants that application of nano calcium decreased these antioxidant activities. In most parameters 4 g/L concentration was more effective. Therefore, commercial application of preharvest nano calcium (4 g/L) can be considered for the maintenance of quality of sweet peppers during storage and marketing.

전처리 방법을 달리한 곰취 인절미의 제조법 표준화 연구

In this study Ragwort, which had various and excellent pharmacological activity, was selected as a functional material, and intended to present an optimum condition of Ragwort Injeolmi by the blanching method, commonly used in the field. The general components, antioxidation, and dietary fiber of Ragwort were analyzed, and produceableness of Ragwort added Injeolmi was reviewed through instrumental inspection and sensory evaluation of various adding ratio of lyophilized Ragwort power and Ragwort pre-processed by blanching. It was proved that the SOD-likely active of Ragwort was 45.69%, total poly- phenol content was 12.45 mg, and total flavonoid content was 10.25 mg. The pH of Injeolmi adding Ragwort powder showed an increasing trend in the order of 0%, 1%, 3%, 5%, while that of Injeolmi adding blanching Ragwort showed increasing trend in the order of 0%, 10%, 15%, 20%, and there were significant difference (p<0.001). The soluble solid content of all sample groups showed constant value, and it was understood that no sugar was added in the process. From chromatography measurement result, a-value (redness) of 1% sample group was the lowest, and there were significant differences among sample groups (p<0.001). During 3 days of storage period, total microbial count of Injeolmi showed increasing trend while the storage period was getting longer. From the acceptability test Injeolmi adding blanching Ragwort had shown generally higher value.

Quality assessment and shelf life prediction of spray dried tamarind pulp powder in accelerated environment using two different packaging materials

Tamarind pulp powder (TPP) was produced using optimum spray drying conditions, packed in two different packaging materials viz., aluminium laminated polyethylene (ALP) and 4-ply laminate pouches (polythene-aluminium-polythene-paper) and stored under accelerated conditions (40 ± 1 °C temperature, 90 % relative humidity). The powder was analyzed for various quality parameters (moisture content, color, acidity, and powder flowability) at an interval of 7 days upto 70 days of storage period. Both packaging material and storage period showed significant effect on the powder properties. Kinetic study of color change of tamarind pulp powder during storage revealed that color change followed zero order reaction kinetics with a rate constant of 0.495 and 0.369 for the powder packed in ALP and 4-ply laminate, respectively. The magnitude of quality changes of TPP measured during accelerated storage suggested that 4-ply laminate was better than ALP for long term storage of spray dried TPP. The shelf life of TPP under accelerated storage condition was predicted on the basis of flowability of the powder and was calculated to be 53 and 66 days in ALP and 4-ply laminate, respectively.

Effects of gamma irradiation on the shelf-life of frozen tiger shrimp, Penaeus monodon (Fabricius, 1798)

The effects of three levels of irradiation (3, 6 and 9 KGy) during storage period (0, 15, 30, 45, 60, 75 and 90 days) were evaluated in frozen tiger shrimp, Penaeus monodon. Biochemical composition was analyzed before and after treatment. Quality of tiger shrimp was assessed through organoleptic, chemical (Total Volatile Nitrogen, TVN and Trimethylamine, TMA) and microbiological (Total Bacterial Count (TBC); Total Mold Counts (TMC); Total Yeast Count, (TYC); Total Coliform Count, (TCC) and Salmonella count) evaluation at an interval of 15 days during the storage period. High doses of radiation affected on the texture of fish. While, the maximum shelf life was observed for 9 KGy irradiated sample. All the samples were acceptable during 90 days of storage period because the upper limit of all spoilage indicators did not exceed the recommended values.International Journal of Natural Sciences (2014), 4(1) 10-15

Quality comparison of elephant apple juices after high-pressure processing and thermal treatment.

