Publications by authors named "Nawaz Aamir"

14 Publications

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Combined application of ascorbic and oxalic acids delays postharvest browning of litchi fruits under controlled atmosphere conditions.

Food Chem 2021 Jul 10;350:129277. Epub 2021 Feb 10.

Department of Horticulture, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan.

The effect of ascorbic acid [AA (40 mmol L)] and oxalic acid [OA (2 mmol L)] on browning of litchi fruit was investigated under 5% CO + 1% O controlled atmosphere (CA) and compared with air at 5 ± 1 °C for 28 days. The combined application of AA and OA suppressed browning index, soluble quinones, and activities of polyphenol oxidase and peroxidase under CA compared with control. The combination of CA along with AA + OA reduced weight loss and maintained higher anthocyanins, total phenolics, membrane integrity, ascorbate peroxidase, catalase, glutathione reductase and superoxide dismutase activities compared with control. In addition, AA + OA + CA combination showed markedly lower malondialdehyde, superoxide anion and hydrogen peroxide with substantially higher soluble solids content, ascorbic acid, titratable acidity and sensory quality compared with control. In conclusion, AA + OA combination could be considered appropriate to delay browning and to conserve litchi fruit visual appearance under CA storage conditions.
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http://dx.doi.org/10.1016/j.foodchem.2021.129277DOI Listing
July 2021

Effect of gum arabic coating on antioxidative enzyme activities and quality of apricot (Prunus armeniaca L.) fruit during ambient storage.

J Food Biochem 2021 04 19;45(4):e13656. Epub 2021 Feb 19.

Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan.

The effect of gum arabic (GA) coating was studied on apricot fruit at 20 ± 1°C for 8 days. GA coating substantially reduced weight loss, disease incidence, malondialdehyde concentration, and hydrogen peroxide compared to the control. GA coating resulted in significantly higher total phenols, ascorbic acid, and antioxidant activity in contrast to the control. GA coating also suppressed cellulase, pectin methylesterase, and polygalacturonase activity in contrast to the non-coated fruit. In addition, GA-coated apricot fruit had substantially higher catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase enzymes activities in contrast with the control. Similarly, GA coating inhibited soluble solids content increase and inhibited the reduction in titratable acidity in coated fruit. The fruit coated with GA coating also had significantly better sensory and overall eating quality compared to the control apricots. In conclusion, GA could be considered an appropriate edible coating for quality conservation of apricots. PRACTICAL APPLICATIONS: Apricot is a well renowned and nutrients rich fruit. However, apricot has comparatively short shelf life potential due to its susceptibility to rapid senescence and deterioration under ambient conditions. GA is an eco-friendly and biodegradable coating which is considered relatively cheap as compared with other coating types. In our present work, application of gum arabic [GA (10%)] edible coating maintained significantly higher quality of harvested apricot fruit as compared with the control. The outcomes of the present work are of global significance with respect to apricot industry. So, GA coating could be considered an appropriate edible coating for quality conservation of the harvested apricot fruit.
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http://dx.doi.org/10.1111/jfbc.13656DOI Listing
April 2021

Tragacanth gum coating modulates oxidative stress and maintains quality of harvested apricot fruits.

Int J Biol Macromol 2020 Nov 23;163:2439-2447. Epub 2020 Sep 23.

Department of Entomology, Faculty of Agriculture and Environmental Sciences, The Islamia University of Bahawalpur, Pakistan.

Tragacanth gum is a polysaccharide-based complex with a good coating property. However, its use in postharvest storage of fresh fruits and vegetables is very limited. In the current work, the effect of tragacanth gum (1%) was investigated on postharvest quality of apricot fruits during storage at 20 ± 1 °C for 8 days. Apricot fruits coated with tragacanth gum coating showed significantly reduced weight loss, decay and electrolyte leakage, hydrogen peroxide and malondialdehyde production. Tragacanth gum coating suppressed increase in total soluble solids and showed higher titratable acidity compared with control. The coated fruits had higher total phenolics and ascorbic acid along with greater 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in contrast with control. Postharvest application of tragacanth gum coating maintained markedly higher activities of ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) enzymes activities as compared with control. In addition, tragacanth gum application suppressed polygalacturonase (PG), pectin methylesterase (PME), and cellulase (CX) enzymes activities, thereby suppressed softening of apricot fruits. Sensory quality attributes such as taste, juiciness, aroma, appearance, and overall acceptability were also significantly higher in tragacanth gum coated fruits compared with control. In conclusion, tragacanth gum coating could be considered suitable for postharvest quality conservation of apricot fruits.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.09.179DOI Listing
November 2020

Effect of pre-storage ascorbic acid and Aloe vera gel coating application on enzymatic browning and quality of lotus root slices.

