Storage Studies of Foam Mat Dried Hill Lemon (Citrus pseudolimon Tan.) Juice Powder

Hill lemon (Citrus pseudolimon Tan.) juice powder was prepared from concentrate of 45°B after foaming with 2% carboxymethyl cellulose (CMC) and drying in a mechanical dehydrator (55(plus-minus)2°C) followed by finishing in vacuum oven (50(plus-minus)2°C and 25(plus-minus)2" Hg vacuum) to a moisture content of about 5%. The juice powder was mixed either with dicalcium phosphate (2%) or powdered cane sugar (50%) to reduce its hygroscopicity. Storage studies of these powders after packing in polypropylene or aluminium laminated pouches indicated an increase in their moisture (133% dwb), hydroxymethyl furfural (15.46 times) and browning (2.86 times) with consequent losses in ascorbic acid (20.98% dwb), acidity (1.72% dwb) and total sugars (0.63% dwb). However, powders packed in aluminium laminated pouches experienced minimum changes in quality as compared to those packed in polypropylene pouches. Sensory evaluation of powdered RTS drinks prepared from juice powder indicated its superiority over commercially available synthetic Rasna Nimbupani beverage. The equilibrium relative humidity (ERH) studies of Hill lemon juice powder categorised them as highly hygroscopic and are therefore required to be stored within RH of 18 to 25%.