Preservation additives thermal processing

Cichoric acid content of six commercially available E. purpurea expressed juice preparations, preserved with ethanol (20%) or by thermal processing, varied significantly between preservation methods (Bauer, 1999b). The thermally treated preparations had an average cichoric acid content of 0.24 g/100 ml of extract. In contrast, the cichoric acid content of the five ethanol preserved preparations was 0.075 g/100 ml extract. Several preparations had no cichoric acid whereas one ethanol-preserved preparation contained 0.14 g cichoric acid/100 ml extract. Within this preparation, the cichoric acid content of several lots varied from 0 to 0.34 g/100 ml extract. Bauer (1999b) hypothesized that the inactivation of PPO by heat may account for the difference in cichoric acid content found between heated and non-heated preparations. Any expressed juice would be expected to contain enzyme inherent to the plant tissue thus, additional processing of the expressed juice preparation is critical for CAP retention. 

We have mentioned above the tendency of atoms to preserve their coordination in solid state processes. This suggests that the diffusionless transformation tries to preserve close-packed planes and close-packed directions in both the parent and the martensite structure. For the example of the Bain-transformation this then means that 111) -> 011). (J = martensite) and <111> -. Obviously, the main question in this context is how to conduct the transformation (= advancement of the p/P boundary) and ensure that on a macroscopic scale the growth (habit) plane is undistorted (invariant). In addition, once nucleation has occurred, the observed high transformation velocity (nearly sound velocity) has to be explained. Isothermal martensitic transformations may well need a long time before significant volume fractions of P are transformed into / . This does not contradict the high interface velocity, but merely stresses the sluggish nucleation kinetics. The interface velocity is essentially temperature-independent since no thermal activation is necessary. 

Equipment and processes for thermal preservation depend on the physical form ol the food and its pll. Foods having a pH < 4.5 often can be sterilized, for commercial purposes, at or near a temperature of I00°C. Commercial sterility lor these products means lhat the product will not spoil owing to microbial growth as long as the pH remains at or below 4.5 The spores of Bacillus <-oagulans are an important exception. This latter microbe is found in tomato products, and these products are often adjusted lo a pH of 4.0 or lower, or given an additional heal treatment. 

This question is discussed in detail in the book by Skarchenko [52], It is noted that dehydrogenation of paraffin hydrocarbons dominates by selectivity over thermal cracking in the presence of iodine or other halogens, sulfur-containing compounds, oxygen and nitrous oxide. For example, in the presence of iodine dehydration dominates in the system, whereas in the case of other additives, independently of their amounts—oxygen, ethylene oxide and nitric acid—the main shift of the process toward cracking is preserved. 

Coal Structure and Thermal Decomposition thermal decomposition is important since all coal conversion processes (combustion, liquefaction and gasification) are initiated by this step In addition, it appears that many of the coal structural elements are preserved in the heavy molecular... 

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