J Food Biochem 2020 03 6;44(3):e13136. Epub 2020 Jan 6.

Department of Horticulture, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan.

The effect of ascorbic acid [AA (1%)] and Aloe vera gel [AVG (50%)] coating alone and in combination was investigated on enzymatic browning and quality of lotus root slices during storage at 20 ± 1°C. The combined application of AA and AVG coating delayed surface browning, reduced increase in relative electrolyte leakage (REL) and showed higher overall visual quality (OVQ). Similarly, AA and AVG combined treatment reduced superoxide anion ( ) and hydrogen peroxide (H O ) production and malondialdehyde (MDA) content, and suppressed peroxidase (POD) and polyphenol oxidase (PPO) activities. In addition, AA and AVG treatment conserved higher AA content, ascorbate peroxidase (APX), superoxide dismutase (SOD) and catalase (CAT) enzymes activities along with higher total phenolics and radical scavenging activity. In conclusion, the combined application of AA and AVG coating could be an appropriate treatment to delay surface browning and quality loss of lotus root slices. PRACTICAL APPLICATIONS: Lotus root is an aquatic rhizome vegetable. The fresh-cut slices of lotus roots are prone to post-cut enzymatic browning and quality deterioration during postharvest storage. Browning induced loss of visual quality and microbial infestations are the leading constraints in extending storage and/or shelf life of lotus root slices. Surface browning results in loss of characteristic color eventually leading to significant reduction in market potential and visual quality. However, quality deterioration and development of browning could be delayed with some suitable postharvest treatments. So, the effect of AA and Aloe vera gel based coating was investigated for quality conservation of lotus root slices. The findings of the current work are of global importance in reducing browning and conserving visual quality of lotus root slices in particular and fresh-cut produce in general.
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http://dx.doi.org/10.1111/jfbc.13136DOI Listing
March 2020

Effect of postharvest oxalic acid application on enzymatic browning and quality of lotus (Nelumbo nuciferaGaertn.) root slices.

Food Chem 2020 May 17;312:126051. Epub 2019 Dec 17.

Department of Horticulture, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University Multan, Pakistan. Electronic address:

Post-cut surface browning is one of the major constraints for shelf-life extension of lotus root slices. In the present study, lotus roots slices were treated with 0, 5 and 10 mmol L oxalic acid and stored at 20 ± 1 °C for 5 days. Results showed that 10 mmol L oxalic acid treated lotus slices exhibited reduced browning, superoxide anion, hydrogen peroxide, electrolyte leakage and malondialdehyde content than control. The 10 mmol L treated slices had better visual quality and higher ascorbic acid and total phenolic contents. In addition, 10 mmol L treated slices showed reduced total bacterial count along with lower soluble quinones, peroxidase and polyphenol oxidase activities in contrast to control. Similarly, 10 mmol L treatment showed higher superoxide dismutase, catalase and ascorbate peroxidase activities as compared to control. In conclusion, 10 mmol L oxalic acid application could be considered suitable to delay post-cut browning of lotus root slices.
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http://dx.doi.org/10.1016/j.foodchem.2019.126051DOI Listing
May 2020

Postharvest application of antibrowning chemicals modulates oxidative stress and delays pericarp browning of controlled atmosphere stored litchi fruit.

J Food Biochem 2019 03 13;43(3):e12746. Epub 2018 Dec 13.

Department of Chemistry and Biochemistry, University of Agriculture Faisalabad, Faisalabad, Pakistan.

