Greater Water-holding Capacity Research Articles

The Role of Organic Amendments and Their Impact on Soil Restoration: A Review

Soil organic matter (SOM) plays a pivotal role in maintaining soil health by enhancing its physical, chemical, and biological properties. It improves soil structure, water retention, nutrient availability, and microbial activity, contributing significantly to sustainable agriculture. Organic amendments, including animal manure, compost, biosolids, crop residues, and various organic by-products, are widely used to restore degraded soils by increasing SOM content. These amendments not only supply essential nutrients but also promote biological aggregation, suppress soil-borne pathogens, and improve soil's resistance to environmental stressors such as drought and heavy metal toxicity. The positive impacts of organic amendments on soil properties are well-documented, with key benefits including increased soil organic carbon (SOC), improved nutrient cycling, enhanced microbial diversity, and greater water-holding capacity. Organic materials such as compost and animal manure have been shown to significantly improve soil fertility and restore degraded soils. The application of green manure and crop residues also boosts soil biodiversity, enhances rhizospheric processes, and supports overall ecosystem resilience. This paper emphasizes the importance of adopting holistic soil management practices that include organic amendments, conservation tillage, and sustainable cropping systems to address soil degradation. By focusing on replenishing SOM, improving nutrient availability, and increasing soil biodiversity, these practices can contribute to the long-term sustainability of agricultural systems and environmental health. The restoration of soil organic matter is essential for enhancing soil quality and mitigating degradation, ultimately ensuring food security and ecosystem stability for future generations.

Optimizing Tilapia-based surimi ink for 3D printing: Enhancing physicochemical properties and printability with Ulva powder

The elderly face malnutrition and dysphagia. 3D printing with high-protein surimi offers an innovative way to customize nutrition and texture of foods for the elderly. This study explored whether tilapia-based surimi ink (TBSI) with Ulva powder (UP, 0–3 %) could improve physicochemical properties and printability as an alternative to traditional pollock-based surimi ink (PBSI). TBSI showed a more uniform microstructure, greater water-holding capacity (WHC), and better printability with consistent extrusion than PBSI. Adding UP to TBSI promoted cross-linking and enhanced microstructure and WHC. Rheological analysis revealed that all inks exhibited shear-thinning behavior. UP increased complex viscosity, storage modulus, and loss modulus. Notably, UP above 2 % improved protein matrix uniformity, structural integrity, and printability, as confirmed by FT-IR and 3D printing tests. The hardness of steamed TBSI fish cake increased when infill density increased. This study highlights the potential of TBSI with UP for 3D printing to prepare personalized and elderly-friendly food.

Effects of galactomannans of varied structural features on the functional characteristics and in vitro digestibility of wheat starch

This study explores the effects of four natural galactomannans (GMs) with varying degrees of branching (fenugreek gum, guar gum, tara gum and locust bean gum) on the functional properties and in vitro digestibility of wheat starch (WS). Results from rapid viscosity analysis (RVA) and low-field nuclear magnetic resonance (LF-NMR) analysis revealed that GMs with lower branching degrees were correlated with higher paste viscosity, peak viscosity, and greater water-holding capacity in the WS-GM mixtures. Additionally, these lower branching GMs more effectively inhibited amylose leaching during starch gelatinization, leading to a softer gel texture and increased transparency of the mixtures. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis demonstrated that starch mixtures containing lower branching GMs exhibited reduced relative crystallinity and enthalpy values during aging. Furthermore, the incorporation of lower branching GMs resulted in decreased starch digestibility in vitro, thereby enhanced resistant starch content. These findings highlight the potential of selectively branched GMs to modulate the functional properties and nutritional profile of WS, providing a promising approach for the development of starch-based products with improved health benefits.

