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1. Effect Of Various Concen Trayious Of Hydrogen Pereoxide On Chemical And Microbiogical Quality Of Raw Buffalo Milk

by Muhammad Ilyas Alam | Prof. Dr. Muhammad Ayaz | Dr. Aftab Ahmed Anjum | Dr. Imran Javed.

Material type: book Book; Format: print Publisher: 2011Dissertation note: Milk is a complex mixture of fat, proteins, carbohydrates, minerals, vitamins and other miscellaneous constituents dispersed in water. Milk production in flush season is much more than in the normal. Milk production and supply fluctuate through out the year and during winter it is surplus to its demand. Surplus milk is available in winter due to new calving, less consumption of milk by the consumer. In winter season ample amount of green fodder is available to the animals which in turn increase the milk production. Milk and milk products being very delicate and perishable food require special handling prior to the consumption and further treatment. Pakistan due to its harsh climatic conditions people are using different methods, for the preservation of milk. They are using different chemicals, additives and antibiotics to enhance the keeping quality of milk. Present study was planned to investigate the various concentration of hydrogen peroxide or raw buffalo milk and its effect on chemical and microbiological quality of raw buffalo milk. Raw buffalo milk samples were collected from Dairy Animal Training and Research Centre, University of Veterinary and Animal Sciences, Ravi campus Pattoki Fifty samples of raw buffalo milk (100ml each) were collected to studied the nutritional composition and microbiological quality of the milk after adding the hydrogen peroxide. The hydrogen peroxide of different concentration i.e. 0.025%, 0.05%, 0.075%and 0.1% were used in this study. There was no significant change in the result regarding various nutritional composition of raw buffalo milk after adding the various concentrations of hydrogen peroxide. There is a slight change in the lactose % during study of 48 h storage of milk at different temperature. Statistically the change which occurred in lactose during storage is significant whereas over all decrease in Solid Not Fat is non significant Mean value of TPC of raw buffalo milk treated with different concentrations of hydrogen peroxide storage at the three different temperatures indicated that at 10° C TPC was very less as compared to control. TPC at 30° C after 48 h was 9.83x106.Which was very less as compared to TPC of control i.e. 1.195 x107. The effect of H2O2 on the quality of the milk is negligible as compared to the losses suffered without it. The hydrogen peroxide definitely have its effect as a preservative.. The use of preservative in milk and dairy products are not new in the countries where ambient temperature remains quite high. Our study suggests that the concentration of hydrogen peroxide to be used for the preservation of raw milk is 0.05 % to 0.1 % Availability: Items available for loan: UVAS Library [Call number: 1291,T] (1).

2. Antimicrobial Potential Of Bovine Lactoferrin Against Foodborne Pathogens

by Ammarah Khatoon (2012-VA-631) | Prof. Dr. Muhammad Ayaz | Mr. Ishtiaque Ahmed | Prof. Dr. Aftab Ahmed Anjum.

