Food Science Commons^™

Preparation Of Selenium Nanoparticles Based On Fish Gelatin Dispersion System And Investigation Of Their Anti-Oxidant Activities, Du Peng-Cheng, Wang Hui, Hu Yue-Ming, Tu Zong-Cai

Food and Machinery

Selenium nano particles (SeNPs) were prepared using fish gelatin dispersion system, and its particle size, morphology, and digestive stability were studied by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The antioxidant capacity of SeNPs were determined. The results showed that fish gelatin was excellent dispersion system for preparation of SeNPs. The particle size of SeNPs and its morphology was barely affected by the concentration of fish gelatin dispersion system. Moreover, SeNPs presented good antioxidant ability. Among them, the DPPH radical scavenging ability of SeNPs prepared by 1.000%, 0.500%, 0.125% fish gelatin dispersion system, and IC50 value were 1.846 …

On The Use Of Vibrational Spectroscopy And Scanning Electron Microscopy To Study Phenolic Extractability Of Cooperage Byproducts In Wine, Berta Baca‑Bocanegra, Julio Nogales‑Bueno, Brian Gorey, Francisco José Heredia, Hugh Byrne, José Miguel Hernández‑Hierro

Articles

Wood is an important source of phenolic compounds, which can be transferred to wine during aging process, improving its properties, from an organoleptic point of view. Therefore, understanding and optimizing the extractability of phenolic compounds from wood are crucial in the oenological field. The structural composition of oak wood samples has been evaluated using Raman and attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopies, and their main spectral features have been linked to phenolic compound extractabilities, as measured by classic chemical analyses. To support the analysis, microscopic images of the samples were also recorded using scanning electron microscopy (SEM). The …

Microstructural Changes To Proso Millet Protein Bodies Upon Cooking And Digestion, Paridhi Gulati, You Zhou, Christian Elowsky, Devin J. Rose

Department of Food Science and Technology: Faculty Publications

Cooking results in a drastic decline in digestibility of proso millet proteins, panicins. Scanning electron and confocal microscopy were used to observe morphological changes in proso millet protein bodies upon cooking and digestion that could be associated with the loss in digestibility. Spherical protein bodies (1–2.5 mm) were observed in proso millet flour and extracted protein. Cooking did not result in any noticeable change in the size or shape of the protein bodies. However, upon digestion with pepsin the poor digestibility of cooked proso millet protein was clearly evident from the differences in microstructure of the protein bodies: large cavities …

Improved Keratinase Production For Feather Degradation By Bacillus Licheniformis Zjuel31410 In Submerged Cultivation, Hui Ni, Qi-He Chen, Feng Chen, Ming-Liang Fu, Ya-Chen Dong, Hui-Nong Cai

Feng Chen

Optimal medium was used to improve the production of keratinase by Bacillus licheniformis ZJUEL31410, which has a promising application in the transformation of feather into soluble protein. The results of single factor design revealed that the concentration of feather at 20 g/l and the initial pH at value 8 was the best for the production of keratinase and the degradation of feather. Ammonia salt and nitrate salt strongly restricted the production of keratinase and the degradation of feather. Result of Box-Behnken design (BBD) experiment which was used to optimize concentrations of glucose, corn steep flour and K2HPO4 for further improvement …

Improved Keratinase Production For Feather Degradation By Bacillus Licheniformis Zjuel31410 In Submerged Cultivation, Hui Ni, Qi-He Chen, Feng Chen, Ming-Liang Fu, Ya-Chen Dong, Hui-Nong Cai

Publications

Optimal medium was used to improve the production of keratinase by Bacillus licheniformis ZJUEL31410, which has a promising application in the transformation of feather into soluble protein. The results of single factor design revealed that the concentration of feather at 20 g/l and the initial pH at value 8 was the best for the production of keratinase and the degradation of feather. Ammonia salt and nitrate salt strongly restricted the production of keratinase and the degradation of feather. Result of Box-Behnken design (BBD) experiment which was used to optimize concentrations of glucose, corn steep flour and K₂HPO_{4 …}

Mechanisms Of Hard-To-Cook Defect In Cowpeas: Verification Via Microstructure Examination, Keshun Liu, Yen-Con Hung, R. Dixon Phillips

