Air drying apples

Preparation of AIR and extraction of pectic fractions For the preparation of the alcohol-insoluble residue (AIR) the apples were peeled, cut into small pieces and boiled in 96% ethanol for lOmin. After this enzyme inactivation step, the sample material was blended, homogenised and filtered through a G3 sintered glass niter funnel. The residue was washed with 96% ethanol, followed by acetone and diethyl-ether, dried overnight at 40°C under vacuum and stored at -20°C in the dark. Portions of about lOg of AIR were fractionated according to the method of Selvendran et al. [10] as shown in figure 1. 

Martin, M.E., Vazquez, M.L., Martinez-Navarrete, N., Chiralt, A., Fito, P., Catala, J.M., and de los Reyes, E. 1998. Combined microwave and air drying of apple (Granny Smith). In Proceedings... 

Nieto, A., Salvatori, D., Castro, M.A., and Alzamora, S.M. 1998. Air drying behaviour of apples as affected by blanching and glucose impregnation. J. Food Engineer. 36, 63-79. 

Lewicki, R. R, Jakubezyk, E. (2004). Effect of hot air temperature on mechanical properties of dried apples. Journal of Food Engineering, 64, 307-314. 

Effect of Vacuum Impregnation and Microwave Application on Structural Changes during Air Drying of Apple... 

Vacuum-impregnated (VI) and nonvacuum-impregnated (NVI) apple slices were dried by air drying (AD) and by combined air-microwave technique (MWD) using a modified household microwave oven, where air temperature and velocity and MW power may be controlled... 

Air-dried Thread the apple rings onto a piece of string and hang the string by an open fire until the apple pieces are completely dried out. 

Borner (1960) states that soil sickness in fruit culture is a problem of economic importance in Germany. This is a replant problem that involves micro-element depletion and nematodes, but also root residues. As little as 1 g of air-dry root bark of an old apple tree per half liter of nutrient solution reduced root and stem growth of apple seedlings up to 50% within 30 days. Phlorizin, a natural constituent of apple root bark, and its breakdown products, are at least partially responsible for this apple soil sickness. 

Energy evaluation based on steam consumption showed a 44% reduction in steam consnmption when a CEPS was used to dehydrate apple pieces as compared with conventional dehydration this is attributed to the time saved for drying from 20% to less than 3% moisture. Process cost for EPS is reported to be similar to the cost of conventional hot air drying. Table 29.6 gives processing conditions (batch versus continuous) for a number of fruits and vegetables [35]. 

Carlson RA, Parkas DF, Curtis RM. Effect of sonic energy on the air drying of apple and sweet potato cubes. J Food Sci 27 793-794, 1972. 

Bazhal et al. (2003) investigated the shrinkage and porosity values of apple after hot-air drying, and found a more severe collapse of structure in the control samples compared to PEF-treated samples. The bulk and skeletal density values were 0.46... 

Sound transfer to a standard laboratory screen with an aperture of 500 pm used in the studies allowed the air-drying time of apples to be reduced by 27%, and of bell peppers by 23% (Schossler et al., 2012a). The ultrasound system used is shown in Fig. 7.9, and the corresponding drying curves are depicted in Fig. 7.10 these show the reduction of the moisture ratio MR over the drying... 

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