Food Technology

 POSTBLEACHING IN HYDROGENATION PROCESS A separate bleaching operation known as post-bleaching immediately following the hydrogenation process has three general purposes: To remove traces of nickel that escape the catalyst recovery filtration. To remove undesirable colors, generally of greenish hue. To removes peroxides and secondary oxidation products. The bleaching process generally employs a bleaching earth and a metal-chelating acid to reduce a residual nickel content to the lowest possible level.  After bleaching,  the spent earth and adsorbed impurities are removed with a pressure filter and the oil is cooled to 130 Fahrenheit before processing. An alternative to post bleaching is the addition of activated carbon to the oil with the catalyst during hydrogenation. Activated carbon is very effective in removing chlorophyll pigments. After filtering, the oil is treated with citric or phosphoric acid and polish filtered to capture the colloidal trace metals remainig ...

   HYDROGENATION Hydrogenation is a reaction of three component: oil, hydrogen and catalyst . the hydrogen gas must be dissolved in the liquid oil before it can diffuse through the liquid to the solid catalyst surface. Each absorbed unsaturated fatty acids can then react with a hydrogen atom to complete the saturation of the double bond, shift it to a new position, or twist it to a higher melting trans-form. Oil  is hydrogenated for two reasons: One reason is to change the naturally occurring fats and oil into the physical form with the consistency and handling characteristics with required functionality. Hydrogenated edible fats and oil products can be prepared with creaming properties, frying stability, sharp melting points and the other functional characteristics desired for specific application. The second reason   for hydrogenation is to increase oxidative stability . Flavor stability is necessary to maintain product acceptability for prolonged periods aft...

                                                           MOUTH-WATERING SUMMER BEVERAGES OF PAKISTAN Pakistan is blessed with all four kinds of weather – summer, winter, autumn and spring. In the southern and south-western parts of the country, in particular, summers can last for up to nine to 10 months, which can be exhaustin g. The temperature in some of these parts rises close to 50 degrees Celsius and, in Sindh, the average temperature during summer stays between 35 and 45 degrees Celsius. Pakistan and summers are famous for the relentless heat. To combat the uncomfortable rise of the mercury, some delicious and refreshing beverages have been created.  Whether it’s about having a full glass of buttermilk lassi or finding watermelons on makeshift stalls, or simply having a glass of rooh afza – summer is a perfect time for u...

  CORN OIL Corn or maize (Zea mays L.) originates from both North and South America. It is one of the most important cereal crops cultivated all over the world next to rice (Oryza sativa) and wheat (Triticum spp.).  A large percent of the corn grains is processed and fed to animals.  Corn is also used for human consumption, fresh or dried and grounded into flour, being an important ingredient in various dishes around the world. Only a small fraction of the corn is used for obtaining corn oil. Corn oil (maize oil) is obtained from seeds (kernels) that only contain 3-5% oil. Usually, oil is extracted from the wet milled germ using a heating process, followed by mechanical expelling and hexane extraction.  PROPERTIES OF CORN OIL The important properties of corn oil include its pleasing flavor, its high levels of polyunsaturated (essential) fatty acids, and its low levels of saturated fatty acids and linolenic acid. It is well known that linolenic acid is especially...