12 results on '"Sithara Suresh"'
Search Results
2. Stability of vitamin C in broccoli based on the chemical reaction kinetics, micro-region state diagram, and empirical correlations
- Author
-
Mohammad Shafiur Rahman, Mohamed Al-Khusaibi, Zahir Al-Attabi, Lyutha Al-Subhi, Nasser Al-Habsi, and Sithara Suresh
- Subjects
Water activity ,Vitamin C ,Moisture ,Nutrition. Foods and food supply ,Chemistry ,hurdle technology ,maximal-freeze-concentration ,food and beverages ,Thermodynamics ,Activation energy ,TP368-456 ,freezing ,Food processing and manufacture ,Chemical kinetics ,Reaction rate constant ,activation energy ,freeze-drying ,water activity ,Degradation (geology) ,glass transition ,TX341-641 ,Glass transition ,Food Science - Abstract
Vitamin C degradation of broccoli at different moisture and temperature was measured as a function of storage time and modeled by first-order reaction kinetics. The variation of rate constant was analyzed based on the activation energy, glass transition, BET-monolayer, micro-region state diagram, and empirical correlations. Three domains of chemical reactions were observed as a function of temperature. In the case of broccoli with freezable water (i.e. moist), the first critical temperature (i.e. Tc) was observed at −20°C (Tc/Tg′′′: 0.829), which was close to the Tg′′′ (i.e. experimental ultimate maximal-freeze-concentration glass transition) (−32.2°C); while second critical temperature (i.e. Ts) was observed at 60.0°C (i.e. Ts/Tg′′′: 1.383). The activation energy values were 13.6, 75.0, and 43.6 kJ/mole for the phase 1 (moist-glassy), phase 2 (moist-glassy-rubbery) and phase 3 (moist-rubbery-flow), respectively. In the case of frozen-broccoli with un-freezable water, the first critical temperature (i.e. Tc) was observed at 5°C (Tc/Tgi: 1.021), which was close to the Tgi (onset glass transition) (−0.8°C); while the second critical temperature (i.e. Ts) was observed at 70.0°C (i.e. Ts/Tgi: 1.260). The second critical temperature was close to the mechanical glass transition temperature. The activation energy values were 13.1, 69.6, and 72.4 kJ/mole for phase 1, phase 2 and phase 3, respectively. Each experimental rate constant was located in the micro-regions of the state diagram. Principal component analysis showed that reaction rates can be grouped into different micro-regions, except one data point in the micro-region 12. This could be due to the wider domain of this region and further sub-micro-regions could be defined. Finally, empirical correlations were developed as dimensionless moisture, temperature, and rate constant, and explored the possibility of developing a generic universal equation.
- Published
- 2021
- Full Text
- View/download PDF
3. Proton relaxation in freeze-dried broccoli as measured by low-frequency nuclear magnetic resonance (LF-NMR) and its relationship with the thermal glass transition
- Author
-
Mohammad Shafiur Rahman, Sithara Suresh, and Nasser Al-Habsi
- Subjects
Materials science ,Nuclear magnetic resonance ,Differential scanning calorimetry ,Moisture ,Proton ,Relaxation (NMR) ,Bound water ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Thermal analysis ,Glass transition ,Water content - Abstract
Low-frequency nuclear magnetic resonance (LF-NMR) was used to identify different proton pools and their mobility in freeze-dried broccoli (moisture 0.01 to 0.25 g g sample−1 and temperature 193 to 443 K) containing un-freezable water. Three pools of protons were determined from transversal T2 (i.e., spin–spin) relaxation times. These were T2b (i.e., tightly bound pools of protons associated with macromolecules), T21 (i.e., protons in the strongly bound water with the solids) and T22 (i.e., protons in the weakly bound or capillary water). Two critical temperatures and one peak temperature from the plot of T2b, T21 and T22 versus temperature were identified and related to the moisture content. The critical temperatures determined from T2b and T21 increased with the increase in moisture up to BET-monolayer followed by an exponential decrease. However, the first critical temperature from T22 increased and reached to a plateau, while the second and third critical temperatures increased linearly with the increase in moisture. The critical temperature from T2b was determined from the intersection of the first and second segments and compared with the onset glass as measured earlier by differential scanning calorimetry (DSC). At moisture 0.01 g g sample−1, this critical temperature showed lower than the thermal glass transition temperature. The opposite trend was observed at or above moisture 0.05 g g sample−1, and the difference between critical temperature and glass transition temperature increased with the increase in moisture content. It was also observed that peak temperatures were close to the solids-melting temperature as measured by thermal analysis. The peak indicated the disruption of the macromolecules and creating interlinked melted or compacted solid mass and caused to decrease the proton mobility.
