bluuebunny/crossref_metadata_2025_split huggingface dataset:
DEVELOPMENT OF A CONTINUOUS METHOD FOR PUFFING AMARANTH (AMARANTHUS SPP.) SEEDS
Authors: TIKEKAR ROHAN V. , KARWE MUKUND V. 
Published: September 2008

ABSTRACT Amaranth (Amaranthus spp.) is a nutritionally dense pseudocereal grown mostly in South America and Asia. Traditionally amaranth seeds are puffed using a hot skillet. Besides being a batch system, in this process there is little control over the temperature and the residence time of the seeds. We have developed a continuous technique for puffing amaranth seeds using a single‐screw extruder with a tapered screw without a die. With this technique we could control the temperature and the residence time for puffing the seeds. It was found that the puffing efficiency of amaranth seeds was a function of temperature and screw speed. The maximum efficiency of 86% was achieved at a barrel temperature of 290C and screw speed of 125 rpm. Sensory analyses with an untrained panel of 33 subjects using samples generated at conditions with puffing efficiency above 75% showed that the sample processed at 250C and 75 rpm was the most acceptable in terms of various sensory attributes and overall liking.PRACTICAL APPLICATIONSThe research aims to develop a new continuous process for the puffing of amaranth seeds. The use of an extruder without a die for puffing these seeds is a novel idea. This process could possibly be used for puffing several other seeds and grains, making it a versatile technology. The sensory work conducted in this paper aims at examining the acceptance of this relatively new product among U.S. consumers.
OPTIMIZATION OF EXTRUSION COOKING OF CORNMEAL AS RAW MATERIAL FOR BAKERY PRODUCTS
Authors: CURIC D. , NOVOTNI D. , BAUMAN I. , KRICKA T. , DUGUM J. 
Published: September 2008

ABSTRACT The objective of this work was the optimization of extrusion process for the production of extruded cornmeal (ECM) that may be used in the production of corn bread by a direct procedure. The extrusion process variables, barrel temperature, Et (111–159C), moisture content, Mc (12.10–24.77%) and screw speed, Ss (160–460 rpm), were considered and their influence on moisture content of milled extrudates (ME), expansion index (EI), bulk density (BD), water solubility index (WSI), water absorption index (WAI) and cold paste viscosity (CPV) of extrudates was investigated. The influence of ECM addition on viscosity of wheat flour and cornmeal mixture was monitored. The optimimum combination of extrusion conditions was Mc = 21.21%; Et = 145C; Ss = 263.5 rpm. The properties of ECM under optimal extrusion conditions were Mc, 10.97%; EI, 4.22; WAI, 7.84 g gel/g dm; WSI, 14.88%; BD, 36.35 g/100 mL and CPV, 1,220 BU. In the quantity of 30% calculated on the wheat flour quantity, the ECM can be used for the production of corn breads by a direct procedure. PRACTICAL APPLICATIONCorn flour obtained by dry milling of maize, namely in a mixture with wheat flour, has been used in Southeastern Europe for centuries in theproduction of bakery products. Cornstarch granules swell more slowly and gelatinize at a higher gelatinization temperature than starch granules of wheat flour, while corn proteins are incapable of dough formation. The properties of finished corn bakery products depend significantly on the quantity and temperature of the boiling water used for the mix (60–100% of total water quantity added to the mix) and the steaming time of the corn flour (3–12 h), which is the first and critical stage in the process of corn bread and rolls production. The quality of finished products depends significantly on the baker's experience.The purpose of this work was to determine the optimal extrusion process variables for the production of the gelatinized cornmeal that can be used in the production of bakery products by a direct procedure, without prior steaming of cornmeal. This could significantly reduce the processing time and energy consumption, while the product will still be of consistent and even better quality.
CLARIFICATION AND PURIFICATION OF AQUEOUS STEVIA EXTRACT USING MEMBRANE SEPARATION PROCESS
Authors: REIS M.H.M. , DA SILVA F.V. , ANDRADE C.M.G. , REZENDE S.L. , WOLF MACIEL M.R. , BERGAMASCO R. 
Published: September 2008

