Phospholipids molecular species, proteins secondary structure, and emulsion microstructure of egg yolk with reduced polar and/or nonpolar lipids.

This study investigated the phospholipids (PLs) molecular species (PLs-MS), protein secondary structure (PSS), and emulsion microstructure of the egg yolk (EY) treated with supercritical-CO2 (T1), hexane (T2), and ethanol {at room temperature (T3) and 65 °C (T4)}. PLs-MS, PSS, and microstructure of EY emulsion were investigated with UPLC-Q-TOF-MS, Fourier-transforms infrared and Raman spectroscopy, and confocal laser scanning microscope, respectively. Predominant PLs molecular fractions were C18:0-C20:4, C18:0-C20:4, C16:0-C18:2, C16:0, C18:0-C18:2, and d18:1/16:0, for phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, lysophosphatidylcholine, sphingomyelin, and phosphatidylserine, respectively. All the PLs-MS were highest for T1 and many of them (C14:0-C16:0, C18:0-C18:1, C18:0-C20:3) were absent in T2, T3, and T4. PSS components (α-helices, ß-sheets, ß-turn, and random coil) were highest for T4, followed by T3, T2, T1, and control (non-treated EY). However, T1-added o/w emulsion showed excellent stability (95.64 %) with smaller and denser oil droplets due to better ionic interactions by synergistic effect of PLs-MS and PSS components.

Evaluation of chicken nugget properties using spent hen meat added with milk fat and potato mash at different levels.

This study was aimed to develop chicken nuggets using spent hen meat (SHM) added with milk fat (MF) and potato mash (PM) at different levels. Four different spent hen nuggets (SHNs) i.e. T1 (75% SHM with 5% MF), T2 (70% SHM with 8% MF and 2% PM), T3 (65% SHM with 11% MF and 4% PM), and T4 (60% SHM with 14% MF and 6% PM) were formulated and compared with the control, using broiler chicken meat without MF and PM. The control, T1, and T2 were not significantly different with respect to protein and fat contents. The emulsion stability (92.2%), frying yield (84.1%), hardness (19.2 N) and chewiness (11.4 N) of T2 were similar to the control. The incorporation of MF and PM resulted in increased taste and flavor scores for SHN. The overall acceptability score was same for the control and T2. The conjugated dienes and thiobarbituric acid-reactive substance results showed that the addition of MF at 8 to 10% did not have an effect on the oxidative stability of SHN during storage. MF-incorporated SHN may be a regular chicken nugget for all consumers due to improved texture and sensory quality with similar fat content to the control.

Volatile and nonvolatile taste compounds and their correlation with umami and flavor characteristics of chicken nuggets added with milkfat and potato mash.

This study investigated the chemical compounds and umami characteristics of chicken nuggets using spent meat (SM) enriched with milkfat (MF) and potato mash (PM). Four different spent nuggets (SNs) i.e. T1 (75% SM, 5% MF), T2 (70% SM, 8% MF, 2% PM), T3 (65% SM, 11% MF, 4% PM), and T4 (60% SM, 14% MF, 6% PM) were developed and compared with control using broiler chicken muscles (without MF and PM). Most abundant volatiles were trimethyldodecane, camphene, 5-ethyl-2,2,3-trimethylheptane, 3,6-dimethylundecane, 2,2,4-trimethylheptane, and α-pinene, and their intensities were highest for T2. Umami-taste characteristics were better explained by partial least squares regression (PLS-R) than other taste variables assessed by electronic tongue. T2 and T3 had higher 5'-nucleotides (GMP, AMP, ADP) and umami-taste amino acids (aspartic and glutamic acids) resulting in increased equivalent umami concentration than the control, T1, and T4. This study may be useful for the egg industries to utilize spent hens.

Changes in physicochemical characteristics and oxidative stability of pre- and post-rigor frozen chicken muscles during cold storage.