Litchi fruit were treated with methionine [(0.25%) MN] and cysteine [(025%) CN] alone or in combination, and kept under 1% O + 5% CO controlled atmosphere (CA) at 5 ± 1ºC for 28 days. Among different treatments, CN was most effective to inhibit browning, than MN and CN + MN under CA conditions. Application of 0.25% CN significantly delayed browning index, reduced disease incidence, weight loss, malondialdehyde (MDA) contents, electrolyte leakage, hydrogen peroxide (H O ), superoxide anion (O ) and polyphenol oxidase (PPO) and peroxidase (POD) activities with higher contents of total anthocyanins under CA-storage. In addition, 0.25% CN treatment showed higher contents of ascorbic acid, total phenolics (TPC), and 2,2-diphenyl-1-picrylhydrazyl-radical scavenging capacity and activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) enzymes having maintained quality attributes. Therefore, 0.25% CN pre-treatment could be considered a promising way for managing browning, and conserving litchi fruit quality under CA-storage. PRACTICAL APPLICATIONS: Litchi fruit are highly perishable due to rapid pericarp browning having limited postharvest market potential. The browning takes place due to enzymatic reactions and phenolic oxidation. However, it can be delayed by exogenous antibrowning treatments and suitable storage environment. The delayed incidence of pericarp browning may help to maintain its quality with extended storage potential suitable for domestic and international markets. So, the outcomes of the current work may help to maintain overall quality and to extend its storage potential that would be helpful in extending its market life with maintained visual quality at domestic and international destinations.
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http://dx.doi.org/10.1111/jfbc.12746DOI Listing
March 2019

Physiological and iTRAQ-Based Quantitative Proteomics Analysis of Methyl Jasmonate-Induced Tolerance in Brassica napus Under Arsenic Stress.

Proteomics 2018 05;18(10):e1700290

Institute of Crop Science and, Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou, P. R. China.

Brassica napus plants exposed to 200 μM arsenic (As) exhibited high-level of stress condition, which led to inhibited growth, enhanced lipid peroxidation, and disrupted cellular ultrastructures. Exogenous application of methyl jasmonate (MeJA) alleviated the As-induced oxidative stress and improved the plant growth and photosynthesis. In this study, changes in the B. napus leaf proteome are investigated in order to identify molecular mechanisms involved in MeJA-induced As tolerance. The study identifies 177 proteins that are differentially expressed in cultivar ZS 758; while 200 differentially expressed proteins are accumulated in Zheda 622, when exposed to As alone and MeJA+As treatments, respectively. The main objective was to identify the MeJA-regulated protein under As stress. Consistent with this, iTRAQ detected 61 proteins which are significantly accumulated in ZS 758 leaves treated with MeJA under As stress. While in Zheda 622, iTRAQ detected 49 MeJA-induced proteins under As stress. These significantly expressed proteins are further divided into five groups on the base of their function, that is, stress and defense, photosynthesis, carbohydrates and energy production, protein metabolism, and secondary metabolites. Taken together, this study sheds light on the molecular mechanisms involved in MeJA-induced As tolerance in B. napus leaves and suggests a more active involvement of MeJA in plant physiological processes.
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http://dx.doi.org/10.1002/pmic.201700290DOI Listing
May 2018

QTc prolongation in acute medical admissions: an often overlooked and potentially serious finding.

Postgrad Med J 2018 02 28;94(1108):123-124. Epub 2017 Sep 28.

Department of Medicine, University Hospital Kerry, Tralee, Ireland.

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http://dx.doi.org/10.1136/postgradmedj-2017-135208DOI Listing
February 2018

Breast cancer liver metastases in a UK tertiary centre: Outcomes following referral to tumour board meeting.

Int J Surg 2017 Aug 20;44:152-159. Epub 2017 Jun 20.

Institute of Liver Studies, King's College Hospital, London, UK. Electronic address:

Introduction: To assess the outcomes from multidisciplinary board meetings (MDM) for patients with breast cancer liver metastases (BCLM) and identify prognostic factors for survival.

Materials And Methods: A retrospective review of MDM records for patients referred with BCLM to a tertiary centre between 2005 and 2016. Patient demographics, clinicopathological factors and intervention type were analysed to find predictive factors for overall survival.

Results: 61 patients with BCLM were referred to the MDM. Treatment pathways included surgical resection (n = 23), radiofrequency ablation (RFA, n = 11), or chemotherapy (n = 27). Surgical resection patients had an improved median overall survival compared to chemotherapy (49 v 20mo; p < 0.001). RFA showed comparable survival benefit (37 v 20mo; p = 0.011). Resection and RFA showed no significant difference in survival over one another (49 v 37mo; p = 0.854). Survival analysis identified that resection (p = 0.002) and RFA (p = 0.001) were associated with improved overall survival compared to chemotherapy. Multivariate analysis identified extrahepatic disease (HR = 14.21; p = 0.044) and R0 resection (HR = 0.068; p = 0.023) as prognostic factors.

