Effect of Fermentation Containers and Raw Materials on Chemical Composition and Sensory Quality of fermented cereals

Effect of fermentation containers (plastic, wooden and earthen), cereals (millet, rice, maize and wheat) and cereal combinations (millet, rice and wheat) on chemical and sensory quality of fermented cereals were studied. Fermentation was carried out for 15 days at 26±2 ºC using defined starter made from S. cerevisiae and R. oryzae in rice flour. Finger millet fermented in plastic container had higher alcohol content (15.81% v/m) and TSS (11.96 ºBx) than that of earthen container while moisture and fixed acid contents remained unaffected. Total esters (1.813 g/l alc), total aldehyde (0.850 g/l alc), total acidity (1.58% m/m) and volatile acidity (0.296% m/m) were higher in millet fermented in earthen container. Fermentation containers had no significant (p>0.05) effect on the taste and smell of millet jand but color was comparatively superior in plastic container. Total ester (31.1 mg % m/v), TSS (3.97 ºBx), pH (4.67), total acid (0.41% m/v)) and fixed acid (0.37% m/v) contents were significantly higher in wheat jand compared to millet, rice, and maize jands, whereas no noticeable difference in volatile acidity (0.02 – 0.048% m/v) and alcohol (5.53 – 6.20% v/v) contents were found among four jands. Sensory evaluation showed that taste and smell of rice jand were superior (liked very much) while that of maize was rated as dislike slightly by the panelists. Addition of rice significantly increased the TSS of fermented millet while total acidity, fixed acidity and alcohol contents were not affected by cereal combinations. Addition of wheat decreased the ester content (0.431 g/l alc) to that of control (100% millet) (0.863 g/L alc). Total aldehyde content was significantly increased by both rice and wheat addition with a maximum value of 1.545 g/l alc in 20% rice added fermented millet. Finger millet substituted with 20% of rice had the maximum fusel oil (9.370 g/l alc) while a minimum value of 5.297 g/l alc was found in 20% wheat substituted fermented millet. Cereal combination did not have significant effect on methanol content and the values were in the range of 2.346 – 3.858 g/L alc. Addition of rice significantly increased the reducing and total sugar contents while 20% wheat addition decreased both the reducing and total sugar contents in fermented millet. Sensory evaluation revealed that cereal combination did not affect the color preference of jands, whereas addition of wheat significantly impaired the taste and smell of jand.DOI: http://dx.doi.org/10.3126/njst.v12i0.6521 Nepal Journal of Science and Technology 12 (2011) 330-339

Haemoglobin H+ equilibria in lamprey (Lampetra fluviatilis) and hagfish (Myxine glutinosa)

Agnathans, comprising lamprey and hagfish species, have been reported to be practically devoid of HCO3-/Cl- exchange across the red blood cell membrane. This suggests that the capacity of their haemoglobin (Hb) to remove H+ is essential for obtaining a high CO2-carrying capacity in the blood. Hydrogen ion titrations were performed on oxygenated and deoxygenated composite Hbs from river lamprey and from Atlantic hagfish at 15 degrees C and an ionic strength of 0.1 (0.1 mol l-1 KCl). Lamprey Hb was characterised by very low buffer values when the degree of oxygenation was constant, whereas the fixed-acid Haldane effect was large (uptake of approximately 0.9 H+ per monomer upon deoxygenation). Hagfish Hb, in contrast, had large buffer values and a moderate fixed-acid Haldane effect. In deoxygenated Hb, the low buffer values in lamprey correlated with the presence of only 1–1.5 titratable ‘neutral’ groups (normally histidines and α -amino groups) per monomer, whereas there were 4–5 titratable ‘neutral’ groups per monomer in hagfish. The large differences in Hb/H+ equilibria between the two species reflect the early evolutionary divergence between lampreys and hagfish. With respect to CO2 transport, the special Hb/H+ equilibria and the high red blood cell pH in lamprey ensure a high concentration of free HCO3- inside the red cells in venous blood, which compensates for the absence of a shift of HCO3- to the plasma. The Hb/H+ equilibria in hagfish are less effective in ensuring a high CO2-carrying capacity given the virtual absence of a red blood cell HCO3-/Cl- exchange, and other adaptations may be involved.

Carbon dioxide transport in alligator blood and its erythrocyte permeability to anions and water

Deoxygenation of alligator red blood cells (RBCs) caused binding of two [Formula: see text] equivalents per hemoglobin (Hb) tetramer at physiological pH. At lowered pH, some[Formula: see text] binding also occurred to oxygenated Hb. The erythrocytic total CO2 content was large, and Hb-bound [Formula: see text], free[Formula: see text], and carbamate contributed about equally in deoxygenated cells. The nonbicarbonate buffer values of RBCs and Hb were high, and the Hb showed a significant fixed acid Haldane effect. Binding of [Formula: see text] on deoxygenation occurred without a change in RBC intracellular pH, revealing equivalence between oxylabile[Formula: see text] and H+ binding. Erythrocyte volume, plasma pH, and plasma [Formula: see text]concentration also varied little with the degree of oxygenation. Diffusional water permeability was higher in oxygenated than deoxygenated RBCs. The RBCs have rapid band 3-mediated Cl− and[Formula: see text] transport, which was not affected by degree of oxygenation, but net fluxes of Cl− and[Formula: see text] via the anion exchanger are small during blood circulation at rest. Most of the CO2 taken up into the blood as it flows through tissue capillaries is carried within the erythrocytes as Hb-bound [Formula: see text] until CO2 is excreted when blood flows through pulmonary capillaries.

A technique for retrieving antigens in formalin-fixed, routinely acid-decalcified, celloidin-embedded human temporal bone sections for immunohistochemistry.

The application of immunohistochemistry to routinely decalcified, celloidin-embedded human temporal bone sections has been hampered because of antigen loss during processing of the specimens. To our knowledge, there has been no published report to date describing immunohistochemical staining of such tissues suitable for examination by light microscopy. Here we report a novel antigen retrieval technique which can be successfully used to stain a variety of antigens in routinely formalin-fixed, trichloroacetic acid-decalcified, celloidin-embedded human temporal bone sections. The new procedure reported here for decalcified human temporal bone tissues simply requires immersing slides for 30 min at room temperature in an antigen retrieval solution. A total of 60 decalcified, celloidin-embedded human temporal bone tissues were tested with monoclonal antibodies (MAb) to 15 different antigens. Of these, 12 MAb showed definite positive staining, while three were negative. This technique may prove very useful in studying the expression of various antigens by immunohistochemistry in formalin-fixed, acid-decalcified, celloidin-embedded tissues.

Hydrogen ion equilibria in fish haemoglobins

H+ titration studies on oxygenated and deoxygenated haemoglobins from carp, rainbow trout, spiny dogfish and pig are reported, and compared with Hb-H+ equilibria in other species and structural information deduced from amino acid sequences. The buffer values of oxygenated and deoxygenated teleost haemoglobins are low in comparison with elasmobranch and mammalian haemoglobins. This correlates with a much lower content of histidine residues and alpha-amino groups in teleost haemoglobins, than that in elasmobranch, dipnoan, amphibian, reptilian, avian and mammalian haemoglobins. The low total histidine content in teleost haemoglobins is paralleled by a reduced number of titratable histidine residues compared with that in mammals. An inverse relationship is observed between the magnitude of buffer values and the magnitude of fixed-acid Haldane effects. The largest Haldane effect and smallest buffer values are seen in carp, followed by trout, whereas the smallest Haldane effect and largest buffer values are seen in dogfish. The H+ equilibria of pig haemoglobin are intermediate between those of teleost and elasmobranch haemoglobins.