Processing quality of improved potato (Solanum tuberosum L.) cultivars as influenced by growing environment and blanching

摘要

A study was conducted to investigate the influence of growing environment and blanching on chips quality of five improved potato cultivars (Chiro, Zemen, Bedassa, Gabissa and Harchassa). The cultivars were grown at Langaie, Kulubi and Haramaya, all in the eastern part of Ethiopia. The highest tuber dry matter content (27.33%) and specific gravity (1.110 gcm-3) were produced by cultivar Harchassa while the lowest dry matter content (20.33%) and specific gravity (1.078 gcm-3) were by cultivar Zemen both grown at Haramaya condition. All the cultivars at all locations produced tubers with a dry matter content greater than 20.0% and a specific gravity of 1.070 gcm-3which are within the acceptable range for chip processing. The tuber pH value ranged from 6.18 to 6.37 for the cultivars regardless of the growing environment. Location did not significantly affect tuber reducing sugar content and the cultivars produced tubers with low reducing sugar content that ranged from 0.036 to 0.051 g 100 g-1fresh weight (FW). For chips making, peeled potatoes were sliced to 2.0 mm thickness, washed and surface-dried. In the blanching treatment, sliced potatoes were blanched at 90°C for about 5 min. Both blanched and unblanched slices were fried at 175°C for about 5 min using vegetable oil.The interaction effect of genotype and growing environment significantly influenced texture, bitterness, sweetness, crispiness and overall acceptability of potato chips. Blanching improved chips color, texture, sweetness, and crispness while reducing sourness and bitterness, ultimately increased the overall acceptability. In all cases, blanching resulted in a better acceptability of potato chips. The study indicated that the tested cultivars can be potentially be used for chips making. However, a comprehensive study under wide frying and blanching condition would be necessary to optimize the best operating conditions. The potato breeders should give emphasis for genotype × environment interaction while developing varieties suitable for processing.