Pub Date : 2018-06-01DOI: 10.12816/AJFS.2018.16347
S. Mohamed, A. Abdel-Nabey, M. Khalil, R. AboSamaha
This study was conducted to determine quality parameters of Nile tilapia (Oreochromis niloticus) and grey mullet (Mugil cephalus) which were collected from different local markets in Alexandria city, Egypt during 2015. Accordingto the overall sensory scores, the Nile tilapia and mullet samples collected from the different local markets could be classified into three categories of quality grade as follows: High quality grade (score between 8 to 10), acceptable grade (score between 5 to 7.9) and unacceptable grade (less than 5).The TVB-N values in the different samples were below the maximum value of 30 mg N/100g flesh (upper limit according to E. O. S. Q. C., 2005, ES: 3494). The TMA-N value of Nile tilapia and grey mullet collected from the different markets were within the recommended standard limits for acceptability.The pH values of Nile tilapia varied from 7.01 to 7.38. The data obtained showed significant differences (P< 0.05) among the samples. Further, Hanuvil market samples had the highest value of pH, while samples collected from El Wardian market had the lowest value of pH, with no significant differences between El Wardian, Alqsy and Bab Omar Pasha market samples. It was found that the pH values of grey mullet samples ranged from 6.74 to 7.18. Hanuvil samples followed by El Amreya samples were recorded to have the highest value of pH with no significant difference between them. On the other hand, Bakkous samples followed by Zananiri samples showed the lowest value of pH with no significant difference between them.The results indicated that the psychrophilic bacterial count of Nile tilapia and grey mullet collected from differentmarkets were higher than mesophilic bacterial count. All Nile tilapia and grey mullet samples had high quality considering that the microbiological upper limit for fresh fish proposed by E. O. S. Q. C. (2005, ES: 3494) not exceed 106 CFU/flesh.
{"title":"Quality Assessment of Nile Tilapia and Grey Mullet Fish Collected from Different Local Markets in Alexandria City, Egypt","authors":"S. Mohamed, A. Abdel-Nabey, M. Khalil, R. AboSamaha","doi":"10.12816/AJFS.2018.16347","DOIUrl":"https://doi.org/10.12816/AJFS.2018.16347","url":null,"abstract":"This study was conducted to determine quality parameters of Nile tilapia (Oreochromis niloticus) and grey mullet (Mugil cephalus) which were collected from different local markets in Alexandria city, Egypt during 2015. Accordingto the overall sensory scores, the Nile tilapia and mullet samples collected from the different local markets could be classified into three categories of quality grade as follows: High quality grade (score between 8 to 10), acceptable grade (score between 5 to 7.9) and unacceptable grade (less than 5).The TVB-N values in the different samples were below the maximum value of 30 mg N/100g flesh (upper limit according to E. O. S. Q. C., 2005, ES: 3494). The TMA-N value of Nile tilapia and grey mullet collected from the different markets were within the recommended standard limits for acceptability.The pH values of Nile tilapia varied from 7.01 to 7.38. The data obtained showed significant differences (P< 0.05) among the samples. Further, Hanuvil market samples had the highest value of pH, while samples collected from El Wardian market had the lowest value of pH, with no significant differences between El Wardian, Alqsy and Bab Omar Pasha market samples. It was found that the pH values of grey mullet samples ranged from 6.74 to 7.18. Hanuvil samples followed by El Amreya samples were recorded to have the highest value of pH with no significant difference between them. On the other hand, Bakkous samples followed by Zananiri samples showed the lowest value of pH with no significant difference between them.The results indicated that the psychrophilic bacterial count of Nile tilapia and grey mullet collected from differentmarkets were higher than mesophilic bacterial count. All Nile tilapia and grey mullet samples had high quality considering that the microbiological upper limit for fresh fish proposed by E. O. S. Q. C. (2005, ES: 3494) not exceed 106 CFU/flesh.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115908036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.12816/AJFS.2018.16349
M. Elabd
The present study aimed to develop an antimicrobial edible coating and to evaluate their efficiencies in preservingguava slices. Guava slices were submitted to four treatments: without coating (control) A, coating with potato starch containing 0.25% or 0.5% chitosan, B and C treatments respectively, and coating with 3% potato starch, 1.5% ascorbic acid and 0.2% potassium sorbate, D treatment. All samples were stored in refrigerator at 4±1°C and 70-75% relative humidity for 18 days. The following characteristics were analyzed: weight loss, firmness, total soluble solids, total titratable acidity, vitamin C, polyphenol oxidase (PPO), catalase (CAT), microbial quality and sensory attributes. Treatments with edible coatings were effective in reducing weight loss and maintaining texture of guava slices. The coatings decreased the increase in total soluble solids and decreased the loss in total titratable acidity compared to the uncoated ones. The lowest activity values of enzymes (PPO and CAT) were recorded for coated samples. The use of edible coatings contributed in reducing microbial growth of guava slices and increasing their shelf-life.