- Published
- 2020
- Full Text
- View/download PDF
4. Metabolic Role of Hyperhomocysteinemia in the Etiology of Chronic Diseases
- Author
-
Sithara Suresh and Mostafa I. Waly
- Subjects
Hyperhomocysteinemia ,medicine.medical_specialty ,Methionine ,Homocysteine ,business.industry ,Homocystinuria ,Pyridoxine ,medicine.disease ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,Diabetes mellitus ,medicine ,Cyanocobalamin ,Vitamin B12 ,business ,medicine.drug - Abstract
The significance of elevated blood homocysteine (Hcy) in clinical practice is a serious subject for researchers and is considered as a marker of certain diseases [1]. Hcy, is a sulfur containing, non-proteinogenic amino acid required for the growth of cells and tissues [2, 3]. It is produced exclusively from methionine (Met), an essential amino acid obtained from diet [4]. Hcy is normally present in human plasma at lower concentrations. The normal range is reported to be 5–15 micromol/L [5]. The level could be affected by health-related behaviours, including diet, excessive coffee intake, alcohol consumption, cigarette smoking, and sedentary lifestyle [6, 7]. Total plasma Hcy could be in the form of free Hcy, protein-bound Hcy, oxidized forms of Hcy, and Hcy-thiolactone [3]. This is used as a predictive risk factor for stroke progression, cardiovascular disorders, test for vitamin B12 deficiency, and screening for inborn errors of Met metabolism. An increase of Hcy is referred to as hyperhomocysteinemia (HHcy) which is a sensitive marker of folate and vitamin B 12 deficiency and is associated with an increased risk of cardiovascular disease (CVD), pregnancy complications, cognitive impairment, stoke, and other diseases [8–10]. Plasma levels between 15 and 30 micromol/L are referred as mild HHcy, whereas levels between 31 and 100 micromol/L are moderate HHcy and levels above 100 micromol/L are described as severe HHcy [11]. There are also other studies which report that HHcy are associated with atherosclerosis, thrombosis, birth defects, osteoporosis, diabetes, and renal disease [2]. It is also reported to be highly prevalent in chronic kidney disease (CKD) patients. There are several risk factors that could lead to HHcy- the main cause being insufficient intake of vitamin B group especially folic acid (B9), pyridoxine (B6), or B12 (cyanocobalamin), and several polymorphisms involved in methionine (Met) metabolism [9]. This could also lead to high excretion of Hcy (oxidized Hcy) in urine (homocystinuria) [12]. The relation between HHcy and morphological changes in the organs are extremely important to improve the diagnostic methods and to develop effective treatment.
