30 



MISC. PUBLICATION 54 0, U. S. DEPT. OF AGRICULTURE 



dure is essentially a batch process and the necessary equipment is 

 heavy and somewhat difficult to obtain. The opening and closing of 

 the heavy steam-tight doors, as is required in loading and unloading 

 the equipment, is laborious and will undoubtedly require considerable 

 time. This factor makes it desirable that the retort be installed in 

 duplicate so that the batch peeling operation will furnish a steady 

 flow of materials to the processing line. 



Probably the steam process is satisfactory for peeling all root prod- 



SUGGESTED LYE 

 CONCENTRATION (PERCENT) 



5 10 15 20 25 



180 

 170 



2 '60 



z 

 o 



| 150 



UJ 



2 140 



Z 



2 130 



z 



UJ 



u 120 

 1 10 



100 

 90 







































































































Figure 13. 



210 220 230 



SUGGESTED OPERATING 

 TEMPERATURES (°F.) 



-Approximate retention time for potatoes in different concentrations 

 of lye solution in preparation for peeling. 



ucts with the exception of carrots and parsnips, the tissuelike skins 

 of which cannot be readily removed from the product by washing 

 without removal of a substantial part of the flesh. Development of 

 a satisfactory continuous pressure cooker would remove the most ob- 

 vious limitation of the process. 



Summary of peeling methods. — Abrasive and lye peelers offer the 

 most positive peeling results and are the most versatile for handling 

 the entire range of root products. Of the two, the lye peeler offers 

 the highest recovery of peeled and trimmed vegetable with the least 

 labor. The costs of equivalent-size peeling equipment for lye and 

 abrasive peeling are about equal. The personal hazard with lye peel- 

 ing may limit its use. Retort peeling shows promise for most of the 

 root vegetables, but suffers from the difficulties inherent in batch pro- 

 cesses. Brine peelers offer high recovery with minimum manual labor, 

 but are restricted to certain vegetables only. Equipment suitable for 