Food Structure

It has been hypothesized that part of the hard-to-cook (HTC) defect in cowpeas is due to decreases in solubility and thermal stability of intracellular proteins during storage since coagulated proteins would limit water to starch and prevent full swelling during cooking. To verify this hypothesis, effects of soaking and heating temperature on texture, water absorption, protein water extractability and microstructure of control and HTC cowpea seeds (aged or treated) were studied. Scanning electron microscopy showed no structural difference between dry control and dry aged seeds. However, after soaking, in contrast to the control, aged seeds exhibited a coarse protein matrix …

Microstructure Of Idli, Enamuthu Joseph, Shelly G. Crites, Barry G. Swanson

Food Structure

The microstructure of idli prepared from seeds of common beans (Phaseolus vulgaris) and rice, and Indian black gram seeds ( Vigna mungo) and rice in the ratio 1:2 was examined . Intact starch granules and protein bodies were observed in the unfermented idli batter. Starch granules disappeared as fermentation time increased to 18 hours and 36 hours. The surface of idli prepared from 36-hour fermented batter was cohesive , dense and sponge- or foam-like. The microstructure of idli prepared from common beans and rice was similar to the microstructure of idli prepared from Indian black gram and rice. Common beans …

Lactose Crystallization In Spray-Dried Milk Powders Exposed To Isobutanol, Carlos A. Aguilar, Gregory R. Ziegler

Food Structure

A study was undertaken to establish whether suspension of dry milk powder in isobutanol and 1-octanol during particle size analysis and preparation for scanning electron microscopy introduced artifacts. The median , volume-based diameter, d[v, 0.5], of spray-dried milk powders containing 27-67% lactose changed over time of exposure to isobutanol. No changes in median diameter were observed when powders were exposed to 1-octanol. Changes in particle si ze resulted from solubilization of amorphous lactose and/or recrystallization of lactose on the particle surface. Both a- and ,6 -lactose were formed during contact with isobutanol as indicated by X-ray diffraction and scanning electron …

A Comparison Of The Effects Of Oven Roasting And Oil Cooking On The Microstructure Of Peanut (Arachis Hypogaea L. Cv. Florigiant) Cotyledon, Clyde T. Young, William E. Schadel

Food Structure

Peanut (Arachis hypogaea L. cv. Florigiant) cotyledon microstructure after oven roasting and oil cooking at 160 C was documented with scanning electron microscopy, light microscopy and transmission electron microscopy . Changes in peanut cotyledon microstructure were compared as thermal processing time at 160°C was increased for both oven roasting and oil cooking. The purpose was to evaluate thermal modifications in the cytoplasmic network, protein bodies and cell-to-cell junctions as thermal processing time in creased for each heating method. Principal findings included differences in the times at which these modifications occurred during the two thermal processes. Oven roasting a t 160 …

Critical Point Drier As A Source Of Contamination In Food Samples Prepared For Scanning Electron Microscopy, Gisele Larocque, A. F. Yang

Food Structure

A valve in a critical-point drier regulating the flow of liquid carbon dioxide was found to be the source of minute metal particles which contaminated the fragments resulting from freeze-fracturing of food samples.

Microstructure Of Mozzarella Cheese During Manufacture, Craig J. Oberg, William R. Mcmanus, Donald J. Mcmahon

Food Structure

Scanning electron microscopy was used to examine structural developments during the manufacture of low-moisture, part-skim Mozzarella cheese made by a stirred curd procedure. The micrographs showed changes in the protein matrix , dispersion of fat globules, and bacteria during processing. Most curd knitting occurred during the curd stirring step, particularly dry stirring. A thin (5 ,urn) curd skin was observed on curd particles at the end of dry stirring. Dry salting prior to stretching resulted in the rapid loss of whey from the curd particle. Protein fibers were aligned and longitudinal columns of whey and fat were formed when the …

Composition And Microstructure Of Commercial Full-Fat And Low-Fat Cheeses, V. V. Mistry, D. L. Anderson

Food Structure

The objective of this study was to analyze the composition of commercial full-fat and low-fat cheeses and to evaluate their microstructure. Commercial cheeses evaluated included full-fat and low-fat Cheddar, Mozzarella , processed, and Swiss cheeses. Cheddar cheeses ranged from 8.2% fat and 5 1.1% moisture in the 75% low-fat product to 33.2% fat and 35.9% moisture in the full-fat cheese . Mozzarella cheeses ranged in fat from a low of 2. I% to a high of 24% with corresponding moisture content of 56.6 to 45.5% respectively. Fatfree processed cheese had 0. 9% fat and 58.7% moisture , while the full …

