Khalida Abdulrahman Shakir
@uobaghdad.edu.iq
University of Baghdad
Scopus Publications
- EXTRACTION, PURIFICATION AND CHARACTERIZATION OF ELASTASE FROM THE DIGESTIVE DUCT OF CATFISH (SILURUS TRIOSTEGUS)
A. M. Kadhim, K. A. Shakir
Iraqi Journal of Agricultural Sciences, 2024
This study was aimed to extract, purify and characterize the pancreatic elastase from the Catfish (silurus trioseegus) digestive duct. Different extraction solutions were used to optimize the extraction condition being (Distilled water, 200 mM NaCl, Phosphate buffer (100 mM, pH 8), the latter buffer Tis-HCl (100 mM, pH 8) both containing 0-100 mM NaCl or CaCl2 separately). Tris-HCl buffer containing 100 mM CaCl2 was the best among the rest extraction solutions. The crude extract was precipitated using a 30 % - 55 % of ammonium sulfate saturation ratio. The crude precipitate was dissolved in the same buffer and dialyzed. Then the dialyzed precipitate was concentrated and applied to CM-52 column (3.5 ×10 cm), elastase activity was appeared in two protein peaks. Each peak fraction were pooled individually and loaded on a Sephadex G-75 column (1.6×62 cm). Elastase activity was recovered only from one peak with 29.54 % yield, 530.70 U total activity and 17.89 U/mg specific activity. The optimum temperature for elastase stability and activity was 0-30 C° and 55 C° respectively. while the optimum pH for the enzyme activity and stability were 9 and 4-9 respectively. The molecular weight was 21898 Da as determined by Gel filtration. - EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF BETA-GLUCOSIDASE FROM APRICOT DEFATTED SEEDS POWDER
Hind K. A., K. A. Shakir
Iraqi Journal of Agricultural Sciences, 2023
The objective of this study, is characterization of partially purified beta-glucosidase (BGS) extracted from apricot defatted seeds powder. The enzyme was extracted using sodium phosphate solution (0.2M, pH 7) containing 2% sodium chloride with mixing ratio of (1:5 solid: liquid) for extraction period of 3 hours at 4C. The crude extract was precipitated by ammonium sulfate at 20-70% saturation, dialyzed then concentrated. The specific activity of the enzyme, folds of purification and the enzymatic yield were 5.45 units/mg, 7.8 fold and 84.5%, respectively. The results showed that the optimum conditions for the enzyme activity were at pH 5.5 and 6.5, the optimum temperature for the enzyme’s activity was 40°C and 55°C, while the thermal stability of the enzyme was between 25-45°C when the enzyme retained more than 90% of its activity over 30 minutes incubation at the optimum pH for activity, and retained 88% of its activity at 50° C. The results also revealed the inhibitory and activator effects of minerals and chemical compounds on the BGS activity. - VICINE AND CONVICINE LEVELS IN DRY AND FRESH BEANS DURING THE GROWTH STAGES AND THE EFFECT OF ENZYMATIC TREATMENT AND PROCESSING CONDITIONS ON THEIR REMOVAL.
