Compositions, taste characteristics, volatile profiles, and antioxidant activities of sweet sorghum (Sorghum bicolor L.) and sugarcane (Saccharum officinarum L.) syrups

Abstract

Distinguishing the taste and aroma of different sugar syrups is important in determining their utility in the food and beverage industries and for their marketing to consumers. Herein, thick sugar syrups were prepared from the squeezed stalk juices of two important sugar crops: sweet sorghum and sugarcane. The sugar syrups were distinguished in terms of composition, taste characteristics, volatile profile, and antioxidant activity. Sweet sorghum syrup contained lower sucrose and total sugar, but retained greater amounts of minerals and organic acids than sugarcane syrup. Correspondingly, sweet sorghum syrup exhibited lower sweetness and higher saltiness and bitterness than sugarcane syrup. Sweet sorghum syrup exhibited a more complex volatile aroma composition, the major components of which were acetaldehyde, 2-methylpropanal, 3-methylbutanal, and 2-methylbutanal, followed by intermediate amounts of ketones, alcohols, and pyrazines. Additionally, sweet sorghum syrup exhibited a higher total phenolic content and superior antioxidant capabilities in oxygen radical absorbance capacity and 1,1-diphenyl-2-picrylhydrazine radical-scavenging activity assays than sugarcane syrup. The results of the present study demonstrate the suitability of sweet sorghum and sugarcane syrups as sweeteners and food ingredients for consumer and industrial applications.