In the present work, the effect of high pressure processing (HPP) on the quality parameters (pH, °Brix, total acidity, viscosity, colour, antioxidant activity, total phenols, total flavonoids, microbial flora, and sensory analysis) of elephant apple (Dillenia indica) juice was investigated. The juice samples were analysed periodically (0, 1, 2, 5, 10, 20, 30, 40, 50 and 60 days) during 60 days of storage period and results were compared with thermally processed as well as with untreated (fresh juice) samples. Slight variations had been observed in the quality parameters like pH, °Brix and total acidity. Other parameters like colour values, antioxidant activity, total phenols and total flavonoids were varied significantly (P < 0.05) in between the treated (HPP and thermal) and untreated juice samples. The microbial counts of the HPP treated samples were lower than the other samples. Sensory results also showed similar results to those of the other analyses that the treated samples were better for consumption rather than the untreated samples. The shelf-life of the HPP processed elephant apple juice was established as 60 days at 4 °C. This study showed that application of HPP effectively maintained quality attributes and extended shelf life of the elephant apple juice. It may be suggested that application of HPP could be considered for commercial application during storage and marketing. © 2016 Society of Chemical Industry.

The effects of different pre-packaging treatments on the quality of kumquat fruit

ABSTRACTThis study aimed at determining the combined effect of pre-packaging treatments. Two surface disinfection (chlorinated and anolyte water), hot water and biocontrol treatments were used. The decay incidence, physiological weight loss (PWL), peel colour, firmness, moisture content (MC) and total soluble solids (TSS) were investigated on kumquat infected with green and blue mould. Fruit subjected to combined treatments displayed better quality, compared to individual treatments. Fruit treated with an integrated treatment of anolyte water, hot water and biocontrol displayed no visible mould growth, the least variation in peel firmness and the least reduction in MC during the 28-day storage period. Chlorinated water only produced the highest decay (13.62%) while fruit subjected to anolyte water only displayed the lowest decay (4.08%) by Day 28. Based on the results, it is recommended that the integration of anolyte water, hot water and biocontrol were among the most effective treatments in maintaining fruit quality.

Evaluation of edible polymer coatings enriched with green tea extract on quality of chicken nuggets.

Aim:The present study was conducted to evaluate the physico-chemical and microbiological characteristics of chicken nuggets coated with sodium alginate (SA) coatings at refrigerated (4±1°C) and frozen (−18±1°C) storage condition at regular periodic intervals.Materials and Methods:Chicken meat nuggets were separated into three groups: Uncoated control (C), coated with alginate coating (T1), and coated with alginate coating incorporated with 1% green tea extract (GTE) (T2). The nuggets were analyzed at regular intervals of 5days for refrigerated storage and 15 days for frozen storage period in terms of pH, 2-thiobarbituric acid value (TBA), peroxide value (PV), total plate count (TPC), water loss, and sensory characteristics.Results:The results indicated that the nuggets coated with alginate-based coatings effectively reduced the spoilage as indicated by pH, TBA, and PVs. pH values of the formulations ranged from 6.15 to 6.34 at refrigerated storage temperature (4±1°C) and 6.49-6.71 at frozen storage temperature (−18±1°C). TBA value of the treatments ranged from 1.28 to 1.54 mg MDA/kg and 1.34 to 1.50 mg MDA/kg under refrigerated and frozen storage temperatures, respectively. Color, flavor, juiciness, tenderness, and overall acceptability of the nuggets differed significantly (p<0.05) with the coated nuggets. The coated nuggets were well acceptable upto 15 days at refrigerated storage temperature (4±1°C) and upto 75 days at frozen storage temperature (−18±1°C). Nuggets coated with GTE incorporated coating solution had a lower TBA-reactive substances values, PVs, and TPCs when compared to the nuggets coated with SA and the control group.Conclusion:Study revealed that incorporation of edible coatings with antioxidants, namely, GTE at 1% level had a significant effect in reducing the fat oxidation. The samples recorded a shelf life of 15 days under refrigerated storage when compared to their controls with 10 days of storage period and 75 days under frozen storage against controls with 60 days. T1, T2, and T3 formulations had higher sensory scores in comparison to the controls. Overall acceptability scores of T1 were higher when compared to the other formulations.

