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Water-holding Capacity (water-holding + capacity)
Selected AbstractsEFFECT OF PACKAGING AND STORAGE TIME ON BEEF QUALITATIVE AND MICROBIAL TRAITSJOURNAL OF FOOD QUALITY, Issue 2010MARIA D'AGATA ABSTRACT The effect of polyvinyl chloride packaging (PP), vacuum packaging (VP) and modified atmosphere packaging (MAP) (60% O2, 30% CO2, 10% N2) on some quality parameters and microbiological profile of beef was studied. Longissimus dorsi samples were examined at 7-day intervals during storage at 4C ± 2C, until 21 days. pH of PP beef increased during storage, whereas in VP and MAP beef remained stable. Superficial color darkened for PP samples, remaining stable until 7 and 21 days for VP and MAP samples, respectively; internal color was not significantly influenced by either storage time and packaging methods. Water-holding capacity was not affected by packaging methods, increasing from 7 to 21 days. VP showed lower lipid oxidation than MAP until 21 days and than PP until 14 days. Total mesophilic counts reached the threshold of 107 ufc/g after 7 days in PP and after 14 and 21 days in MAP and VP, respectively. PRACTICAL APPLICATIONS The results of this study confirmed that meat packaged in polyvinyl chloride packaging (PP) must be stored for few days to not fall into pH, color and microbiological alterations; meat packaged in modified atmosphere packaging (MAP), even though maintained appreciable superficial colorimetric characteristics, showed a high microbiological growth from 14 days of storage; meat vacuum packaged (VP), although the worst colorimetric appearance, showed the best keeping properties in terms of microbiological profile and lipid oxidation lower than MAP until 21 days of storage. Nevertheless, the fact that the internal color of meat is similar among different packaging systems, independently from time of storage, may suggest that VP system may be useful for prolonged storage of big pieces of meat. [source] Formation of Soy Protein Isolate Cold-set Gels: Protein and Salt EffectsJOURNAL OF FOOD SCIENCE, Issue 1 2005Anne Maltais ABSTRACT: The influence of protein and calcium concentration on soy protein cold-set gel formation and rheology has been investigated. Cold-set gels can be formed at soy protein concentrations from 6% to 9% and calcium concentrations from 10 to 20 mM. Gel properties can be modulated by changing the protein and/or CaCl2 concentrations. An increase in CaCl2 concentration from 10 to 20 mM increased gel opacity while an increase in protein concentration from 6% to 9% decreased opacity. Water-holding capacity improved with increasing protein concentration and decreasing CaCl2 concentration. The elastic modulus (G') increased with protein and calcium chloride concentrations. Microscopy revealed an increase in the diameters of aggregates and pores as CaCl2 concentration increased and as protein concentration decreased. Cold-set gels with a broad range of characteristics can be obtained from soy protein. [source] TEXTURAL CHARACTERIZATION OF SOY-BASED YOGURT BY THE VANE METHODJOURNAL OF TEXTURE STUDIES, Issue 2 2002IGOR V. KOVALENKO ABSTRACT The vane method was applied to evaluate failure characteristics of soy-based yogurts prepared from five soybean varieties at Brix values of 6, 8, and 10°. Yield stress, yield strain, and water-holding capacity were compared. Yield stress values ranging from 133 to 420 Pa at 2.5% protein and 498 to 1171 Pa at 4.0% protein were dependent on soybean variety and increased with increasing protein concentration. The average yield strain of samples was not affected by protein or variety. Compared to commercial dairy yogurt, soy yogurt had 132 to 445% higher yield stress at similar protein content, and was less deformable based on yield strain measurements. Water-holding capacity of soy yogurts was variety dependent, although this dependence was less pronounced at higher protein concentrations. The vane method may be effectively used as a rapid and inexpensive technique for detecting textural differences of soy-based yogurts. [source] Quality of farmed Atlantic cod: effects of season and storageAQUACULTURE RESEARCH, Issue 8 2010Hilde Herland Abstract Farming of Atlantic cod makes it possible to supply cod throughout the year. The aim of this study was to investigate the effects of season and postmortem ice storage on the quality parameters of farmed cod. Farmed Atlantic cod were sampled from the same pen in the period February 2006,March 2007. Cod whole body and somatic weight, condition factors and hepatosomatic index were all affected by season, all decreasing during maturation and spawning in the winter. Muscle pH and water were influenced by season, increasing during maturation and spawning and then decreasing after spawning. Season also affected the colour of the fillet. There was a significant increase in whiteness post-spawning and a decrease during the second maturation. Water-holding capacity (WHC), levels of trimethylamine oxide and trimethylamine, as well as microbiological data, did not vary due to season. Muscle pH, water content, WHC and microbial counts increased during storage for all samplings. [source] Vegetation structure and biodiversity along the eucalypt forest to rainforest continuum on the serpentinite soil catena in a subhumid area of Central Queensland, AustraliaAUSTRAL ECOLOGY, Issue 3 2006RAY L. SPECHT Abstract The deep lateritic earths that cap the serpentinite outcrop in the Rockhampton , Marlborough area on the Tropic of Capricorn in Central Queensland have been eroded to expose the underlying ultramafic rock. Water-holding capacity of these nutrient-poor soils increases in a gradient from the skeletal soils to the deep lateritic earths and results in a continuum of structural formations from open-woodland to woodland to open-forest. A couple of closed-forest (rainforest) stands have developed where seepage into Marlborough Creek occurs throughout the year. Aerodynamic fluxes (frictional, thermal and evaporative) in the atmosphere as it flows over and through the vegetation influence the annual foliage growth in all strata in the continuum from skeletal soils to deep lateritic earths. The lateral growth of each plant is abraded so that the sum of the foliage projective covers of overstorey (FPCo) and understorey (FPCu) strata , that is ,(FPCo + FPCu) , remains constant throughout the serpentinite soil catena. As more water becomes available in the soil catena, the mineral nutrient levels in overstorey leaves increase, making developing leaves more vulnerable to insect attack. Although the number of leaves produced annually on each vertical foliage shoot in the overstorey increases along the soil-water gradient, ,(FPCo + FPCu) remains constant in all stands. The carbon isotope ratios (a measure of stomatal resistance) and leaf specific weights (LSWs) (a measure of the proportion of structural to cytoplasmic content