- Published
- 2021
- Full Text
- View/download PDF
5. Broccoli (Brassica oleracea) Reduces Oxidative Damage to Pancreatic Tissue and Combats Hyperglycaemia in Diabetic Rats
- Author
-
Mohamed A. Al-Kindi, Sithara Suresh, Bader R.S. Al-Ruqaishi, Halima K. Al-Issaei, Nejib Guizani, Mohammad Shafiur Rahman, Ahmed Al-Salami, Sultan Al-Maskari, and Mostafa I. Waly
- Subjects
0301 basic medicine ,030109 nutrition & dietetics ,Nutrition and Dietetics ,Antioxidant ,DNA damage ,business.industry ,medicine.medical_treatment ,Intraperitoneal injection ,Type 2 diabetes ,Glutathione ,Pharmacology ,medicine.disease ,Streptozotocin ,medicine.disease_cause ,03 medical and health sciences ,chemistry.chemical_compound ,chemistry ,Diabetes mellitus ,medicine ,business ,Oxidative stress ,Food Science ,medicine.drug - Abstract
Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The protective effects of natural extracts against diabetes are mainly dependent on their antioxidant and hypoglycaemic properties. Broccoli (Brassica oleracea) exerts beneficial health effects in several diseases including diabetes; however, the mechanism has not been elucidated yet. The present study was carried out to evaluate the potential hypoglycaemic and antioxidant properties of aqueous broccoli extracts (BEs) in diabetic rats. Streptozotocin (STZ) drug was used as a diabetogenic agent in a single intraperitoneal injection dose of 50 mg/kg body weight. The blood glucose level for each rat was measured twice a week. After 8 weeks, all animals were fasted overnight and sacrificed; pancreatic tissues were homogenized and used for measuring oxidative DNA damage, biochemical assessment of glutathione (GSH), and total antioxidant capacity (TAC) as well as histopathological examination for pancreatic tissues was examined. Diabetic rats showed significantly higher levels of DNA damage, GSH depletion, and impaired TAC levels in comparison to non-diabetics (P
- Published
- 2017
- Full Text
- View/download PDF
6. Thermal characteristics and state diagram of freeze-dried broccoli: Freezing curve, maximal-freeze-concentration condition, glass line and solids-melting
- Author
-
Sithara Suresh, Mohammad Shafiur Rahman, Nasser Al-Habsi, and Nejib Guizani
- Subjects
Materials science ,Thermodynamics ,04 agricultural and veterinary sciences ,Condensed Matter Physics ,040401 food science ,Freezing point ,0404 agricultural biotechnology ,Phase (matter) ,Thermal ,Physical and Theoretical Chemistry ,State diagram ,Glass transition ,Instrumentation ,Line (formation) ,Dimensionless quantity - Abstract
Stability of foods during processing and storage can be determined from their phase and state diagrams. In this study, state diagram of broccoli was developed considering freezing curve, glass line, maximal-freeze-concentration conditions, solids-melting and BET-monolayer line. The freezing point, glass transition and solids-melting were measured and modeled by Chen’s model, Gordon-Taylor model, and Flory-Huggins model, respectively. The ultimate maximal-freeze-concentration conditions ( T m ′) u (i.e. end temperature of freezing) and ( T g ′′′) u [i.e. end glass transition at ( T m ′) u ] were found as −30.0 °C and −32.2 °C, respectively, and solids content (i.e. X s ′) at this point was 0.70 g/g sample. The solids-water interaction (χ) during melting was estimated as 0.69 (dimensionless) from Flory-Huggins model, and BET-monolayer was observed as 0.089 g/g dry-solids at 20 °C.
- Published
- 2017
- Full Text
- View/download PDF
7. Risk Factors for Cancer: Genetic and Environment
- Author
-
Mostafa I. Waly, Mohammad Shafiur Rahman, and Sithara Suresh
- Subjects
business.industry ,Multifactorial disease ,Stressor ,Cancer ,medicine.disease ,Cumulative risk ,03 medical and health sciences ,0302 clinical medicine ,Environmental risk ,030220 oncology & carcinogenesis ,Environmental health ,Medicine ,030212 general & internal medicine ,business ,Alcohol consumption - Abstract
The preventive measures of diseases are based on the risk and their severity. However, in reality, multiple risks are involved and cumulative risk factor is defined as the combination of threats from exposure to multiple agents or stressors. Cancer is a multifactorial disease caused by combined effects of both genetic and environmental factors. The environmental risk factors include non-genetic factors, such as diet, alcohol consumption, smoking, lifestyle, and infectious agents. The environmental factors include wide exposure of chemicals from environment, atmosphere, and foods. The genetic factors and their interrelationships with the environmental factors also play an important role. Consequently, it is important to understand both genetic and environmental risk factors properly to take actions towards the reduction of the overall risk. It is also important to be aware of the risk factors and initiate communications between different parties to combat cancer.