{"title":"Effect of Antimicrobial Edible Coatings on Quality and Shelf Life of Minimal Processed Guava (Psidium guajava)","authors":"M. Elabd","doi":"10.12816/AJFS.2018.16349","DOIUrl":"https://doi.org/10.12816/AJFS.2018.16349","url":null,"abstract":"The present study aimed to develop an antimicrobial edible coating and to evaluate their efficiencies in preservingguava slices. Guava slices were submitted to four treatments: without coating (control) A, coating with potato starch containing 0.25% or 0.5% chitosan, B and C treatments respectively, and coating with 3% potato starch, 1.5% ascorbic acid and 0.2% potassium sorbate, D treatment. All samples were stored in refrigerator at 4±1°C and 70-75% relative humidity for 18 days. The following characteristics were analyzed: weight loss, firmness, total soluble solids, total titratable acidity, vitamin C, polyphenol oxidase (PPO), catalase (CAT), microbial quality and sensory attributes. Treatments with edible coatings were effective in reducing weight loss and maintaining texture of guava slices. The coatings decreased the increase in total soluble solids and decreased the loss in total titratable acidity compared to the uncoated ones. The lowest activity values of enzymes (PPO and CAT) were recorded for coated samples. The use of edible coatings contributed in reducing microbial growth of guava slices and increasing their shelf-life.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124678399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.12816/AJFS.2018.16350
F. Abdel-Salam, G. Moharram, E. El-Zalaki
The objective of this study was to estimate the effect of pomegranate cultivar on the physical properties and the distributionof bioactive compounds in the different parts of its fruits. Three traditional Egyptian cultivars namely, Edkawy, Manfaloty, and Sahrawy in addition to Wonderful from the recent introduced accessions. The results showed significant variations in the peels, arils and rinds percentage, length, diameter, volume of fruit and arils, calyx diameter and index, peel thickness and peel thickness index, colour measurements (L*, a*, b* and h) of the outer peel and arils among the fruits of the four cultivars. Also, significant differences in bioactive compounds (type and content) were noted among the cultivars and the different parts of the pomegranate fruit. Edkawy fruits had the highest content of bioactive components followed by Wonderful, Manfaloty and Sahrawy, respectively. Total phenolics and total tannins were located mainly in the fruit peels while total anthocyanins and total flavonoids are concentrated in fruit arils and juice.
{"title":"Physical Properties and Some Bioactive Compounds of Four Pomegranate Cultivars (Punica granatum L.) Grown in Egypt","authors":"F. Abdel-Salam, G. Moharram, E. El-Zalaki","doi":"10.12816/AJFS.2018.16350","DOIUrl":"https://doi.org/10.12816/AJFS.2018.16350","url":null,"abstract":"The objective of this study was to estimate the effect of pomegranate cultivar on the physical properties and the distributionof bioactive compounds in the different parts of its fruits. Three traditional Egyptian cultivars namely, Edkawy, Manfaloty, and Sahrawy in addition to Wonderful from the recent introduced accessions. The results showed significant variations in the peels, arils and rinds percentage, length, diameter, volume of fruit and arils, calyx diameter and index, peel thickness and peel thickness index, colour measurements (L*, a*, b* and h) of the outer peel and arils among the fruits of the four cultivars. Also, significant differences in bioactive compounds (type and content) were noted among the cultivars and the different parts of the pomegranate fruit. Edkawy fruits had the highest content of bioactive components followed by Wonderful, Manfaloty and Sahrawy, respectively. Total phenolics and total tannins were located mainly in the fruit peels while total anthocyanins and total flavonoids are concentrated in fruit arils and juice.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114781633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.12816/AJFS.2018.16345
I. El-Batawy, S. Mahdy, M. A. El-Naga
The effect of substituting water (50 and 100%) with cheese whey (CW) and UF milk permeate (UFMP) as the by-product of some dairy industries on the quality of Egyptian Baladi bread were investigated. Changes in the physical,chemical and organoleptic properties of bread products were determined. Substituting the water by either whey or permeate in Baladi bread manufacture caused significant effect on dough mixing properties (Farinograph) and slight increase in ratio of solution absorption for the dough preparation. A significant (P<0.05) increase was observed in the values of mixing tolerance index (MTI) for permeate dough at two substitution levels. The values of energy, extensibility,resistance of extension and proportion number increased significantly (P<0.05) in both whey or permeate dough by increasing replacing level. Whey or permeate had significant effects on texture profile analysis of Baladi bread. Total solids, protein, ash, carbohydrate and minerals contents were faound to increase significantly (P<0.05) in resultant bread with increasing the ratio of whey or permeate added to the bread blend. The values of alkaline water retention capacity for all tested bread samples were reduced significantly (P<0.05) during storage. Substitution of water with whey or permeate in Baladi bread formula especially 100% could be enhance the sensory properties in the resultant product. It could be concluded that, Egyptian Baladi bread can made by adding cheese whey or milk permeateas a water substitute up to 100%. This fortification could enhance the quality attributes, acceptability and nutritive value of the product.