in a leaf) of overstorey and understorey strata, however, are constant throughout the continuum. The well-watered rainforest pockets , where seepage occurs , form the end point of this serpentinite continuum. LSWs and carbon isotope ratios of the canopy trees are similar to those in the sheltered understorey in the eucalypt communities. A gradient of foliage attributes is observed from evergreen canopy trees (12 m) to subshrubs (2 m) in the sunlit life forms that compose the complex structure of the rainforest stands in the humid to subhumid climate of Central Queensland. As alpha diversity (number of species per hectare) is correlated with annual shoot growth per hectare, species richness along the serpentinite continuum is almost half that of nearby plant communities on medium-nutrient soils. The one to two eucalypt species per hectare are about a tenth of the number recorded on adjacent medium-nutrient soils. [source] Effect of storage on the gel-forming properties of yam-containing surimi gelsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2007Yun-Chin Chung Summary The breaking forces, deformations and water-holding capacities of pollock surimi gels (PSG) containing 20% fresh Tainung No. 1 (TNG1) yam (Dioscorea alata) stored at room temperature, 17 and 10 °C, were determined for 12 weeks to evaluate the feasibility of using fresh yam as a healthy ingredient and an alternative source for starch in surimi seafoods. The results showed that the texture properties of TNG1-PSG decreased during storage regardless of the storage temperatures, except for an insignificant change found in the water-holding capacity at 10 °C. Most changes in the texture properties occurred within 1 week, thus the use of fresh TNG1 immediately after harvest is required for producing TNG1-PSG with good texture properties. Frozen storage of TNG-PSG was also undertaken at ,20 °C for 6 months. After 6-months of storage, the breaking force and water-holding capacity of TNG1-PSG decreased by about 22% and 19%, respectively. [source] Role of pH and Ionic Strength on Water Relationships in Washed Minced Chicken-breast Muscle GelsJOURNAL OF FOOD SCIENCE, Issue 3 2003H.G. Kristinsson ABSTRACT The relationship between pH, ionic strength, and water balance of chicken-breast muscle gels was investigated. An increase in gel pH (pH 6.4 to 7.4) without added NaCl led to dramatic increases in water-holding capacity and water uptake (P < 0.05). Gels at 150 mM NaCl exhibited less ability to adsorb water than salt-free gels (P < 0.05 at pH 6.8 to 7.4) and had lower water-holding capacities (P < 0.05) and fold scores at and below pH 7. Varying salt concentration of the gel-bathing solutions had dramatic effect on the water uptake of the gels. The results show that strong water-absorbing gels can be produced at low ionic strengths and suggest that the negative charge of the muscle proteins is the driving force for water uptake and retention. [source] Carbon dioxide uptake, water relations and drought survival for Dudleya saxosa, the ,rock live-forever', growing in small soil volumesFUNCTIONAL ECOLOGY, Issue 4 2007P. S. NOBEL Summary 1Although many plants grow in rock crevices and other regions of small soil volume, including over 20 000 epiphytic and hemi-epiphytic species, analyses of the actual soil volume occupied, the water availability in that soil, the water-storage capacity in the shoots and underground organs, and the photosynthetic pathway utilized have rarely been combined. 2Dudleya saxosa (M.F. Jones) Britton and Rose (Crassulaceae), growing in the Sonoran Desert, has very shallow roots that occupied soil volumes averaging only 43 × 10,6 m3 per medium-sized plant. This volume of soil can hold about the same amount of water (10 g) as can be stored in the leaves, corm and roots combined (11 g), but at a sufficiently high water potential for transfer to the plant for less than 1 week after a substantial rainfall. 3About 80% of the net carbon dioxide uptake by D. saxosa over a 24-h period occurred during the daytime (C3) under wet conditions, the daily total decreasing by 34% and the pattern shifting to nocturnal net CO2 uptake (CAM) after 46 days' drought. Seventy-seven days' drought eliminated its daily net CO2 uptake. 4Stomatal frequency was only 67 mm,2 on the adaxial (upper) surface and twofold lower on the abaxial surface. The cuticle was thick, 34 µm for the adaxial surface. Leaves had 24 mesophyll cell layers, leading to a high mesophyll cell surface area per unit leaf area of 142. 5The three leaf anatomical features plus utilization of CAM increased net CO2 uptake per unit of water transpired, and helped D. saxosa thrive in a small soil volume, with the underground corm being a major supplier of water to the succulent leaves during 2.5 months of drought. The maximum water-holding capacity of the soil explored by the roots closely matched the maximum water-holding capacity of the plant, reflecting the conservative strategy used by D. saxosa in a stressful semi-arid environment. [source] Contrasting effects of repeated summer drought on soil carbon efflux in hydric and mesic heathland soilsGLOBAL CHANGE BIOLOGY, Issue 10 2008ALWYN SOWERBY Abstract Current predictions of climate change include altered rainfall patterns throughout Europe, continental USA and areas such as the Amazon. The effect of this on soil carbon efflux remains unclear although several modelling studies have highlighted the potential importance of drought for carbon storage. To test the importance of drought, and more importantly repeated drought year-on-year, we used automated retractable curtains to exclude rain and produce repeated summer drought in three heathlands at varying moisture conditions. This included a hydric system limited by water-excess (in the UK) and two mesic systems with seasonal water limitation in Denmark (DK) and the Netherlands (NL). The experimental rainfall reductions were set to reflect single year droughts observed in the last decade with exclusion of rain for 2,3 months of the year resulting in a 20,26% reduction in annual rainfall and 23,38% reduction in mean soil moisture during the drought period. Unexpectedly, sustained reduction in soil moisture over winter (between drought periods) was also observed at all three sites, along with a reduction in the maximum water-holding capacity attained. Three hypotheses are discussed which may have contributed to this lack of recovery in soil moisture: hydrophobicity of soil organic matter, increased water use by plants and increased cracking of the soil. The responses of soil respiration to this change in soil moisture varied among the sites: decreased rates were observed at the water-limited NL and DK sites whilst they increased at the UK site. Reduced sensitivity of soil respiration to soil temperature was observed at soil moisture contents above 55% at the UK site and below 20% and 13% at the NL and DK sites, respectively. Soil