Spray‐Drying of Amylase Hydrolyzed Sweetpotato Puree and Physicochemical Properties of Powder

Abstract

Spray‐drying, which has been used for commercial production of functional ingredients from several fruits and vegetables, has not yet been studied for sweetpotato processing. Thus, the objective was to determine the effects of viscosity reduction of sweetpotato puree with alpha‐amylase, maltodextrin (MD) addition, and inlet air temperature on the physicochemical characteristics of spray‐dried sweetpotato powder. A face‐centered cube design was used to evaluate the effects of amylase level (0, 3.75, and 7.5 mL/kg puree), MD concentration (0%, 10%, and 20%), and inlet air temperature (150 °C, 190 °C, and 220 °C) on powder characteristics. Model‐fitting using response surface methodology was performed to examine the effects of independent variables on the moisture content, color, water absorption, solubility, particle size, bulk density, and glass transition temperature. The data were fit to a full second order polynomial equation. However, only the linear and quadratic terms proved to be significant for most dried powder attributes. MD significantly increased powder solubility, altered the hue value, and raised the glass transition temperature of the powder. Pretreatment with alpha‐amylase resulted in a lower glass transition temperature and a decrease in particle size. Overall, results show that good quality sweetpotato powders can be produced using this drying method, with potential applications in food and nutraceutical products.

Spray Drying of Honey: The Effect of Drying Aids on Powder Properties

“…in the following pairs of experiments: 3,5 and 4,6) reveals that a lower bulk density was observed in those samples which were dried using GA in comparison to those dried with MD. As shown in the Table 1, GA/honey mixtures had higher viscosity than MD/honey, which could lead to the production of larger droplets and particles, and this parameter is known to be negatively correlated with the bulk density: as typically, bulk density increases upon particle size decrease [Goula & Adamopoulos, 2005;Grabowski et al, 2006].…”

Influence of spray drying operating conditions on microencapsulated rosemary essential oil properties

“…Numerous materials, such as wall materials (encapsulating agents), are available for spray drying microencapsulation of food flavors (JAFARI et al, 2008;YANG;XIAO;DING, 2009). Gum Arabic is used by the flavor industry in spray drying applications protecting the core material from oxidation and volatilization (SHAIKH; BHOSALE; SINGHAL, 2006).…”

“…Ahmed et al (2010), in a study on encapsulation of purple sweet potato by spray drying, found solubility values ranging from 40.24 to 56.95%. Several reports attribute superior properties to other carrier agents related to water solubility, such as maltodextrin (GRABOWSKI; TRUONG; DAUBERT, 2006;AMOPOULOUS, 2010).…”

“…Handling and flow properties can be improved by converting a liquid to solid encapsulated form. The microencapsulation procedure protects hygroscopic materials from moisture and maintain the stability of ingredients that are volatile or sensitive to heat, light, or oxidation (JAFARI et al, 2008).…”

Influence of process conditions on the physicochemical characteristics of cumaru (Amburana cearensis) powder produced by spray drying

“…According to Tonon et al (2008) at higher inlet air temperatures, there is a greater temperature gradient between the atomized feed and the drying air, resulting in a greater driving force for water evaporation, thus producing powders with lower moisture content. Grabowski et al (2006) also observed a reduction of powder moisture content with increasing temperatures, studying the spray drying of sweet potato puree.…”