H. K. Ali, K. A. Shakir
Iraqi Journal of Agricultural Sciences, 2023
Beans (Vicia faba) contain some anti-nutritional compounds, especially vicine and convicine and their non-sugar derivatives, divicine and isouramil, which are responsible for the occurrence of Favism in people with hereditary deficiency of Glucose-6-phosphate dehydrogenase (G6PD). These study objective was estimation of vicine and convicine content and their distribution in dry and green bean parts during the growth stages, and the effect of beta-glucosidase from defatted apricot seed powder and some home-based processing conditions on elimination of these compounds from the bean. The results showed that the content of vicine & convicine in bean ranged from 22.7 mg/100 g in the seedling stage to 46.8 mg/100 g in the pods stage at 139 days. As for vicine, it ranged from 12.6 mg /100g to 29 mg/100g at the above stages respectively. While for convicine it ranged from 10.1 mg/100g to 17.8 mg/100 respectively. The enzymatic treatments showed significant elimination of those compounds as compared to non-enzymatic treatments. Additionally, other factors such as soaking temperature, pH, and time as well as cooking process had a positive effect on the elimination of those glucosides. - EVALUATION OF ANTIOXIDANT FUNCTIONALITY OF FISH COLLAGEN ENZYMIC HYDROLYSATE
Abbas & Shakir
Iraqi Journal of Agricultural Sciences, 2021
This study aimed to investigate the anti- oxidative function of catfish collagen hydrolysate in beef minced meat samples through 10 days storage at 4 o C. Collagen hydrolysate were added to minced meat sample at two different concentrations (50 & 100 mg/100gm) . The experiment consist from control sample (C without additives) , BHT sample ( B with 200ppm butylated hydroxytoluene ) , collagenase hydrolysate samples C.C.H1, C.C.H2 (100&50 mg/100gm minced meat) respectively, and collagenase-trypsin hydrolysate samples C.H.T1 & C.H.T2 respectively (50,100mg/100gm minced meat). Peroxide values (PV), thiobarbutyric acid TBA, free fatty acid (FFA) , pH , total volatile nitrogen TVN values and total plate count assay at 0., 3, 7., 10 days were determined . PV of the BHT, C.C.H2 , C.H.T2, C.C.H1, C.H.T1 groups were significantly (p<0.05) lower than control during storage period .Meanwhile C.C.H2 and C.H.T2 groups gave the lowest TBA values through the storage period . There were no significant difference found between the C.C.H2 , C.H.T2 groups and BHT added group in all studied factors. In conclusion, the fish collagen enzymatic hydrolysates are a promising natural antioxidant and good alternative for synthetic antioxidant. - FUNCTIONAL PROPERTIES OF CATFISH SKIN COLLAGEN HYDROLYSATES
A. A. Ayat, K. A. Shakir
Iraqi Journal of Agricultural Sciences, 2021
Collagen hydrolysates were obtained from catfish skin collagen hydrolysis using catfish collagenase, pepsin and trypsin individually and mixed for 15-300min. The degree of hydrolysis , antioxidant activity based on, DPPH radical-scavenging activity (RSA), and reducing power (RP) for all obtained hydro lysates were studied , then the collagenase hydrolysate was (CH) was selected to be evaluated for antibacterial activity , functional properties including solubility, emulsification and foaming properties besides the toxicity . The highest values for RSA (72.5%) has been noticed when DH reached (24.30%) after 30 min. of hydrolysis by collagenase (CH). The water and oil holding capacities for this hydro lysate was compared to that for ASC (acid soluble collagen and PSC (pepsin soluble collagen), the results showed that the values recorded by CH were significantly higher than ASC & PSC. The molecular weight of CH peptides ranged from 180 to 11 Da. as analyzed by SDS- PAGE. The toxicity assay result revealed that CH is safe for human consumption. There was no antibacterial function for CH toward E.coli and S. aureus. At concentration of 2mg/ml. This study suggests that catfish collagen hydro lysate could be a good natural alternative for synthetic antioxidants in food industries. - Production of Xylose Reductase and Xylitol by Candida Guilliermondii Using Wheat Straw Hydrolysates
Kklaif & et al.
Iraqi Journal of Agricultural Sciences, 2020
The objective of this study is to evaluate the production of Xylose reductase (XR) and Xylitol by Candida guilliermondii using wheat straw hydrolysates (WSH) supplemented with 2.0 g/l of (NH4)2SO4 and 0.1 g/l of CaCl2.2H2O as fermentation media . Wheat straw hydrolysis run at 121°C for 15 min. by diluted sulfuric acid . The fermentation process was conducted on a shaker bath (150 rpm) at 30C for 20 h in three separate flasks using different concentration of Xylose being , 30% Xylose , WSH(27.13 g/l Xylose)and WSH plus 30 g/l Xylose. The best concentration( WSH plus 30 g/l Xylose ) was chosen to run the fermentation process for XR production at different incubation temperature ( 20, 25, 30, 35, 40, 45 C, different pH values (5, 5.5, 6, 6.5 and 7) and different fermentation period (5 , 10 , 15,20 ,25 ,30 h ). The results indicated that the optimum condition for XR production was using 30%Xylose plus WSH at pH 6 over 20h incubation at 30 C. The crude extract of Xylose reductase was used to reduce Xylose into Xylitol with simultaneous oxidation of NADPH. The crude extract of XR was able to convert about 90 % 0f the Xylose to Xylitol through 24 h. incubation at 30°C.According to these findings WSH can be used as a promising source for Xylose to produce Xylose reductase enzyme by Candida guilliermondii and the crude extract could be used successfully in conversion of Xylose to Xylitol. - Sesame oil extraction and antioxidant activity of lignans from locally cultivated sesame seeds (Sesamum indicum L.)
