Quality vacuum drying

This quick evaporation will produce foam or bubbles in the product. This is unacceptable in most cases, since the original structure is changed and that part of the product which is vacuum dried will have different qualities than the freeze-dried part. Often the product frozen in this way can not be freeze-dried at all. 

Aliquots of 50 pmol were pipetted into pre-washed 1.5 ml polypropylene microfuge tubes and vacuum dried. Several aliquots were analyzed by committee members to insure sample quality before distribution. Two aliquots of ABRF-94SEQ were sent to each of the 258 ABl member facilities along with instructions for sample solubilization, a short questionnaire, a data analysis worksheet, and several commonly used methods for cysteine and tryptophan analysis. Members were encouraged to try at least one of the methods described. All results were returned to an independent third party who, after removing all identifying labels, forwarded the anonymous data to the committee for analysis. 

Extensive results have been reported in the literature on drying of wood as well. Again, all quality indicators are positive. Several vendors worldwide have already commercialized the vacuum-superheated steam-drying systems. It is noteworthy that besides enhancement of the product quality, the drying times are reduced two- to five-fold resulting in significant reduction in cost of inventory in the dryer. 

Vacuum dryers have been commercially available for many years and their use is regarded as a standard practice in Europe for the drying of high-quality hardwoods economically, which would otherwise be difficult to dry (Hilderbrand, 1989). Descriptions of vacuum drying are given by Ressel (1994), Audebert and Temmar (1997), and Jomaa and Baixeras (1997). 

Smith, W.B. and Smith, A., 1994. Radio-frequency/vacuum drying of red oak Energy quality value, in Proceedings of the Fourth International lUFRO Wood Drying Symposium, Rotorua, New Zealand, pp. 263-270. 

Smith WB, Smith A, Neauhauser EF. Radio-frequency/vacuum drying of red oak energy, quality, value. Proc. 4 lUFRO Inti. Wood Drying Conference, Rotorua, New Zealand, 1994, pp 263-270. 

Bauer, S. A. W., Schneider, S., Behr, J., Kulozik, U., Foerst, P. (2012). Combined influence of fermentation and drying conditions on survival and metabolic activity of starter and probiotic cultures after low-temperature vacuum drying. Biotechnology for Enhancing Plant Production and Food Quality, 759(4), 351-357. 

Vacuum drying. This technique is similar to roller drying, but the rollers are operated under vacuum. This enables lower evaporation temperatures to be achieved and results in a product that is friable, easily reconstituted, and of good flavor quality. 

A belt-trough dryer has been used to produce very high-quality diced potato [4,5]. Only vacuum drying or freeze-drying can produce a more porous product than products dried using a belt-trough dryer. The dryer consists of an endless, closely... 

Loch-Bonazzi et al. [33] evaluated the quality of mushrooms dried by various processes such as hot air, vacuum, freeze-drying in an adsorbent fluidized bed and vacuum freeze-drying. Results of their study indicated that vacuum freeze-dried produets were of superior quality in terms of density, rehydration eap-acity, and color. They also reported that most flavor compounds disappear during preparation and freezing steps. Microwave vacuum drying of mushroom has been explored by Pappas et al. [34]. Their experimental results indicated that microwave-vacuum drying exhibits superior drying performance as well as improved rehydration characteristics. 

In terms of dried product quality, the volume and density of the carrots changed in a similar manner upon both VD and LPSSD. However, although both vacuum-dried and low-pressure superheated steam-dried carrots exhibited similar volumetric shrinkage (calculated from the change in the volume of a sample compared... 

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