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- Crystallization (10)
- Sunflower oil (9)
- Polarized light microscopy (6)
- Nutrition (5)
- Sucrose esters (5)
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- Cooling rate (4)
- High-melting milk fat fraction (4)
- Lactobacillus (4)
- Microstructure (4)
- Mozzarella Cheese (4)
- Nucleation (4)
- Rheology (4)
- Solid fat content (4)
- Anhydrous milk fat (3)
- Cheese flavor (3)
- Differential scanning calorimetry (3)
- High intensity ultrasound (3)
- Induction times (3)
- Nonstarter lactic acid bacteria (3)
- Polymorphism (3)
- Amino acid catabolism (2)
- Bifidobacterium (2)
- Cheddar cheese (2)
- Curriculum (2)
- Emulsifier (2)
- Emulsifiers (2)
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- Health (2)
- High-melting fraction of milk fat (2)
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Articles 61 - 90 of 97
Full-Text Articles in Nutrition
Physical Properties Of Low-Trans Shortenings As Affected By Emulsifiers And Storage Conditions, Silvana Martini, Maria L. Herrera
Physical Properties Of Low-Trans Shortenings As Affected By Emulsifiers And Storage Conditions, Silvana Martini, Maria L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
The quality of shortenings, such as solid fat content (SFC) and texture, strongly depends on temperature fluctuations during storage and handling. The quality of a shortening might be affected not only by temperature fluctuations but also by its chemical composition and the presence of emulsifiers. The objective of this work was to investigate the effect of emulsifier addition and storage conditions on the texture, thermal behavior and SFC of low-trans shortenings formulated with palm oil, palm kernel oil, and vegetable oils such as sunflower and soybean oils. Several conclusions can be drawn from this study: (a) The crystallization behavior of …
Effect Of Processing Conditions On The Crystallization Behavior And Destabilization Kinetics Of Oil-In-Water Emulsions, Silvana Martini, Megan Tippetts
Effect Of Processing Conditions On The Crystallization Behavior And Destabilization Kinetics Of Oil-In-Water Emulsions, Silvana Martini, Megan Tippetts
Nutrition, Dietetics, and Food Sciences Faculty Publications
The objective of this research was to systematically study the effect of processing conditions on the crystallization behavior and destabilization mechanisms of oil-in-water emulsions. The effect of crystallization temperature (T c) and homogenization conditions on both thermal behavior and destabilization mechanisms were analyzed. Results show that the crystallization of lipids present in the emulsions was inhibited when compared with bulk lipids as evidenced by a lower onset and peak temperature (T on and Tp, respectively) in differential scanning calorimetry crystallization exotherms. The smaller the droplet size in the emulsion, the more significant the inhibition (lower T on and T p). …
The Seventh Internationalconference On The Genetics Of Streptococci, Lactococci And Enterococci, R. A. Burne, D. Bessen, Jeff Broadbent, J. P. Claverys
The Seventh Internationalconference On The Genetics Of Streptococci, Lactococci And Enterococci, R. A. Burne, D. Bessen, Jeff Broadbent, J. P. Claverys
Nutrition, Dietetics, and Food Sciences Faculty Publications
The Seventh International Conference on the Genetics of Streptococci, Lactococci, and Enterococci, sponsored by the American Society for Microbiology, was held 18 to 21 June 2006, overlooking the sea in Saint Malo, Bretagne, France. The conference began in 1981 as the Streptococcal Genetics meeting, at a time when the genera Enterococcus and Lactococcus were still classified as Streptococcus spp. Through the years, this meeting has served as a quadrennial platform to showcase cutting-edge advances in the dissection of the underlying genetics of growth control, metabolism, extrachromosomal elements, substrate utilization, competence development, antibiotic resistance, and virulence of this fascinating group of …
Advances In Startercultures And Cultured Foods, T. M. Cogan, J. Steele, Jeff Broadbent, N. P. Shah, Z. Ustunol
Advances In Startercultures And Cultured Foods, T. M. Cogan, J. Steele, Jeff Broadbent, N. P. Shah, Z. Ustunol
Nutrition, Dietetics, and Food Sciences Faculty Publications