ABSTRACTStevia rebaudiana Bertoni is a native plant from South America and its active constituents have been considered the “sweeteners of the future.”Stevia is a natural diet‐sweetening source, safe to health and without calories. However, the obtained raw extract is foul smelling, bitter tasting, dark brown colored, and presents suspension matter due to organic and inorganic compounds. Therefore, further purification/clarification is essential in order to get a product of commercial quality. In this work ceramic membranes were applied in the stevia extract clarification process. The process was carried out under different membrane pore sizes and at different pressure values. The best clarification result was obtained with the membrane of 0.1 µm at 4 bar. On the other hand, the best condition for the flux was obtained with the membrane of 0.2 µm at 6 bar. The process with all the tested membranes and conditions achieved recovery of sweeteners higher than 90%. Finally, a filtration mathematical model was applied to describe the flux behavior, showing that the main fouling phenomenon during the process occurred because of the complete blocking of pores.PRACTICAL APPLICATION Stevia is the world's only all‐natural sweetener with zero calories, zero carbohydrates and a zero glycemic index. However, the obtained stevia extract has a dark brown appearance, mainly because of the presence of impurities. In this work the membrane separation process was studied for stevia extract clarification and purification in order to get a product with higher commercial acceptability. The obtained results showed that total clarification and recuperation of sweeteners was almost achieved. Nonetheless, membrane fouling is an inevitable problem during membrane filtration. The mathematical analysis of the fouling occurrences showed that the complete blocking of pores is the main cause for the membrane permeability decrease.
OPTIMIZATION OF PERMEABILIZATION PROCESS FOR LACTOSE HYDROLYSIS IN WHEY USING RESPONSE SURFACE METHODOLOGY
Authors: KAUR GURPREET , PANESAR PARMJIT S. , BERA MANAV B. , SINGH BAHADUR 
Published: September 2008

ABSTRACT To overcome the permeability barrier and prepare whole cell biocatalysts with high activities, permeabilization of Kluyveromyces marxianus var. lactis NCIM 3566 in relation toβ‐galactosidase activity was optimized using cetyltrimethylammonium bromide (CTAB) as permeabilizing agent. Permeabilized whole cells can be advantageous over pure enzyme preparations in terms of cost‐effectiveness and increased stability maintained by the intracellular environment. Response surface methodology (RSM) was applied to optimize concentration of CTAB, temperature and the treatment time for maximum permeabilization of yeast cells. The optimum operating conditions for permeabilization process to achieve maximum enzyme activity obtained by RSM were 0.06% (w/v) CTAB concentration, 28C temperature and process duration of 14 min. At these conditions of process variables, the maximum value of enzyme activity was found to be 1,334 IU/g. The permeabilized yeast cells were highly effective and resulted in 90.5% lactose hydrolysis in whey.PRACTICAL APPLICATION β‐Galactosidase is one of the most promising enzymes, which has several applications in the food, fermentation and dairy industry. However, the industrial applications of β‐galactosidase have been hampered by the costs involved in downstream processing. The present investigation was focused on developing the low‐cost technology for lactose hydrolysis based on permeabilization process. Disposal of lactose in whey and whey permeates is one of the most significant problems with regard to economics and environmental impact faced by the dairy industries. Keeping this in view, lactose hydrolysis in whey has been successfully performed using permeabilized Kluyveromyces marxianus cells. Hydrolysis of lactose using β‐galactosidase converts whey into a potentially very useful food ingredient, which has immense applications in food industries. Its use has increased significantly in recent years, mainly in the dairy products and in digestive preparations. Lactose hydrolysis causes several potential changes in the manufacture and marketing of dairy products, including increased solubility, sweetness and broader fermentation possibilities.
EFFECT OF HIGH‐PRESSURE PROCESSING ON TEXTURE AND DRYING BEHAVIOR OF PINEAPPLE
Authors: KINGSLY A.R.P. , BALASUBRAMANIAM V.M. , RASTOGI N.K. 
Published: September 2008