Iraqi Journal of Agricultural Sciences, 2019 - Prepration of sesame seed protein isolate and studying the effect of enzymtic hydrolysis in antioxidant activities
Iraqi Journal of Agricultural Sciences, 2019 - Evaluation the antioxidant activity of sesame coat and sesame cake extracts
Iraqi Journal of Agricultural Sciences, 2019 - Production Of Xylose Using Acid Hydrolysis Of Wheat Straw
Iraqi Journal of Agricultural Sciences, 2018 - Hydrolysis Of Wheat Straw Under Alkali Conditions
H. F. Al-Rubaia'ay, K. A. Shakir
Iraqi Journal of Agricultural Sciences, 2018 - Extraction, purification and partial characterization of phytic acid from defatted sesame oil cake
Iraqi Journal of Agricultural Sciences, 2018 - Studying the factors effecting the production of okra protein concentrate and isolate and their thermal properties
Iraqi Journal of Agricultural Sciences, 2016 - Study of the functional and nutritional properties of defatted okra powder and Okra Protein Isolate and Concentrate
Iraqi Journal of Agricultural Sciences, 2016 - Characterization of Iraqi sheep milk lysozyme with respect to molecular weight and hydrolytic activity
Khalida Shakir, Marie K. Walsh, Salih A. Mohammed
Dairy Science and Technology, 2013
RECENT SCHOLAR PUBLICATIONS
- EVALUATION OF ANTI-OXIDANT AND ANTI-BACTERIAL FUNCTIONALITIES OF COMMON CARP (CYPRINUS CARPIO) ENZYMIC ELASTIN HYDROLYSATE
AM Kadhim, KA Shakir
Iraqi Journal of Agricultural Sciences 57 (4), 1149-1162 , 2026
2026 - EFFECT OF EXTRACTION METHODS ON FUNCTIONAL AND PHYSICOCHEMICAL PROPERTIES OF RICE AND WHEAT STARCH
ZA Mahdi, K Shakir
Iraqi Journal of Agricultural Sciences 57 (3), 1013-1027 , 2026
2026 - EFFECT OF PARTIAL REPLACEMENT OF WHEAT AND RICE FLOUR BY MODIFIED STARCH ON CAKE AND BISCUIT QUALITATIVE AND SENSORY PROPERTIES
ZHA Mahdi, KA Shakir
Iraqi Journal of Agricultural Sciences 57 (2), 488-501 , 2026
2026 - تأثير الاستبدال الجزئي لطحين الحنطة والرز بالنشا المحور على الصفات النوعية والحسية للكيك والبسكويت
ZHA Mahdi, KA Shakir
2026 - Impact of green parts powder of locally cultivated carrot (Daucus carota L.) on qualitative and sensory properties of biscuits and cake
NS Mahdi, KA Shakir
Iraqi Journal of Agricultural Sciences 56 (Special), 20-32 , 2025
2025
Citations: 5 - EXTRACTION, PURIFICATION AND CHARACTERIZATION OF ELASTASE FROM THE DIGESTIVE DUCT OF CATFISH (SILURUS TRIOSTEGUS)
AM Kadhim, KA Shakir
Iraqi Journal of Agricultural Sciences 55 (Special), 258-266 , 2024
2024
Citations: 1 - EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF BETA-GLUCOSIDASE FROM APRICOT DEFATTED SEEDS POWDER
KA Hind, KA Shakir
Iraqi Journal of Agricultural Sciences 54 (5), 1263-1272 , 2023
2023
Citations: 2 - Vicine and convicine levels in dry and fresh beans during the growth stages and the effect of enzymatic treatment and processing conditions on their removal.
HK Ali, KA Shakir
Iraqi Journal of Agricultural Sciences 54 (5), 1252-1262 , 2023
2023
Citations: 4 - EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF BETA-GLUCOSIDASE FROM APRICOT DEFATTED SEEDS POWDER
H KA, KA Shakir
Iraqi Journal of Agricultural Sciences 54 (5) , 2023
2023 - OPTIMUM CONDITIONS FOR PHENYLALANINE AMMONIA LYASE EXTRACTION AND PURIFICATION FROM LOCALLY CULTIVATED GRAPE SEEDS
SY Hadeel, SA Khalida
Iraqi Journal of Agricultural Sciences 54 (2), 525-534 , 2023
2023
Citations: 6 - Characterization of phenylalanine ammonia lyase purified from locally cultivated grape seeds (Vitis Vinifera L.)