{"title":"Utilization of Cheese Whey and UF Milk Permeate in Manufacture of Egyptian Baladi Bread","authors":"I. El-Batawy, S. Mahdy, M. A. El-Naga","doi":"10.12816/AJFS.2018.16345","DOIUrl":"https://doi.org/10.12816/AJFS.2018.16345","url":null,"abstract":"The effect of substituting water (50 and 100%) with cheese whey (CW) and UF milk permeate (UFMP) as the by-product of some dairy industries on the quality of Egyptian Baladi bread were investigated. Changes in the physical,chemical and organoleptic properties of bread products were determined. Substituting the water by either whey or permeate in Baladi bread manufacture caused significant effect on dough mixing properties (Farinograph) and slight increase in ratio of solution absorption for the dough preparation. A significant (P<0.05) increase was observed in the values of mixing tolerance index (MTI) for permeate dough at two substitution levels. The values of energy, extensibility,resistance of extension and proportion number increased significantly (P<0.05) in both whey or permeate dough by increasing replacing level. Whey or permeate had significant effects on texture profile analysis of Baladi bread. Total solids, protein, ash, carbohydrate and minerals contents were faound to increase significantly (P<0.05) in resultant bread with increasing the ratio of whey or permeate added to the bread blend. The values of alkaline water retention capacity for all tested bread samples were reduced significantly (P<0.05) during storage. Substitution of water with whey or permeate in Baladi bread formula especially 100% could be enhance the sensory properties in the resultant product. It could be concluded that, Egyptian Baladi bread can made by adding cheese whey or milk permeateas a water substitute up to 100%. This fortification could enhance the quality attributes, acceptability and nutritive value of the product.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124079228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.21608/ajfs.2018.16344
Badawy Z.
{"title":"Anti- and Pro-Oxidative Effect of α-Eleostearic Acid on the Autoxidation of Linoleic Acid","authors":"Badawy Z.","doi":"10.21608/ajfs.2018.16344","DOIUrl":"https://doi.org/10.21608/ajfs.2018.16344","url":null,"abstract":"","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"EM-31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126526034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.12816/ajfs.2018.16346
S. El-Sebeay, Lamia M. Hafez
Celiac disease (CD) is a longevity food intolerance to gluten. Quinoa has complete nutritional characteristics and is gluten free, so it is tolerable for CD. The objective of this study was to estimate chemical, sensory and biological evaluation of some formulated quinoa products as an alternative food suggested for CD. Quinoa, rice, corn, chick-pea flours and their products (cake, biscuit and toast) in different ratio were prepared and examined for sensory properties. It was found that; the best acceptable blends were quinoa flour: rice flour: corn flour with rito1:1:1in cake and toast and quinoa flour: rice flour: chick-pea flour with rito1:1:1in biscuit. Biological evaluation was done on 32 albino male rates classified into four equal groups of eight rats each. Group 1 was the control group, the other groups were fed on the products for 8 weeks. Weight gain and relative organ weights were estimated. Blood picture, lipid profile, alanine transaminase (ALT), aspartate transaminase (AST), total protein, albumin, bilirubin, creatinin, uric and glucose were estimated. The results revealed that quinoa flour was free of gluten and the percentage of saponin after washing was 0.2 %. Quinoa flour had 16.4% protein, 8.2 % fat and was rich in Ca, P, Na, K, Mg and Cu. The percentage of some essential amino acids in quinoa flour surpassed the FAO model. Quinoa flour had low percentage of saturated and monounsaturated fatty acids, but it had high contents of polyunsaturated fatty acids ω6 and ω3. Cake and biscuit were higher in protein, fat and fiber than toast, while toast was the highest in minerals content except for Cu. The biological evaluation for the three products showed that; the weight gain decreased in all the treated groups. All the parameters of the blood tests were as that of the control except for the hemoglobin level. Total lipids, cholesterol, triglycerides and low density lipoprotein (LDL) were higher in cake fed group than the control group. Liver functions and kidney functions were not affected by feeding on the products; there were no differences in AST and bilirubin levels between the treated groups. Further research, including human clinical trials, is needed and recommended.