respiration rates recovered to predrought levels in the NL and DK sites during the winter re-wetting period that indicates any change in soil C storage due to changes in soil C efflux may be short lived in these mesic systems. In contrast, in the hydric UK site after 2 years of drought treatment, the persistent reduction in soil moisture throughout the year resulted in a year-round increase in soil respiration flux, a response that accelerated over time to 40% above control levels. These findings suggest that carbon-rich soils with high organic matter content may act as a significant source of CO2 to the atmosphere following repeated summer drought. Nonrecovery of soil moisture and a persistent increase in soil respiration may be the primary mechanism underlying the reported substantial losses of soil carbon from UK organic soils over the last 20 years. These findings indicate that the water status of an ecosystem will be a critical factor to consider in determining the impact of drought on the soil carbon fluxes and storage. [source] Model predicting dynamics of biomass, structure and digestibility of herbage in managed permanent pastures.GRASS & FORAGE SCIENCE, Issue 2 2006Abstract To investigate seasonal and annual interactions between management and grassland dynamics, a simple mechanistic model of the dynamics of production, structure and digestibility in permanent pastures was constructed. The model is designed to respond to various defoliation regimes, perform multiple-year simulations and produce simple outputs that are easy to use as inputs for a model of ruminant livestock production. Grassland communities are described using a set of average functional traits of their constituent grass groups. The sward is subdivided into four structural compartments: green leaves and sheath, dead leaves and sheath, green stems and flowers, and dead stems and flowers. Each compartment is characterized by its biomass, age and digestibility. Only above-ground growth is modelled, using a light-utilization efficiency approach modulated by a seasonal pattern of storage and mobilization of reserves. Ageing of plant parts is driven by cumulative thermal time from 1 January and by biomass flows. Age affects senescence, abscission and digestibility of green compartments and, therefore, the quality of green leaves and stems can increase or decrease over time in relation to net growth and defoliation dynamics. The functional traits having the greatest impact on model outputs are seasonal effects, period of reproductive growth and effects of temperature on photosynthetic efficiency. The functional traits of the grass groups were parameterized for temperate pastures of the Auvergne region in France. The other model inputs are few: proportion of functional groups, basic weather data (incident photosynthetically active radiation, mean daily temperature, precipitation and potential evapotranspiration) and site characteristics (nitrogen nutrition index, soil water-holding capacity). In the context of a whole-farm simulator, the model can be applied at a field scale. [source] The effects of log erosion barriers on post-fire hydrologic response and sediment yield in small forested watersheds, southern California,HYDROLOGICAL PROCESSES, Issue 15 2001Peter M. Wohlgemuth Abstract Wildfire usually promotes flooding and accelerated erosion in upland watersheds. In the summer of 1999, a high-severity wildfire burned a series of mixed pine/oak headwater catchments in the San Jacinto Mountains of southern California. Log erosion barriers (LEBs) were constructed across much of the burned area as an erosion control measure. We built debris basins in two watersheds, each about 1 ha in area, one with LEBs, the other without, to measure post-fire hydrologic response and sediment yield and to evaluate the effectiveness of the LEBs. The watersheds are underlain by granitic bedrock, producing a loamy sand soil above large extents of weathered bedrock and exposed core stones (tors) on the surface. Measured soil water-repellency was similar over the two catchments. Rain gauges measured 348 mm of precipitation in the first post-fire year. The ephemeral stream channels experienced surface flow after major rainstorms, and the source of the water was throughflow exfiltration at the slope/channel interface. Post-fire overland flow produced some rilling, but hillslope erosion measured in silt fences away from any LEBs was minor, as was sediment accumulation behind the LEBs. Stream channels in the catchments exhibited minor net scour. Water yield was much greater in the LEB-treated watershed. This resulted in 14 times more sediment yield by weight than the untreated watershed. Average soil depths determined by augering were nearly double in the catchment without the LEBs compared with the treated watershed. This suggests that differences in water and sediment yield between the two catchments are due to the twofold difference in the estimated soil water-holding capacity in the untreated watershed. It appears that the deeper soils in the untreated watershed were able to retain most of the precipitation, releasing less water to the channels and thereby reducing erosion and sediment yield. Thus, the test of LEB effectiveness was inconclusive in this study, because soil depth and soil water-holding capacity may have masked their performance. Published in 2001 John Wiley & Sons, Ltd. [source] Location-related differences in structure and function of the stratum corneum with special emphasis on those of the facial skinINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2008H. Tagami Synopsis Between the two different kinds of the skin covering the body, the glabrous skin is found only on the palmo-plantar surface because of its rather simple function to protect the underlying living tissue with its remarkably thick stratum corneum (SC) from strong external force and friction. Thus, its barrier function is extremely poor. In contrast, the hair-bearing skin covers almost all over the body surface regardless of the presence of long hair or vellus hair. In regard to its SC, many dermatologists and skin scientists think that it is too thin to show any site-specific differences, because the SC is just present as an efficient barrier membrane to protect our body from desiccation as well as against the invasion by external injurious agents. However, there are remarkable regional differences not only in the living skin tissue but also even in such thin SC reflecting the function of each anatomical location. These differences in the SC have been mostly disclosed with the advent of non-invasive biophysical instruments, particularly the one that enables us to measure transepidermal water loss (TEWL), the parameter of the SC barrier function, and the one that evaluates the hydration state of the skin surface, the parameter of the water-holding capacity of the SC that brings about softness and smoothness to the skin