Microwave‐convective hot airdried jamun (Syzygium cumini L.) pulp powder: Optimization of drying aids

Abstract

Drying of fruit pulp into powder needs drying aids for achieving desirable powder properties. This article aims to optimize drying aids, such as maltodextrin (MD), tricalcium phosphate (TCP), and glycerol monostearate (GMS) in jamun (Syzygium cumini L.) pulp blend formulation to produce microwave‐convective hot air‐dried jamun pulp powder. Response surface methodology using rotatable central composite design was followed with independent variables MD (1–15), TCP (0–2), and GMS (1–3), % dry basis of pulp, on hygroscopicity (HG), rate of moisture sorption estimated at 60\u2009min (RMS₆₀), flow time (FT), and overall color difference (ΔE*) as responses of the product. The statistically significant factors were: MD for HG; MD, TCP, and GMS for RMS₆₀ and FT; and TCP and GMS for ΔE*. The optimized formulation reduced HG, RMS₆₀, and FT by 29.67, 45.24, and 60%, respectively with respect to the control, with ΔE* being 6.98. PRACTICAL APPLICATIONS: The antidiabetic and antioxidant properties of jamun (Syzygium cumini L.) fruit are well established. The therapeutic values of jamun pulp and skin are mainly due to the presence of various phytochemicals. However, it is considered as underutilized fruit due to its highly perishable nature. Properly matured fruit can be stored for maximum 2 days at room temperature and 3 weeks at low temperature. Hence, immediate processing and conversion into value‐added products of jamun fruits are needed for better distribution and utilization during off‐season. Processing of fruit pulp into dry powder is a popular practice to obtain shelf‐stable product having wide scope of utilization. However, preparation of fruit powder has many challenges, the main problem being their stickiness due to the presence of low molecular weight sugars and organic acids. Therefore, production of stable free‐flowing jamun pulp powder with selection of suitable drying aids in proper concentration has enough industrial relevance.