{"title":"Chemical and Biological Evaluation of Some Products from Quinoa-Based Blends for Celiac Disease","authors":"S. El-Sebeay, Lamia M. Hafez","doi":"10.12816/ajfs.2018.16346","DOIUrl":"https://doi.org/10.12816/ajfs.2018.16346","url":null,"abstract":"Celiac disease (CD) is a longevity food intolerance to gluten. Quinoa has complete nutritional characteristics and is gluten free, so it is tolerable for CD. The objective of this study was to estimate chemical, sensory and biological evaluation of some formulated quinoa products as an alternative food suggested for CD. Quinoa, rice, corn, chick-pea flours and their products (cake, biscuit and toast) in different ratio were prepared and examined for sensory properties. It was found that; the best acceptable blends were quinoa flour: rice flour: corn flour with rito1:1:1in cake and toast and quinoa flour: rice flour: chick-pea flour with rito1:1:1in biscuit. Biological evaluation was done on 32 albino male rates classified into four equal groups of eight rats each. Group 1 was the control group, the other groups were fed on the products for 8 weeks. Weight gain and relative organ weights were estimated. Blood picture, lipid profile, alanine transaminase (ALT), aspartate transaminase (AST), total protein, albumin, bilirubin, creatinin, uric and glucose were estimated. The results revealed that quinoa flour was free of gluten and the percentage of saponin after washing was 0.2 %. Quinoa flour had 16.4% protein, 8.2 % fat and was rich in Ca, P, Na, K, Mg and Cu. The percentage of some essential amino acids in quinoa flour surpassed the FAO model. Quinoa flour had low percentage of saturated and monounsaturated fatty acids, but it had high contents of polyunsaturated fatty acids ω6 and ω3. Cake and biscuit were higher in protein, fat and fiber than toast, while toast was the highest in minerals content except for Cu. The biological evaluation for the three products showed that; the weight gain decreased in all the treated groups. All the parameters of the blood tests were as that of the control except for the hemoglobin level. Total lipids, cholesterol, triglycerides and low density lipoprotein (LDL) were higher in cake fed group than the control group. Liver functions and kidney functions were not affected by feeding on the products; there were no differences in AST and bilirubin levels between the treated groups. Further research, including human clinical trials, is needed and recommended.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130316929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.12816/AJFS.2018.16348
I. El-Sayed, A. Ibrahim, S. Awad
Milk quality and stabilizers were investigated to revere their effects on undesirable changes in sensory of UHT milk as influenced by storage at 25°C or 37°C. The obtained results showed that the total microbial count, psychrophilicbacteria, mesophilic & thermophilic spore forming bacteria were higher in grade B (GB) milk than in grade A (GA) milk. Seven treatments were carried out with GA, GB, reconstituted full cream milk powder (FCMP), FCMP mix with GA and GB milk, meanwhile, two commercial stabilizers were separately evaluated. Mesophilic and thermophilicspore forming bacteria exhibited high scores and were found in standardized pasteurized GB milk comparing with GA milk. The type of stabilizer has no any effect on the UHT milk quality. The treatments of UHT milk made using GB milk received low levels of sensory properties (color & flavor), as well as, fat separation and sedimentation could be noted during storage when compared to that made from GA milk or FCMP. The fat separation and sedimentationwere more pronounced in treatments stored at 37 °C when compared to that stored at 25°C. Results of SDS-PAGE and RP-HPLC did not show any significant differences among all treatments in proteolysis during storage period. Accordingly’ the fat separation and sedimentation were not related only to proteolysis but were related to quality of milk used in processing.
