Effects of additives (NaCl, citric acid, and ethanol) on the cooking quality and sensory quality of vermicelli produced from freeze–thaw-dehydrated whole potato powder

Abstract To conform to the trend of whole-food diets in recent years, whole potato powder has been used for the processing of extruded vermicelli. The effects of different additives, such as NaCl, citric acid and ethanol, on the cooking quality and sensory quality of whole potato vermicelli obtained via twin-screw extrusion were investigated. The colour, gelatinisation properties, water absorption, cooking loss, texture profile analysis, scanning electron microscopy analysis and correlation analysis of the whole potato vermicelli were determined and discussed. The brightness of the whole potato vermicelli increased from 52.0 to 55.4 at 1% NaCl addition and increased from 52.0 to 54.9 at 0.8% citric acid addition, and the water absorption of the whole potato vermicelli increased from 83.1% to 159.1% at 0.4% citric acid addition and increased from 83.1% to 258.9% at 8% ethanol addition. The cooking loss of the whole potato vermicelli decreased from 5.3% to 5.1% at 8% ethanol addition, indicating that ethanol could improve the cooking quality of whole potato vermicelli. The texture properties of the whole potato vermicelli decreased with the addition of ethanol, and the ΔH of the whole potato vermicelli decreased from 3.7 to 1.8 J g−1 at 0.8% citric acid addition and decreased from 3.7 to 1.5 J g−1 at 8% ethanol addition, respectively. Moreover, the addition of ethanol was negatively correlated with the max force, break distance, stretching work, hardness, adhesiveness and chewiness of the whole potato vermicelli. The addition of NaCl was positively correlated with the peak gelatinisation temperature. All three additives affected the microstructure of the whole potato vermicelli, including roughening the cross section and increasing the number of pores. In this study, NaCl improved the gelatinisation properties of whole potato vermicelli, citric acid and ethanol improved the water absorption of the whole potato vermicelli, and citric acid improved the anti-browning effects of the whole potato vermicelli.