Effects of Extrusion Conditions on the Physicochemical Properties of Extruded Red Ginseng

Abstract

The effects of variable moisture content, screw speed and barrel temperature on the physicochemical properties of red ginseng powder extrudates were investigated. The raw red ginseng powders were processed in a co-rotating intermeshing twin-screw extruder. Primary extrusion variables were feed moisture content (20 and 30%), screw speed (200 and 250 rpm) and barrel temperature (115 and 130°C). Extruded red ginseng showed higher crude saponin contents (6.72~7.18%) than raw red ginseng (5.50%). Tested extrusion conditions did not significantly affect the crude saponin content of extrudates. Increased feed moisture content resulted in increased bulk density, specific length, water absorption index (WAI), breaking strength, elastic modulus and crude protein content and decreased water solubility index (WSI) and expansion (p<0.05). Increased barrel temperature resulted in increased total sugar content, but decreased reducing sugar content in the extrudate (p<0.05). Furthermore, increased barrel temperature resulted in increased amino acid content and specific length and decreased expansion and bulk density of extrudates only at a higher feed moisture content. The physicochemical properties of extrudates were mainly dependent on the feed moisture content and barrel temperature, whereas the screw speed showed a lesser effect. These results will be used to help define optimized process conditions for controlling and predicting qualities and characteristics of extruded red ginseng.

Process optimization of extrusion variables and its effect on properties of extruded cocoyam (Xanthosoma sagittifolium) noodles

“…This is quite important, as fats act as lubricants during extrusion cooking and reduces friction. Studies have also shown that extrusion cooking can cause structural and physicochemical changes, especially a redistribution of insoluble fiber to soluble ones (Castells et al., 2005; Gui et al., 2012). As such, SS and BT significantly ( p  < 0.05) affected the crude fiber of the noodles.…”

“…Extrusion cooking is a high‐temperature, short‐time process in which food materials are cooked in a tube by a combination of moisture, pressure, temperature, and mechanical shear, resulting in molecular transformation, gelatinization, protein denaturation, and disruption of bonds leading to products with new shapes and textures (Castells, Marin, Sanchis, & Ramos, 2005; Gui, Gil, & Ryu, 2012; Sobowale, Ayodeji, & Adebiyi, 2017). Extrusion further leads to the reduction in anti‐nutritional factors, increase in product microbiological safety, and much better consumer acceptability (Korkerd, Wanlapa, Puttanlek, Uttapap, & Rungsardthong, 2016; Sumathy, Ushakumari, & Malleshi, 2007).…”

‘The effect of inulin addition on structural and textural properties of extruded products under several extrusion conditions’

“…A high porosity extrudate has soft texture leading to lowering of the maximum stress, as maximum stress represents the hardness of the extrudates. The reduction of stiffness of extruded snacks with temperature has been reported for rice based extrudates (Ding et al 2005;Gui et al 2013). In order to produce extrudates enriched with inulin with these characteristics, the optimal value of inulin concentration is between 5 and 10 %.…”

Physical properties of supercritical fluid extrusion products composed of milk protein concentrate with carbohydrates

“…The length was then divided by the mass to calculate the specific length. This was repeated ten times to give an average specific length (Gui et al ., ; Karkle et al ., ; Alam et al ., ). The specific length was calculated using the equation: where L e is the length of the extrudates and m e is the mass of the extrudates (Karkle et al ., ; Alam et al ., ).…”