{"title":"Effect of Milk Quality and Stabilizers on Some Physicochemical Properties of UHT-Milk","authors":"I. El-Sayed, A. Ibrahim, S. Awad","doi":"10.12816/AJFS.2018.16348","DOIUrl":"https://doi.org/10.12816/AJFS.2018.16348","url":null,"abstract":"Milk quality and stabilizers were investigated to revere their effects on undesirable changes in sensory of UHT milk as influenced by storage at 25°C or 37°C. The obtained results showed that the total microbial count, psychrophilicbacteria, mesophilic & thermophilic spore forming bacteria were higher in grade B (GB) milk than in grade A (GA) milk. Seven treatments were carried out with GA, GB, reconstituted full cream milk powder (FCMP), FCMP mix with GA and GB milk, meanwhile, two commercial stabilizers were separately evaluated. Mesophilic and thermophilicspore forming bacteria exhibited high scores and were found in standardized pasteurized GB milk comparing with GA milk. The type of stabilizer has no any effect on the UHT milk quality. The treatments of UHT milk made using GB milk received low levels of sensory properties (color & flavor), as well as, fat separation and sedimentation could be noted during storage when compared to that made from GA milk or FCMP. The fat separation and sedimentationwere more pronounced in treatments stored at 37 °C when compared to that stored at 25°C. Results of SDS-PAGE and RP-HPLC did not show any significant differences among all treatments in proteolysis during storage period. Accordingly’ the fat separation and sedimentation were not related only to proteolysis but were related to quality of milk used in processing.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131508237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.21608/ajfs.2021.187135
Noha Khalil, N. Dabour, El-Ziney M, E. Kheadr
Food bio-preservation has gained considerable attention during the last decade. It is considered a promising alternative to classical means of food preservations and meets current consumer demands for the consumption of safe, nutritious, and chemicalfree products. The main techniques of food bio-preservation, include the application of bacteriocins, bacteriophages, endolysins, and protective cultures, which compose mainly of lactic acid bacteria. To date, the use of lactic acid bacteria (as protective cultures) or their metabolites in foods is known as the main acceptable tool of food bio-preservation. This review focus on the concept of food bio-preservation and its techniques, and the role of lactic acid bacteria and their antimicrobials in food bio-preservation. Among lactic acid bacteria, particular attention is given to Lactobacillus plantarum, a versatile species with important antimicrobial activity. This species is known to produce numerous bacteriocins and antifungal-active compounds. Also, Lactobacillus plantarum is extensively used in the production of many fermented foods either as a starter culture and probiotic microorganism.
{"title":"Food Bio-Preservation: An Overview with Particular Attention to Lactobacillus plantarum","authors":"Noha Khalil, N. Dabour, El-Ziney M, E. Kheadr","doi":"10.21608/ajfs.2021.187135","DOIUrl":"https://doi.org/10.21608/ajfs.2021.187135","url":null,"abstract":"Food bio-preservation has gained considerable attention during the last decade. It is considered a promising alternative to classical means of food preservations and meets current consumer demands for the consumption of safe, nutritious, and chemicalfree products. The main techniques of food bio-preservation, include the application of bacteriocins, bacteriophages, endolysins, and protective cultures, which compose mainly of lactic acid bacteria. To date, the use of lactic acid bacteria (as protective cultures) or their metabolites in foods is known as the main acceptable tool of food bio-preservation. This review focus on the concept of food bio-preservation and its techniques, and the role of lactic acid bacteria and their antimicrobials in food bio-preservation. Among lactic acid bacteria, particular attention is given to Lactobacillus plantarum, a versatile species with important antimicrobial activity. This species is known to produce numerous bacteriocins and antifungal-active compounds. Also, Lactobacillus plantarum is extensively used in the production of many fermented foods either as a starter culture and probiotic microorganism.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"281 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134484010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.21608/ajfs.2019.54684
K. Kerti
The repeated usage of heating oils has been proven hazardous due to the degradation process by chemical reactions that lead to changes in the quality of the oil. There are numerous analytical methods which are capable of monitoring the quality deterioration in heating oils due to their repeated heating in deep fat frying processes. This work explores the effect of heating on the physical behaviour of soybean and rapeseed oils and their blends. Colour measurements, electrical impedance and differential scanning calorimetry (DSC) were used for monitoring the changes in oils and their blends due to the heating process. The results revealed that all methods are able to respond to the oil changes due to the heating process with different levels of accuracy. It was obvious that, colour measurements represented a high level of standard deviation. Electrical impedance showed its ability to be a candidate as a rapid monitoring method. Also, DSC was able to follow small changes in oils along with heating. Further tests are required to confirm the efficacy of the aforementioned methods using more oil blends to generalize the results..