With 2005 retail sales close to $4.8 million, cultured dairy products are driving the growth of dairy foods consumption. Starter cultures are of great industrial significance in that they play a vital role in the manufacturing, flavor, and texture development of fermented dairy foods. Furthermore, additional interest in starter bacteria has been generated because of the data accumulating on the potential health benefits of these organisms. Today, starter cultures for fermented foods are developed mainly by design rather than by the traditional screening methods and trial and error. Advances in genetics and molecular biology have provided opportunities for genomic studies …
Polymorphism And Growth Behavior Of Low-Trans Fatty Acids Blends Formulated With And Without Emulsifiers, Marina Cerdeira, Silvana Martini, Roberto J. Candal, Maria L. Herrera
Polymorphism And Growth Behavior Of Low-Trans Fatty Acids Blends Formulated With And Without Emulsifiers, Marina Cerdeira, Silvana Martini, Roberto J. Candal, Maria L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
Polymorphism and growth behavior of blends of a high-melting fraction of milk fat (HMF) and sunflower oil (SFO) formulated with and without the addition of sucrose esters (SE) P-170, P-1670, and S-170 were studied by pulsed 1H NMR spectroscopy, X-ray diffraction, and polarized light microscopy. The effect of SE on the solid content maximum (S max) or crystallization rate was observed only at low supercooling (values of ΔT below 15°C). The Avrami k n decreased as n values increased, indicating that SE inhibited growth and impeded nucleation. Addition of SFO modified the polymorphic behavior of milk fat, most likely owing …
A Probabilistic Approach To Model The Nonisothermal Nucleation Of Triacylglycerol Melts, Alejandro G. Marangoni, Thomas C. Aurand, Silvana Martini, Michel Ollivon
A Probabilistic Approach To Model The Nonisothermal Nucleation Of Triacylglycerol Melts, Alejandro G. Marangoni, Thomas C. Aurand, Silvana Martini, Michel Ollivon
Nutrition, Dietetics, and Food Sciences Faculty Publications
Crystallization studies are usually performed under isothermal conditions. Kinetic parameters characterizing the isothermal nucleation and growth processes can be obtained using classical nucleation and growth models. However, crystallization regimes found in nature, as well as those used in food and pharmaceutical processing, are rarely isothermal. Focusing on the nucleation stage, the approach followed in this work was to define a new parameter to characterize the driving force of nucleation, the supercooling-time exposure (β), which not only depends on the difference between the melting temperature (Tm) and the onset temperature of nucleation (Tc) ΔTc but also on the induction time of …
The Water Vapor Permeability Of Polycrystalline Fat Barrier Films, Silvana Martini, D. A. Kim, M. Ollivon, A. G. Marangoni
The Water Vapor Permeability Of Polycrystalline Fat Barrier Films, Silvana Martini, D. A. Kim, M. Ollivon, A. G. Marangoni
Nutrition, Dietetics, and Food Sciences Faculty Publications
The water vapor permeability of fat barrier films has been associated with structural characteristics such as polymorphism, crystal size, and chemical composition, among others. However, no mechanistic models have been proposed to describe this relationship. In this study, we have determined the effects of processing conditions on the structure and physicochemical characteristics of four fats and their relationship to water vapor permeability. Results suggest that the solids' volume fraction and the domain size of the fat crystals seem to be the most important factors controlling water vapor migration. Moreover, materials with relatively large crystalline domains will yield malleable films with …
Enhanced Nutty Flavor Formation In Cheddar Cheese Made With Malty Lactococcus Lactis Adjunct Culture, M. E. Carunchia Whetstine, M. A. Drake, Jeff Broadbent, Donald J. Mcmahon
Enhanced Nutty Flavor Formation In Cheddar Cheese Made With Malty Lactococcus Lactis Adjunct Culture, M. E. Carunchia Whetstine, M. A. Drake, Jeff Broadbent, Donald J. Mcmahon
Nutrition, Dietetics, and Food Sciences Faculty Publications