SY Hadeel, SA Khalida
Iraqi Journal of Agricultural Sciences 54 (2), 516-524 , 2023
2023
Citations: 7 - Functional Properties of Collagen Extracted from Catfish ( Silurus triostegus ) Waste
AA Abbas, KA Shakir, MK Walsh
Foods 11 (5), 633 , 2022
2022
Citations: 45 - Functional properties of catfish skin collagen hydrolysates
AA Ayat, KA Shakir
Iraqi Journal of Agricultural Sciences 52 (6), 1528-1540 , 2021
2021
Citations: 12 - Evaluation of antioxidant functionality of fish collagen enzymic hydrolysate
AA Abbas, KA Shakir
The Iraqi Journal of Agricultural Science 52 (4), 876-884 , 2021
2021
Citations: 4 - Antioxidant Activity of Sesame Seed Lignans in Sunflower and Flaxseed Oils
SY Hadeel, SA Khalida, MK Walsh
Food Research 4 (3), 612-622 , 2020
2020
Citations: 18 - PRODUCTION OF XYLOSE REDUCTASE AND XYLITOL BY Candida guilliermondii USING WHEAT STRAW HYDROLYSATES
HF Kklaif, JM Nasser, KA Shakir
Iraqi Journal of Agricultural Sciences 51 (6), 1653-1660 , 2020
2020
Citations: 5 - EVALUATION THE ANTIOXIDANT ACTIVITY O F SESAME COAT AND SESAME CAKE EXTRACTS
HYSMJKFAHKASRRR Prof.
Iraqi Journal of Agricultural Sciences 50 (3), 776- 782 , 2019
2019
Citations: 15 - SESAME OIL EXTRACTION AND ANTIOXIDANT ACTIVITY OF LIGNANS FROM LOCALLY CULTIVATED SESAME SEEDS (Sesamum indicum L.)
HYSKA Shakir
Iraqi Journal of Agricultural Sciences 50 (1), 382- 398 , 2019
2019
Citations: 5 - PREPRATION OF SESAME SEED PROTEIN ISOLATE AND STUDYING THE EFFECT OF ENZYMTIC HYDROLYSIS IN ANTIOXIDANT ACTIVITIES
AMKKA Shakir
Iraqi Journal of Agricultural Sciences 50 (2), :327-310 , 2019
2019
Citations: 5 - Production of xylose using acid hydrolysis of wheat straw.
HF AL-Rubaia’ay, KA Shakir
Iraqi Journal of Agricultural Sciences 49 (2) , 2018
2018
Citations: 5
MOST CITED SCHOLAR PUBLICATIONS
- Functional Properties of Collagen Extracted from Catfish ( Silurus triostegus ) Waste
AA Abbas, KA Shakir, MK Walsh
Foods 11 (5), 633 , 2022
2022
Citations: 45 - Optimization of culture conditions to produce phytase from Aspergillus tubingensis SKA .
SS Qasim, KA Shakir, AB Al-Shaibani, MK Walsh
2017
Citations: 39 - Antioxidant Activity of Sesame Seed Lignans in Sunflower and Flaxseed Oils
SY Hadeel, SA Khalida, MK Walsh
Food Research 4 (3), 612-622 , 2020
2020
Citations: 18 - EVALUATION THE ANTIOXIDANT ACTIVITY O F SESAME COAT AND SESAME CAKE EXTRACTS
HYSMJKFAHKASRRR Prof.
Iraqi Journal of Agricultural Sciences 50 (3), 776- 782 , 2019
2019
Citations: 15 - Production of xylitol from agricultural waste by enzymatic methods
MK Walsh, HF Khliaf, KA Shakir
Am. J. Agric. Biol. Sci 13, 1-8 , 2018
2018
Citations: 14 - ISOLATION, SCREENING AND PRODUCTION OF PHYTATE DEGRADING ENZYME (PHYTASE) FROM LOCAL FUNGI ISOLATE.
