Prevalence of Antibiotic Resistance in Dairy Strains of Streptococcus ...

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DPS - 11Plasmid Profile Analysis ofLactobacillus delbrueckii ssp bulgaricusN. Kavitha and B. DhanalakshmiDept. of Dairy Science, Madras Veterinary College, Chennai.Lactobacillus delbrueckii ssp bulgaricus is well known as starter culture component of yoghurtand cheese. The tremendous acid production and proteolysis by these cultures have significantimpact on the organoleptic quality of dairy products. Hence an attempt was made to study someimportant metabolic functions and also genetic basis for these functions in Lactobacillus delbrueckiissp bulgaricus. A total of thirty nine isolates from dahi and yoghurt samples and two standard strainsLactobacillus delbrueckii ssp bulgaricus. NCDC 04 and NCDC 08 were subjected to plasmid profileanalysis using QIAGEN plasmid midi kit. The titratable acidity of the strains varied between 0.54 and1.73 per cent lactic acid and their proteolytic activity varied between 195 and 360ìg of tyrosine per mlof reconstituted non fat dry milk after 24 hours of incubation. On plasmid DNA analysis, six isolatesand one standard strain were found to contain plasmids of molecular size between 13.02 and 2.40 kbwith a minimum of 1 and maximum of 3 plasmids. The lactic cultures were subjected to elevatedtemperature (45°C) and intercalating dye—ethidium bromide and acridine orange. Subsequently theirlactose metabolism and proteolytic activity were correlated with plasmids and it was found that thosefunctions were plasmid mediated. Thus there is no doubt that increasing our knowledge aboutplasmids and their properties in Lactobacillus delbrueckii ssp bulgaricus will be useful in future todevelop improved and efficient starter cultures.DPS - 12Effect of Homogenization on Free RadicalScavenging Activity of MilkN.T. Vishwanatha; R.B. Sangwan; Rajesh K. Bajaj; Bimlesh Mann and Y.S. RajputDairy Chemistry Division, National Dairy Research Institute, Karnal -132001 (Haryana)Milk is a complex food whose consumption confers a number of nutritional benefits andantioxidative defense against oxidative stress. Free radical scavenging (FRS) activity of milk servesas an important nutritional property to gauze the potential benefits against oxidative damage andvarious diseases. Besides, FRS components such as proteins, vitamins, enzymes and other smallmolecules (urate, biliverdin etc.) present in milk play an important role in preventing lipid peroxidationand maintaining quality of milk. Different processing treatments are known to influence theantioxidant potential of milk. Cow and buffalo milk adjusted to different fat levels of 0.5- 4.0 % and0.5 -6.0 % , respectively, were subjected to pasteurization (72 0 C, 15s) / homogenization (2500psi,500psi) and evaluated for their FRS activity using 2,2’ azinobis 3-ethyl benz thiazoline 6-sulfonic acid(ABTS+) cationic radical as indicator reagent. It was expressed as equivalent to mM of Trolox,a water soluble vitamin E analogue as reference antioxidant. With the increase of fat content, theFRS activity increased both in homogenized and unhomogenized milk; however, it was more in caseof buffalo milk as compared to cow milk. Homogenization resulted in a decrease in FRS activity bothin cow and buffalo milk.
DPS - 13Modified Methods for Detection ofSucrose and Starch in Milk, Khoa and BurfiShaikh Ahesanvarish I. and Des RajDivision of Dairy Chemistry, National Dairy Research Institute, Karnal - 132001 (Haryana)Five adulterants namely sucrose, glucose, starch, urea and NaOH were added to milk.The milk thus adulterated was used for the preparation of khoa and burfi. The BIS (IS:1479, 1960)methods needed modification as they failed to detect the sucrose and starch in presence ofneutralizers especially when NaOH was added at ³ 0.1% in milk. For detection of sucrose, BIS methodwas modified by replacing the use of solid resorcinol pinch and HCl with a solution prepared bydissolving 0.5 g resorcinol in 35 ml of 12 N HCl making volume 100 ml with water. Addition of 1 ml ofthis solution to 1 ml test portion of sample was recommended. The modified method was notinterfered by any other adulterants for the detection of sucrose. Even formalin when used at 0.4% forpreservation purposes did not interfere. The minimum detectable limit was 0.05% sucrose along withother adulterants in milk and khoa. While for detecting starch, method was modified by adding 0.3 mlof 1 N sulphuric acid in the test portion of milk sample after boiling and cooling. The starch detectionby modified method was not interfered by any other adulterants. The modified method could detectstarch at minimum 0.05% level in milk and in the khoa and burfi prepared from the adulterated milk.The storage period up to 3 weeks of study of khoa samples after preservation with formalin (0.4%)did not have any effect on the detection of starch.DPS - 14Detection of Ghee Adulteration withCoconut Oil/Palm OilSofia P Zachariah, M K Bhavadasan, and B Surendra NathSouthern Campus, National Dairy Research Institute, Bangalore - 560 030.Ghee is an expensive product and is susceptible to be adulterated with vegetable oils.Several methods like determination of physico-chemical characteristics, phytosterol acetate test, chromatographicmethods, colour reactions etc, have been developed for the detection ofadulteration in ghee. However, these tests have limitations to detect adulteration of ghee. Detectionof coconut oil /palm oil in ghee is all the more difficult as their analytical characteristics are close tothose of ghee. The present study demonstrates the effectiveness of certain tests to detectadulteration of ghee with coconut oil /palm oil. It is concluded that determination of physico-chemicalcharacteristics mentioned in PFA for ghee cannot detect adulteration of ghee with coconut oil /palmoil. Determinations of Polenske value and crystallization time of fat at 17 0 C seem to be helpful todetect adulteration with these oils. A modified TLC method involving resolution of unsaponifiablematter could be used for routine analysis of ghee samples to detect adulteration. More reliablemethods for the detection of ghee were found to be the determination of yield of liquid fraction fromghee at 25 0 C and estimation of phytosterol by HPLC.17
Page 3 and 4: DPS - 5Studies on Bioactive Isoflav
Page 5: DPS - 9Characterization of Dairy La
Page 9 and 10: DPS - 17Studies on Development and
Page 11 and 12: DPS - 21Effect of Incorporation of
Page 13 and 14: DPS - 25 Optimization of Ingredient
Page 15 and 16: DPS - 29Studies on Suitability of S
Page 17 and 18: DPS - 33Development of a Comprehens
Page 19 and 20: DPS - 37Admixing of Buttermilk to B
Page 21 and 22: DPS - 41Evaluation of Selected Tech
Page 23 and 24: DPS - 45Rate of Acidity Development
Page 25 and 26: DPS - 49Is A Probiotic Dahi Safe Fo
Page 27 and 28: DPS - 53Process Optimization for Ma

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