Nutty flavor in Cheddar cheese is desirable, and recent research demonstrated that 2- and 3-methyl butanal and 2-methyl propanal were primary sources of nutty flavors in Cheddar. Because malty strains of Lac-tococcus lactis (formerly Streptococcus lactis var. malti-genes) are characterized by the efficient production of these and other Strecker aldehydes during growth, this study investigated the influence of a malty L. lactis adjunct culture on nutty flavor development in Cheddar cheese. Cheeses made with different adjunct levels (0, 10(4) cfu/mL, and 10(5) cfu/mL) were ripened at 5 or 13 degrees C and analyzed after 1 wk, 4 mo, and 8 …
Microencapsulating Properties Of Trehalose And Of Its Blends With Sucrose And Fructose, Marina Cerdeira, Silvana Martini, Maria L. Herrera
Microencapsulating Properties Of Trehalose And Of Its Blends With Sucrose And Fructose, Marina Cerdeira, Silvana Martini, Maria L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
A low melting fraction of milk fat (LMF), with a dropping point (MDP) of 16.7 °C, was encapsulated by freeze-drying emulsions formulated with trehalose or its blends with 30 wt% lactose or sucrose as hydrophilic phase, and with a mixed of 50 wt% of the palmitic sucrose esters (SE) β-170 and β-1670 as emulsifiers. Trehalose or trehalose/sucrose matrices were very efficient to encapsulate LMF (retention values were 82.8%± 3.2% and 90.5%± 3.7%, dry basis, respectively), whereas trehalose/lactose showed a significant decline in initial retention (42.5%± 2.5%, dry basis). The role of emulsion stability, water content, physical state of the matrix, …
In-Situ Monitoring Of Solid Fat Content By Means Of P-Nmr And Ultrasonics, Silvana Martini, Constantin Bertoli, Maria Lidia Herrera, Ian Neeson, Alejandro Marangoni
In-Situ Monitoring Of Solid Fat Content By Means Of P-Nmr And Ultrasonics, Silvana Martini, Constantin Bertoli, Maria Lidia Herrera, Ian Neeson, Alejandro Marangoni
Nutrition, Dietetics, and Food Sciences Faculty Publications
An ultrasonic technique was developed to study the crystallization process of edible fats on-line. A chirp wave was used instead of the conventional pulser signal, thus achieving a higher signal-to-noise ratio. This enabled measurements to be made in concentrated systems [≈20% solid fat content (SFC)] through a 8.11-cm thick sample without significant signal loss. Fat samples were crystallized at 20, 25, and 30°C at a constant agitation rate of 400 rpm for 90 min. The crystallization process was followed by ultrasonic spectroscopy and a low-resolution pulsed nuclear magnetic resonance spectrometer. Specific relationships were found between ultrasonic parameters [integrated response, time …
New Technologies To Determine Solid Fat Content On-Line, Silvana Martini, Maria Lidia Herrera, Alejandro Marangoni
New Technologies To Determine Solid Fat Content On-Line, Silvana Martini, Maria Lidia Herrera, Alejandro Marangoni
Nutrition, Dietetics, and Food Sciences Faculty Publications
The determination of solid fat content (SFC) is an important analytical procedure in the food industry. The most common way to determine SFC is by low-resolution pulsed NMR (p-NMR). Although this technique is very sensitive and easy to use, it has the disadvantage that it cannot be used for on-line measurements. The present work compares new technologies to determine SFC on-line. On-line ultrasonic spectroscopy and NMR-MOUSE (NMR mobile universal surface explorer) techniques were compared with off-line p-NMR measurements and there was a good correlation between the values obtained. Ultrasonic measurements accurately described the SFC variation, whereas NMR-MOUSE determinations need to …
Attenuation Of Ultrasonic Waves: Influence Of Microstructure And Solid Fat Content, Silvana Martini, Constantin Bertoli, Maria Lidia Herrera, Ian Neeson, Alejandro Marangoni
Attenuation Of Ultrasonic Waves: Influence Of Microstructure And Solid Fat Content, Silvana Martini, Constantin Bertoli, Maria Lidia Herrera, Ian Neeson, Alejandro Marangoni
Nutrition, Dietetics, and Food Sciences Faculty Publications
Ultrasonic technology can be used to monitor the crystallization of fats and determine solid fat content (SFC) online. Ultrasonic waves are attenuated as crystals form and grow, and this attenuation occurs first at higher frequencies. The attenuation of the ultrasonic signal does not depend on the induction times of crystallization of the systems, or on their thermal behavior; but it does depend on SFC and on microstructure, particularly on the crystal size. At low SFC values (≈5%), bigger crystals generate more attenuation. At intermediate SFC values (≈10%), crystal size does not affect signal attenuation and SFC is the key factor …