- Published
- 2018
- Full Text
- View/download PDF
8. Broccoli (
- Author
-
Sithara, Suresh, Mostafa Ibrahim, Waly, Mohammad Shafiur, Rahman, Nejib, Guizani, Mohamed Abdullah Badar, Al-Kindi, Halima Khalfan Ahmed, Al-Issaei, Sultan Nasser Mohd, Al-Maskari, Bader Rashid Said, Al-Ruqaishi, and Ahmed, Al-Salami
- Subjects
oxidative stress ,Articles ,type 2 diabetes ,broccoli extract ,streptozotocin ,hyperglycaemia - Abstract
Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The protective effects of natural extracts against diabetes are mainly dependent on their antioxidant and hypoglycaemic properties. Broccoli (Brassica oleracea) exerts beneficial health effects in several diseases including diabetes; however, the mechanism has not been elucidated yet. The present study was carried out to evaluate the potential hypoglycaemic and antioxidant properties of aqueous broccoli extracts (BEs) in diabetic rats. Streptozotocin (STZ) drug was used as a diabetogenic agent in a single intraperitoneal injection dose of 50 mg/kg body weight. The blood glucose level for each rat was measured twice a week. After 8 weeks, all animals were fasted overnight and sacrificed; pancreatic tissues were homogenized and used for measuring oxidative DNA damage, biochemical assessment of glutathione (GSH), and total antioxidant capacity (TAC) as well as histopathological examination for pancreatic tissues was examined. Diabetic rats showed significantly higher levels of DNA damage, GSH depletion, and impaired TAC levels in comparison to non-diabetics (P
- Published
- 2017
9. Thermal characteristics, chemical composition and polyphenol contents of date-pits powder
- Author
-
Mohamed Al-Ruzeiki, Sithara Suresh, Halima Al-Dohani, Mohammad Shafiur Rahman, Nejib Guizani, Ahlam Al-Hadhrami, and Issa Al-Kindi
- Subjects
Exothermic reaction ,Materials science ,Annealing (metallurgy) ,Enthalpy ,Analytical chemistry ,Crystallite ,Flory–Huggins solution theory ,Glass transition ,Endothermic process ,Food Science ,Amorphous solid - Abstract
Polyphenol contents in date-pits varied from 21–62 mg gallic acid equivalents (GAE)/g date-pits when acetone–water, ethanol–water, methanol–water and water alone were used as solvents for extraction at temperatures 22, 45, and 60 °C. The BET and GAB monolayer values of date-pits were estimated as 4.3 and 4.1 g/100 g dry-solids. The DSC thermogram of freeze-dried date-pits showed an endothermic peak due to the melting of oil, and a second endothermic peak for solids-melting (i.e. non-fat). The first shift indicated the glass transition (i.e. T g ) while the second exothermic shift after solids-melting indicated the interactions of the components in melted solids. The melting peak temperature was decreased due to the plasticization of solids with water and the melting enthalpy was increased with the increasing water content due to the formation of more order in the amorphous, semi-crystallites and crystallites parts. The Flory–Huggins modelling of peak temperature estimated the water–solids interaction parameter as 0.0068. The melting peak temperature increased exponentially with increasing heating rate and the data was fitted with Mehl–Johnson–Avrami and Kissinger models. Annealing close to the onset of melting indicated that melting peak temperature increased exponentially with increasing annealing time, while melting enthalpy decreased with the increasing annealing time.