Conclusions: Surgical resection of BCLM may improve the overall survival in selected patient groups. This study identifies a cohort of patients, without extrahepatic disease and responsive to chemotherapy, who may particularly benefit from surgery.
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http://dx.doi.org/10.1016/j.ijsu.2017.06.049DOI Listing
August 2017

Irradiation Maintains Functional Components of Dry Hot Peppers (Capsicum annuum L.) under Ambient Storage.

Foods 2016 Sep 12;5(3). Epub 2016 Sep 12.

Department of Horticulture, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan 32200, Pakistan.

Hot peppers used as natural flavoring and coloring agents are usually irradiated in prepacked form for decontamination. The effects of gamma radiation on the stability of functional components such as capsaicinoids and antioxidant compounds (carotenoids, ascorbic acid and total phenolics) were investigated in hot peppers (). Whole dried peppers packed in polyethylene bags were gamma irradiated at 0 (control), 2, 4, and 6 kGy and subsequently stored at 25 °C for 90 days. The irradiation dose did not substantially affect the initial contents of capsaicinoids, ascorbic acid and total phenolics, though the concentration of carotenoids declined by 8% from the control (76.9 mg/100 g) to 6 kGy radiation dose (70.7 mg/100 g). Similarly, during storage for 90 days at ambient temperature the concentrations of capsaicinoids and total phenolics remained fairly stable with mean percent reductions from 3.3% to 4.2%, while the levels of total carotenoids and ascorbic acid significantly ( < 0.05) declined by 12% and 14%, respectively. Overall, neither irradiation nor subsequent ambient storage could appreciably influence the contents of functional components in hot peppers. These results revealed that gamma irradiation up to 6 kGy can be safely used for decontamination to meet the needs for overseas markets without compromising product quality.
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http://dx.doi.org/10.3390/foods5030063DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5302406PMC
September 2016

Seed priming with polyethylene glycol induces antioxidative defense and metabolic regulation of rice under nano-ZnO stress.

Environ Sci Pollut Res Int 2016 Oct 20;23(19):19989-20002. Epub 2016 Jul 20.

Seed Science Center, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.

The present study was carried out to investigate the beneficial impact of seed priming with polyethylene glycol (PEG) under different concentrations of zinc oxide nanoparticles (nano-ZnO), i.e., 0, 250, 500, and 750 mg L(-1) in two cultivars of Oryza sativa (Zhu Liang You 06 and Qian You No. 1). Physiological parameters were improved by priming with 30 % PEG in both cultivars under stress treatments. Seed priming with 30 % PEG improved α-amylase activities and total soluble sugar contents of both cultivars under nano-ZnO stress. In addition, glutathione reductase (GR) activity, reactive oxygen species (ROS) accumulation, and proline contents decreased after the priming treatment in both cultivars under different nano-ZnO concentrations. Expression of GR1, GR2, Amy2A, and Amy3A genes in shoots and roots of both cultivars increased and had higher transcription levels under the nano-ZnO stress condition. Fourier transform infrared spectroscopy (FTIR) analysis did not show any significant effects of the priming treatment on the band observed at 3400, 900, 1600, and 1000 cm(-1) corresponding to alkenyl stretch (C = C), carboxyl acid (O-H), nitrile (C = N), and aromatic (C-H), respectively, in both cultivars under nano-ZnO stress.
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http://dx.doi.org/10.1007/s11356-016-7170-7DOI Listing
October 2016

Seed priming with polyethylene glycol regulating the physiological and molecular mechanism in rice (Oryza sativa L.) under nano-ZnO stress.

Sci Rep 2015 Sep 30;5:14278. Epub 2015 Sep 30.

Seed Science Center, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.

The present study was designed to highlight the impact of seed priming with polyethylene glycol on physiological and molecular mechanism of two cultivars of Oryza sativa L. under different levels of zinc oxide nanorods (0, 250, 500 and 750 mg L(-1)). Plant growth parameters were significantly increased in seed priming with 30% PEG under nano-ZnO stress in both cultivars. Whereas, this increase was more prominent in cultivar Qian You No. 1 as compared to cultivar Zhu Liang You 06. Significant increase in photosynthetic pigment with PEG priming under stress. Antioxidant enzymes activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) as well as malondialdehyde (MDA) contents were significantly reduced with PEG priming under nano-ZnO stress. Gene expression analysis also suggested that expression of APXa, APXb, CATa, CATb, CATc, SOD1, SOD2 and SOD3 genes were down regulated with PEG priming as compared to non-primed seeds under stress. The ultrastructural analysis showed that leaf mesophyll and root cells were significantly damaged under nano-ZnO stress in both cultivars but the damage was prominent in Zhu Liang You 06. However, seed priming with PEG significantly alleviate the toxic effects of nano-ZnO stress and improved the cell structures of leaf and roots in both cultivars.
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http://dx.doi.org/10.1038/srep14278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4588511PMC
September 2015

Physiological changes and sHSPs genes relative transcription in relation to the acquisition of seed germination during maturation of hybrid rice seed.