Myosin heavy chain isoform expression and meat quality characteristics of different muscles in yak (Bos grunniens)

Myosin heavy chain (MHC) isoforms and meat quality characteristics of different muscles were investigated to explore their potential relationships in yaks. Results showed that semitendinosus (ST), longissimus thoracis (LT), and infraspinatus (IS) have a greater ratio of MHC IIb (47.84%), MHC IIa (73.27%), and MHC I (24.26%), respectively, than the other two muscles. Compared with LT or ST, IS exhibited more intense color, greater water-holding capacity, and initial tenderness with higher intermuscular fat (IMF) and collagen (of lower cross-linking level), presenting overall better quality. Variations in MHC isoforms accounted for the muscle-specific meat quality. Specifically, MHC I was positively associated with redness, myoglobin, IMF, collagen, pH, and thermal stability and negatively associated with myofibril fragmentation index, fiber thickness, collagen cross-linking, and drip loss. These results provide insights into the relationships between MHC isoforms and meat quality in yaks and the MHC I isoform has an extensive influence on meat quality.

Autophagy accelerates cell death after desiccation and hydration stress in Physcomitrium

Autophagy is the process responsible for degrading cytoplasmic components in lysosomes and vacuoles. Autophagy-deficient mutants are generally more sensitive to environmental stress than their wild-type (WT) plants. In this study, however, we found that autophagy-deficient (atg) mutants of Physcomitrium, in which an autophagy-related gene, either ATG5 or ATG7, is disrupted, are more tolerant to extreme desiccation stress than WT plants. The colonies were treated with the phytohormone abscisic acid, desiccated using silica gel, and hydrated on a nutrient-sufficient medium. atg mutant colonies survived this stress program and produced green colonies whereas the WT colonies did not. Evans Blue staining revealed obvious cell death in both colonies, but the rate was higher in WT than in atg5 colonies. atg cells had a higher protein content, accumulated more sucrose, and had greater water-holding capacity than WT cells. These factors likely reduce the rate of cell death with less damage during the stress program. On the other hand, inhibition of autophagy during the hydration step with the inhibitor 3-methyladenine increased survival, suggesting that autophagy occurring during the hydration step is involved in cell death. We conclude that Physcomitrium autophagy-deficient cells are more tolerant to extreme desiccation stress than WT cells due to higher water-holding capacity and the promotion of cell death by autophagy through an unknown mechanism. These findings challenge the conventional understanding of the role of autophagy in cell survival against stress and highlight the importance of further research in this area.

Effects of partial replacement of unwashed Antarctic krill surimi by Litopenaeus vannamei surimi on the heat-induced gelling and three-dimensional-printing properties.

There is an emerging consumption of the Antarctic krill (AK) muscle-based food due to its excellent nutritional value and enormous biomass storage capacity. However, the coarse texture of the muscle and the weak gelling properties of AK protein impede its expansion in surimi-based products. This investigation successfully prepared heat-induced gels of AK surimi with desirable textural properties by including Litopenaeus vannamei in varying proportions. Higher concentrations of L. vannamei resulted in improved three-dimensional printability, greater water-holding capacity (WHC), larger viscoelastic modulus, and a well-formed microstructural matrix of AK surimi, due to an increased level of myofibrillar protein. Compared with AK, L. vannamei muscle had double the salt-soluble protein content, which was corroborated by increased intensity of bands of actin, paramyosin, tropomyosin, and myosin light chains on reducing SDS-PAGE. DSC results indicated that a high ratio of L. vannamei elevated the denaturation temperature and enthalpy of myosin, sarcoplasmic protein, and actin, suggesting a high degree of cross-linking. It was also found that when hydroxypropyl cassava starch was added at 0.5% (w/w), WHC and gel strength were further improved with a more compact gel matrix. The successful preparation of unwashed mixed surimi with AK meat fully exploited in this study provides an option for AK surimi-based product industrialization.

