A Delay between Hot Water Treatment and Processing of Potato Tubers Reduces Browning Development on Fresh Cut Slices

Oxidative browning is a serious quality limitation for fresh-cut potato (Solanum tuberosum) that has been successfully controlled by heat treatment in other commodities. The use of brief heat stress treatments using 55?C water (HW) applied to ?Russet Burbank? tubers for 10, 20, 30 or 40 min prior to cutting was evaluated for potential to control tissue browning. Following heat treatment, tubers were cooled in 8?C water for 10 min, drained, then held at 20?C for 0 or 1 day before peeling and slicing. Control tubers were not previously immersed in hot water (N-HW). Sliced, rinsed, and blotted slices were placed in perforated plastic bags and stored at 5?C for 6 days. Exposure to HW for 30 or 40 min caused severe heat injury. Browning developed in all treatments as indicated by color measurements and discoloration score (index of extent of discolored area on the slice surface) after storage. Hot water treatment for 10 min best reduced browning, but only when treated tubers were left intact for 1 day at 20 ?C before cutting, as indicated by discoloration scores and changes in lightness, a*, and hue angle values, which were significantly different than either the control or the other HW treatments. Generally, the severe browning that developed in control slices (N-HW) was associated with significantly higher phenolic content after storage compared with day 0 (1.58 versus 1.27 mg?g-1 f.w.), as well as post-storage polyphenoloxidase (PPO) activity (10.47 Units/g f.w.) that was similar to initial activity (12.36 Units/g f.w.). On the other hand, HW treatment prevented phenolic synthesis during storage, resulting in significantly lower content (1.37-1.43 mg?g-1 f.w.) after storage compared with the N-HW slices (1.58 mg?g-1 f.w.) and reduced PPO activity (8.51-9.42 Units/g f.w.) compared with the initial activity before storage (12.36 Units/g f.w.). Full list of authors and source:Tsouvaltzis, P.; Deltsidis, A. I.; Brecht, J. K.University of Florida, Horticultural Sciences Department, 32611-0690, Gainesville, Florida, United StatesInternational Horticulture Congress, Lisboa 2010, ISHS The source of the picture is xn--frutaslogroo-khb.com ? ?