Storage Of Sunflower-Seeds: Variation On The Wax Content Of The Oil, Silvana Martini, Maria Cristina Anon
Storage Of Sunflower-Seeds: Variation On The Wax Content Of The Oil, Silvana Martini, Maria Cristina Anon
Nutrition, Dietetics, and Food Sciences Faculty Publications
Storage conditions of oil seeds before industrial extraction might influence the quality of the crude oil. The objective of this work was to study the influence of sunflower seed storage conditions (temperature and time) on the quality of the resulting oil in terms of its wax content and composition. Sunflower seeds were stored under different conditions, 10, 21 and 37 °C, in sealed recipients. Extractions of the seeds with hexane were made to obtain the oil at different storage times. The amount of oil extracted (25–40%) showed no significant differences with storage conditions. Wax content of the samples was determined …
Diabetes Stepping Up To The Plate: An Education Curriculum Focused On Food Portioning Skills, D. Pauline Williams, Heidi Leblanc, Nedra K. Christensen
Diabetes Stepping Up To The Plate: An Education Curriculum Focused On Food Portioning Skills, D. Pauline Williams, Heidi Leblanc, Nedra K. Christensen
Nutrition, Dietetics, and Food Sciences Faculty Publications
The Diabetes Stepping up to the Plate program was developed to determine the effectiveness of food portion based diabetes education. One hundred fifty-one individuals enrolled in the diabetes series. Food portion knowledge and skills tests, height, weight, and waist-to-hip ratio (WHR) were measured pre- and post-program. Data was analyzed through paired t-tests and correlations. Evaluation showed a decrease in HbA1C, waist/hip circumference, WHR, and BMI, and an improvement in food portion knowledge and skills. Seventy-five participants completed pre- and post-data collection parameters, although more participants completed all classes in the series. Extension can play a role in successful diabetes education.
Effect Of Sucrose Esters On The Crystallization Behavior Of Bulk Oil Systems, Silvana Martini, M. Cerdeira, M. L. Herrera
Effect Of Sucrose Esters On The Crystallization Behavior Of Bulk Oil Systems, Silvana Martini, M. Cerdeira, M. L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
Sucrose esters (SE) of FA can be used in foods as emulsifiers because they are nontoxic, tasteless, odorless, and are digested to sucrose and FA in the stomach. They can also be used in pharmaceuticals and cosmetics and in other products where a nonionic, nontoxic, biodegradable emulsifier is required. In addition to their major function of producing and stabilizing emulsions, SE have numerous other functional roles as texturizers, film formers, and modifiers of bulk-phase crystallization behavior (with bulk phase meaning a homogeneous oil phase). A few reports have dealt with the effect of SE on the crystallization behavior of fats …
Effects Of Salts On Crystallization Kinetics And Rheological Behavior Of Concentrated , -Trehalose Solutions, Marina Cerdeira, M. C. Puppo, Silvana Martini, M. L. Herrera
Effects Of Salts On Crystallization Kinetics And Rheological Behavior Of Concentrated , -Trehalose Solutions, Marina Cerdeira, M. C. Puppo, Silvana Martini, M. L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
The effect of addition of CaCl2 2H2O and MgCl2 6H2O on crystallization kinetics and the rheological behavior of a 70% trehalose solution was studied by polarized light microscopy and dynamic oscillatory rheometry. Salts caused a delay on nucleation with induction times for crystallization longer for Mg2+ than for Ca2+. Divalent cations were incorporated into crystals, changing the growth of certain faces preferentially, which resulted in changes in morphology. Addition of CaCl2 2H2O in a high salt/trehalose molar ratio dramatically increased complex modulus (G*), indicating a stronger viscoelastic behavior. A gel-like structure was formed when Ca2+ was added to trehalose solution. …
Effect Of Sucrose Ester Addition On Nucleation And Growth Behavior Of Milk Fat-Sunflower Oil Blends, Marina Cerdeira, Silvana Martini, Richard W. Hartel, Maria Lidia Herrera
