potassium-bicarbonate and ammonium-bicarbonate

Microalgae have been considered as promising alternative for CO

Topics: Bicarbonates; Biological Oxygen Demand Analysis; Biomass; Carbon; Carbon Cycle; Carbon Dioxide; Glycine max; Hydrogen-Ion Concentration; Microalgae; Nitrogen; Phosphorus; Potassium Compounds; Recycling; Wastewater; Water Purification

The objective of this study was to determine whether addition of hydrocolloids, buffer ingredients, salt, and sodium phosphate improve the color, texture, and pH of normal and pale, soft, and exudative (PSE) meat. Specific solutions include potassium bicarbonate (KHCO), ammonium bicarbonate (NHHCO), hydroxypropyl methylcellulose (HPMC), and konjac flour (KF). Three studies were carried out. First, the stability and viscoelastic properties of the different solutions was determined. Second, fresh normal (pH 5.6-5.9) and PSE (pHu < 5.4) Longissimus dorsi muscles were ground and assigned a treatment solution: control (fresh normal), water, NaCl/SP, KHCO, NHHCO, KF, HPMC, KHCO/KF, KHCO/KF/NaCl/SP (sodium phosphate), NHHCO/HPMC, and NHHCO/HPMC/NaCl/SP. Third, treatment solutions with suitable viscoelastic properties and stability, were added, homogenized, stuffed into tubes, and cooked to an internal temperature of 75C to form gels, and torsion and texture profile analysis performed. The PSE treated samples containing bicarbonate/hydrocolloid treatments had similar hardness-first bite, hardness-second bite, and gumminess values to the normal-control samples while the NHHCO treated samples had air pockets in the cooked gel. Third, consumers (n = 92) evaluated control and PSE beef/pork frankfurters produced with the following treatments: KHCO, KHCO/HPMC, and KHCO/KF. Treatment had no effect (p > .05) on overall like/dislike of flavor, but PSE frankfurters were preferred (p < .05) to the controls. The use of KHCO with hydrocolloids, salt and SP improved the color, pH and texture properties of PSE ground pork; further research to examine the effectiveness in whole PSE pork muscle systems is needed.. Meat processors could use KHCO with HPMC or KF as ingredients to improve color, texture, and pH of PSE meat. The reduction of variation between PSE and normal pork muscle would improve pork quality and add value to PSE meat products.

Topics: Amorphophallus; Animals; Bicarbonates; Color; Consumer Behavior; Flour; Food Handling; Hypromellose Derivatives; Meat Products; Muscle, Skeletal; Potassium Compounds; Sodium Chloride; Swine; Taste

The stability of the hemopexin-heme (Hx-heme) complex to dissociation of the heme prosthetic group has been examined in bicarbonate buffers in the presence and absence of various divalent metal ions. In NH(4)HCO(3) buffer (pH 7.4, 20 mm, 25 degrees C) containing Zn(2+) (100 microm), 14% of the heme dissociates from this complex (4.5 microm) within 10 min, and 50% dissociates within 2 h. In the absence of metal ions, the rate of dissociation of this complex is far lower, is decreased further in KHCO(3) solution, and is minimal in NaHCO(3). In NH(4)HCO(3) buffer, dissociation of the Hx-heme complex is accelerated by addition of divalent metals with decreasing efficiency in the order Zn(2+) > Cu(2+) >> Ni(2+) > Co(2+)>>Mn(2+). Addition of Ca(2+) prior to addition of Zn(2+) stabilizes the Hx-heme complex to dissociation of the heme group, and addition of Ca(2+) after Zn(2+)-induced dissociation of the Hx-heme complex results in re-formation of the Hx-heme complex. These effects are greatly accelerated at 37 degrees C and diminished in other buffers. Overall, the solution conditions that promote formation of the Hx-heme complex are similar to those found in blood plasma, and conditions that promote release of heme are similar to those that the Hx-heme complex should encounter in endosomes following endocytosis of the complex formed with its hepatic receptor.

Topics: Bicarbonates; Electrolytes; Heme; Hemopexin; Humans; Hydrogen-Ion Concentration; Kinetics; Metals; Potassium Compounds; Sodium Bicarbonate; Spectrophotometry; Spectrophotometry, Ultraviolet