surface. These in vivo instrumental measurements of the SC have disclosed the presence of remarkable differences in the functional properties of the SC particularly between the face and other portions of the body. The SC of the facial skin is thinner, being composed of smaller layers of corneocytes than that of the trunk and limbs. It shows unique functional characteristics to provide hydrated skin surface but relatively poor barrier function, which is similar to that observed in retinoid-treated skin or to that of fresh scar or keloidal scars. Moreover, there even exist unexpected, site-dependent differences in the SC of the facial skin such as the forehead, eyelid, cheek, nose and perioral regions, although each location occupies only a small area. Between these locations, the cheek shows the lowest TEWL in contrast to the perioral region that reveals the highest one. Moreover, these features are not static but change with age particularly between children and adults and maybe also between genders. Among various facial locations, the eyelid skin is distinct from others because its SC is associated with poor skin surface lipids and a thin SC cell layer composed of large corneocytes that brings about high surface hydration state but poor barrier function, whereas the vermillion borders of the lips that are covered by an exposed part of the oral mucosa exhibit remarkably poor barrier function and low hydration state. Future studies aiming at the establishment of the functional mapping in each facial region and in other body regions will shed light on more delicate site-dependent differences, which will provide us important information in planning the strategy to start so called tailor-made skin care for each location of the body. Résumé Entre les deux types différents de peau couvrant le crops, on trouve la peau glabre uniquement sur la surface palmo-plantaire du fait de sa fonction plutôt simple de protection du tissu vivant sous-jacent par un stratum corneum (SC) trés épais vis-à-vis des forces extérieures et de la friction. De ce fait, sa fonction barrière est extrêmement pauvre. Au contraire, la peau velue courve la presque totalité de la surface du crops, que ce soit par la présence de longs cheveux ou de duvet. En ce qui concerne son SC, la plupart des dermatologues et des scientifiques de la peau pensent qu'il est trop mince pour montrer une différence spécifique au site, attendu que le SC est simplement présent en tant que membrane barriére efficace pour protéger notre corps de la dessiccation ainsi que pour lutter contre l'invasion d'agents nuisibles externes. Cependant, il existe des différences importantes entre les sites, non seulement dans la peau vivante, mais également dans ce SC aussi mince, qui révèlent la fonctin de chaque site anatomique. Ces différences dans le SC ont surtout été révélées avec l'apparition d'instruments biophysiques non invasifs, en particulier celui qui nous permet de mesurer la perte transépidermale en eau (TEWL), le paramétre de la fonction barrière du SC et celui qui évalue l'état d'hydratation de la surface de peau, le paramètre de la capacité en rétention de l'eau du SC qui est liéà la souplesse et à la douceur à la surface de peau. Ces mesures instrumentales in vivo du SC ont révélé la présence de différences remarquables entre les propriétés fonctionnelles du SC particulièrement entre le visage et d'autres parties du corps. Le SC de la peau de la face est plus mince, car li est composé de couches plus petites de corneocytes que celui du tronc et des membres. Il montre des caractéristiques fonctionnelles uniques pour permettre l'hydratation de la surface de peau, mais une fonction barrière relativement faible, semblable à celle observée dans la peau traitée avec un rétinoïde ou à celle d'une cicatrice récente ou de cicatrices kéloidales. De plus, il existe des différences sites-dépendantes inattendues dans le SC de la peau de la face comme le front, la paupière, la joue, le nez et les régions périorales, et ce, bien que chaque emplacement occupe seulement un petit secteur. Entre ces divers emplacements, la joue montre le TEWL le plus bas par comparaison avec la région périorale qui montre le plus élevé. De plus, ces caractéristiques ne sont pas fixes, mais changent avec l'âge en particulier entre enfants et adultes et peut-être aussi entre sexes. Entre les diverses régions de la face, la peau de la paupière se distingue parce que son SC est associéà une peau pauvre en lipides de surface constituée par une mince couche de cellule composée de grand cornéocytes qui provoquent un haut état d'hydratation superficiel, mais une faible fonction barrière. A l'inverse les bordures vermillion des lévres recouvertes par une partie exposée de muqueuse orale, possèdent une fonction barrière très faible et un état d'hydratation bas. Les études futures visant àétablir la configuration fonctionnelle de chaque région de la face et d'autres régions du corps mettrons en lumière des différences sites-dépendantes plus subtiles, qui nous fourniront des informations importantes pour planifier la stratégie pour commencer le soin de la peau sur mesure si attendu pour chaque partie du corps. [source] Wool peptide derivatives for hand careINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2008C. Barba Hands experience much greater wear and tear during normal daily routines compared with most other parts of the body, and thereby demand specific needs from cosmetics targeted at hand care. Keratin proteins are the major structural component of the outer layers of the skin. In this work a novel keratin fraction from wool, which has high cystine content present in the S-sulphonated form, has been developed to target hand care applications. In vivo long-term studies were performed to evaluate the water-holding capacity and elasticity of hand skin following topical application of keratins. Moreover, protection of healthy skin against detergent-induced dermatitis was evaluated after topical application of the keratin-active formulation. Significant results in the measured biophysical parameters were found, which indicated an improvement in the skin's water-holding capacity, hydration, and elasticity for volunteers with dry skin as a result of the keratin peptide treatment. Results also indicated that the keratin peptide treatment can prevent some of the damaging effects associated with surfactant exposure. [source] Influence of starter culture type and incubation temperatures on rheology and microstructure of low fat set yoghurtINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 4 2009HABIB ABBASI The effects of different cultures and incubation temperatures on the physical properties of low fat yoghurts were investigated. The samples were incubated with exopolysaccharide (EPS)-producing and non-EPS-producing cultures at 37, 42 and 45°C. All measured parameters except firmness were influenced by culture type and incubation