Development and nutritional analysis of functional sweet potato beverage through response surface optimization

This paper has designed a working sweet potato drink with hawthorn added to it and has optimized the formula of the hawthorn added to the drink through response surface methodology. The base material was fresh sweet potato and it was processed through the stages of washing, peeling, thermal softening, pulping, blending and lab bottling. The effects of sweet potato, dried hawthorn, sucrose, citric acid and xanthan gum on product performance were initially screened in single-factor experiments. This was followed by a four-factor Box–Behnken design where DPPH radical scavenging rate was used as the response variable. The optimal formula was 25.19% sweet potato, 2.06% dried hawthorn, 7.14% sucrose, 0.79% citric acid, and 0.80% xanthan gum. In these conditions, the beverage had a DPPH inhibition rate of 81.37, a content of ascorbic acid of 38.16 mg/100 mL, a reducing sugar content of 7.85 and a starch content of 9.62. Descriptive quality screening in the laboratory was a bright golden-yellow in color, balanced sweet–sour in flavor, balanced sweet potato-hawthorn aroma and acceptable physical stability with a total quality score of 85.3 ± 4.5. The findings suggest that optimization of response surface can be applied to develop nutritionally relevant sweet potato beverage with positive antioxidant properties and product quality. Stability of storage and pilot-scale processing should be confirmed in the future work.