111: Enhancing the Aroma of Whole Sorghum Flour Using Supercritical Carbon Dioxide: Application of Treated Flour in 3D Printing of Sorghum Cookies

Introduction

There is a growing demand for grain sorghum in food applications because of its sustainability and various health benefits, such as its anti-inflammatory, anti-diabetes, and anticancer properties. Grain sorghum is a gluten-free and drought-resistant option that could become popular with consumers seeking healthier food choices. Sorghum flour contains substantial amounts of alcohols, aldehydes, and alkanes responsible for undesirable woody, grassy, and gasoline-like aromas. Therefore, this study aimed to develop an innovative, environmentally friendly approach based on SC-CO2 to enhance the flavor of sorghum flour, and utilize the treated flours in 3D printing cookies.

Methods

The SC-CO2 extraction conditions (8.18-41.82 MPa, 33.18-66.81°C, 1.32-4.68 h) were optimized for the maximum volatile removal. Cookies were 3D printed using sorghum flour treated with SC-CO2 at the optimized conditions, along with another two conditions at minimum pressure and temperature. Apparent viscosities, storage (G′) and loss (G′′) moduli, and pasting properties of the doughs were measured. The dough formulations were subjected to a texture profile analysis, while the hardness of the cookies was investigated with a three-point rig test. A three-factor orthogonal central composite design was generated at 5 levels with duplicates for the optimization.

Results

The maximum volatile removal (~89%) was achieved from sorghum flour with SC-CO2 extraction at 60°C, 15 MPa, and 2 h. The optimal 3D printability of sorghum cookies was achieved using 5:3 g flour/mL water ratio, 1.5 mm nozzle diameter, and a print speed of 2,500 mm/min. All the dough samples displayed a shear-thinning behavior, and there was no visible change in apparent viscosity after the SC-CO2 treatments. Increasing the SC-CO2 extraction pressure from 8 to 15 MPa did not significantly affect the viscosity of the samples. All samples displayed distinct pasting properties. SC-CO2 treatments significantly decreased the cookie dough's adhesiveness and the cookies’ surface redness (a*).

Significance

Sorghum can adapt to climate change and be an alternative gluten-free flour source. This study is expected to (i) produce a sustainable source of gluten-free flour ingredients with a bland aroma, (ii) improve/modify the flavor of food ingredients and offer an alternative product with clean label options, and (iii) avert toxic organic solvent usages.

Authors: Arda Tuhanioglu, Ali Ubeyitogullari