temperature. Firmness, G, and G, were maximised at 42°C for both cultures. Increased incubation temperature and EPS culture led to a higher water-holding capacity but lower syneresis, G, and G,. The EPS treatment incubated at 37°C showed even lower syneresis than non-EPS treatments incubated at higher temperatures. [source] Fat, wheat bran and salt effects on cooking properties of meat patties studied by response surface methodologyINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2010Hasibe Tekin Summary Response surface methodology was used to investigate the main effects and interactions of composition (processing) variables such as fat (10,30%), wheat bran (5,15%) and NaCl (0,2%) on cooking properties of beef patties. In addition, the ridge analysis was conducted to find the values of processing variables that maximise and minimise the cooking parameters (moisture retention, fat retention, reduction in thickness, reduction in diameter, cooking yield, shrinkage and water-holding capacity). It was found that the moisture and fat retention, reduction in thickness and cooking yield values decreased; however, reduction in diameter and shrinkage values increased, respectively, as the amount of fat increased. However, wheat bran addition increased fat retention, moisture retention, cooking yield and water-holding capacity values of the patties. Increasing NaCl levels decreased water-holding capacity value by its quadratic effect and moisture and fat retention value by its interaction effect with wheat bran. [source] The effect of long-term frozen storage on the quality of frozen and thawed mashed potatoes with added cryoprotectant mixturesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2009Cristina Fernández Summary Cryoprotectant mixtures were added to frozen/thawed (F/T) mashed potatoes in the form of amidated low-methoxyl (ALM) pectin and xanthan gum (XG), kappa-carrageenan (,-C) and XG and sodium caseinate (SC) and XG, and the effect of frozen storage was examined. F/T mashed potatoes without added biopolymers had higher storage modulus G, after freezing and frozen storage, associated with sponge formation due to amylose retrogradation. Oscillatory measurements indicated weakening of the structure of mashed potatoes without biopolymers and with added ,-C/XG and SC/XG mixtures at the end of storage due to ice recrystallisation, whereas the structure of samples with added ALM/XG mixtures was reinforced by increasing time in storage. Mashed potatoes with added mixtures exhibited water-holding capacity for 1 year. Samples with added ,-C/XG mixtures were more structured, although when both ,-C/XG and SC/XG mixtures were included in mashed potato, very acceptable sensory quality was maintained in usual frozen storage conditions. [source] Effect of storage on the gel-forming properties of yam-containing surimi gelsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2007Yun-Chin Chung Summary The breaking forces, deformations and water-holding capacities of pollock surimi gels (PSG) containing 20% fresh Tainung No. 1 (TNG1) yam (Dioscorea alata) stored at room temperature, 17 and 10 °C, were determined for 12 weeks to evaluate the feasibility of using fresh yam as a healthy ingredient and an alternative source for starch in surimi seafoods. The results showed that the texture properties of TNG1-PSG decreased during storage regardless of the storage temperatures, except for an insignificant change found in the water-holding capacity at 10 °C. Most changes in the texture properties occurred within 1 week, thus the use of fresh TNG1 immediately after harvest is required for producing TNG1-PSG with good texture properties. Frozen storage of TNG-PSG was also undertaken at ,20 °C for 6 months. After 6-months of storage, the breaking force and water-holding capacity of TNG1-PSG decreased by about 22% and 19%, respectively. [source] The hydrophilic, foaming and emulsifying properties of casein concentrates produced by various methodsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2006Janesca A. Roman Summary The hydrophilic and surfactant properties of casein concentrates made by different processes such as isoelectric precipitation and neutralization (commercial casein, CC) coagulation by rennet (casein clots, COC) and microfiltration/diafiltration (casein micelles, CM) were studied. Water absorption capacity (WAC), water solubility (WS) and water-holding capacity (WHC) were highest for CM and lowest for COC. Solubility was higher in water and in pH 5.5, 0.10 m NaCl solution for both CM and COC. Foaming capacity was better for CM than for CC at pH 4.0 and for CC at pH 6.0 and 8.0. Foam stability was low for both CM and CC at pH 4.0 but it was high for CM at pH 6.0 and 8.0 and for CC in the absence of salt. Emulsifying capacity was higher for CC at pH 4.0 and 7.0. Stability of emulsion was high for CC at pH 4.0 and for CM at pH 7.0. [source] Genetic aspects concerning drip loss and water-holding capacity of porcine meatJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2007D. G. J. Jennen Summary The amount and distribution of water inside the meat has a considerable influence on its properties. High losses of fluid in the form of drip may affect financial output, nutritional value, consumer appeal and/or technological properties of porcine meat. Therefore, a deeper insight into the traits water-holding capacity (WHC) and drip is favourable on behalf of producers, industry and consumers. Similar to most meat quality traits, WHC and drip loss (DRIP) are moderately heritable. The genetic correlation between these two traits is high. Correlation to other meat quality traits, such as pH value, cooking loss, reflectance, etc. is existent as predictable. Two major genes are known, RYR1 on chromosome 6 and RN on chromosome 15, to influence meat quality in general and WHC in particular. Furthermore, a number of candidate genes exist, e.g. phosphoglycerate mutase 2. Within the variety of quantitative trait loci (QTL) experiments, a number of QTL have been identified. QTL for DRIP and/or WHC have been found on chromosome 1, 2, 4, 5, 6, 11, 13, 14, 15, 18; for cooking loss on 7, 14 and18, and for pH value on nearly all chromosomes. Recently, a QTL study for meat quality and body composition traits in a Duroc,Pietrain (DUPI) resource population has been conducted at the University of Bonn, Germany. Four QTL for DRIP were identified on chromosomes 2, 3, 5 and 18. The QTL regions are in agreement with previously published QTL for this and other related traits. Further research and finemapping has begun and candidate genes located within the QTL regions are currently under investigation. Combination and comparison of results should lead to deeper insights in the genetic background of meat quality and DRIP. [source] Atopic xerosis: employment of noninvasive biophysical instrumentation for the functional analyses of the mildly abnormal stratum corneum and for the efficacy