Reduction of bacteria and human immunodeficiency virus Type 1 infectivity of platelet suspension in plasma using xenon flash-pulse light in a bench-scale trial.

Current pathogen reduction systems for platelet concentrates (PCs) require addition of chemical compounds and/or reduction of plasma content in PCs. We have investigated a new method using xenon (Xe) flash-pulse light without additional compounds or plasma replacement. An aliquot of apheresis platelets (PLTs) in plasma inoculated with bacteria or human immunodeficiency virus Type 1 (HIV-1) was irradiated with Xe flash-pulse light (Xe flash phototreatment). Bacterial growth was monitored up to 6 days of storage, whereas HIV-1 infectivity was assayed just after treatment. Pairs of Xe flash-phototreated and untreated PCs were examined for PLT lesion during the storage period. Under the current conditions, a low titer (1.8 colony-forming units [CFUs]/mL) of Staphylococcus aureus did not proliferate during the 6-day storage period, but grew in some cases at high-titer (24.0 CFUs/mL) inoculation. HIV-1 infectivity was reduced by 1.8 log. PLT recovery of the treated PCs was lower than untreated ones. An increase of mean PLT volume and glucose consumption, together with a decrease of hypotonic shock response and pH, were enhanced by the treatment. CD62P- and PAC-1-positive PLTs increased after the treatment, indicating the induction of PLT activation. Among biologic response modifiers, soluble CD40 ligand was significantly increased in the treated PCs on Day 6. Xe flash phototreatment could prevent bacterial proliferation and reduce HIV-1 infectivity in 100% plasma PCs without any additional compounds, but enhanced PLT storage lesions. Further improvement is required to increase the potency of pathogen inactivation with reducing PLT damage.

Effect of different potato varieties and tuber sizes on physiological changes under ambient storage performance

The storability and sprouting behavior of three grades (small, medium and large tubers) from four Indian potato cultivars was studied under ambient conditions to assess the quality changes due to physiological losses and sprouting bhaviour of potato tubers. It was found that physiological loss in weight (%), decay loss on number and weight basis (%), sprout loss on number and weight basis (%), total loss (%), general appearance, presence of black or hollow heart were affected significantly by the different varieties as well as by the size. The loss in weight of tubers due to physiological activities, decaying and sprouting increased with the increased in storage period and the loss was more in larger than smaller and medium tubers. Kufri Badshah showed the best control over sprouting, whereas, 100% sprouting was observed in Kufri Bahar with all possible combinations during storage. The maximum value for cumulative physiological loss in weight was observed in variety Kufri Bahar (12.07%), whereas, minimum was in Kufri Pushkar (7.44%). The maximum decay loss was observed in variety Kufri Pushkar (7.89 and 8.72%) and minimum in Kufri Bahar (0.00 and 4.58%) on 80th and 90th day of storage period. Black or hollow heart was absent completely in all the possible treatments. So far general appearance of the tubers was concerned, the larger tubers shrivelled more and earlier than the medium and small sized tubers. Different varieties behaved differently during the entire storage period.

Effect of composite edible coating from gelatin and glycerol triacetate on prolonging shelf life of refrigerated strawberry

Postharvest treatments of strawberries are necessary to maintain high quality of the product for longer periods, to reduce postharvest losses and to add quality value .The ability of three solution of edible films (6%gelatin-6%gelatin with 10% glycerol triacetate - 6%gelatin with 20% glycerol triacetate), to extend the shelf-life of strawberry fruit over 12 days was studied. Strawberries were immersed in the films solutions for 1 minute and after coated were dried at 15 ºC for 24 hours. The strawberries were then kept under refrigeration .The quality of coated and non-coated strawberries was evaluated by weight loss , titratable acidity, total soluble solids and total sugar concentration ,vitamin C and visible decay during over a 12-day storage period. Results showed that the merge of fat material with gelatin films extend shelf-life of strawberries and keep the quality of the strawberries during storage, when compared with control fruits, but it did not delay of visible decay during refrigerated storage.