Characterization of Poultry Litter Biochar and Activated Biochar as a Soil Amendment for Valorization

Biochar applications to soils may enhance soil quality, hydrological properties, and agronomic productivity. Modification of biochar by activation via introduction of heteroatoms at different pyrolysis conditions can alter physical and chemical characteristics, which may enhance soil properties, although the extent of this is unknown. The objective of this study was to investigate the impacts of pyrolysis temperature (400, 500, 600, and 700 °C) on activated (activated with methanesulfonic acid) and unactivated biochar produced from poultry litter to identify optimum production conditions for end use as a soil amendment. Physical, chemical, and surface properties of biochars were determined using wet chemistry and spectroscopic analyses. Results showed that activation with methanesulfonic acid increased biochars’ oxygen content, while decreasing its point of zero charge and electrical conductivity. Conversion of raw poultry litter to activated and unactivated biochar increased concentration of P (3-fold), K (1.8-fold), Ca (3-fold), Mg (2.3-fold), and S (4.8-fold), with concentrations increasing with increasing temperatures (p < 0.05) except for C and N. Activated biochar had lower recovery of C and N, but greater water-holding capacity than unactivated biochar. Concentrations of NH4-N, NO3-N, and water-soluble P were greater in unactivated biochar (p < 0.05). Among all biochars, activated biochar produced at 400 °C had the lowest bulk density, total P, K, Ca, and Mg, and greatest water-holding capacity, water-soluble P, Ca, and Mg concentrations, thereby suggesting improved soil amendment characteristics and subsequent soil health under poultry litter biochars produced under these conditions.

Dietary supplementation with biosynthesised nano-selenium affects growth, carcass characteristics, meat quality and blood parameters of broiler chickens

Context Selenium is an essential micronutrient that plays an important role in livestock nutrition. Aims The present experiment was conducted to evaluate the effects of green synthesised nano-selenium (GNS) on growth, carcass characteristics, meat quality and blood indices of broiler chickens when compared with sodium selenite (SS) as inorganic selenium. Methods A total of 360 1-day-old Ross 308 broiler chickens were randomly divided into four experimental treatments, with six replicates of 15 birds per each. The treatments were as follows: (1) basal diet supplemented with 0.15 mg/kg of SS (control group), and (2–4) basal diet supplemented with 0.075, 0.15 and 0.3 mg/kg of GNS, respectively. Key results The results showed that there was no influence of GNS supplementation on the growth of broiler chickens (P > 0.05). The relative weights of the carcass, breast, leg, pancreas, gizzard, and abdominal fat at 21 and 42 days were not affected by treatment. However, at 42 days, the lowest relative weight of the liver was for birds fed diets containing 0.3 mg/kg GNS. Compared with SS, the meat of birds fed GNS dietary supplements at 0.3 mg/kg had greater water-holding capacity, redness, yellowness and chroma values, and lower meat thiobarbituric acid reactive substances and drip loss values (P < 0.05). Compared with SS, broiler chickens fed diets supplemented with GNS at 0.3 mg/kg had greater amounts of total protein in serum. In this study, no major differences were observed in serum glucose, cholesterol, lipoprotein, thyroid hormone, and liver function levels and biomarkers of kidney function. Conclusions Taken together, the findings from this study indicate that GNS improved the quality of meat relative to SS, but had no effect on growth efficiency, carcass characteristics or broiler blood indices. Implications These results provide a basis for the application of eco-friendly GNS as an alternative of inorganic selenium in a mineral premix in chicken broiler diets.

Effect of Dry-Aging on Quality and Palatability Attributes and Flavor-Related Metabolites of Pork Loins.

This study evaluated the effect of dry-aging on quality, palatability, and flavor-related compounds of pork loins. Ten pork loins were obtained at 7 days postmortem, divided into three equal portions, randomly assigned into three different aging methods (wet-aging (W), conventional dry-aging (DA), and UV-light dry-aging (UDA)), and aged for 21 days at 2 °C, 70% RH, and 0.8 m/s airflow. The results showed similar instrumental tenderness values across all treatments (p > 0.05), while DA and UDA had a greater water-holding capacity than WA (p < 0.05). Both DA and UDA were observed to have comparable color stability to WA up to 5 days of retail display (p > 0.05). Greater lipid oxidation was measured in both DA and UDA at the end of display compared to WA (p < 0.05). The UV light minimized microorganisms concentration on both surface and lean portions of UDA compared to other treatments (p < 0.05). The consumer panel was not able to differentiate any sensory traits and overall likeness between the treatments (p > 0.05). Metabolomics analysis, however, identified more flavor-related compounds in dry-aged meat. These findings suggested that dry-aging can be used for pork loins for value-seeking consumers, as it has a potential to generate unique dry-aged flavor in meat with no adverse impacts on meat quality and microbiological attributes.