Age Related Changes In The Microstructure Of Mozzarella Cheese, L. J. Kiely, P. S. Kindstedt, G. M. Hendricks, J. E. Levis, J. J. Yun, D. M. Barbano

Food Structure

Changes that occurred in the microstructure of low-moisture, part skim Mozzarella made with a mixed starter consisting of Streptococcus salivarius ssp. thermophilus and Lacwbacillus delbrueckii ssp. bulgaricus and coagulated with fermentation -produced chymosin , were examined during 50 days of ripening at 4 °C. Im mediately after manufacture (day 3), a homogeneous and continuous phase of amorphous paracasein represented a three-dimensional protein network in the cheese. A large number of irregularly shaped and sized microcavi ties were present. During 50 days of aging , an increase in the porosity of the defatted paracasein matrix was apparent. These changes were coincidental …

Microstructure Of Black, Green And Red Gram, Enamuthu Joseph, Shelly G. Crites, Barry G. Swanson

Food Structure

The three most commonly consumed legumes (grams or pulses) in India, black gram (Vigna mungo (L.) Hepper), or urd , green gram (Vigna radiata (L.) Wilczek) or mung, and red gram (Cajanus cajan (L.) Millsp.) or tur, were examined by scanning electron microscopy . Seed coat and internal features were examined to differentiate these legumes from common beans (Phaseolus vulgaris) , adzuki beans (Vigna angu/aris) and lentils (Lens culinaris). Cross-sections of the seed coats of black, green and red gram contained single layers of columnar palisade cells extending as double palisade layers at the hilum regions. The funiculi located above …

Effect Of Draw Ph On The Development Of Curd Structure During The Manufacture Of Mozzarella Cheese, L. J. Kiely, P. S. Kindstedt, G. M. Hendricks, J. E. Levis, J. J. Yun, D. M. Barbano

Food Structure

The impact of varying the pH of whey at whey drainage (5.9, 6.15 or 6.4) on the development of curd structure during the manufacture of Mozzarella cheese was investigated using scanning electron microscopy. Dramatic changes in curd structure were apparent with stage of manufacture , in particular the stretching step which aligned the protein fibers.

Of additional interest is the effect of draw pH on the structure of curd at whey drainage. When whey was drained at pH 6.4, an open poorly fused network of paracasein particles was observed in the cheese curd. Jn contrast, lowering the draw pH (6.15 …

The Cellular Structure Of Selected Apple Varieties, K. G. Lapsley, F. E. Escher, E. Hoehn

Food Structure

Apple cultivars (Sauergrauech, Klarapfel, James Grieve, Granny Smith, Mcintosh, Robinette) which had different textures based on sensory and instrumental analysis (particularly in firmness and mealiness) were examined by conventional scanning electron microscopy (SEM), cold-stage SEM (cryoSEM) and confocal scanning laser microscopy (CSLM) using various preparative procedures. Advantages, lim itations and artifacts of each technique are discussed.

SEM with glutaraldehyde-fixation and criticalpoint- drying produced minimal tissue distortion and the fracture pattern and appearance of mealy versus non mealy tissue was different. Freeze-drying unfixed tissue caused cell collapse and firm versus soft varieties could not be differentiated. Freeze-fracturing and cryoSEM of apple …

Structure And Rheology Of String Cheese, S. Taneya, T. Izutsu, T. Kimura, T. Shioya

Food Structure

String cheese samples ranging in pH from 5.0 to 5.9 were prepared by kneading Mozzarella curd and stretching it 2 to 80 times. Rheological properties were examined by compression, stress relaxation , and flow property tests. Stringiness was tested by a device specifically designed for this purpose: a standardized string was pulled from the sample at a direction perpendicular to the orientation of the curd and the amount of fibres resulting from this process was quantitated using digital image analysis.