{"title":"Monitoring the Quality of Heating Oils and their Blends by Different Physical Methods","authors":"K. Kerti","doi":"10.21608/ajfs.2019.54684","DOIUrl":"https://doi.org/10.21608/ajfs.2019.54684","url":null,"abstract":"The repeated usage of heating oils has been proven hazardous due to the degradation process by chemical reactions that lead to changes in the quality of the oil. There are numerous analytical methods which are capable of monitoring the quality deterioration in heating oils due to their repeated heating in deep fat frying processes. This work explores the effect of heating on the physical behaviour of soybean and rapeseed oils and their blends. Colour measurements, electrical impedance and differential scanning calorimetry (DSC) were used for monitoring the changes in oils and their blends due to the heating process. The results revealed that all methods are able to respond to the oil changes due to the heating process with different levels of accuracy. It was obvious that, colour measurements represented a high level of standard deviation. Electrical impedance showed its ability to be a candidate as a rapid monitoring method. Also, DSC was able to follow small changes in oils along with heating. Further tests are required to confirm the efficacy of the aforementioned methods using more oil blends to generalize the results..","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128549092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.21608/ajfs.2021.187130
E. El-Zalaki
Papain was precipitated from cysteine hydrochloride extract of fresh latex of papaya fruits planted in Alexandria Governorate, Egypt. Three precipitants; namely, ethyl alcohol, acetone and sodium chloride resulted in proteolytic activity recovery 84.8 (of three fractions), 85.2 and 76.7 %, respectively. Acetone was found to be the most promising rapid and simple conditions for preparing acetone dry powder of partially purified crude papain. Papain properties indicated that the maximum activity was attained at pH 7.5–8.0, and temperature of 75 -85°C. The activity was not affected by Na+ or Ca++ ions. Various degrees of inhibition were exerted by Ni+,+, Co++, Pb ++,and Hg++., while Cu++, caused complete inhibition .On the other hand, the proteolytic activity increased to various levels, in the presence of Sn++, cyanide, thioglycolic acid, and cysteine hydrochloride. The catalytic activation (49%) of Sn++ was found to depend to some extent on the concentration. A mixed stored papain-oryzae protease preparation ,was found to retain 71, 63, and 54 % of its proteolytic activity upon storage at 25°C for 1, 2 ,and 3 months ,respectively. The retained activity was more pronounced, being 92, 80,and 69 %, respectively upon storage at –5°C for the aformentioned durations, accordingly, storage at –5°C for up to 2 months, was recommended. The storage stability of papain powder and solutions were studied. A papain-oryzae protease preparation was formulated for further use in meat tenderization.
{"title":"Preparation and Properties of Papain Precipitated from Fresh Latex of Papaya Fruits (Carica papaya)","authors":"E. El-Zalaki","doi":"10.21608/ajfs.2021.187130","DOIUrl":"https://doi.org/10.21608/ajfs.2021.187130","url":null,"abstract":"Papain was precipitated from cysteine hydrochloride extract of fresh latex of papaya fruits planted in Alexandria Governorate, Egypt. Three precipitants; namely, ethyl alcohol, acetone and sodium chloride resulted in proteolytic activity recovery 84.8 (of three fractions), 85.2 and 76.7 %, respectively. Acetone was found to be the most promising rapid and simple conditions for preparing acetone dry powder of partially purified crude papain. Papain properties indicated that the maximum activity was attained at pH 7.5–8.0, and temperature of 75 -85°C. The activity was not affected by Na+ or Ca++ ions. Various degrees of inhibition were exerted by Ni+,+, Co++, Pb ++,and Hg++., while Cu++, caused complete inhibition .On the other hand, the proteolytic activity increased to various levels, in the presence of Sn++, cyanide, thioglycolic acid, and cysteine hydrochloride. The catalytic activation (49%) of Sn++ was found to depend to some extent on the concentration. A mixed stored papain-oryzae protease preparation ,was found to retain 71, 63, and 54 % of its proteolytic activity upon storage at 25°C for 1, 2 ,and 3 months ,respectively. The retained activity was more pronounced, being 92, 80,and 69 %, respectively upon storage at –5°C for the aformentioned durations, accordingly, storage at –5°C for up to 2 months, was recommended. The storage stability of papain powder and solutions were studied. A papain-oryzae protease preparation was formulated for further use in meat tenderization.","PeriodicalId":443317,"journal":{"name":"Alexandria Journal of Food Science and Technology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115467100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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