The relationship between acidification (pH) and meat quality traits of polish white breed pigs

The paper presents the results of a study on the relationship between acidification (pH) and standard quality characteristics of the meat of Polish Large White × Polish Landrace pig crossbreds. The meat for the study was obtained from 184 F1 Polish Large White × Polish Landrace fatteners from a herd free of the stress-sensitivity gene. The obtained results were analysed in groups formed according to the meat’s measured pH45 values (≤ 6.3; 6.3–6.7; > 6.7) and pHu values (≤ 5.3; 5.3–5.6; > 5.6). Increasing measured pH45 values were paralleled by greater water-holding capacity and plasticity, lower drip loss, darker colour L* as assessed visually and with equipment, and greater content of muscle pigments (P < 0.01) of the evaluated meat. Higher pHu values had a more pronounced impact on WHC, free drip loss, tenderness, water content, and colour parameters: a*, b*, chroma C* (P < 0.01), and hue angle ho (P < 0.05). The obtained simple correlations between pH45 and pHu acidity and meat-quality characteristics indicate that the measured pH45 value was correlated more closely than ultimate acidification (P < 0.01) with visually assessed colour intensity, tactilely assessed meat hardness, colour lightness L* (P < 0.01), hue angle ho (P < 0.05), and muscle pigment content. On the other hand, pHu was more strongly correlated with water-holding capacity, drip loss, meat tenderness as well as water and protein content (P < 0.01).

Effects of thinning and understory removal on the soil water-holding capacity in Pinus massoniana plantations

Forest management practices play an important role in regulating the soil water-holding capacity of plantation. However, most studies focus on soil water dynamics present during large-scale forest loss and afforestation events, while little is known about how soil water under different forest management practices responds to rainfall events and which factors mainly regulate soil water-holding capacity. In this study, a stable hydrogen isotope was used to explore the contribution of three natural rainfall events (8.9, 13.3 and 67.7 mm) to soil water (CRSW) in a Pinus massoniana plantation under four forest management practices (no thinning (NTN), understory removal (USR), light-intensity thinning (LIT) and heavy-intensity thinning (HIT)) in the Three Gorges Reservoir Area of the Yangtze River Basin in China. Furthermore, a structural equation model was employed to determine the effects of vegetation biomass and soil properties on the CRSW. The results showed that plantation soil under different forest management practices exhibited different water-holding capacities. Following light (8.9 mm) and moderate (13.3 mm) rainfall events, the CRSW in the HIT stand was slightly higher than that in the other stands. Following heavy (66.7 mm) rainfall event, the CRSW of most layers in USR stand was not different from the other three stands, while the CRSW in the LIT and NTN stands was significantly higher than that in the HIT stand in the 0–100 cm soil layers, suggesting that soil in the LIT and NTN stands had a greater water-holding capacity than that in the HIT stand. In addition, soil properties were the main factors directly affecting the CRSW, explaining 60% and 37% of the variation in the CRSW on the first and seventh days after heavy rainfall, respectively. Overall, compared to the HIT stand, the LIT and NTN stands showed greater capacity in retaining rainwater. Therefore, under expected global changes with frequent occurrences of extreme precipitation events, methods involving light-intensity and no thinning should be employed to build up soil and water conservation functions, which will be critical for keeping water-holding capacity and moderating floods.

