Effect of sodium bicarbonate on techno-functional and rheological properties of pale, soft, and exudative (PSE) meat batters

Exploring the effect of pH-shifting on the gel properties and interaction of heat-induced Flammulina velutipes polysaccharide-porcine myofibrillar protein for improving the quality of Flammulina velutipes-pork patties

This study primarily investigated the impact of pH-shifting on the gel properties of Flammulina velutipes polysaccharide (FVP)-porcine myofibrillar protein (MPs) gels, aiming to improve the quality of Flammulina velutipes-pork patties. Our findings revealed that the water holding capacity (81.72 %), oil holding capacity (87.41 %), emulsion activity index (81.05 %), emulsion stability index (52.58 %), and rheological properties of FVP-MPs gels were all enhanced under optimal pH 9 conditions. Alkaline conditions led to a more compact structure, with hydrogen bond interactions and hydrophobic interactions being the primary molecular forces. The physicochemical and sensory properties of pork patties prepared at pH 9 were enhanced, with key odor active substances such as 1-Penten-3-ol, 1-Propanol-M and 2-Ethylbutanal-M contributing to an improved flavor. This study provides comprehensive insights into the gel properties and interaction behavior of FVP-MPs gels under varying pH conditions, highlighting the potential for enhancing meat product quality by incorporating Flammulina velutipes at optimal pH values.

Physico-chemical properties of natural actomyosin from breast and thigh meat of fast- and slow-growing chicken: a comparative study

Physico-chemical behaviors of natural actomyosin (NAM) from slow-growing Korat chicken (KC) breast and thigh at low (0.2 M) and high (0.6 M) NaCl concentrations were evaluated and compared to those from their corresponding muscles in fast-growing broiler chicken (BC). NAM from KC breast and thigh meat showed higher solubility than their corresponding in BC (p < 0.05). Breast NAM from both chickens showed the highest solubility at 0.4 M NaCl, while thigh NAMs showed the highest solubility at 0.8 M (p < 0.05). SDS-PAGE revealed higher protein extractability for breast NAMs at low ionic strength, regardless of breed and structural protein, particularly troponin, appeared to vary within muscle and breed. NAM from KC showed higher Ca2+-ATPase activity, surface hydrophobicity, but lower total sulfhydryl groups content (p < 0.05). Particle size of NAM solutions varied with ionic strength, in which KC-NAM showed larger size than at lower ionic strength, while BC-NAM appeared to be greater at higher ionic strength. NAM from KC breast showed higher thermal stability as higher initial (T0) and maximum (Tmax) denaturation temperatures of 48.4 and 54.8°C, respectively, recorded by microdifferential scanning calorimetry. The KC-NAM, particularly from breast, exhibited lower turbidity within 40-50°C, while turbidity increased in BC samples at low ionic strength when heated at 60°C. Dynamic rheology revealed different storage modulus (G') depending on breed, muscle type and ionic strength. Breast BC-NAM formed more elastic gel with higher end point G' at 80°C (Ge'; p < 0.05). Ionic strength showed reverse effects on different breeds as a stronger Ge' value achieved in KC- NAM at low ionic strength, while high ionic strength induced stronger gel in BC samples. Aggregation of NAMs began at lower temperatures at higher ionic strength and actin dissociation probably occurred in breast NAM from KC as observed by a drop of G' at around 70°C. The results of this study revealed differences between NAM of the two breeds, by which higher gel elasticity are expected in KC at lower ionic strength.

The improvement effects of Lentinus edodes powder marination on sous vide cooked chicken patties: Physicochemical attributes, oxidative properties and flavor characteristics

The improvement effects of Lentinus edodes powder (LEP) marination with different concentrations (0, 6-14 %) on physicochemical, oxidative and flavor quality of chicken patties were evaluated. Greater pH, redness, yellowness, water holding capacity and their strong correlations were observed in LEP-marinated samples. Changed water distribution, inhibited lipid oxidation and enhanced protein oxidation occurred through LEP marination. The highest gel strength and resilience and the lowest hardness and chewiness were obtained in 10 % LEP-marinated sample. Meanwhile, taste activity values of amino acids and saltiness peaked and umami rose in this sample. 124 volatiles were detected and 16 compounds were simultaneously detected by gas chromatography-ion mobility spectrometry and gas chromatography-mass spectrometry. Hexanal, 1,2,4-trithiolane and 1-hexanol were considered as the key differential aroma-active compounds according to odor activity values and chemometric analysis. This study confirmed LEP as a prospective ingredient to improve the quality of meat products.

