Sensory evaluation of roasted sweet potatoes influenced by different cultivars: A correlation study with respect to sugars, amino acids, volatile compounds, and colors

Abstract

In this study, color values, amino acid, and sugar composition (sucrose, fructose, glucose, and maltose) of fresh and roasted sweet potatoes from 11 cultivars were determined. Sensory evaluation (overall acceptability), GC‐MS, electronic nose, and electronic tongue were also used to analyze the flavor compounds and sensory index. The results of overall acceptability indicated that Yanshu No. 25 and Pushu No. 32 were preferred to the other ones. Besides, there was a certain correlation between colors, sugars, amino acids, volatiles, and overall acceptability. However, maillard and other reactions during the roasting process of sweet potatoes are complicated, and the formation of characteristic flavor is more complex, which requires further research. Therefore, the results of this paper can provide theoretical basis for improving the quality characteristics of roasted sweet potatoes. Practical applications The sensory characteristics of roasted sweet potatoes included color, aroma, and taste. However, there is little information about the effect of roasting on the quality of roasted sweet potatoes; no study has been conducted to investigate the effects of roasting on the changes in volatile compounds and sensory qualities of sweet potatoes, especially for different cultivars. The results of this study could illustrate which index was the most important factor that affected the overall acceptability of roasted sweet potatoes, and provided theoretical basis for improving the quality characteristics of roasted sweet potatoes, which could further promote the healthy development of roasted sweet potato industry.

Effects of Roasting Sweet Potato (Ipomoea batatas L. Lam.): Quality, Volatile Compound Composition, and Sensory Evaluation

“…During roasting, peeled sweet potatoes' starch and polysaccharides will form a secondary crusty peel. The sweet potatoes undergoing the two treatments were dark brown due to the decrease in L* value and the increase in a* value, and the degree of browning rises rapidly [8]. After roasting for more than 2.5 h, the two sweet potatoes exhibited similar roasting effects, and both were brown with a hard-shell surface.…”

“…The volatile composition of roasted sweet potatoes was modified from Hou et al [8] and identified with an HP-6890 gas chromatograph combined with a 5973 Turbo Pump Mass Selective Detector (MSD), and a DB-wax capillary column (60 m × 0.25 mm × 0.25 µm), were purchased by Agilent Technologies Co. (Santa Clara, CA, USA). Each 1.5 g sample was heated to 60 • C in a vial and the headspace was sampled with a DVB/CAR/PDMS fiber (Supelco Inc., Bellefonte, PA, USA) for 60 min.…”

“…Sensory evaluation was measured by the method of previous studies [8,15,18]. In this study, 60 panelists (students and staff of NCHU) were inducted in the evaluation room in batches.…”

“…and L * values, which is mainly due to roasting at high temperatures for a long time. Roasting causes caramelization and the Maillard reaction, producing dark polymers [8,21] and affecting the acceptability of the final products [22,23].…”

“…Changes in appearance, aroma, flavor, taste, and aftertaste may affect consumer acceptance, and different consumer groups will be attracted by different sensory characteristics [7]. Hou et al [8] showed a positive correlation between the color, sugar composition, free amino acids, volatile compounds, and overall acceptability of roasted sweet potatoes, especially between 2-furanmethanol and overall acceptability. Leksrisompong et al [9] analyzed consumer preference and descriptive analysis and found that, overall, preference for roasted sweet potatoes is mainly dominated by flavor preference, followed by taste preference.…”