ABSTRACT The effect of high‐pressure processing on texture and drying behavior of pineapple slices was investigated. Pineapple slices were high pressure processed at 50, 100, 300, 500 and 700 MPa at 25C for 10 min. The control, hot water‐blanched and high‐pressure processed samples were then dehydrated at 70C. Application of high pressure reduced the sample hardness, springiness and chewiness while it had no significant effect on cohesiveness of pineapple. Elevated pressure treatment (≥500 MPa) reduced drying time more effectively than for the other pretreated samples. Experimental dehydration data were empirically fitted using six thin‐layer drying models. Among the models tested, logarithmic model best described the drying behavior of pineapple slices. The effective moisture diffusivity was found to increase with an increase in the level of pressure up to 500 MPa, and the samples processed at 500 and 700 MPa had higher diffusivity values than blanched samples. PRACTICAL APPLICATIONSThis work shows that high‐pressure blanching of pineapple can be an alternative for hot water blanching, before dehydration. The results may find application in development of quality snack food from pineapple fruits.
HEATING UNIFORMITY AND RATES IN A DOMESTIC MICROWAVE COMBINATION OVEN
Authors: RAKESH V. , DATTA A.K. , AMIN M.H.G. , HALL L.D. 
Published: September 2008

ABSTRACT Physics‐based modeling complemented with magnetic resonance imaging (MRI) for validation can provide a novel means to understand and thereby optimize combination heating processes. The objectives of this study were to compare heating patterns in a combination of radiant, forced air and microwave oven measured by MRI with those predicted by coupled electromagnetics‐heat transfer model; quantify speed and uniformity of heating for the different combination modes; determine the effect of food dielectric properties on heating patterns; and delineate the nature of individual heating modes and their combinations. The modes of radiant heating through heating elements and forced convection by fan led to a more uniform heating compared with the faster (but less uniform) heating method provided by the microwaves. Combination methods were faster than radiant, forced‐air and microwave‐only heating. Although the speed of heating increased appreciably for combination modes, the nonuniformity of heating did not increase as much. PRACTICAL APPLICATIONSThe results from the study can be used to develop design recommendations/guidelines for combination heating for different thermal processes such as baking, broiling, roasting and reheating of different materials, grouping them based on their properties. The research can benefit the consumers, food services and equipment manufacturers to understand the combination heating process in a better way and to, thereby, use it efficiently. Without a fundamental understanding of the effect of various combinations, optimization of heating can be intractable. The fundamental approach used in this study would, therefore, help consumers and food services in preparation of safe and high‐quality foods through combination heating. The work would also help equipment manufacturers in optimizing the designs of combination‐heating ovens.
A New Tetracycline Efflux Gene,
tet
(40), Is Located in Tandem with
tet
(O/32/O) in a Human Gut Firmicute Bacterium and in Metagenomic Library Clones
Authors: Kazimierczak Katarzyna A. , Rincon Marco T. , Patterson Andrea J. , Martin Jennifer C. , Young Pauline , Flint Harry J. , Scott Karen P. 
Published: September 2008

ABSTRACT

The bacterium
Clostridium saccharolyticum
K10, isolated from a fecal sample obtained from a healthy donor who had received long-term tetracycline therapy, was found to carry three tetracycline resistance genes:
tet
(W) and the mosaic
tet
(O/32/O), both conferring ribosome protection-type resistance, and a novel, closely linked efflux-type resistance gene designated
tet
(40).
tet
(40) encodes a predicted membrane-associated protein with 42% amino acid identity to
tetA
(P). Tetracycline did not accumulate in
Escherichia coli
cells expressing the Tet(40) efflux protein, and resistance to tetracycline was reduced when cells were incubated with an efflux pump inhibitor.
E. coli
cells carrying
tet
(40) had a 50% inhibitory concentration of tetracycline of 60 μg/ml. Analysis of a transconjugant from a mating between donor strain
C. saccharolyticum
K10 and the recipient human gut commensal bacterium
Roseburia inulinivorans
suggested that
tet
(O/32/O) and
tet
(40) were cotransferred on a mobile element. Sequence analysis of a 37-kb insert identified on the basis of tetracycline resistance from a metagenomic fosmid library again revealed a tandem arrangement of
tet
(O/32/O) and
tet
(40), flanked by regions with homology to parts of the VanG operon previously identified in
Enterococcus faecalis
. At least 10 of the metagenomic inserts that carried
tet
(O/32/O) also carried
tet
(40), suggesting that
tet
(40), although previously undetected, may be an abundant efflux gene.
Effect of Protein Binding on the Pharmacological Activity of Highly Bound Antibiotics
Authors: Schmidt Stephan , Röck Katharina , Sahre Martina , Burkhardt Olaf , Brunner Martin , Lobmeyer Maximilian T. , Derendorf Hartmut 
Published: September 2008