Using Potassium Bicarbonate to Improve the Water-Holding Capacity, Gel and Rheology Characteristics of Reduced-Phosphate Silver Carp Batters

To study the use of partial or total potassium bicarbonate (PBC) to replace sodium tripolyphosphate (STPP) on reduced-phosphate silver carp batters, all the batters were composed of silver carp surimi, pork back fat, ice water, spices, sugar, and sodium chloride. Therein, the sample of T1 contained 4 g/kg STPP; T2 contained 1 g/kg PBC, 3 g/kg STPP; T3 contained 2 g/kg PBC, 2 g/kg STPP; T4 contained 3 g/kg PBC, 1 g/kg STPP; T5 contained 4 g/kg PBC, and they were all produced using a bowl chopper. The changes in pH, whiteness, water- and oil-holding capacity, gel and rheological properties, as well as protein conformation were investigated. The pH, cooking yield, water- and oil-holding capacity, texture properties, and the G' values at 90 °C of the reduced-phosphate silver carp batters with PBC significantly increased (p < 0.05) compared to the sample without PBC. Due to the increasing pH and enhanced ion strength, more β-sheet and β-turns structures were formed. Furthermore, by increasing PBC, the pH significantly increased (p < 0.05) and the cooked silver carp batters became darkened. Meanwhile, more CO₂ was generated, which destroyed the gel structure, leading the water- and oil-holding capacity, texture properties, and G' values at 90 °C to be increased and then decreased. Overall, using PBC partial as a substitute of STPP enables reduced-phosphate silver carp batter to have better gel characteristics and water-holding capacity by increasing its pH and changing its rheology characteristic and protein conformation.

The Effect of Sodium Bicarbonate Injection on the Physico-Chemical Quality of Post-Harvest Trout

The muscle hardness of fish is an important parameter associated with meat quality, and the post-mortem decrease in the pH of fish tissue pH affects its physical properties. We hypothesized that maintaining a high pH in fish tissue after death would prevent protein denaturation and consequent textural deterioration. This study aimed to determine the effectiveness of sodium bicarbonate (SBC) injections in preventing tissue softening caused by low pH after death in trout. We injected varying molar concentrations of SBC in rainbow trout (Oncorhynchus mykiss; 0 M, 0.5 M, 0.75 M, and 1 M) after harvest, and the product quality was assessed at 0, 24, 48, 72, and 96 h of ice storage. Quality was evaluated using proximate analyses for color, pH, water holding capacity (WHC), texture profile, and rigor index. The 0 M group had the lowest pH, and the 0.75 M group had the highest pH at all time points during storage. We observed improved tissue texture during storage in fish treated with 0.75 and 1 M SBC. The texture profile analysis showed higher hardness, frangibility, and stickiness in the tail than in the other regions. These varying results can be explained by significant differences between parts of the fish and sampling point selection. We also observed the highest pH and WHC values in the groups injected with 0.75 and 1 M SBC during storage.

Effects of combined chickpea protein isolate and chitosan on the improvement of technological quality in phosphate-free pork meat emulsions: Its relation to modifications on protein thermal and structural properties

The effects of combined chickpea protein isolate (CPI, 1%, w/w) and chitosan (CHI, 1%, w/w) on the technological, thermal, and structural properties of phosphate-free pork meat emulsions (PPMEs) were investigated. The results showed that CPI + CHI significantly improved the emulsion stability (P < 0.05), synergistically elevated the hardness and chewiness, and did not negatively impact the color attributes, which endowed the PPMEs with similar or even better technological performances compared to the high-phosphate control. These alterations were related to the reduced myosin enthalpy values, the rearrangement of free water into immobilized water, the synergistic reduction in α-helical structure and increase in β-sheet structure, the increased trans-gauche-trans SS conformation intensity of the Raman bands, and the formation of interactive protein gel networks where small-sized fat particles were evenly dispersed in the protein matrix. Therefore, combined CPI and CHI shows promise as a phosphate replacer for meat products.