Effects of selenium-chitosan on growth performance, carcass traits, meat quality, and blood indices of broiler chickens

The current experiment was conducted to evaluate the effects of Se-chitosan as organic Se, Na selenite, vitamin E, and their various combinations on growth performance, carcass traits, meat quality, and blood indices of broiler chickens. A total of 480 one-d-old broiler chickens were randomly assigned to the Se source (inorganic and organic), Se inclusion (0.15 and 0.30 mg/kg), and vitamin E (0 and 80 IU/kg) in a 2 × 2 × 2 factorial arrangement of treatments with 5 pens per treatment and 12 broiler chickens per pen. Broiler chickens fed 0.30 mg Se/kg had a greater body weight gain and a lower feed conversion ratio at 11 to 24 d (P < 0.05). The relative weight of the liver was lower in broiler chickens fed diets supplemented with 0.30 mg Se/kg at 21 d (P < 0.05). Broiler chickens fed diets supplemented with Se-chitosan or 0.30 mg Se/kg had lower thiobarbituric acid reactive substances, drip loss, and cooking loss and greater water holding capacity (WHC) values in muscles (P < 0.05). The yellowness of the broiler chicken muscle fed diets supplemented by Se-chitosan was greater (P < 0.05). In addition, an interaction between Se inclusion rate and vitamin E was observed for WHC in breast and thigh meat, so that broiler chickens fed 0.30 mg Se/kg plus vitamin E had a greater WHC compared to other treatments (P < 0.05). The broiler chickens fed diets supplemented by 0.30 mg Se/kg had greater total protein and albumin concentrations and lower concentrations of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase (P < 0.05). In addition, alkaline phosphatase activity was lower for broiler chickens fed diets supplemented with vitamin E (P < 0.05). In addition, broiler chickens fed 0.30 mg Se/kg plus vitamin E had the greater total protein concentrations compared to other treatments, while greater concentrations of aspartate aminotransferase and alanine aminotransferase were observed in broiler chickens fed 0.15 mg Se/kg without vitamin E (P < 0.05). Dietary supplements did not affect concentrations of thyroid hormones. It could be concluded that Se-chitosan as a novel Se source is a simple and cost-effective approach to improve meat quality and the dietary inclusion of 0.30 mg Se/kg improved meat quality and blood indices of broiler chickens.

Effects of dietary supplementation of a probiotic (Bacillus subtilis) on bone mass and meat quality of broiler chickens

The aim of this study was to investigate the effect of a dietary probiotic supplement on bone mass and meat quality of broiler chickens. Two hundred ten 1-day-old male Ross 708 broiler chicks were divided among 21 floor pens (10 chicks per pen). The pens were randomly distributed to 1 of 3 dietary treatments containing a probiotic, Bacillus subtilis, at 0 (control), 0.25 (0.25X), and 0.5 (0.5X) g/kg (n = 7). Gait score, footpad dermatitis (FPD), leg straightness, and hock burn (HB) were examined at day 33, and a latency-to-lie test was performed at day 34. At the end of the experiment (day 35), plasma, right leg, and litter samples were collected for mineral contents, meat quality, bone morphometric parameters, and litter quality assessments. The results indicated that probiotic-fed birds stood much longer during the latency-to-lie test with a greater tibial length, weight, and strength as well as higher plasma levels of calcium and phosphorus compared with the controls. In addition, probiotic-fed birds' leg muscle had higher color lightness at both 30 min and 5 h postmortem and greater water-holding capacity with a trend for less cooking loss (P = 0.056) and lower pH values (P < 0.05) at 5 h postmortem. Probiotic-fed birds' leg meat was tastier (P < 0.05) at 24 h after slaughter. These probiotic effects were greater in the 0.5X group than in the 0.25X group. There were no treatment effects on other measured parameters including gait score, HB, FPD, tibial lateral and medial wall thickness, diaphysis and medullary canal diameters, robusticity and tibiotarsal indexes, plasma magnesium concentrations, and litter moisture and pH values (P > 0.05). These findings indicate that the probiotic supplement could be a useful management tool for improving broiler production and welfare by enhanced bone mass and meat quality.