J Sci Food Agric 2016 Mar 30;96(5):1764-71. Epub 2015 Jun 30.

Seed Science Center, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.

Background: During the production of early hybrid rice seed, the seeds dehydrated slowly and retained high moisture levels when rainy weather lasted for a couple of days, and the rice seeds easily occurred pre-harvest sprouting (PHS) along with high temperature. Therefore it is necessary to harvest the seeds before the PHS occurred.

Results: The seeds of hybrid rice (Oryza sativa L. subsp. indica) cv. Qianyou No1 that harvests from 19 to 28 days after pollination (DAP) all had high seed vigour. The seed moisture content at 10 DAP was 36.1%, and declined to 28.6% at 19 DAP; the contents of soluble sugar and total starch increased significantly with the development of seeds. The soluble protein content, the level of abscisic acid (ABA) and gibberellin (GA3 ), and ascorbate peroxidase (APX) activity continued to decrease from 10 DAP to 19 DAP. The seeds at 19 DAP had the highest peroxidase (POD) activity and lowest catalase (CAT) activity while the superoxide dismutase (SOD) activity had no significant difference among the different developing periods. The relative expressions of genes 64S Hsp18.0 and Os03g0267200 transcripts increased significantly from 10 to 19 DAP, and then decreased. However, no significant change was recorded in soluble protein, sugar and GA3 after 16 DAP, and they all significantly correlated with seed viability and vigour during the process of seed maturity.

Conclusion: The seeds of hybrid rice Qianyou No1 had a higher viability and vigour when harvested from 19 DAP to 28 DAP, the transcription levels of 64S Hsp18.0 and Os03g0267200 increased significantly from 10 DAP to 19 DAP and the highest value was recorded at 19 DAP. The seeds could be harvested as early as 19 DAP without negative influence on seed vigour and viability.
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http://dx.doi.org/10.1002/jsfa.7283DOI Listing
March 2016

Stability of Capsaicinoids and Antioxidants in Dry Hot Peppers under Different Packaging and Storage Temperatures.

Foods 2015 Mar 31;4(2):51-64. Epub 2015 Mar 31.

Institute of Horticultural Sciences, University of Agriculture, Faisalabad 38000, Pakistan.

The maintenance of the quality and storage life of perishable fruits and vegetables is a major challenge for the food industry. In this study, the effects of different temperatures, packaging materials and storage time on the stability of capsaicinoids and antioxidants, such as total carotenoids, ascorbic acid and total phenolic compounds, were studied in three commercially cultivated hot pepper hybrids, namely Sky Red, Maha and Wonder King. For this purpose, dry whole pods were packed in jute bags and low-density polyethylene bags (LDPE), stored for five months under controlled conditions at 20, 25 or 30 C and analyzed on Day 0 and at 50-day intervals until Day 150. The three hot pepper hybrids differed significantly with respect to their capsaicinoids and antioxidant concentrations, but the results indicated that with the increase in storage temperature and time, a gradual and steady decrease in these levels was equally observed for all hybrids. Overall, mean concentrations after five months were significantly reduced by 22.6% for ascorbic acid, 19.0% for phenolic compounds, 17% for carotenoids and 12.7% for capsaicinoids. The trends of capsaicinoids and antioxidants evolution were decreasing gradually during storage until Day 150, this effect being more pronounced at higher temperature. Furthermore, the disappearance rates of capsaicinoids and antioxidants were higher in peppers packed in jute bags than in those wrapped with LDPE. In conclusion, despite the sensitivity of capsaicinoids and antioxidants to oxygen, light and moisture, the packaging in natural jute or synthetic LDPE plastic bags, as well as the storage at ambient temperature preserved between 77.4% and 87.3% of the initial amounts of these health- and nutrition-promoting compounds during five months' storage.
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http://dx.doi.org/10.3390/foods4020051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5302323PMC
March 2015
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