- Published
- 2013
- Full Text
- View/download PDF
10. Predictors of breastfeeding problems in the first postnatal week and its effect on exclusive breastfeeding rate at six months: experience in a tertiary care centre in Northern India
- Author
-
Kamlesh Kumari Sharma, Manju Saksena, Ramesh Agarwal, Sithara Suresh, Anu Thukral, and Manju Vatsa
- Subjects
Adult ,Male ,medicine.medical_specialty ,Pediatrics ,medicine.medical_treatment ,Breastfeeding ,Developing country ,India ,Tertiary care ,Tertiary Care Centers ,Breast Diseases ,medicine ,Humans ,Caesarean section ,Prospective Studies ,Prospective cohort study ,Obstetrics ,business.industry ,Cesarean Section ,Infant, Newborn ,Infant ,General Medicine ,Odds ratio ,After discharge ,Confidence interval ,Breast Feeding ,Socioeconomic Factors ,Female ,business - Abstract
In spite of the countless benefits of breastfeeding, prevalence of exclusive breastfeeding (EBF) has been far from optimal in the developing world. Breastfeeding problems at or after 4 weeks has been reported as one among the constraints to EBF. The study aimed to determine the breastfeeding problems in the 1 st postnatal week, their predictors and impact on EBF rate at 6 months. Under a prospective cohort design, 400 mother-newborn dyads were assessed for breastfeeding problems before discharge and at 60 ± 12 h of discharge. Nearly 89% of the mother-newborn dyads had one or more BF problems before discharge. Major concern was difficulty in positioning and attaching the infant to the breast (88.5%), followed by breast and nipple problems (30.3%). BF problems continued to persist even after discharge in a significant proportion of the mothers (72.5%). The only independent predictor of BF problems in the 1 st week was the caesarean section (odds ratio: 1.9, 95% confidence interval: 1.3-3.2, P < 0.05). There was a marked improvement in the EBF status (69.5%) at 6 months, and BF problems did not predict EBF failure at 6 months.
- Published
- 2014
11. Ginger extract attenuates preliminary steps of streptozotocin-mediated oxidative stress in diabetic rats
- Author
-
Mohammad Shafiur Rahman, Mostafa I. Waly, Sithara Suresh, and Nejib Guizani
- Subjects
medicine.medical_specialty ,Nutrition and Dietetics ,Antioxidant ,business.industry ,medicine.medical_treatment ,Insulin ,Ginger Extract ,Intraperitoneal injection ,Glutathione ,Streptozotocin ,medicine.disease_cause ,medicine.disease ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,Diabetes mellitus ,medicine ,Pharmacology (medical) ,Neurology (clinical) ,business ,Oxidative stress ,medicine.drug - Abstract
Objective: Although the role of streptozotocin (STZ) in the pathogenesis of diabetes in rats has been well investigated, as evidenced by several citations, to our knowledge no study has been carried out yet to examine the preliminary steps of STZ-mediated oxidative stress in pancreatic rat tissues. This study aimed to evaluate the hypoglycemic and potential antioxidant properties of ginger extract (GE) in diabetic rats. Materials and Methods: Forty-eight male Sprague-Dawley rats weighting 250-300 g were allocated to groups as follows: Nondiabetic control group (n = 12) that received chow diet; nondiabetic control group that received chow diet plus oral feeding of GE (n = 12); diabetic group (n = 12) that received chow diet; and diabetic group (n = 12) that received chow diet plus oral feeding of GE. The drug STZ was used as a diabetogenic agent in a single intraperitoneal injection dose of 60 g/kg body weight, and the blood glucose level for each rat was measured twice a week. After 12 weeks, all animals were overnight fasted and sacrificed; serum was collected for biochemical measurements of glucose, insulin, and oxidative stress indices [advanced oxidation protein products (AOPP), protein carbonyls, and nitrates plus nitrites]. The pancreas tissues were dissected and homogenized for antioxidant measurements [glutathione (GSH) and total antioxidant capacity (TAC)]. Results: Diabetic rats treated with GE showed a significant protective effect against STZ-induced hyperglycemia and oxidative stress as compared with the control group. Conclusion: Our results suggested that GE possesses potential benefits in controlling type 2 diabetes mellitus (T2DM) and that it may also prevent pancreas damage.
- Published
- 2015
- Full Text
- View/download PDF
12. Corrigendum to 'Thermal characteristics, chemical composition and polyphenol contents of date-pits powder' [J. Food Eng. 119/3 (2013) 668–679]
- Author
-
Ahlam Al-Hadhrami, Mohamed Al-Ruzeiki, Sithara Suresh, Nejib Guizani, Mohammad Shafiur Rahman, Issa Al-Kindi, and Halima Al-Dohani
- Subjects
Polyphenol ,Chemistry ,Food science ,Chemical composition ,Food Science - Published
- 2014
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.