Effects of Landscape, Soils, and Weather on Yields, Nitrogen Use, and Profitability with Sensor-Based Variable Rate Nitrogen Management in Cotton

Farmers may be reluctant to adopt variable rate nitrogen (VRN) management because of uncertain profits. This study assessed field landscape, soil, and weather effects on optical sensing (OS)-based VRN on cotton (Gossypium hirsutum L.) N rates, yields, and net returns (NRs). Field data were collected from 21 locations in Louisiana, Mississippi, Missouri, and Tennessee, USA, between 2011 and 2014. Data included yields, N rates, and NRs for the farmer practice (FP), OS-based VRN, and OS-based VRN supplemented with other information. Production data were augmented with landscape, soils, and weather data, and ANOVA and logistic regressions were used to identify field conditions where VRN was profitable, provided risk management benefits, and improved N efficiency. Key findings indicate that NRs were improved with VRN by applying additional N on more erodible soils. Higher organic matter soils also benefited from VRN through enhanced yields and NRs. VRN may also have provided risk management benefits by providing a lower probability of NRs below NRs for the FP on soils associated with greater water-holding capacity, higher organic matter levels, or deeper profiles. Results from this study may help identify farm fields with similar characteristics for adoption of VRN management.

Influence of cutting methods and heat treatment on selected technological properties and structure of pork longissimus thoracis et lumborum muscle

The aim of this study was to determine the influence of cutting methods on the fiber structure and quality attributes of the cooked pork loin muscle. The culinary portions were cut perpendicularly (D, diagonal) or along the muscle fibers (P, parallel). The samples were heated to 72 °C in water bath (85 °C or 95 °C), steam (100 °C), or oven (125 °C or 150 °C). The P samples had a significantly smaller cooking loss (2–4.5%), greater water-holding capacity (3–5%), and lower shear force (0.35–2.2 N) than D samples except for the 100P, whose cooking loss was higher (by 1.9%) than the 100D. Heat-induced structural changes in the muscle, sarcomere shortening, and destruction of the perimysium and endomysium were affected by the cutting methods and cooking conditions. The findings justify the advisability of cutting individual culinary portions from pork loin muscle in parallel to the muscle fibers in order to increase raw meat efficiency.

Natural variation on whole-plant form in the wild is influenced by multivariate soil nutrient characteristics: natural selection acts on root traits.

In the complex soil nutrient environments of wild populations of annual plants, in general, low nutrient availability restricts growth and alters root-shoot relationships. However, our knowledge of natural selection on roots in field settings is limited. We sought to determine whether selection acts directly on root traits and to identify which components of the soil environment were potential agents of selection. We studied wild native populations of Arabidopsis thaliana across 4 years, measuring aboveground and belowground traits and analyzing soil nutrients. Using multivariate methods, we examined patterns of natural selection and identified soil attributes that contributed to whole-plant form. In a common garden experiment at two field sites with contrasting soil texture, we examined patterns of selection on root and shoot traits. In wild populations, we uncovered selection for above- and belowground size and architectural traits. We detected variation through time and identified soil components that influenced fruit production. In the garden experiment, we detected a distinct positive selection for total root length at the site with greater water-holding capacity and negative selection for measures of root architecture at the field site with reduced nutrient availability and water holding capacity. Patterns of natural selection on belowground traits varied through time, across field sites and experimental gardens. Simultaneous investigations of above- and belowground traits reveal trait functional relationships on which natural selection can act, highlighting the influence of edaphic features on evolutionary processes in wild annual plant populations.

Water retention in different types of protective gel compositions for plant rhizosphere

The research investigates thermodynamic characteristics of water-retention capacity in different types of high swelling polymer hydrogels mixed with mineral soil substrates. The use of a combination of methods of equilibrium centrifugation and thermodesorption of soil moisture allowed for the first time to estimate the water-retaining curves and dispersion of gel compositions in the range of absolute values of thermodynamic potentials from 0 to 1 million J/kg. The introduction of hydrogels in concentrations of 0.1-0.3% total weight of the enclosing mineral material leads to a 5-15 fold increase in the total energy of water retention, 3-8 fold increase in water capacity and available moisture range, bringing investigated hydrophysical characteristics of the original sandy substrate at the level of the fertile loamy soils. The new types of acrylic hydrogels with amphiphilic fillers obtained by the author’s technology had a greater water-holding capacity and a better structuring effect in comparison with the “Aquasorb” European trade mark. The incorporation of the electrolyte additives in the form of trace elements and ionic silver into the polymer matrix practically does not change the swelling capacity, allowing adding elicitor and antimicrobial properties to these compositions without compromising the effect of water retention.