Force-deformation curves implied that the curd prepared by kneading may be considered to be an incompressible viscoelastic body similar to …

Effect Of Lactose And Protein On The Microstructure Of Dried Milk, V. V. Mistry, H. N. Hassan, D. J. Robison

Food Structure

Skim milk of approximately 3% total protein was ultrafiltered to 16.2% protein and 4.1 % lactose, and then diafiltered to reduce lactose to 2.1% and 0.9%. Total protein con ten t was maintained at approximately 17%. A ponion of the skim milk was condensed in a rising film evaporator to 14.7% protein and 15.7% lactose . All concentrates were spray dried at 120 to 125 °C inlet air temperature and 75 to 80 C outlet temperature using a rotary atomizer in a pilot plant spray dryer . Moisture content of the powders were 4.7 to 6.3% and lactose content ranged …

Characterization Of The Pore Structure Of Starch Based Food Materials, Z. Hicsasmaz, J. T. Clayton

Food Structure

Macroscopic pore structure parameters (bulk density, true density and porosity) and microscopic pore structure parameters (percentage closed pore volume and pore size distribution) for a highly expanded type (Wonder White Sandwich Bread) and a relatively compact type (Chessmen Butter Cookies) starch based food material were determined and their pore structures were compared. Bulk density determined by solid displacement and true density determined by pycnometry yielded porosity measurement s o f 0.9 for bread and 0.6 for cookies. Percentage closed pore volume calculated by comparing the true density of porous samples of bread and cookies with the true density of !heir …

Scanning Electron Microscopy Studies Of A Typical Spanish Confectionery Product: "Xixona Turron", M. A. Lluch, M. J. Galotto, A. Chiralt

Food Structure

The microstructure of "Xixona turron" , a typical Spanish confectionery product, made with toasted almonds, sugar and honey, was elucidated, in order to confirm the nature of those physical changes occurring in its manufacturing process, which has not been previously studied. The effect of the major components of "Xixona turron" (oil, proteins and sugar) on its structural c!Jange was established. The initial oil suspension of sugar syrup drops and proteins undergoes a phase inversion , becoming an oil /water emulsion when hot, and a solid-like structure, when the aqueous sugar continuous phase solidifies at room temperature. In order to determine …

Scanning Electron Microscopy And Ultraviolet Absorption Microspectrophotometry Of Plant Cell Types Of Different Biodegradabilities, D. E. Akin, L. L. Rigsby

Food Structure

Phenolic components within cell walls are the greatest limitation to biodegradation of plants, but the location and types of compounds within specific walls are poorly understood . Leaf blades of warm-season (Coastal and Coastcross-1 bermuda grasses and sudangrass) and cool-season grasses (orchardgrass and tall fescue) and leaflets of legumes (alfalfa and lespedeza) were evaluated before and after incubation with rumen microorganisms for 7 days to determine cell types and wall structures most resistant to biodegradation. UV absorption microspectrophotometry was used to characterize aromatics within selected undegraded cell types, which had been shown in digestion studies to vary in biodegradability, from …

Microstructure And Firmness Of Labneh (High Solids Yoghurt) Made From Cow's, Goat's And Sheep's Milks By A Traditional Method Or By Ultrafiltration, A. Y. Tamime, M. Kalab, G. Davies, H. A. Mahdi

Food Structure

Two types of Labneh (high solids yoghurt) were made from goat's and sheep 's milk: (a) traditional style Labneh was produced by straining yoghurt in a cloth bag, and (b) UF Labneh was made by ultrafiltration (UF) of warm yoghurt. A portion of all products were smoothened by a passage through a lactic curd homogenizer. Irrespective of their origin , the Labneh samples contained 20.5-22.5% total solids (including minerals and un-metabolized lactose), 6.7-8.2% protein, and 7.8- 8.9% fat.

Homogenization markedly decreased firmness of the goat's and sheep's Labnehs and is therefore not re~ commended in industrial production . Firmness of …

Structure And Rheology Of Dairy Products: A Compilation Of References With Subject And Author Indexes, David N. Holcomb

Food Structure

No abstract provided.