SS Qasim, KA Shakir, AB Al-Shaibani
Iraqi Journal of Agricultural Sciences 47 (1) , 2016
2016
Citations: 14 - Functional properties of catfish skin collagen hydrolysates
AA Ayat, KA Shakir
Iraqi Journal of Agricultural Sciences 52 (6), 1528-1540 , 2021
2021
Citations: 12 - STUDYING THE FACTORS EFFECTING THE PRODUCTION OF OKRA PROTEIN CONCENTRATE AND ISOLATE AND THEIR THERMAL PROPERTIES
AA Kareem, KA Shakir
IRAQI JOURNAL OF AGRICULTURAL SCIENCES 47 (6), 1505-1513 , 2016
2016
Citations: 10 - STUDYING THE FACTORS EFFECTING THE PRODUCTION OF OKRA PROTEIN CONCENTRATE AND ISOLATE AND THEIR THERMAL PROPERTIES
AA Kareem, KA Shakir
The Iraqi Journal of Agricultural Sciences 47 (6), 5959-5957 , 2016
2016
Citations: 10 - Characterization of phenylalanine ammonia lyase purified from locally cultivated grape seeds (Vitis Vinifera L.)
SY Hadeel, SA Khalida
Iraqi Journal of Agricultural Sciences 54 (2), 516-524 , 2023
2023
Citations: 7 - CHARACTERIZATION OF L-ASPARAGINASE PURIFIED FROM POLE BEANS.
HN Al Zobaidy, KA Shakir, GM Strasburg
Iraqi Journal of Agricultural Sciences 47 (1) , 2016
2016
Citations: 7 - OPTIMUM CONDITIONS FOR PHENYLALANINE AMMONIA LYASE EXTRACTION AND PURIFICATION FROM LOCALLY CULTIVATED GRAPE SEEDS
SY Hadeel, SA Khalida
Iraqi Journal of Agricultural Sciences 54 (2), 525-534 , 2023
2023
Citations: 6 - Impact of green parts powder of locally cultivated carrot (Daucus carota L.) on qualitative and sensory properties of biscuits and cake
NS Mahdi, KA Shakir
Iraqi Journal of Agricultural Sciences 56 (Special), 20-32 , 2025
2025
Citations: 5 - PRODUCTION OF XYLOSE REDUCTASE AND XYLITOL BY Candida guilliermondii USING WHEAT STRAW HYDROLYSATES
HF Kklaif, JM Nasser, KA Shakir
Iraqi Journal of Agricultural Sciences 51 (6), 1653-1660 , 2020
2020
Citations: 5 - SESAME OIL EXTRACTION AND ANTIOXIDANT ACTIVITY OF LIGNANS FROM LOCALLY CULTIVATED SESAME SEEDS (Sesamum indicum L.)
HYSKA Shakir
Iraqi Journal of Agricultural Sciences 50 (1), 382- 398 , 2019
2019
Citations: 5 - PREPRATION OF SESAME SEED PROTEIN ISOLATE AND STUDYING THE EFFECT OF ENZYMTIC HYDROLYSIS IN ANTIOXIDANT ACTIVITIES
AMKKA Shakir
Iraqi Journal of Agricultural Sciences 50 (2), :327-310 , 2019
2019
Citations: 5 - Production of xylose using acid hydrolysis of wheat straw.
HF AL-Rubaia’ay, KA Shakir
Iraqi Journal of Agricultural Sciences 49 (2) , 2018
2018
Citations: 5 - PURIFICATION OF PHYTASE PRODUCED FROM A LOCAL FUNGAL ISOLATE AND ITS APPLICATIONS IN FOOD SYSTEMS.
SS Qasim, KA Shakir, AB Al-Shaibani
Iraqi Journal of Agricultural Sciences 47 (1) , 2016
2016
Citations: 5 - Characterization of Iraqi sheep milk lysozyme with respect to molecular weight and hydrolytic activity
K Shakir, MK Walsh, SA Mohammed
Dairy Science & Technology 93 (6), 699-705 , 2013
2013
Citations: 5 - Vicine and convicine levels in dry and fresh beans during the growth stages and the effect of enzymatic treatment and processing conditions on their removal.
HK Ali, KA Shakir
Iraqi Journal of Agricultural Sciences 54 (5), 1252-1262 , 2023
2023
Citations: 4