Material type: book Book; Literary form: not fiction Publisher: 2014Dissertation note: Health is recourse of everyday life, but not the object to live. It is positive to give special importance to personal and social resources. However, in Pakistan and other developing countries conditions are different, most people have low income and they live in un-sanitized environment. They eat un-hygienic food and also lack safe drinking water. People do not adopt any preventive measure to minimize the risk of contamination. Food storage is also un-hygienic. These conditions lead towards contamination and result in foodborne infections and gastro-enteritis. Foodborne illnesses are always a serious health issue in the Pakistan and throughout the world. Individual’s record for foodborne illnesses is impossible but it is reported that 7 out of 10 people suffer from foodborne illness caused by different microbes each year worldwide (WHO survey 2012). Foodborne illness is caused by eating contaminated food with pathogenic bacteria. Some common pathogens are Escherichia coli, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Listeria monocytogens, Bacillus cereus, Staphylococcus aureus and Salmonellaspecies. Incubation period for onset of symptoms of food poisoning ranges from hours to days. Nausea, vomiting, abdominal cramps, fever and diarrhea are symptoms which appear commonly in most of food poisoning. However, foodborne illnesses if left untreated can lead severe dehydration, imbalance of intestinal micro flora, digestive disorders and even death in some cases. It was recorded that 2.2 million people killed from foodborne illness globally every year and the burden arising from foodborne diseases is larger (Kuchenmuller et al. 2009). Antibioticsare massively used to overcome food poisoning; however, from health point of view they badly affect thenormal micro flora of gut but also microbes become antibiotic resistance. The problem needs to be dealt with some other way like adding bio preservatives or antimicrobial agents in food. To control microbes in foods, numerous methods have been adopted including the use of synthetic and natural antimicrobial agents. Scope of natural antimicrobial agents are increasing day by day and different natural sources are being utilized to get these agents. Among these natural sources milk is best and widely utilized source from long times. Milk contains many biologically active compounds among which lactoferrin is one of them. Lactoferrin is a multifunctional globular glycoprotein from transferrin family, an iron-binding protein. It is part of innate immune system and has antibacterial activity known as far back as 1930. It was first isolated in 1939 from cow milk (Charrondiere et al. 2011). Lactoferrin belongs to the transferrin family having ability to bind iron two times higher than other transferrin proteins. Its molecular weight is 80 kDa and has about 700 amino acids depending upon species e.g. cow, buffalo, goat and sheep (Adlerova et al. 2008). Lactoferrin molecule consists of simple polypeptide chain folded into two symmetrical and highly homologous lobes (N and C) connected by a hinge region. Both lobes bind two metal ions in synergy with carbonate (CO32-). Not only Fe2+ and Fe3+ ions but Cu2+, Zn2+ and Mn2+ ions can also bind. Lactoferrin can bind Fe3+ reversibly so it can exist as free of Fe3+ (Apo-Lf) or in association with Fe3+ (Holo-Lf) and exhibits different three dimensional structure depending upon binding to Fe3+. Apo-Lf has an open structure and holo-Lf has closed which provide resistance to proteolysis. At iron-binding site Aspirin, two Tyrosine, and Histidine amino acids are directly involved in each lobe and Arginine is bound to CO32- ions. Number and position of Cystine-residues allows intermolecular disulfide bridges and Asparagine-residues in both lobes provide several sites for N-glycosylation (Farnaud and Evans 2003). Lactoferrin is produced by mucosal epithelial mammary cells of human, cows, buffaloes, goat, horses, many other mammals and fish. It is widely distributed in body tissues and present in mucosal surfaces, specific granules of leukocytes and in biological fluids like tears, saliva, digestive fluids, seminal fluids and most abundant in milk comprising the second highest protein in human milk after casein. Concentration of lactoferrin in different species is for cow milk (80-500 mg/L), buffalo milk (50-320 mg/L), camel milk (200-728 mg/L), goat milk (98-150 mg/L) and sheep milk (20-140 mg/L) (Krol et al. 2011). Many physiological functions of lactoferrin have been attributed. It plays an important role in iron regulation, non-specific immune response, regulation of cells growth and differentiation, protection from cancer, anti-inflammatory, anti-oxidant and strong antimicrobial activity against bacteria, fungi, yeast, viruses and parasites (Conneely et al. 2005). Another dominant role of lactoferrin is during involution of mammary gland. Concentration of lactoferrin increased dramatically from 0.1-0.3mg/ml in normal milk to 20-30mg/ml by 30 days in dry period. It is particularly important for bacteriostatic properties and non-specific defense against invading bacteria. Lactoferrin also affects phagocyte function and limit oxidative degeneration of cell components during inflammation and involution (Welty et al. 1976). Lactoferrin exhibits strong antimicrobial activity against different bacteria, virus, protozoa, fungi and yeast (Hancock and Janssen 2009). The antibacterial activity of lactoferrin is due to two mechanisms; by binding the iron at infection sites, making it unavailable to bacteria and direct interaction of N-terminal of lactoferrin with micro-organism (Cruz et al. 2009, Orsi 2004). Lactoferrin acts differently with Gram-positive and Gram-negative bacteria (Sharma et al. 2013). It damages Gram-positive cell wall through interaction with negatively charged lipoteichoic acid causing reduction in negative charge on cell wall and favor contact between lysozyme and inner peptidoglycan (Fayad 2012). Gram-negative bacteria are destroyed by interaction of lactoferrin with external lipopolysaccharides by preventing contact with Ca2+ and Mg2+ ions which cause release of lipopolysaccharides, increase permeability and ensures damage (Ochoa and Cleary 2009, Ekins et al. 2004). Milk and milk products are one of main diet in Pakistan and all over the world. During manufacturing different milk products, a number of by-products are obtained. Among them, cheese whey is produced in high volumes. It is commonly dumped off into sewerage which cause serious environmental problem as it contain high organic matter as well as loss of valuable nutrients it contain. Whey has Biological Oxygen Demand (BOD) ranges from 40,000 to 60,000 ppm (Sayadi et al. 2006) while permitted limit for BOD of domestic sewerage is 200 to 300 ppm. In order to overcome this problem there is need of effective and permanent way for treatment of whey. However, conversion of whey into non-food items like biogas is unreasonable as it is rich in unique nutrients. Now-a-days there is an interest growing on to find new ways of whey utilization throughout the world. One option is to use the whey in processes in which saleable food or pharmaceutical products can be obtained. Whey could be subjected to different techniques to isolate different components like lactose, lysozyme and immunoglobulin. Likewise, lactoferrin can be isolated from cheese whey by cation exchange chromatography without loss of its biological properties in single step method and about 90% purity (Wu et al. 2011, Moradian et al. 2014). In this study, we anticipated to use lactoferrin from bovine milk as natural antimicrobial agent. It has been shown that lactoferrin hasstrong antimicrobial activity against different bacteria, fungi, yeast, viruses and parasites (Conneely et al. 2005). In our country, very little work has been carried out onlactoferrin as natural anti-microbial agent. In fact, all over the world, the research scenario is now changing and concentrating toward the extraction of natural agents for product safety and health improvement. The lactoferrin has a potent anti-microbial activity against common foodborne pathogens. Due to the negative health effects of synthetic anti-microbial agents, the uses of natural sources are being encouraged all over the world. Our main focus of this study is to check the anti-microbial activity of lactoferrin against three pathogenic bacteria Escherichia coli, Staphylococcus aureus and Salmonella enteritidis isolatedduring our previous study. Availability: Items available for loan: UVAS Library [Call number: 2265-T] (1).

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