assessment of skin care productsJOURNAL OF COSMETIC DERMATOLOGY, Issue 2 2006Hachiro Tagami MD Summary The subtle dryness of the skin surrounding the lesions of atopic dermatitis (AD) is called atopic dry skin or atopic xerosis (AX). AX is more susceptible to the development of AD skin lesions under various environmental stimuli than the clinically normal skin of the people who have or have had or will have AD, which might be called normal atopic skin (NAS) that shows no functional differences as compared to the skin of normal individuals. Routine histopathologic studies of AX that involve the invasive procedures of biopsy are not so helpful in clarifying the underlying pathogenesis. Modern, noninvasive biophysical instrumentation provides rich and quantitative information about various functional aspects of skin. The stratum corneum (SC) of AX reveals not only decreased hydration but also mildly impaired barrier function demonstrable as an increase in transepidermal water loss, elevated pH values, and an increased turnover rate of the SC consisting of thick layers of smaller-sized corneocytes. These data suggest that AX is related to mildly increased epidermal proliferation as a result of the presence of subclinical cutaneous inflammation. Although AX skin does not display any impairment in the recovery of barrier function after physical skin irritation by tape-stripping, it produces a much more severe, long-lasting inflammatory response together with a delay in barrier repair after chemical irritation such as that induced by sodium lauryl sulphate. The SC of AX is biochemically characterized by reduction in the amounts of ceramides, especially ceramide I, sebum lipids, and water-soluble amino acids. None of these changes in SC functions are seen in NAS, which includes not only the normal-looking skin of AD patients long after regression of all active lesions but also of latent atopic skin such as neonates who later develop AD. This suggests that all of the observed functional as well as biochemical abnormalities of AX are a reflection of subclinical inflammation. The presence of the underlying inflammation in AX also differentiates it from senile xerosis. The mildly impaired SC functions of AX can be improved by daily repeated applications of effective moisturizers, i.e., corneotherapy, which is effective in preventing the exacerbating progression of AX to AD resulting from inadvertent scratching of the skin that facilitates the penetration of environmental allergens into the skin. The biophysical confirmation of such efficacy of moisturizers, including cosmetic bases on the mildly impaired barrier function and decreased water-holding capacity of the SC of AX, definitely substantiates the importance of skin care for the cosmetic skin problems that affect every individual in the cold and dry season ranging from late autumn to early spring. [source] INFLUENCE OF SODIUM TRIPOLYPHOSPHATE (STP) TREATMENT AND COOKING TIME ON COOK LOSSES AND TEXTURAL PROPERTIES OF RED MEATSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2007S. BELGIN ERDOGDU ABSTRACT Sodium tripolyphosphates (STPs) are important functional additives used in meat products. STPs reduce cook losses and improve textural properties, especially by increasing the water-holding capacity of proteins. However, increases in cooking time or temperature enhance meat proteins' denaturation, resulting in a reduced water-holding capacity. The amount of STPs diffused into meats would play an important role for these changes. Therefore, the objectives of this research were to determine the effects of processing conditions (cooking time, STP concentration and dipping time) on cook losses and textural properties of red meats, and to relate these changes with diffused amount of STPs. For this purpose, meats (2 × 2 × 2 cm in size) were dipped in different concentrations of STP solutions (2, 4 and 6%) for 10, 20 and 30 min, and were cooked in boiling water for 5, 10 and 15 min. Cook losses were calculated from weight changes, and textural properties were determined by applying texture profile analysis to data obtained using Texture Analyzer TA-XT2i (Stable Micro Systems, Godalming, Surrey, U.K.). STPs were found to decrease cook losses and hardness values. While an increase in STP concentration increased cohesiveness, increase in cooking time resulted in higher hardness, gumminess, chewiness and cook losses. An increase in dipping times also decreased the cook losses and hardness. The results showed that STP concentration, STP dipping and cooking times had significant effects on the changes of textural properties and cook losses of meats. These results may be used for further meat processing optimization studies if they get correlated with sensory data obtained at the same conditions. PRACTICAL APPLICATIONS Cooking to assure safety of food products leads to changes in sensory attributes. The major changes occurring in meats are shrinkage, toughening of tissues, releasing of meat juice and color due to the effect of thermal treatment on proteins. Based on these, resulting cook losses for economical considerations and changes in textural properties affecting consumer satisfaction are widely recognized. Because the meat processing industry uses sodium tripolyphosphates (STPs) to improve textural properties and to reduce cook losses, the objective of this research was to determine the effects of STPs and cooking time on cook losses and textural properties of red meats. The results showed that STPs and cooking time affected the changes in cook losses and textural properties significantly. In addition to these results, an optimization study for decreasing cook losses while improving textural properties should be conducted where these changes are attributed to be significant for human perception using a sensory panel. [source] Effects of High Pressure on Texture and Microstructure of Sea Bass (Dicentrarchus labrax L.) FilletsJOURNAL OF FOOD SCIENCE, Issue 8 2005Romuald Chéret ABSTRACT High pressure is an innovative non-thermal food-preservation technology. We studied the effect of high-pressure treatment up to 500 MPa for 5 min on physical characteristics of sea bass fillets after 0, 7, and 14 d of refrigerated storage. Color results exhibited an increase of lightness and a slight change of hue, which might be imperceptible in cooked fish. High-pressure treatment induced a decrease of exudation and water-holding capacity. Pressure treatment above 300 MPa provoked higher fish hardness after storage than in untreated sample, proving the ability of high pressure to improve textural quality of chilled, stored fish fillet. These assessments were corroborated with microstructure observations. We showed that high-pressure treatment at 500 MPa allowed, after 7 d of storage, a total aerobic count equivalent to that of untreated fresh fish fillet to be obtained. Thus, high pressure might be considered to be a technology