Studies on Drying Characteristics of Beetroot (Beta Vulgaris L.) and Development of Its Chips With Quality Evaluation

Abstract

Present investigation was carried out to develop beetroot chips. The effects of different drying methods and different pretreatments were studied. There were two drying methods i.e. sun drying and hot air tray drying at three temperatures (50⁰C, 60⁰C and 70⁰C). There were three pretreatments i.e. KMS, blanching and KMS+Blanching and untreated (control) samples were also studied. The drying was done under natural convection in direct sun drying method while under forced convection in hot air tray drying at an air velocity of 1.8 m/s. The temperature and relative humidity of drying air, and weight loss of the drying material were monitored at regular selected time interval. Drying rate and moisture ratio were computed to study the drying characteristics of beetroot chips. The quality of dried beetroots was studied in terms of moisture content, ash content, Ph, acidity and ascorbic acid. Sensorial attributes like colour, taste, texture and overall acceptability of chips were analyzed just after preparation and during storage of 30, 60 and 90 days under ambient condition packaged in low density polyethylene. The present study revealed that the highest drying rate of 5.51(g/min) and lowest final moisture level of 5.45(%db) was recorded in hot air tray drying of beetroot chips at air temperature of 70⁰C and air flow rate of 1.8 m/s. The increase in drying air temperature increased the drying rate and also the drying level in all the methods. The beetroot chips produced under tray drying at temperature 70⁰C with KMS+Blanching pretreatment was observed with lowest moisture content value and higher overall acceptability organoleptic score during storage of 90 days. All other beetroot chips were also acceptable after 90 days of storage in LDPE. The cost of production for beetroot chips was observed to be Rs.215/kg.