CHEMICAL AND PHYSICAL FACTORS IN PEELING APPLES AND POTATOES

ABSTRACT Seven apple varieties and Russet Burbank potatoes were peeled by caustics to save labor and reduce peeling losses. The procedures included the use of an automated peeling line employing warm caustics followed by pressurized steam, and a reel‐washer. For apples peeled at 150°F and with added wax‐penetrant the peeling losses ranged from 3–8%. The replacement of NaOH by KOH gave reductions in peeling losses of up to 25%. For potatoes dipped in caustics at 170°F the peeling losses ran from 8–17%, depending mainly upon prior storage times. The possibility of peeling potatoes in very hot (280°F) concentrated (50%) KOH was tried and gave excellent results, with no heat‐ring, and a KOH loss of only 0.56%.