able to improve safety and textural quality of fresh fish fillets. [source] Effect of Chemically Modified Soy Proteins and Ficin-tenderized Meat on the Quality Attributes of SausageJOURNAL OF FOOD SCIENCE, Issue 1 2003R. Ramezani ABSTRACT: The purpose of this investigation was to use ficin-tenderized meat and cysteine-modified soy proteins in the production of bologna and to evaluate the effect of these modifications on water-holding capacity (WHC), emulsion stability (ES), texture, and protein solubility. The effect of ficin on meat protein was also evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Results indicated that both ficin-tenderized meat and modified soy proteins substantially improved WHC, ES, and other quality factors. SDS-PAGE results showed the disappearance of several protein bands in ficin-treated meat. Solubility of meat proteins increased when ficin was used for meat tenderization. The results of this study indicated that some quality attributes of meat products can be improved by enzymatic and chemical modification of protein sources in the manufacture of meat products. [source] Gelling Properties of Whey Proteins After Enzymic Fat HydrolysisJOURNAL OF FOOD SCIENCE, Issue 4 2000C. Blecker ABSTRACT: The effect of residual fat hydrolysis upon the gelation of whey protein concentrate (WPC) was studied. Gelling properties of a commercial WPC and lipase-treated WPC were evaluated on the basis of least concentration endpoint gelation, penetration test, texture profile analysis and water-holding capacity. Heat treatment of lipase-treated WPC led to gels with the highest hardness, springiness, cohesiveness and water retention. Such transformed WPC could be advantageously used to help improve texture in formulated meat, bakery, and confectionery products. [source] Soil N transformations after application of 15N-labeled biomass in incubation experiments with repeated soil drying and rewettingJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2004Hans-Werner Olfs Abstract The effects of repeated soil drying and rewetting on microbial biomass N (Nbio) and mineral N (Nmin) were measured in incubation experiments simulating typical moisture and temperature conditions for soils from temperate climates in the post-harvest period. After application of in vitro15N-labeled fungal biomass to a silty loam, one set of soils was exposed to two drying-rewetting cycles (treatment DR; 14 days to decrease soil moisture to 20,% water-holding capacity (WHC) and subsequently 7 days at 60,% WHC). A control set (treatment CM) was kept at constant moisture conditions (60,% WHC) throughout the incubation. Nbio and Nmin as well as the 15N enrichment of these N pools were measured immediately after addition of 15N-labeled biomass (day 0) and after each change in soil moisture (day 14, 21, 35, 42). Drying and rewetting (DR) resulted in higher Nmin levels compared to CM towards the end of the incubation. Considerable amounts of Nbio were susceptible to mineralization as a result of soil drying (i.e., drying enhanced the turnover of Nbio), and significantly lower Nbio values were found for DR at the end of each drying period. Immediately after biomass incorporation into the soil (day 0), 22,% of the applied 15N was found in the Nmin pool. Some of this 15Nmin must have been derived from dead cells of the applied microbial biomass as only about 80,% of the microbes in the biomass suspension were viable, and only 52,% of the 15Nbio was extractable (using the fumigation-extraction method). The increase in 15Nmin was higher than for unlabeled Nmin, indicating that added labeled biomass was mineralized with a higher rate than native biomass during the first drying period. Overall, the effect of drying and rewetting on soil N turnover was more pronounced for treatment DR compared to CM during the second drying-rewetting cycle, resulting in a higher flush of mineralization and lower microbial biomass N levels. Stickstoffumsatz im Boden nach Applikation 15N-markierter Biomasse in Inkubationsversuchen mit wiederholten Trocknungs-Wiederbefeuchtungszyklen Der Einfluss wiederholter Bodentrocknung und -wiederbefeuchtung auf mikrobiellen Biomasse-N (Nbio) und mineralischen N (Nmin) wurde in Inkubationsversuchen untersucht. Bodenfeuchte und -temperatur wurden entsprechend den typischen Bedingungen in der Nachernte-Periode gemäßigter Klimazonen simuliert. Nach Applikation von in-vitro15N-markierter Biomasse zu einem Krumenboden (schluffiger Lehm) wurde eine Hälfte der Inkubationsgefäße zwei Trocknungs-Wiederbefeuchtungs-Zyklen ausgesetzt (Behandlung DR, d. h., innerhalb von 14 Tagen Absenkung der Bodenfeuchte auf 20,% der Wasserhaltekapazität (WHC) und danach 7 Tage bei 60,% WHC). Die Vergleichsgefäße wurden konstant bei 60,% der WHC inkubiert (Behandlung CM). Nbio und Nmin sowie die 15N-Anreicherung dieser N-Pools wurden sofort nach der Applikation der 15N-markierten Biomasse (Tag 0) und nach jeder Änderung in der Bodenfeuchte (Tag 14, 21, 35, 42) gemessen. Trocknung und Wiederbefeuchtung (DR) resultierte in höheren Nmin -Gehalten im Vergleich zu CM gegen Ende der Inkubation. Bei Bodentrocknung unterlagen höhere Biomasse-Anteile der Mineralisation (d. h., Trocknung forcierte den Umsatz von Nbio), so dass jeweils am Ende der Trocknungsperiode in DR niedrigere Nbio -Gehalte gefunden wurden. Sofort nach der Einarbeitung der Biomasse in den Boden (Tag 0) wurde 22,% des applizierten 15N im Nmin -Pool gefunden. Ein Teil dieses 15Nmin dürfte von bereits toten Zellen der eingesetzten Mikroben-Biomasse stammen, da nur ca. 80,% der Mikroorganismen in der verwendeten Biomasse-Suspension als lebend eingestuft werden konnte und nur 52,% des 15Nbio mittels Fumigations-Extraktions-Methode extrahierbar war. Aus dem deutlicheren Anstieg im 15Nmin im Vergleich zum unmarkierten Nmin kann geschlossen werden, dass während der ersten Trocknungsperiode zugesetzte markierte Biomasse mit einer höheren Rate als bodenbürtige Biomasse mineralisiert wurde. Insgesamt war der Effekt des Trocknens und der Wiederbefeuchtung auf den N-Umsatz im Boden für die Behandlung DR im Vergleich zu CM im zweiten Zyklus ausgeprägter. Dies zeigt sich in einem höheren Mineralisationsschub und in einem niedrigeren Gehalt an Biomasse zum Ende der Inkubation. [source] TEXTURAL CHARACTERIZATION OF SOY-BASED YOGURT BY THE VANE METHODJOURNAL OF TEXTURE STUDIES, Issue 2 2002IGOR V. KOVALENKO ABSTRACT The vane method was applied to evaluate failure characteristics of soy-based yogurts prepared from five soybean varieties at Brix values of 6, 8, and 10°. Yield stress, yield strain, and water-holding capacity were compared. Yield stress values ranging from 133 to 420 Pa at 2.5% protein and 498 to 1171 Pa at 4.0% protein were dependent on soybean variety and increased with increasing protein concentration. The average yield strain of samples was not affected by protein or variety. Compared to commercial dairy yogurt, soy yogurt