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Food Science

Food Structure

Fluorescence microscopy

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Full-Text Articles in Life Sciences

Effects Of Processing On The Microstructure Of Oat (Avena Sativa) Bran Concentrate And The Physicochemical Properties Of Isolated B-Glucans, K. Autio, Y. Malkki, T. Virtanen Jan 1992

Effects Of Processing On The Microstructure Of Oat (Avena Sativa) Bran Concentrate And The Physicochemical Properties Of Isolated B-Glucans, K. Autio, Y. Malkki, T. Virtanen

Food Structure

Fluorescence microscopy was used to study the microstructure of oat cell walls during concentration of oat bran and isolation of ,B-glucans. The bran concentrate separated from c.v. Nasta contained mainly the aleurone and subaleurone endosperm layers, whereas that separated from a commercial bran mixture contained more endosperm . In contrast to Nasta, the commercial bran mixture contained ,B-glucan degrading enzymes, which survived the ,B-glucan isolation procedure. In the presence of enzymes, the solubility and yield of ,B-glucans improved but the viscosity decreased when it was measured at the same ,B-glucan concentration. For inactivation of the enzymes, 80% ethanol at 78 ...


Structural Characteristics Of Pennisetum Americanum (Pearl Millet) Using Scanning Electron And Fluorescence Microscopy, C. M. Mcdonough, L. W. Rooney Jan 1989

Structural Characteristics Of Pennisetum Americanum (Pearl Millet) Using Scanning Electron And Fluorescence Microscopy, C. M. Mcdonough, L. W. Rooney

Food Structure

Fluorescence bright field and scanning electron microscopy were used to characterize the structure of selected mature pearl millet caryopses from the World Germplasm Collection. Kernel shape (globose, lanceolate, obovate and hexagonal). kernel endosperm color (while. yellow and grey) and external appearance (color) of the samples were documented for 96 varieties. Color of the pearl millet kernel was due to the combined effects of pigmentation in the pericarp. aleurone and endosperm. as well as the pericarp thickness. White kernels had few pigmented areas. yellow kernels had pigments primarily in the epicarp and endosperm. and brown kernels had pigments in the epicarp ...


Grittiness In A Pasteurized Cheese Spread: A Microscopic Study, H. W. Modler, S. H. Yiu, U. K. Bollinger, M. Kalab Jan 1989

Grittiness In A Pasteurized Cheese Spread: A Microscopic Study, H. W. Modler, S. H. Yiu, U. K. Bollinger, M. Kalab

Food Structure

Coagulation of pasteurized (63 C for 30 min) milk and blending of the resulting curd with high-fat cream followed by heat treatment (44 to 80 C for 10 min) of the blend in preparation of a hot-pack cheese spread led to the formation of a gritty product. Microscopic examination of hard particles causing the grittiness indicated that they consisted of compacted protein. Staining for calcium failed to detect any elevated concentration of this element in the particles. They were amorphous and contained no crystalline structures.

Encapsulation of the gritty curd in agar gel tubes made it possible to freeze-fracture the ...


Fluorescence Microscopy Studies On (1,3) - B-D-Glucan In Barley Endosperm, A. W. Macgregor, G. M. Ballance, L. Dushnicky Jan 1989

Fluorescence Microscopy Studies On (1,3) - B-D-Glucan In Barley Endosperm, A. W. Macgregor, G. M. Ballance, L. Dushnicky

Food Structure

Development of (1,3;1,4)-B-D-glucan and (1,3)-B-D-glucan in kernels of Himalaya and Bonanza barley has been followed by fluorescence microscopy using calcofluor and aniline blue fluorochromes. Specific enzymes were used to confirm the identity of these two polysaccharides in sections of endosperm tissue. All barley lines tested contained both types of B-glucan but (1,3;1,4)-B-glucan was synthesized at an earlier stage of development than was (1,3)-BGlucan. Small bead-like deposits of (1,3)-B-glucan were detected in all cultivars examined. These deposits were present throughout the endosperm and appeared to be associated ...


Fluorescence And Light Microscopic Analysis Of Digested Oat Bran, S. H. Yiu, R. Mongeau Jan 1987

Fluorescence And Light Microscopic Analysis Of Digested Oat Bran, S. H. Yiu, R. Mongeau

Food Structure

The Structural and chemical compositions of digested oat bran were analyzed by fluorescence and other types of light microscopy. The digestion of oat bran was carried out under two conditions - in vitro, by incubation with human saliva, and in vivo, by feeding rats with an oat-bran supplemented diet. Comparison of the digestive breakdown among different structural components of oat bran was conducted by microscopically examining samples obtained from the tents of the large intestine (LIC) of the rats. Results of the examinations revealed that the (1-3) (1-4) - B - D - glucan - rich cell wall of the subaleurone layer, along with its ...