Effect Of Sucrose Ester Addition On Nucleation And Growth Behavior Of Milk Fat-Sunflower Oil Blends, Marina Cerdeira, Silvana Martini, Richard W. Hartel, Maria Lidia Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
The effects of addition of the sucrose esters (SE) P-1670, P-170, and S-170 to a high-melting fraction of milk fat (HMF) and its blends with sunflower oil (SFO) on nucleation and growth were studied by laser polarized light turbidimetry and polarized light microscopy (PLM). The three SE delayed nucleation of HMF at the temperatures selected. P-1670 did not modify average crystal size after 3 h at crystallization temperature (Tc) or crystal size distribution and modified crystallization kinetics only slightly. P-170 and S-170, however, markedly diminished crystal size and narrowed crystal size distribution. Activation free energies of nucleation at equivalent supercooling, …
Crystallization Of Sunflower Oil Waxes, Silvana Martini, M. C. Anon
Crystallization Of Sunflower Oil Waxes, Silvana Martini, M. C. Anon
Nutrition, Dietetics, and Food Sciences Faculty Publications
Activation free energies of nucleation (ΔG c ) were calculated using induction times of crystallization measurements. Results showed that ΔG c decreased exponentially as wax concentration increased at a constant crystallization temperature (T c ). In contrast, for a constant supersaturation, ΔG c increased from 12 to 22°C but decreased between 22 and 35°C. Melting behavior of purified waxes and solutions of purified waxes in sunflower oil were studied by DSC after crystallization at fast and slow cooling rates (20 and 1°C/min, respectively). Low supercooling temperatures (T c >65°C) showed an increase in the onset temperature (T 0 ) as …
Influence Of Coagulant Level On Proteolysis And Functionality Of Mozzarella Cheese Made Using Direct Acidification, R. I. Dave, C. J. Oberg, Donald J. Mcmahon
Influence Of Coagulant Level On Proteolysis And Functionality Of Mozzarella Cheese Made Using Direct Acidification, R. I. Dave, C. J. Oberg, Donald J. Mcmahon
Nutrition, Dietetics, and Food Sciences Faculty Publications
Nonfat (0% fat), reduced-fat (11% fat), and control (19% fat) mozzarella cheeses were made using direct acidification to test the influence of three levels (0.25X, 1X, and 4X) of coagulant concentration on proteolysis, meltability and rheological properties of cheeses during 60 d of storage at 5°C. Changes in meltability, level of intact αs1-casein and β-casein (by capillary electrophoresis), 12.5% TCA-soluble nitrogen, and complex modulus were measured. There were differences in rate of proteolysis and functional properties as a function of fat content of the cheese, but some of these differences could be attributed to differences in moisture contents …
Influence Of Adjunct Use Andcheese Microenvironment On Nonstarter Lactic Acid Bacteria Populations In Cheddar-Type Cheese, Jeff Broadbent, K. Houck, M. E. Johnson, C. J. Oberg
Influence Of Adjunct Use Andcheese Microenvironment On Nonstarter Lactic Acid Bacteria Populations In Cheddar-Type Cheese, Jeff Broadbent, K. Houck, M. E. Johnson, C. J. Oberg
Nutrition, Dietetics, and Food Sciences Faculty Publications
This study investigated population dynamics of starter, adjunct, and nonstarter lactic acid bacteria (NSLAB) in reduced-fat Cheddar and Colby cheese made with or without a Lactobacillus casei adjunct. Duplicate vats of cheese were manufactured and ripened at 7°C. Bacterial populations were monitored periodically by plate counts and by DNA fingerprinting of cheese isolates with the random amplified polymorphic DNA technique. Isolates that displayed a unique DNA fingerprint were identified to the species level by partial nucleotide sequence analysis of the 16S rRNA gene. Nonstarter biota in both cheese types changed over time, but populations in the Colby cheese showed a …
Effect Of Processing Conditions On Microstructure Of Milk Fat Fraction/Sunflower Oil Blends., Silvana Martini, M. L. Herrera, R. W. Hartel
Effect Of Processing Conditions On Microstructure Of Milk Fat Fraction/Sunflower Oil Blends., Silvana Martini, M. L. Herrera, R. W. Hartel
Nutrition, Dietetics, and Food Sciences Faculty Publications