ABSTRACT

During antibiotic drug development, media are frequently spiked with either serum/plasma or protein supplements to evaluate the effect of protein binding. Usually, previously reported serum or plasma protein binding values are applied in the analysis. The aim of this study was to evaluate this approach by experimentally measuring free, unbound concentrations for antibiotics with reportedly high protein binding and their corresponding antimicrobial activities in media containing commonly used protein supplements. Free, unbound ceftriaxone and ertapenem concentrations were determined in bacterial growth medium with and without bovine/human serum albumin, as well as adult bovine serum and human plasma using in vitro microdialysis. The corresponding antimicrobial activity was determined in MIC and time-kill curve experiments using
Escherichia coli
ATCC 25922 and
Streptococcus pneumoniae
ATCC 6303 as test strains. A semimechanistic maximum effect model was simultaneously fitted to the data and respective EC
50
(concentration at half-maximum effect) values compared. Protein binding differed significantly for ceftriaxone (
P
< 0.05) between human plasma (76.8 ± 11.0%) and commercially available bovine (20.2 ± 8.3%) or human serum albumin (56.9 ± 16.6%). Similar results were obtained for ertapenem (human plasma, 73.8 ± 11.6%; bovine serum albumin, 12.4 ± 4.8%; human serum albumin, 17.8 ± 11.5%). The MICs and EC
50
s of both strains were significantly increased (
P
< 0.05) for ceftriaxone when comparing human and bovine serum albumin, whereas the EC
50
s were not significantly different for ertapenem. Free, unbound antibiotic concentrations differed substantially between plasma and protein supplements and correlated well with antimicrobial efficacy. Therefore, free, active concentrations should be measured in the test system instead of correcting for literature protein binding values.
Development, Stability, and Molecular Mechanisms of Macrolide Resistance in
Campylobacter jejuni
Authors: Caldwell Dave Bryson , Wang Ying , Lin Jun 
Published: September 2008

ABSTRACT

Previous studies of macrolide resistance in
Campylobacter
were primarily focused on strains from various origins or used in vitro systems. In this study, we conducted both in vitro and in vivo experiments to examine the development, stability, and genetic basis of macrolide resistance in
Campylobacter jejuni
using erythromycin-resistant (Ery
r
) mutants derived from the same parent strain. Chickens inoculated with low-level Ery
r
mutants (MIC = 32 or 64 μg/ml) at 15 days old did not shed highly Ery
r
mutants (MIC > 512 μg/ml) after prolonged exposure to a low dose of tylosin. The low-level Ery resistance was not stable in vitro or in vivo in the absence of macrolide selection pressure. However, high-level Ery resistance displayed remarkable stability in vitro and in vivo. Ribosomal sequence analysis of 69 selected Ery
r
mutants showed that specific point mutations (A2074G or A2074C) occurred in all highly Ery
r
mutants. No mutations in ribosomal protein L4 were observed in any of the in vitro-selected Ery
r
mutants. However, three specific mutations in L4, G74D, G57D, and G57V, were widely found among in vivo-selected Ery
r
mutants. Insertion of three amino acids, TSH, at position 98 in ribosomal protein L22 was observed only in mutants selected in vitro. Inactivation of the CmeABC efflux pump dramatically reduced Ery MICs in Ery
r
mutants. Together, these findings suggest that multiple factors contribute to the emergence of highly Ery
r
Campylobacter
in chicken, reveal resistance level-dependent stability of macrolide resistance in
C. jejuni
, and indicate that
C. jejuni
utilizes complex and different mechanisms to develop Ery resistance in vitro and in vivo.
Genetic Analysis of Fenhexamid-Resistant Field Isolates of the Phytopathogenic Fungus
Botrytis cinerea
Authors: Fillinger Sabine , Leroux Pierre , Auclair Christiane , Barreau Christian , Al Hajj Charbel , Debieu Danièle 
Published: September 2008

ABSTRACT

The hydroxyanilide fenhexamid, one of the latest antibotrytis fungicides, active especially against leotiomycete plant-pathogenic fungi, inhibits 3-ketoreductase of the C-4-demethylation enzyme complex during ergosterol biosynthesis. We isolated
Botrytis cinerea
strains resistant to various levels of fenhexamid from French and German vineyards. The sequence of the gene encoding 3-ketoreductase,
erg27
, varied according to levels of resistance. Highly resistant isolates, termed HydR3
+
, all presented a modification of the phenylalanine at the C terminus of the putative transmembrane domain at position 412, either to serine (85% of the isolates), to isoleucine (11.5% of the isolates), or to valine (3.5% of the isolates). The introduction of the