Structural Characteristics Of Eleusine Corocana (Finger Millet) Using Scanning Electron And Fluorescence Microscopy, C. M. Mcdonough, L. W. Rooney, C. F. Earp Jan 1986

Structural Characteristics Of Eleusine Corocana (Finger Millet) Using Scanning Electron And Fluorescence Microscopy, C. M. Mcdonough, L. W. Rooney, C. F. Earp

Food Structure

The objective of this study was to document the microstructure of finger millet wlth scanning electron and fluorescence microscopies. Finger millet is an utricle which is spheri ca 1 and about 1 . 5 ITlT1 in diameter. The membranous peri carp of finger millet was loosely associated with the seed at maturity. Beneath the loose pericarp wa s a five-layered testa that varied from red to purple in color. The outer layer was the only testa layer that autofl uoresced, suggesting the presence of phenolic acids, i .e., ferulic acid. The aleurone layer was beneath the testa , and was one cell ...


Fluorescence Characterization Of The Mature Caryopsis Of Sorghum Bicolor (L.) Moench, C. F. Earp, L. W. Rooney Jan 1986

Fluorescence Characterization Of The Mature Caryopsis Of Sorghum Bicolor (L.) Moench, C. F. Earp, L. W. Rooney

Food Structure

Fluorescence microscopy was used to characterize the mature car yaps is of Sorghum bicolor (L.) Moench . Acid Fuchsin, a protein specific dye used in bright field microscopy, caused protein bodies and matrix in the sorghum endosperm to fluoresce. ANS (8-ani lino-1- naphthal e ne sulfonic acid) also caused the protein bodi es and matrix in the endosperm to fluoresce. Varietal differences in endosperm protein dist r ibution were evident when viewed after sta ยท ning with Acid Fuchsin . Nile Blue A caused fl uorescence in neutral lipids such as those in :he lipid bodies in the aleurone and scutellum of sorg ...


A Fluorescence Microscopic Study Of Cheese, S. H. Yiu Jan 1985

A Fluorescence Microscopic Study Of Cheese, S. H. Yiu

Food Structure

Fluorescence techniques were used to study the microstructure of several varieties of cheese. The size and distribution of fat globules in various cheeses were demonstrated by fluorescent staining using Nile Blue A as a marker. Acridine Orange was used as a dye to detect structural differences between casein matrices of various cheese varieties. Differences between the ripe and the less- ripe zones of Ca membert cheese were detected by staining the cheese sections with Acridine Orange and Nile Blue A separately, and then comparing the re sults of the stainings. The Nile Blue A stain ing s howed that fat ...


Preliminary Evaluation Of Lectins As Fluorescent Probes Of Seed Structure And Composition, S. Shea Miller, S. H. Yiu, R. G. Fulcher, I. Altosaar Jan 1984

Preliminary Evaluation Of Lectins As Fluorescent Probes Of Seed Structure And Composition, S. Shea Miller, S. H. Yiu, R. G. Fulcher, I. Altosaar

Food Structure

Several commercially available fluoresceinisothiocyanate and rhodamine isothiocyanateconjugated plant lectins have been applied to cereal and oilseed tissues to permit identification and localization of specific structures and carbohydrates by fluorescence microscopy . Ulex europeaus Agglutinin I (UEAl) and Ricinis communis Agglutinin I (RCA I) showed specificity for the amyloids in rapeseed cotyledonary cell walls . Wheat Germ Agglutinin (WGA) bound to rapeseed coat mucilage, as well as fungal hyphae in infected wheat . Lens culinaris Agglutinin (LCA) bound only to starch in cereal sections, and at higher magnifications of isolated starch granules , the annular structure was clearly visible.


B-Glucans In The Caryopsis Of Sorghum Bicolor (L.) Moench, C. F. Earp, C. A. Doherty, R. G. Fulcher, L. W. Rooney Jan 1983

B-Glucans In The Caryopsis Of Sorghum Bicolor (L.) Moench, C. F. Earp, C. A. Doherty, R. G. Fulcher, L. W. Rooney

Food Structure

Fluorescence microscopy was used to determine the location of B- glucans in sorghum. Sections from three genetically different sorghum cultivars were stained with Calcofluor or Congo Red , fluorochromes which have been reported to react with 13-glucans. Autofluorescence, indicative of ferulic acid in other cereals, was observed in untreated sections. When stained sections were treated with endo -B-glucanase , fluorescence was reduced or entirely eliminated in pericarp, aleurone and endosperm cell walls. 13-Glucans were i so lated from the endosperm of three sorghum cultivars. When reacted with the two dyes, Calcofluoror Congo Red , precipitates formed immediately, a reaction which is similar to ...


Fluorescence Microscopy Of Cereals, R. G. Fulcher Jan 1982

Fluorescence Microscopy Of Cereals, R. G. Fulcher

Food Structure

The fluorescence microscope is one of the most sensitive instruments available for morphological and microchemical analysis of biological material, and especially of cereal grains. Recent innovations in illuminating systems, fluorescence chemistry, and specimen preparation have combined to provide significant improvements over conventional bright-field microscopy in both specificity and sensitivity. A variety of relatively specific fluorescent markers has been devised for routine and high resolution detection of all major cereal components. Several examples of useful fluorescent markers are described, including appropriate methods for specimen preparation, fluorescence analysis, and photography.