The effect of processing conditions on the crystallization of blends of a high-melting milk fat fraction and sunflower oil was investigated. Two cooling rates were selected for all studies: 0.1°C/min (slow rate) and 5.5°C/min (fast rate). Blends were crystallized in two conditions: (i) with agitation in an 80-mL crystallizer (dynamic), and (ii) on a microscope slide without agitation (static). The selected crystallization temperatures were 25, 30, and 35°C for both cooling rates. Photographs of the development of crystals with time were taken in both static and dynamic conditions, and the crystal size distribution was determined at the moment that the …
Effect Of Sucrose Esters And Sunflower Oil Addition On Microstructure Of A High-Melting Milk Fat Fractions, Silvana Martini, M. C. Puppo, R. W. Hartel, M. L. Herrera
Effect Of Sucrose Esters And Sunflower Oil Addition On Microstructure Of A High-Melting Milk Fat Fractions, Silvana Martini, M. C. Puppo, R. W. Hartel, M. L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
The effects of sunflower oil (SFO) and the sucrose esters (SE) P-1670, P-170, and S-170 on crystalline microstructure of a high-melting milk fat fraction (HMF) was studied by polarized-light microscopy (PLM) and confocal laser scanning microsopy (CLSM). The addition of SFO markedly diminished crystal size and delayed crystallization kinetics, as observed in PLM images. Addition of P-1670 modified crystallization behavior only slightly. Addition of P-170 and S-170, however, markedly diminished crystal size and led to more transparent crystals, with lower amount of solids in each crystal. These results show that the microstructural properties of HMF were modifed by addition of …
Effect Of Sucrose Esters On Isothermal Crystallization And Rheological Behaviors Of Blends Of High-Melting Milk Fat Fraction And Sunflower Oil, M. C. Puppo, Silvana Martini, R. W. Hartel, M. L. Herrera
Effect Of Sucrose Esters On Isothermal Crystallization And Rheological Behaviors Of Blends Of High-Melting Milk Fat Fraction And Sunflower Oil, M. C. Puppo, Silvana Martini, R. W. Hartel, M. L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
Crystallization kinetics and rhelogical behavior of blends of high-melting milk-fat fraction (HMF) and sunflower oil (SFO) with and without addition of the sucrose esters P-170, S-170, and P-1670 were investigated. Addition of sucrose esters delayed crystallization, as was evidenced by the longer induction times of crystallization (t) and the lower maximum solid fat content (Smax). Values of penetration force and time corresponding to the 1st peak of curves force compared with time also diminished with addition of SFO. When sucrose esters were added, a solid fat content greater than 10% at the 1st crystallization temperature was necessary to give a …
Practical Considerations In Nucleation Studies, Silvana Martini, M. L. Herrera
Practical Considerations In Nucleation Studies, Silvana Martini, M. L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
No abstract provided.
X-Ray Diffraction And Crystal Size, Silvana Martini, M. L. Herrera
X-Ray Diffraction And Crystal Size, Silvana Martini, M. L. Herrera
Nutrition, Dietetics, and Food Sciences Faculty Publications
X-ray diffraction technique is one of the best methods to study polymorphism of fats systems. The only information authors usually report is the interplanar distances calculated from the angles at which diffraction lines appear; these clearly determine the polymorphic form. However, in many other fields using crystallography, X-ray patterns are also used to determine crystal size from the broadening of the diffraction line at half the line of maximum intensity. To investigate the meaning of the diffraction line width in fat systems and the relationship with other techniques widely used to determine crystal size, we crystallized a blend of 30–70% …
Proteolytic Specificity Of Lactobacillus Delbrueckii Subsp. Bulgaricus Influences Functional Properties Of Mozzarella Cheese, B. S. Oommen, Donald J. Mcmahon, C. J. Oberg, Jeff Broadbent, M. Strickland
Proteolytic Specificity Of Lactobacillus Delbrueckii Subsp. Bulgaricus Influences Functional Properties Of Mozzarella Cheese, B. S. Oommen, Donald J. Mcmahon, C. J. Oberg, Jeff Broadbent, M. Strickland
Nutrition, Dietetics, and Food Sciences Faculty Publications
