Standardization of process protocol for the production of banana pseudostem juice powder

Abstract

Banana stem, appearing as a waste of the banana plant is very good for health. One can use banana stem for its high nutritive value in different ways. It is also a source of energy and can be used in treatment of kidney stone. It forms an integral part of most South Indian health conscious families. Juice from banana stem is a well-known remedy for urinary disorders. It improves the functional efficiency of kidney and liver thereby alleviating the discomforts and diseased condition in them. It helps in the dissolution of calcium oxalate, a cause for the formation of kidney stones. But the major problem associated with the pseudostem juice is its perishability and immediate browning reactions. It leads to the reduction of its acceptability by consumers. Considering the above cited facts a study was undertaken to obtain powdered product from pseudostem juice. The objectives of the study were to develop a process protocol for microencapsulated banana pseudostem juice powder and quality analysis and storage studies of the powder. Microencapsulation was done with pseudo stem juice as the core material and maltodextrin as the wall material. The pieces of pseudostem was treated was treated with 0.3% citric acid and steam blanched at two different temperatures for 30 sec and 1min. By peroxidase test, the time for steam blanching was standardized as 1min. The substance to be encapsulated (the filtered juice) and a carrier (maltodextrin) is homogenized as a suspension in water (the slurry). The slurry is then fed into a spray drier. The composition of filtered juice was ginger juice (2% and 4%), maltodextrin (20% & 25%) and two concentrations of sugar (12% and 15%). The process parameters were optimized as inlet temperature of 180oC, outlet temperature of 68oC, feed pump rpm as 12, main blower rpm- 1600. The physicochemical characteristics such as pH, total soluble solids, bulk density, wettability and moisture content of powder were determined. The pH of powder was found to be 6.8, TSS as 15oBrix, moisture content was found to be 4% w.b, bulk density as 0.47 g/ml, wettability as 80 seconds.. Based on sensory analysis, maltodextrin concentration of 20% and ginger juice concentration of 2% and sugar concentration of 15% was standardized for the production of microencapsulated pseudostem ginger juice powder by spray drying. The results indicated that moderate wall material concentration (20%), low inlet air temperature (180oC), and moderate feed flow rate are the best spray drying conditions. The study suggests that banana pseudostem powder can be taken as a ready to drink beverage as a food supplement for diabetes and kidney stones.