Life Sciences Commons^™

Ion-Induced Electron Emission From Solids, Wolfgang O. Hofer

Scanning Microscopy

A review of ion-induced electron emission is presented which concentrates on the mechanisms relevant to imaging, analysis, and processing of surfaces by ion beams. In this field of applications, the main interest in electron emission lies in kinetic emission by heavy, i.e. multi-electron (Z > 2) ions of energy ≤ 100 keV.

Effect Of High-Pressure Homogenization On A Sterilized Infant Formula: Microstructure And Age Gelation, Y. Pouliot, M. Britten, B. Latreille

Food Structure

Age thickening and gelation of an Infant formula was Induced by applying high pressure homogenization prior to in-can sterilization. The Initial viscosity of the preparation increased with Increasing homogenization pressure. Thickening rate upon storage, as monitored by viscosity changes, was also proportional to the pressure applied during homogenization. Optical and electron micrographs of 6 month-old samples showed evidence of aggregation. The effect of dissociating agents on the viscosity and microstructure of these samples suggested a contribution of hydrogen bonds and calcium bridges to the gel integrity. The alteration of the mineral balance of aged samples also Indicated a gel strengthening …

Microstructure And Firmness Of Processed Cheese Manufactured From Cheddar Cheese And Skim Milk Powder Cheese Base, A. Y. Tamime, M. Kalab, G. Davies, M. F. Younis

Food Structure

Processed cheese (10 different types) was made from Cheddar cheese and a cheese base produced from reconstituted skim milk powder by blending and melting with commercial emulsifying salts at 9Q<>C. In one experiment, the cheese base was subjected 10 accelerated cheese ripening by added enzyme. The finished products had 50.1- 53.5% total solids, 18.2-19.3% protein, 47.4-49.7% fat in dry matter, and 2.7-3.0% salt in water; pH was 5.3-5.4 after three months of storage at 10 C and 30 C.

The experimental cheeses were markedly firmer than the control cheeses. All processed cheeses exhibited a similar pattern of firmness whereby …

Porosity, Specific Gravity And Air Content In Blue Cheeses, K. M.K. Kebary, H. A. Morris

Food Structure

Porosity and specific gravity were determined in Blue cheeses made from (A) homogenized 14% fat pasteurized cream standardized to 3.9% fat with pasteurized skim milk, (B) homogenized 14% fat raw cream standardized to 3.9% fat with raw skim milk, and (C) pasteurized milk (3.9% fat). There were no significant differences between cheeses made from (A) a nd (B) in porosity and specific gravity. Cheeses made from (A) and (8) had greater porosity, lower specific gravity and more, but smaller holes than cheese made from (C). The negative linear relation ship between porosity and specific gravity, and the insignificant differences in …

The Effect Of Tumbling, Sodium Chloride And Polyphosphates On The Microstructure And Appearance Of Whole-Muscle Processed Meats, P. D. Velinov, M. V. Zhikov, R. G. Cassens

Food Structure

The properties of a whole-muscle processed meat were determined. The complex action of socium chloride, polyphosphates and mechanical agitation caused extraction of myofibrillar protein, swelling of fibers and loss of cross-strations. A new functional ability was found for the extracted proteins to form a fine cover or membrane on the surface of the whole muscle during cooking. These changes produced a product with improved cooking yield and color appearance.

A Method For The Examination Of The Microstructure Of Stabilized Peanut Butter, Clyde T. Young, William E. Schadel

Food Structure

A method for light and scanning electron microscopy of damaged resting peanut seed tissue was adapted as a research tool for evaluating the microstructural features of commercially available stabilized peanut butter. This method was used in the present study to evaluate the degree of homogenization of stabilized peanut butter by examining the spatial relationship which exists among the microstructural features. Light and scanning electron microscopy of three commercially available stabilized peanut butters revealed varying degrees of homogenization of broken cell and tissue fragments, protein bodies, and starch grains within a matrix of stabilized oil.

Transmission And Scanning Electron Microscopy Of Peanut (Arachis Hypogaea L. Cv. Florigiant) Cotyledon After Roasting, Clyde T. Young, William E. Schadel

Food Structure

Changes in the microstructure of peanut (Arachis~ L. cv. Florigiant) cotyledon after roasting at a temperature of 160°C for 16 minutes were investigated with transmission and scanning electron microscopy. Thermal modifications were documented with photomicrographs of t he cytoplasmic network , protein bodies, starch grains and cell-to-cell junctions after oven roasting. These thermal modifications include disruption of the cytoplasmic network, distension of protein bodies, decreased stain affinity of starch grains , and disintegration of middle lamellae in some cell-t o-cell junctions.

Thermotropic Behavior Of Coconut Oil During Wheat Dough Mixing: Evidence For A Solid-Liquid Phase Separation According To Mixing Temperature, Christine Le Roux, D. Marion, H. Bizot, D. J. Gallant

Food Structure

Freeze fracture electron microscopy and differential scanning calorimetry were used to study the behavior of coconut oil during cake batter processing. The greatest modifications of fat crystallization are due to the mixing temperature of batter more than the physical state of the fat before is incorporation and the wheat flour hydration. mixing at a temperature below the melting point of coconut oil involves a liquid/solid fat segregation in the cake batter. The endogenous wheat flour lipids and proteins appear to stabilize this fat partition. These results are likely related to previous observations which correlate loaf volume and mixing temperature of …

Applications Of Microscopy In The Paper Industry: Case Histories Of The Mead Corporation, A. J. Leonardi, B. A. Blakistone, S. W. Kyryk

Food Structure

Microscopial application in the Mead Corporation are herein discussed: 1) defining proper starch cook for maintaining paper quality, 2) microbial degradation of paperboard used for beverage cartons, and 3) examination of high oxygen barrier plastic cups for hermetic seal and barrier construction. Visualization of the cooked starch by iodine staining and polarized light (PL) microscopy is a quick diagnostic aid to Mead mills. Scanning electron microscopy (SEM) and particularly PL proved useful in examining fiber biodegration by fungi on Coated Natural Kraft beverage cartons. Nomarski differential interference contrast (DIC), PL, and SEM aided in qualifying lid materials for Mead's Crosscheck …