Tomato Fruit Marketability, Blossom-End Rot Incidence and Quality as Affected by Different Calcium Sources and Time of Application Under Calcareous Soil

Two field experiments were carried out during the winter seasons of 2011/2012 and 2012/ 2013 at The Experimental Farm of The Faculty of Environmental Agricultural Sciences, El-Arish, Suez Canal University, North Sinai Governorate, Egypt. The experiment aimed to study the effect of spraying tomato plants (Solanum lycopersicum) GS 12 cv. with different calcium sources (calcium chloride, calcium carbonate and calcium chelate as well as without calcium) at different times of application, viz, T1: spraying one time at full blooming, T2: spraying one time after 15 days from T1, and T3: spraying two times at T1 + T2 on marketable yield, unmarketable yield (expressed as fruits infected by blossom end rot (BER)), and quality of fruits after 10 days of beginning the storage period. Plants were grown under low tunnels. Spraying tomato plants with Ca+ as CaCl2 or CaCO3 and other Ca sources increased the marketable yield/ fed. , and also increased fruit shelf life period expressed as decreasing in fruit weight loss and increasing fruit firmness. Foliar application of CaCl2 recorded the lowest values of lycopene contents in both seasons. Time of calcium application did not reflect any significant effect on both marketable and nonmarketable yield as well as marketability (%) and BER incidence (%), and almost pH and TSS values. Application of T3 increased the fruit contents of vitamin C (V.C), while using T2 decreased the content of lycopene. All interaction treatments with control (without application of calcium) decreased marketable yield, marketability (%), but it increased unmarketable yield, BER incidence (%), fruit weight loss and TSS in the 2nd season. Therfore, spraying tomato plants grown under low tunnels in calcareous soil with Ca in different sources had positive effects on both marketable yield and blossom-end rot incidence, total yield, marketability%, BER% and on fruit quality after 10 days of storage period compared to control.

Microbial Vitality of Probiotic Milks Supplemented With Cereal or Pseudocereal Grain Flours

&lt;p&gt;Probiotic products containing &lt;em&gt;Lactobacillus rhamnosus&lt;/em&gt; GR-1 have been shown to help decrease the risk of urogenital infections, delay the decline of CD4 lymphocytes in patients with human immunodeficiency virus, and survive in the intestinal tract without stimulating immune or inflammatory responses. Cereal and pseudocereal grains can act as prebiotic agents and could be an economical way of improving the nutritional value, functional qualities, and overall health benefits of probiotic products. The purpose of this study was to measure the growth and survival of &lt;em&gt;L. rhamnosus&lt;/em&gt; GR-1 in fermented probiotic skim milk supplemented with a grain flour over a 28-day storage period. The objective was to determine if supplementation of the grain flours would have a positive effect on the microbial vitality of &lt;em&gt;L. rhamnosus&lt;/em&gt; GR-1 in the final product and during storage. Five probiotic skim milk samples supplemented with a grain flour were prepared: oat (3% weight to volume ratio), lentil (3% w/v), rice (3% w/v), barley (3% w/v), and quinoa (3% w/v) along with one control probiotic skim milk sample. Results showed that the oat, rice, barley and quinoa flours supported the growth of &lt;em&gt;L. rhamnosus&lt;/em&gt; GR-1 at viable levels (10&lt;sup&gt;8&lt;/sup&gt;CFU/mL) during the first 14 days of storage; however, only skim milk supplemented with rice flour sustained the growth over the 28-day storage period. Future studies should conduct a sensory evaluation of this fermented probiotic rice flour milk as well as study rice milk inoculated with probiotics to produce a dairy-free and possible gluten-free product.&lt;/p&gt;