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allele into a fenhexamid-sensitive strain by means of a replicative plasmid conferred fenhexamid resistance on the resulting transformants, showing that the mutations at position 412 are responsible for fenhexamid resistance. Weakly to moderately resistant isolates, termed HydR3
−
, showed different point mutations between the strains in the sequenced regions of the
erg27
gene, corresponding to amino acid changes between positions 195 and 400 of the protein. The

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alleles on the replicative vector introduced into a sensitive strain did not confer resistance to fenhexamid. Genetic crosses between HydR3
−
and sensitive strains showed strict correlation between the sequenced mutation in the
erg27
gene and the resistance phenotypes, suggesting that these mutations are linked to fenhexamid resistance. The HydR3 mutations possibly modify the affinity of the 3-ketoreductase enzyme for its specific inhibitor, fenhexamid.
Identification of the Genetic Basis for Clinical Menadione-Auxotrophic Small-Colony Variant Isolates of
Staphylococcus aureus
Authors: Lannergård Jonas , von Eiff Christof , Sander Gunnar , Cordes Tina , Seggewiβ Jochen , Peters Georg , Proctor Richard A. , Becker Karsten , Hughes Diarmaid 
Published: September 2008

ABSTRACT

Small-colony variants (SCVs) of
Staphylococcus aureus
are associated with persistent infections and may be selectively enriched during antibiotic therapy. Three pairs of clonally related
S. aureus
isolates were recovered from patients receiving systemic antibiotic therapy. Each pair consisted of an isolate with a normal phenotype and an isolate with an SCV phenotype. These SCVs were characterized by reduced susceptibility to gentamicin, reduced hemolytic activity, slow growth, and menadione auxotrophy. Sequencing of the genes involved in menadione biosynthesis revealed mutations in
menB
, the gene encoding naphthoate synthase, in all three strains with the SCV phenotype. The
menB
mutations were (i) a 9-bp deletion from nucleotides 55 to 63, (ii) a frameshift mutation that resulted in a premature stop codon at position 230, and (iii) a point mutation that caused the amino acid substitution Gly to Val at codon 233. Fluctuation tests showed that growth-compensated mutants arose in the SCV population of one strain, strain OM1b, at a rate of 1.8 × 10
−8
per cell per generation. Sequence analyses of 23 independently isolated growth-compensated mutants of this strain revealed alterations in the
menB
sequence in every case. These alterations included reversions to the wild-type sequence and intragenic second-site mutations. Each of the growth-compensated mutants showed a restoration of normal growth and a loss of menadione auxotrophy, increased susceptibility to gentamicin, and restored hemolytic activity. These data show that mutations in
menB
cause the SCV phenotype in these clinical isolates. This is the first report on the genetic basis of menadione-auxotrophic SCVs determined in clinical
S. aureus
isolates.
Recovery of a Functional Class 2 Integron from an
Escherichia coli
Strain Mediating a Urinary Tract Infection
Authors: Márquez Carolina , Labbate Maurizio , Ingold Ana J. , Chowdhury Piklu Roy , Ramírez Maria S. , Centrón Daniela , Borthagaray Graciela , Stokes H. W. 
Published: September 2008

ABSTRACT

A class 2 integron was found in an
Escherichia coli
isolate mediating a urinary tract infection. Unlike other class 2 integrons from pathogens, the encoded IntI2 protein was functional. The integron possessed a
dfrA14
cassette, and a second novel cassette in which a lipoprotein signal peptidase gene is predicted.
Inhibition of Voriconazole Metabolism by Chloramphenicol in an Adolescent with Central Nervous System Aspergillosis
Authors: Hafner Verena , Albermann Nadine , Haefeli Walter E. , Ebinger Friedrich 
Published: September 2008

ABSTRACTFor an adolescent with bacterial meningitis and subsequent cerebral aspergillosis, intravenous voriconazole dose requirements substantially decreased during coadministration with intravenous chloramphenicol and considerably rose after discontinuation of the antibiotic. In agreement with in vitro evidence, these data suggest that chloramphenicol is a rather significant inhibitor of hepatic CYP3A4 and/or CYP2C19.