The objective of this study was to investigate the effects of rigor state on physicochemical characteristics and the oxidative stability of chicken leg and breast muscles as a function of freezing time. Breast and leg muscles were excised from 24 broiler chickens at 30 min or 1.5 h postmortem (PM), frozen overnight at - 75 °C immediately, and then stored at - 20 °C for 90 days to measure the meat quality traits. Results showed that longer freezing led to deterioration of meat quality with higher deterioration for post-rigor frozen muscles. Pre-rigor frozen muscles had higher pH, water holding capacity (around 90%), and sarcomere length with a lower thaw and cook loss than post-rigor frozen muscles. The Warner-Bartzler shear force (WBSF) values for chicken leg and breast muscles were insignificant (except pre-rigor leg muscles which had significantly higher WBSF value only at 90th day of storage). The lightness (L*) value increased significantly with increasing storage for all samples. Post-rigor muscles had significantly higher TBARS values (0.62 mg MDA/kg) than the pre-rigor muscles. The leg muscles had better physicochemical characteristics compared to breast muscles, except for the cook loss. Therefore, immediate freezing (prior to onset of rigor) could be an effective way to minimize the quality deterioration of frozen chicken muscles.

Physicochemical properties, sensory traits and storage stability of reduced-fat frankfurters formulated by replacing beef tallow with defatted bovine heart.

The consumer interests for low-fat meat products are increasing to reduce obesity and chronic diseases. Reduced-fat frankfurter (RFF) was prepared by replacing beef tallow with defatted bovine heart (DBH) produced by supercritical-CO2 (SC-CO2) and hexane. Six different frankfurters i.e. control (20% beef fat), T1 (30% fat replacement with non-defatted bovine heart), T2 and T3 (20% and 30%, respectively, fat replacement with SC-CO2-treated DBH), T4 and T5 (20% and 30%, respectively, fat replacement with hexane-treated DBH), were formulated. Physicochemical properties, sensory traits and storage stability of the control and RFFs were investigated. T3 had highest native proteins (18.50 g/100 g) resulting in increased viscosity, emulsion stability, hardness and redness (a⁎) with lowest energy value and cooking loss. T2 showed better sensory attributes than the control and other RFFs. Incorporation of SC-CO2-treated DBH in frankfurter by replacing fat led to higher oxidative stability and lower microbial content during storage than the control, T1, T4 and T5.

Thermal and functional characteristics of defatted bovine heart using supercritical CO2 and organic solvent.

BACKGROUND: Consumer demand for low-fat foods has been increasing as a result of attempts to reduce obesity and chronic diseases. Bovine heart was defatted using supercritical CO2 (SC-CO2 ) at different pressures together with solvent extraction to produce a protein-based functional ingredient for low-fat food products. Thermal and functional characteristics of control and defatted samples were compared. RESULTS: Supercritical CO2 treatment at high pressure results in more removal of fat, producing a protein-rich defatted bovine heart (DBH). The differential scanning calorimeter (DSC) thermograms and SDS-PAGE bands for SC-CO2 -treated DBHs were similar to those of the control sample, indicating high protein stability and better functionality. Hexane-treated DBH showed no major thermal peaks and very diffuse bands in SDS-PAGE, indicating denaturation of proteins during solvent extraction. No denaturation of proteins in SC-CO2 -treated DBHs resulted in significantly higher water/oil absorption capacities (3320.00 and 2630.00 g kg-1 , respectively), total soluble solids (822.20 and 208.71 g kg-1 at pH 3.5 and 6.5, respectively), foaming capacities (149.37%), and emulsion activity (66.89%) than the hexane-treated DBH. CONCLUSION: Supercritical CO2 treatment of DBH led to higher thermal stability and functional properties than the control and hexane-treated DBH. Defatted bovine heart using SC-CO2 can be a functional ingredient for various low-fat and high-protein food products for health-conscious consumers. © 2018 Society of Chemical Industry.

Yield and physicochemical properties of low fat tofu prepared using supercritical carbon dioxide treated soy flours with different fat levels.