Postmortem calpain changes in ostrich skeletal muscle

The objective of this study was to study the postmortem calpain change in ostrich muscle. Iliotibialis cranialis and Obturatorius medialis muscles were removed from the both sides of carcasses (n=8). The muscles from the left side were sampled after 0, 1, 2, 3, and 7days of storage at 5°C, while the right-side muscles were taken at 1-, 3-, and 7-day postmortem for shear force measurements. The results showed that the calpain-1 activity was not detected in ostrich muscle during the entire 7-day postmortem storage period, while the calpain-11 was. The unautolyzed calpain-11 activity decreased and the autolyzed calpain-11 activity increased with time postmortem. Desmin content and shear force did not change during postmortem storage although a minor degradation of desmin was observed. Therefore, our results suggest that limited postmortem proteolysis (as suggested by the limited degradation of desmin) and tenderization might be due to the lack of calpain-1 and/or insufficient calpain-11 activity present in ostrich muscle.

In vitro analysis of volume-reduced washed platelet concentrates stored in bicarbonated Ringer's solution containing less than 5% residual plasma.

Volume-reduced washed platelet (PLT) concentrates (PCs) can prevent circulatory overload and allergic reactions in patients undergoing PLT transfusions. For these reasons, they are in demand for paediatric settings and for patients at risk of circulatory overload. Here, we evaluated the quality of volume-reduced washed PCs stored for 5 days in a novel acetate-free PLT additive solution (PAS) containing glucose and bicarbonate (BRS-A) with <5% residual plasma protein. PCs from two apheresis donations were mixed and divided equally into control and test units. For the test unit (volume-reduced washed PCs), PLTs were washed and stored in 90 ml BRS-A with <5% plasma protein. PLTs in the control unit were stored in 200 ml 100% plasma without any washing manipulations. The in vitro properties of PLTs in both units were compared over a 5-day storage period. The procedure for volume-reduced washed PCs effectively removed >98% plasma protein in 100% plasma PCs and yielded an approximately twofold lower mean volume (91 ml) compared to that observed with the control units. Immediately after washing, the mean PLT concentration of the test units was 20·5 × 10(11) /l, twofold higher than that of the control units. The pH (37°C) levels in the test unit remained above 7·0 for 5 days. Glucose consumption and lactate production rates of the test units on days 1-3 were higher than those of the control units, leading to glucose exhaustion in the test unit by Day 3. Hypotonic shock responses and CD62P and CD42b expression levels in both units were comparable during 5-day storage. Considering the pH buffering capacity of BRS-A, a 90-ml volume may be acceptable for maintaining the in vitro quality of washed PLTs for at least 2 days.

Effect of Activating Lacto Peroxidase System (LPS) On Quality and Storage Stability of Soft Cheese

Utilization of intrinsic enzymatic activity to increase the quality and storage stability of food product is a novel biological and biochemical technique. The aim of present research was to minimize the microbial, physiochemical and protein degradation changes in soft cheese to enhance its quality and shelf life by activating lacto peroxidase system in raw buffalo milk and ultimately using it for cheese production and studying its quality and storage stability. For this purpose buffalo milk samples were collected from Diary Research Farm at University of Agriculture Faisalabad, Pakistan. In collected milk samples LPS was activated by equimolar concentration at 20 ppm of NaSCN and H2O2 and resulting samples were used for soft cheese production. Analysis at 0, 7, 14 and 21 days of storage period were conducted under 4oC. Collected data were analyzed by using one way analysis of variance under completely randomized design (CRD). Means were compared by using LSD test at probability level of p<0.05. Results showed minimum contamination in microbial count, especially bacteria of salt tolerant, at the end of 21 days storage period. Significantly lowered yeasts, molds, Coliform and bacterial count (p<0.05) were observed in LPS activated cheese samples as compared to other. Moreover, proteolysis results determined by Urea-PAGE gel electrophoresis for casein fractions extracted from the three samples showed lower value for LPS treated cheese sample in contrast to others samples. Hence, the present study supports the Lacto peroxidase system (LPS) as a quality-cum-economical preservative technique as compared to other techniques in practice.

