Freeze quality parameters

The storage of freeze-dried carrots for 24 months in sealed cans under air and N2 and in glass containers under vacuum at room temperature was studied by Gegow [4.29]. Fifteen quality parameters were evaluated and found to be comparable to those of frozen carrots. The carotenes were only reasonably preserved under vacuum. 

Maelkki Nikkilae, Aalto and Heinonen [31, 32] stress the importance of the raw material quality of onions. Stieger [33] has investigated the suitablity of various strawberry varieties. Processes for flavour preservation have been thoroughly examined with cultivated mushrooms, leading to an illumination of the most important freeze drying parameters [34[. 

Table III. Quality Parameters of Fresh Orange Juice Which was Freeze Concentrated (FCNP), Then Pasteurized for 6 Sec at 80 (FC80), 97 (FC97) and 111°C (FC111)...

In the case of yeast, control of freeze-drying was defined from the literature for Saccharomyces cerevisiae (Mazur 1970 Souzu 1999). It was performed by freezing at -40°C with a vacuum level of 30 Pa and a heating plate temperature of 25°C. Survival ratio was determined as the most relevant quality parameter. 

Influence of Freezing and Freeze-Drying Parameters on Physical Quality Factors 63... 

This section is devoted to the discussion and analysis of typical data showing the infiuence of the freezing and freeze-drying parameters on the main physical quality factors encountered during freeze-drying of dmgs. 

The quality of the compound collection is one key to high quality biological results. DMSO is a widely used solvent and many studies dealing with the long-term storage of compounds in this solvent have been conducted. The important parameters to maintain stability and concentration are Freeze/thaw cycles, storage temperature and duration, container material, humidity, and oxygen. 

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