The consumer demands for low fat foods are increasing to reduce obesity and chronic diseases. Low-fat tofu (LFT) was prepared using soy flours treated with supercritical CO2 (SC-CO2) at pressures of 10, 20, and 30 MPa. After SC-CO2 treatment, the residual oil contents of the soy flours were 12.07, 8.12, and 1.64%, respectively, whereas that of the control soy flour was 18.20%. The objective of this study was to investigate the yield and quality characteristics of LFTs, compared to the control tofu. All SC-CO2-treated LFTs had significantly higher protein and moisture contents than the control tofu. The yields (g/100 g soy flour) of SC-CO2-treated tofu were 442.69, 507.44, and 535.47 g, respectively, at three fat levels, whereas the yield was 385.23 g in case of the control tofu. The SC-CO2-treated LFTs had softer textural attributes due to increasing moisture contents. In addition, the LFTs obtained higher sensory scores owing to softer texture and lower beany flavor than control sample. SC-CO2-treated soy flours showed higher solubility in soy milk, leading to higher yield, produced softer texture of tofu, and increased nutritional value with low fat and high protein content.

The Quality Improvement of Emulsion-type Pork Sausages Formulated by Substituting Pork Back fat with Rice Bran Oil.

The effects of pork back fat (PBF) substitution with various concentrations of rice bran oil (RBO) (50%, 45%, 40% and 35%) on the physicochemical characteristics and sensory attributes of emulsion-type pork sausages were studied. The modified pork sausages were compared with control sausages produced using PBF only. The sausages with RBO had significantly lower (p<0.05) moisture content than the control sausages. Sausages made from PBF substituted with 40% RBO showed the lowest cooking loss. Substitution of PBF with RBO had no significant effect on the emulsion stability of pork sausages. All sausages with RBO showed significantly lower (p<0.05) hardness values than control sausages. Sausages with RBO also had significantly higher values (p<0.05) of unsaturated fatty acid and polyunsaturated to saturated fatty acid contents than the controls. RBO substitution had no effect on the flavor intensity of sausages, but it improved the tenderness and produced a softer texture.

Association of leisure-time physical activity with total and cause-specific mortality: a pooled analysis of nearly a half million adults in the Asia Cohort Consortium.

BACKGROUND: Most previous studies evaluating the association between leisure-time physical activity (LTPA) and risk of death were conducted among generally healthy individuals of European ancestry. We investigated the association of LTPA with all-cause and cause-specific mortality among East Asian populations, including healthy individuals and those with existing chronic diseases, which has been less well characterized. METHODS: We performed pooled analyses among 467 729 East Asian individuals recruited in nine prospective cohorts included in the Asia Cohort Consortium. Cox proportional hazards regressions were used to derive hazard ratios (HRs) and 95% confidence intervals (CIs) associated with LTPA after adjusting for age, sex, education and marital and smoking status. RESULTS: During a mean follow-up period of 13.6 years, 65 858 deaths were identified. Compared with those who reported no or less than 1 h of LTPA per week, an inverse association was observed between the amount of LTPA and all-cause and cause-specific mortality (P for trend < 0.001). The strength of the inverse association was stronger for death due to cardiovascular diseases and causes other than cancer deaths. An inverse association of LTPA with total mortality was observed among individuals with a severe and often life-threatening disease: cancer, stroke or coronary heart disease [hazard ratio (HR) = 0.81, 95% CI = 0.73-0.89 for high vs low LTPA) and those with other chronic diseases such as diabetes or hypertension (HR = 0.86, 95% CI = 0.80-0.93 for high vs low LTPA). No clear modifying effects by sex, body mass index or smoking status were identified. CONCLUSIONS: Regular participation in LTPA is associated with reduced mortality in middle-aged and elder Asians regardless pre-existing health conditions.

Comparative study of the quality characteristics of defatted soy flour treated by supercritical carbon dioxide and organic solvent.