Effect of Packaging Material and Storage Conditions on Quality of Beetroot Powder

Beetroot powder was prepared by pre-treating beetroot slices in the mixture of 5% salt and 72.76°Brix sugar at 50.59°C for 3h, and drying in cabinet dryer at 65°C and in microwave oven at 1080 W (optimized conditions), followed by grinding in laboratory mill and sieving with 30 mesh sieve. The time taken to bring the moisture content from 183.77 to 56.36% (db) by convective drying was 6 hours and from 56.36 to 4.65% (db) by microwave finish drying was about 6 min. The powder was stored upto 60 days of storage period in 150 gauge of high density polyethylene (HDPE) as well as laminated aluminum film packages (LAP) at room temperature and low temperature (5°C). Retention of less moisture content, water activity, minimum color degradation, browning index and better sensory characteristics was obtained in samples packed in laminated aluminium package of 150 gauge stored at 5°C. It implied that beetroot powder packed in LAP film packages can be best stored for long term storage under refrigerated conditions without any major loss in quality.

Physiological Changes in Red Onion Bulbs at Different Storage Temperature

Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polyethylene pouch at 2.5℃, 6℃, 7℃ and 13℃ for 60 days of storage period. Weight loss, total soluble solids (TSS), number of sprouted and rotten bulbs were measured at an interval of 10 days throughout storage. The greatest decrease (23.25%) in weight was observed throughout storage for onions stored at ambient conditions. TSS was observed to increase in all samples until 40 days of storage and then decreased up to 60 days. Lowest TSS (14.89 ?Bx) was found in onion stored at ambient conditions at the end of storage. Maximum sprouted (67.25%) and rotten (17.78%) onions were observed for onions stored at 13℃, whereas minimum sprouted and rotten onions were found at 2.5℃ at 60 days of storage. Results also recommend lowest temperatures (2.5℃ - 6℃) for prolong storage life of onion with no detrimental effects.

Prostate Cancer Biomarker Detection with Carbon Nanotubes Modified Screen Printed Electrodes

AbstractDNA hypermethylation is an epigenetic alteration and a promising biomarker for early prostate cancer detection. Simple, sensitive, easy to handle and rapid detection methodologies are imperative for point of care diagnostics especially for cancer. Herein, we describe for the first time a regenerable and compatible electrochemical biosensor for detection of Glutathione S‐Transferase P‐1 (GSTP‐1) gene hypermethylation related to prostate cancer via DNA hybridization onto the disposable Carbon and Multi Walled Carbon Nanotubes (MWCNT) Screen Printed Electrodes (SPEs). In the study, capture probes were adsorbed onto the SPEs by simple passive adsorption and then hybridization was achieved by sending the complementary target onto the probe‐modified electrodes. The selectivity of the biosensor was proved by control studies. Differential Pulse Voltammetry (DPV) technique was used to detect hybridization via guanine oxidation signals changes. The total time of the optimized method was nearly 1h, measurements took for less than 1 min, and the biosensor response was stable up to 40 days of storage period at 4 °C. The main advantages of the biosensor are very low detection limit (picomolar range) and capability of reusing the biosensor for at least 3 times after very simple regeneration process that is a unique property to reduce the cost of the assay. In addition, this is the first study that demonstrates the detection of GSTP‐1 hypermethylation electrochemically by using SPEs in order to create point of care diagnostics. The optimum parameters for the biosensor, as well as its future prospects to enhance the performance of DNA biosensors were also presented.