Growth studies on the lactic streptococci: IV. Some observations on redox potential
Summary Redox potential changes at 30°C in anaerobic reconstituted skim-milk cultures of Streptococcus cremoris AM1 and AM2 and Streptococcus lactis ML8 have been investigated in batch cultures and continuous cultures maintained at constant pH by the addition of fresh medium. Str. lactis ML8 was more strongly reducing than either Str. cremoris AM1 or AM2. The positive Eh values which can arise in dense continuous cultures of lactic streptococci are not likely to affect either the lactic acid formation or proteolytic activity of the resultant bacterial concentrate. An electrolytic reduction cell is described which allows variations in redox potential in cultures to be controlled simply and effectively.
Eh and pH gradients in Camembert cheese during ripening: Measurements using microelectrodes and correlations with texture
Abstract This study investigated the use of microelectrodes to continuously and simultaneously monitor pH and redox potential (Eh) gradients in Camembert cheeses from the rind to the core, as a function of ripening time (15 and 35 days). Cheeses were shown to be heterogeneous throughout their mass. An Eh gradient existed from the rind to the core. The surface was oxidizing (+330 to +360 mV) and the core was reducing and became more so in the course of ripening (−300 to −360 mV). A relationship between firmness and Eh was shown. pH gradients were in line with those previously described in the literature and related to ammonium and lactate gradients. Gradients evolved from the rind to the core (pH 7.7 to 5.2 at 15 d and 7.5 to 6.8 at 35 d). These findings showed that both the Eh and pH constituted control parameters for cheese ripening.
Influence of Diluted Spent Wash of Sugar Industries Application on Yield of and Nutrient Uptake by Sugarcane and Changes in Soil Properties
A pot experiment was conducted to study the effect of irrigation with tube well water (S0) as well as with spent wash diluted for 25 (S25), 50 (S5O) and 100 (S100) times on yield of and nutrient uptake by sugarcane grown on Typic Chromustert. The results revealed that application of spent wash diluted at any level increased the sugarcane yield and nutrient uptake significantly over S0. Less diluted spent wash gave higher yield of biomass than the concentrated one. Though, there was tendency for slight increase in the soil salinity due to use of spent wash, yet the nutrient availability of P, K and S increased considerably. Further, there was indication of betterment in some physical conditions of soil.