Defatted soy flour is a potential source of food protein, amino acids, ash and isoflavones. The supercritical carbon dioxide (SC-CO2) and a traditional organic solvent extraction methods were used to remove fat from soy flour, and the quality characteristics of a control soy flour (CSF), defatted soy flour by SC-CO2 (DSFSC-CO2) and defatted soy flour by an organic solvent (DSF-OS) were compared. The SC-CO2 process was carried out at a constant temperature of 45 °C, and a pressure of 40 MPa for 3 h with a CO2 flow rate of 30 g/min. The DSFSC-CO2 had significantly higher protein, ash, and amino acids content than CSF and DSF-OS. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated that CSF and DSFSC-CO2 had protein bands of similar intensity and area that indicated no denaturation of protein, whereas DSF-OS showed diffuse bands or no bands due to protein denaturation. In addition to higher nutritional value and protein contents, DSFSC-CO2 showed superior functional properties in terms of total soluble solids content, water and oil absorption, emulsifying and foaming capacity. The SC-CO2 method offers a nutritionally and environmentally friendly alternative extraction processing approach for the removal of oil from high-protein food sources. It has a great potential for producing high-protein fat-free, and low-calorie content diet than the traditional organic solvent extraction method.

Nutritional Quality and Physicochemical Characteristics of Defatted Bovine Liver Treated by Supercritical Carbon Dioxide and Organic Solvent.

Defatted bovine liver (DBL) is a potential source of protein and minerals. Supercritical carbon dioxide (SC-CO2) and a traditional organic solvent method were used to remove lipid from bovine liver, and the quality characteristics of a control bovine liver (CBL), bovine liver defatted by SC-CO2 (DBLSC-CO2) at different pressures, and bovine liver defatted by organic solvent (DBL-OS) were compared. The DBLSC-CO2 samples had significantly higher (p<0.05) protein, amino acid, carbohydrate, and fiber contents than CBL and DBL-OS. There was a higher yield of lipid from CBL when using SC-CO2 than the organic solvent method. SDS-PAGE analysis demonstrated that the CBL and DBLSC-CO2 had protein bands of a similar intensity and area, whereas DBL-OS appeared extremely poor bands or no bands due to the degradation of proteins, particularly in the 50 to 75 kDa and 20 to 25 kDa molecular weight ranges. In addition, DBLSC-CO2 was shown to have superior functional properties in terms of total soluble content, water and oil absorption, and foaming and emulsification properties. Therefore, SC-CO2 treatment offers a nutritionally and environmentally friendly approach for the removal of lipid from high protein food sources. In addition, SC-CO2 may be a better substitute of traditional organic solvent extraction for producing more stable and high quality foods with high-protein, fat-free, and low calorie contents.

Porosity and the effect of structural changes on the mechanical glass transition temperature.

Continuing an investigation on the fundamentals and applications of a recently proposed concept, i.e., the mechanical or network glass transition temperature, we now report data on the macrostructural changes in dehydrated apple tissue in relation to apparent porosity. Care was taken to keep the moisture content of the matrix constant (approximately 81%) while the volume fraction of total pores ranged from 0.38 to 0.79. Reproducible mechanical profiles identified the first derivative of shear storage modulus as a function of temperature to be the appropriate indicator of the mechanical Tg at the conjunction of the William-Landel-Ferry/free volume theory and the modified Arrhenius equation. Information on the microstructural characteristics and morphology of porous apple preparations was also made available via modulated differential scanning calorimetry and scanning electron microscopy. The work reveals and discusses discrepancies in the Tg-porosity relationship obtained from calorimetry and mechanical analysis attributable to the different extent to which the two techniques respond to degrees of molecular mobility.

Structural changes in apple rings during convection air-drying with controlled temperature and humidity.

The structure of heat pump dried apple slices, developed as a function of air temperature and constant humidity, was studied by measuring porosity and using electron microscopy. The porosity of the apple rings increased linearly when the moisture content decreased during drying and then reached a constant value. In all dried apple slices, a degree of cellular collapse occurred. Case hardening occurred in the surface of the dried tissue when the apple slices were dried at 40-45 and 60-65 degrees C, and in the extreme case (at 60-65 degrees C) cracks were formed on the surface.