Drying Characteristics of Yam Varieties: A Comparative Analysis

Abstract

The drying characteristics of five yam varieties (white yam, purple yam, three leaves yam, water yam and yellow yam) were investigated under three drying methods, using electric oven, natural sun and solar dryer). The yam tubers were washed, hand-peeled, sliced to size of 10mm thickness and each variety was divided into three sets for use at the three different drying methods. They were dried to a constant weight at a temperature of 33oC.The drying was repeated 6 times and the average of the weights taken. In all the drying methods the yam varieties had moisture ratio ranges of 0.21 – 0.08 % and the drying rates of 20%/hr – 10%/hr for solar dryer, 16%/hr – 10.1 %/hr for oven dryer and 23%/hr – 19.05%/hr for sun dryer while constant weight was attained at 180 to 300 minutes in oven- dried samples, 390 to 480 minutes for solar-dried samples and 780 to 960 minutes for sun-dried samples. In oven drying method purple yam dried faster (180 mins) followed by yellow yam (240 mins) and white yam (300 mins). Drying was accomplished in two days under sun drying method with three leave yam, purple yam and yellow yam having the same least time of drying while the white yam and water yam had the same highest drying period.

Karakteristike sušenja pet Jam (familija Dioscoreaceae, rod Dioscorea) varijeteta: Beli jam, Ljubičasti jam, Trolisni jam, Vodeni jam i Žuti jam) ispitivane su u tri varijante sušenja: elektična sušara, prirodno sušenje na suncu i solarna sušare. Jam krtole (gomolji) su isprane, ručno oguljene, isečene na veličinu debljine od 10 mm. Svaki Jam varijetet je podeljen u tri seta za upotrebu i tri različita postupka sušenja. Sušeni uzorci imaju konstantnu težinu na temperaturi od 33°C. Sušenje je ponovljeno 6 puta zbog prosečnih rezultata merenja. U svim metodama sušenja, odnos Jam varijeteta ima razliku vlage u rasponu od 0,21 do 0,08 %, a stope sušenja 20% /h - 10% /h za solarnu sušaru, 16%/h - 10,1% / h za sušenje u električnoj sušari 23% /h - 19,05% /h za sušenje na suncu. Konstantna težina uzoraka je postignuta od 180 do 300 minuta u uzorcima osušenim u električnoj sušari, 390 do 480 minuta za uzorke osušene u solarnoj sušari, i 780 do 960 minuta za uzorke osušene na suncu. Kod metode sušenja u električnoj sušari Ljubičasti jam se suši brzo (180 min), a zatim Žuti jam (240 min) i Beli jam (300 min). Sušenje je završeno za dva dana metodom sušenja na suncu, za varijetet Trolisni jam, Ljubičasti i Žuti varijetet jam, koji imaju isto najmanje vreme sušenja, dok Beli i Vodeni Jam imaju isti najduži period sušenja.