Low-moisture part-skim Mozzarella cheeses were manufactured from 2% fat milk and aged for 21 d. Treatments included cheeses made with one of three different strains of Lactobacillus delbrueckii ssp. bulgaricus in combination with a single strain of Streptococcus thermophilus. A fourth, control treatment consisted of cheeses made with only S. thermophilus. Although total proteolytic ability of these strains, as indicated by the o-phthaldialdehyde analysis, was similar in each of the three strains of L. bulgaricus, these strains exhibited different proteolytic specificities toward the peptide, αs1-CN (f 1-23). On the basis of their αs1-CN (f 1-23) cleavage patterns …
Effect Of Cooling Rate On Crystallization Behavior Of Milk Fat Fraction/Sunflower Oil Blends, Silvana Martini, M. L. Herrera, R. W. Hartel
Effect Of Cooling Rate On Crystallization Behavior Of Milk Fat Fraction/Sunflower Oil Blends, Silvana Martini, M. L. Herrera, R. W. Hartel
Nutrition, Dietetics, and Food Sciences Faculty Publications
The effect of cooling rate (slow: 0.1°C/min; fast: 5.5°C/min) on the crystallization kinetics of blends of a highmelting milk fat fraction and sunflower oil (SFO) was investigated by pulsed NMR and DSC. For slow cooling rate, the majority of crystallization had already occurred by the time the set crystallization temperature had been reached. For fast cooling rate, crystallization started after the samples reached the selected crystallization temperature, and the solid fat content curves were hyperbolic. DSC scans showed that at slow cooling rates, molecular organization took place as the sample was being cooled to crystallization temperature and there was fractionation …
Effect Of Cooling Rate On Nucleation Behavior Of Milk Fat-Sunflower Oil Blends, Silvana Martini, M. L. Herrera, R. W. Hartel
Effect Of Cooling Rate On Nucleation Behavior Of Milk Fat-Sunflower Oil Blends, Silvana Martini, M. L. Herrera, R. W. Hartel
Nutrition, Dietetics, and Food Sciences Faculty Publications
The effect of cooling rate on the crystallization behavior of mixes of high-melting milk fat fraction (HMF) and sunflower oil (SFO) was studied by following nucleation with laser-polarized turbidimetry. The initial crystals were photographed, and their thermal and polymorphic behaviors, as well as chemical composition, were investigated by calorimetry, X-ray diffraction, and capillary gas chromatography. Activation energies of nucleation were calculated using the Fisher−Turnbull equation. Despite small differences in Mettler dropping points for different ratios of SFO to HMF, induction times were significantly different between samples and were shorter at a slow cooling rate for the same supercooling. Rapidly cooled …
Tyrosine And Phenylalanine Catabolism Bylactobacillus Cheese Flavor Adjuncts, S. Gummalla, Jeff Broadbent
Tyrosine And Phenylalanine Catabolism Bylactobacillus Cheese Flavor Adjuncts, S. Gummalla, Jeff Broadbent
Nutrition, Dietetics, and Food Sciences Faculty Publications
Bacterial metabolism of Tyr and Phe has been associated with the formation of aromatic compounds that impart barny-utensil and floral off-flavors in cheese. In an effort to identify possible mechanisms for the origin of these compounds in Cheddar cheese, we investigated Tyr and Phe catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under simulated Cheddar cheese-ripening (pH 5.2, 4% NaCl, 15°C, no sugar) conditions. Enzyme assays of cell-free extracts indicated that L. casei strains catabolize Tyr and Phe by successive, constitutively expressed transamination and dehydrogenation reactions. Similar results were obtained with L. helveticus strains, except that the dehydrogenase …
Reversibility Of The Temperature-Dependent Opacity Of Nonfat Mozzarella Cheese, R. I. Dave, Donald J. Mcmahon, Jeff Broadbent, C. J. Oberg
Reversibility Of The Temperature-Dependent Opacity Of Nonfat Mozzarella Cheese, R. I. Dave, Donald J. Mcmahon, Jeff Broadbent, C. J. Oberg
Nutrition, Dietetics, and Food Sciences Faculty Publications
Salted and unsalted nonfat mozzarella cheese was made by direct acidification and stored at 4 degrees C over 60 d. Changes in cheese opacity were measured by using reflectance L* values while the cheese was heated from 10 to 90 degrees C, then cooled to 10 degrees C, and reheated to 90 degrees C. A characteristic opacity transition temperature (T(OP)) was obtained for each cheese. Both salt content and storage time influenced T(OP). Opacity during heating, cooling, and reheating formed a hysteresis. At d 1, the unsalted cheese became opaque when heated to 20 degrees C, but the salted cheese …