had 132 to 445% higher yield stress at similar protein content, and was less deformable based on yield strain measurements. Water-holding capacity of soy yogurts was variety dependent, although this dependence was less pronounced at higher protein concentrations. The vane method may be effectively used as a rapid and inexpensive technique for detecting textural differences of soy-based yogurts. [source] Environmental dew point and skin and lip weatheringJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2010C Devillers Abstract Xerosis represents a physiological response of the stratum corneum (SC) to environmental threats. The influence of the environmental dew point (DP) is not fully understood. This parameter is the air temperature at which the relative humidity is maximum. This study aimed to assess the relationship between the environmental DP and the water-holding capacity of the skin and lower lip vermilion. For comparison, SC property was evaluated after occlusive application of cooled and uncooled hydrogel pads. Electrometric measurements using a dermal phase meter (DPM) device were performed on the back of the hands, the cheeks and the lower lip of 40 healthy menopausal women. Assessments were performed in the outdoor conditions during winter and spring. The same measurements were recorded after hydrogel pads, at room temperature or cooled to 4 °C, were placed for 15 min on the test sites. The environmental DP was recorded at each evaluation time. The SC water-holding capacity was discretely influenced by the DP. In the open-air environmental conditions, a positive linear relationship was found on the cheeks between the DP and DPM values. The relationship was weaker on the lips. Conversely, a consistent increase in DPM values was recorded immediately after removal of the cooled and uncooled hydrogel pads. The observations made in the open-air testing conditions are consistent with the predicted events following the Arrhenius law. By contrast, the combination of cooling and occlusion by the hydrogel pads is responsible for the reverse effect on the SC. [source] Properties of refrigerated ground beef treated with potassium lactate and sodium diacetateJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2008Miros, aw Fik Abstract BACKGROUND: Ground meat is product that perishes easily and therefore various preservatives are applied to prolong its shelf life. The aim of this study was to investigate the effect of potassium lactate and sodium diacetate (Protec K-DI preparation) on general proteolytic activity, protein degradation, texture, colour and water-holding capacity of vacuum-packaged ground beef. RESULTS: The activity of endogenous proteolytic enzymes, and hence the rate of protein hydrolysis changed significantly (P < 0.05) during refrigerated storage. The proteolysis was more intensive in the meat with the preservative than in a control sample. According to the results of SDS-PAGE, the level of myosin in ground beef decreased with increasing storage time, whereas the preservative did not have a significant effect (P > 0.05) on these changes. However, its impact was the most significant in the case of tropomyosin and troponin T content, as well as changes of 30 kDa protein content. The preservative as well as the increase in storage time influenced an increase in content of polypeptides, peptides and some amino acids in the samples, and had an inhibiting effect on unfavourable changes in ground beef hardness. The preservative addition allowed the meat to maintain desired meat colour, and the main pigment during refrigerated storage was oxymyoglobin (MbO2). CONCLUSION: Results showed that the Protec K-DI preparation can be useful in minced meat production as a good stabiliser of colour and texture despite the increase observed in proteolytic activity after the preservative addition. Copyright © 2007 Society of Chemical Industry [source] Influence of water and nitrogen deficit on fruit ripening and aroma potential of Vitis vinifera L cv Sauvignon blanc in field conditionsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2005Catherine Peyrot des Gachons Abstract S -Cysteine conjugate precursors of three volatile thiols were monitored in Vitis vinifera L cv Sauvignon blanc grapes during fruit ripening to assess the influence of vine water and nitrogen status on the grape aroma potential in field conditions. Four dry farmed plots were studied in the Pessac-Léognan and Graves appellations (Bordeaux area) in 1998, which was a very dry vintage, and in 1999, when regular summer rainfall occurred. Soil water-holding capacity ranged from very low to high. Soil total nitrogen content was related to soil organic matter content, which was highly variable on the four plots. Vine vigour was enhanced by both high water and nitrogen status. Major compounds in grapes depended mainly on vine water status. Water deficit-stressed vines produced small berries with low sugar and low total acidity. Grape aroma potential was highest in vines under mild water deficit and moderate nitrogen supply. Severe water deficit stress seemed to limit aroma potential, as did nitrogen deficiency. Consequences for site selection and irrigation management for Sauvignon blanc are discussed. Copyright © 2004 Society of Chemical Industry [source] Influence of the season on the relationships between NMR transverse relaxation data and water-holding capacity of turkey breast meatJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2004Maurizio Bianchi Abstract In the last few years the poultry industry has seen a significant deterioration in meat quality properties during the summer season. The objective of this study was to evaluate the seasonal effect (summer and winter) on turkey meat quality assessed by both conventional and low-resolution nuclear magnetic resonance (LR-NMR) analysis. Eighty-eight breast muscle samples (35 winter and 53 summer) from BUT-Big 6 turkeys belonging to 16 different flocks, were randomly collected from a commercial processing plant. The samples were analysed for transverse relaxation times (T2) by LR-NMR and for initial pH (15 min post mortem), ultimate pH (24 h post mortem) and pH after cooking, temperature at 15 min post mortem, water-holding capacity (WHC, drip loss, filter paper press wetness and cooking loss) at 24 h post mortem, colour of raw and cooked meat and chemical composition (moisture, lipids and proteins). The results indicate that, during the summer season, turkey breast meat undergoes a relevant WHC decrease. Cluster analysis of the raw LR-NMR data evidenced the presence of two groups corresponding to samples harvested in each different season. Correlations between the LR-NMR signal and the conventional parameters measuring WHC were obtained by a recently proposed type of principal component regression (PCR) termed relative standard deviation PCR. Copyright © 2004 Society of Chemical Industry [source] | ||||||||||||||||||||||