Recent Developments In The Application Of X-Ray Microanalysis To The Study Of Food Systems, B. E. Brooker

Food Structure

Low temperature scanning electron microscopy in conjunction with X-ray microanalysis can be used to study not only the internal structure of intact bulk food systems but also the distribution of their constitutive chemical elements. However, the considerable practical problems that are usually encountered when performing X-ray analysis on frozen samples include: a) the controlled deposition of a good quality carbon film to prevent charging, b) producing digital elemental distribution maps of elements whose X-ray spectral energy peaks partially or completely overlap and c) controlling the plane of fracture through the specimen and ensuring that the resulting topography allows meaningful analysis …

Application Of Scanning Electron Microscopy And X-Ray Microanalysis To Investigate Corrosion Problems In Plain And Enamelled Three Piece Welded Food Cans, James E. Charbonneau

Food Structure

Scanning Electron Microscopy (SEM) and X-Ray Microanalysis (EDS) have been used to investigate rapid detinning, pitting corrosion and cosmetic corrosion in plain tin plate food cans and pitting corrosion, underenamel corrosion, enamel flaking , sulfide black corrosion and stress corrosion cracking in enamelled food cans.

Through the use of SEM - EDS it was determined that (SnL a /FeK a) Y2 X -ray line intensities arc proportional to the tin coating weight on tinplate. The method was applied to a rapid detinning problem in canned grapefruit sections. The cause of the early corrosion failure was found to be reversed tinplate. …

Crystal Morphology Of Shortenings And Margarines, P. Chawla, J. M. Deman, A. K. Smith

Food Structure

An improved method is proposed for isolation of fat crystals with isobutanol, followed by fixation using osmium tetroxide vapours or cryo-fixation and visualization in the Scanning Electron Microscope (SEM). The cryo-fixation method revealed the presence of well defined needle-shaped or rod-shaped fat crystals. The osmium fixed crystals did not appear as distinct. The crystals existed as single crystals, platelets and spherulites. Polarized light micrographs did not show the details of the crystal morphology that were observed in the SEM.

Microstructure Of Peanut Seed: A Review, Clyde T. Young, William E. Schadel

Food Structure

Mature peanut seed microstructure of importance to the food industry is examined with regard to: (1) anatomy and cytology of peanut seed; (2) the effects of environment on peanut seed; and (3) the effects of various processing procedures on peanut seed. Current peanut seed microstructure research by the authors is directed toward evaluation of the quality of processed peanuts including using TEM, SEM and LM to evaluate the effects of different times of oven roasting at the same temperature, and a method for evaluating quality of homogenization of broken cell and tissue fragments, protein bodies and starch in stabilized peanut …

Particle Characteristics Of Flake-Cut Meat, P. R. Sheard, A. Cousins, P. D. Jolley, C. A. Voyle

Food Structure

The size of flake-cut meat is an Important quality determinant of comminuted meat products which. potentially. depends upon a large number of factors. Temperature and whether or not the meat is pre-broken have a major Influence on the resulting particle size distribution, as does aperture size. Meat flaked at -7'C produced two to three times more flakes than at -3' C. Under some conditions the particles produced were as little as 0.4 mm thick and characteristically were thicker at one end.

High speed photography, used to visualise the cutting action. Indicated that size reduction occurs In a controlled manner providing …

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

Food Structure

Changes in the microstructure of peanut (Arachls ~ L. cv Florunner) cotyledons after roasting at a temperature of 160°C (16 min) were investigated with light and scanning electron microscopy. Major changes included: (1) pitting and pock -marking of the epidermis of the cotyledons caused by the escape of steam and on released during roasting; (2) loss of cellular organization of the cytoplasmic network surrounding the Jipid bodies, protein bodies, and starch grains ; (3) alteration of the structures of cytoplasmic network. lipid bodies, and protein bodies; and (4) heat destruction of some middle lamellae of cell - t o-cell junctions.

Microscopic Measurement Of Apple Bruise, N. K. Kim, Y. C. Hung

Food Structure

Microstructural differences between unbruised and bruised apple tissues were evaluated. Cell connections appeared to be looser in bruised tissue than in unbruised tissue. Bruised tissue exhibited more empty regions which are not occupied by cells than unbruised tissue. Empty reg ions in unbruised and bruised tissues were about 0.7 and 2.4 per mm2, respectively, comprising 0.7% and 2.7% of the respective total volume. Stereology is a body of mathematical methods relating three-dimensional parameters defining a structure to two- dimensional measurements. Two methods based on a stereological principle were also used to quantify the fraction of total volume occupied by cells. …