Modification of heat-induced whey protein gels by basic amino acids

Various amino acids have been studied as gelation enhancers. This study investigated the effect of histidine, lysine, and arginine on gelling properties of heat-induced whey protein isolate (WPI) gels at different pHs. Basic amino acids modified WPI gels in a pH- and amino acid-dependent manner. Hardness and gumminess of the WPI gel was improved by arginine at pH 7.59 while springiness was enhanced by histidine at pHs 7.59 and 9.74 and by lysine at pH 7.59 (P < 0.05). At pH 2.0, WPI formed a weak gel. Lysine and arginine facilitated β-lactoglobulin cross-linking at pH 2.0 and reduced protein leach out from the gel (P < 0.05). At pH 5.2, WPI formed a particulate gel with poor water holding capacity (WHC). Lysine improved WHC of the WPI gel at pH 5.2 by changing the structure of the gel network. At pHs away from 5.2, basic amino acid treatments resulted in a more uniform and porous gel matrix and a greater WHC (P < 0.05). In conclusion, different basic amino acids may be applied as WPI gel enhancers depending on the pH and desired attributes of the product.

Physicochemical properties and microstructure of surimi treated with egg white modified by tea polyphenols

Effects of egg white (EW) modified by different concentrations (0.2%, 0.4%, 0.6%, 0.8% w/w) of tea polyphenols (TP) on physicochemical properties and microstructure properties of surimi gel were investigated. FTIR analysis showed that TP modification changed the secondary structure of EW proteins, reduced α-helix content but increased the content of β-folding. The TP-modified EW showed significant effects (P < 0.05) in increasing the breaking force and deformation of surimi and resulted in the formation of a stronger network in surimi gel with greater water-holding capacity, as indicated by a lowered expressible moisture content, decreased solubility and increased storage modulus (G′) and loss modulus (G″) by dynamic viscoelastic measurement. Protein pattern analysis suggested that the TP-modified EW might contribute to the decrease in the myosin heavy chain (MHC) band intensity of surimi through cross-linking with surimi proteins, which might further increase the superior setting phenomenon of surimi gel. Moreover, a finer and more ordered network of the gel was observed. Therefore, TP-modified EW is efficient in improving the properties of surimi gel, and for the best effect, a concentration of 0.6% is recommended.

Carcass traits and meat quality of quails from both sexes and eight distinct strains

Our objective was to evaluate carcass traits and meat quality of quails from different strains and both sexes pertaining to three breeding-improvement programs. Quails from seven meat-type strains (UFV1, UFV2, UFV3, EV1, EV2, LF1 and LF2) and from one egg-laying (Japanese quail) strain (LAY) were slaughtered at 35 days of age. A completely randomised 8 (strain) × 2 (sex) factorial design was used for data analysis. Bodyweight, hot carcass weight and breast (musculus pectoralis major and m. pectoralis minor) and legs (thigh and drumstick) weights and their respective yields were determined. Ultimate pH, colour measurements, water-holding capacity, cooking loss and shear force were assessed. No difference in ultimate pH, shear force and hue was observed. The UFV3 strain had the greatest bodyweight at slaughter. The UFV3 strain had the greatest hot carcass weight in both sexes. The heaviest breasts were observed in both sexes of the UFV3 strain and in males of the UFV2 strain. The UFV3 quails had greater leg weight. The hot carcass yields of meat-type strains were greater than that of the LAY strain. The UFV3 and LAY females furnished a greater breast yield than did male quails. For males, the UFV1 strain had a greater yield of breast than that of LAY quails. The LAY quails presented the greatest yields of leg. The LAY quails had the least luminance, and the greatest water-holding capacity, cooking loss, red and yellow intensity, and chroma. In summary, meat obtained from meat-type strains had a greater water-holding capacity, lower cooking loss and greater luminance than that of the LAY strain. In addition, the meat-type strains grew appreciably faster, but the difference in yields of breast and leg meat between meat and layer strains was small. We conclude that meat-type strains, especially the UFV3, are more appropriate for enterprises focussed on meat production.