Abstract
Traditional hot air drying of asparagus is known to lead to a powder with a poor aroma profile. We here concentrated asparagus juice into asparagus concentrate (21.7% w/w) and spray-dried it with maltodextrin DE12 as carrier agent to improve the volatile profiles of asparagus powder and to valorise fresh asparagus side-streams. We performed headspace GC-MS with untargeted metabolomics to assess the overall metabolite profile of the spray-dried asparagus powders and identified 70 volatile compounds. The maltodextrin content was positively correlated to the retention of an asparagus key odorant 1-octen-3-ol, as well as other alcohols and aldehydes. Nevertheless, drying conditions had limited effect on the volatile retention of the powders. Moreover, higher outlet temperatures increase the presence of volatiles that were formed during drying, such as 3-methylthio-propanal. From our analyses, it was further found that an increased concentration of maltodextrin was correlated to a lower moisture content, a higher glass transition temperature (Tg) and a narrower size distribution of the spray-dried powders. The Tg of all powders was described with the Gordon-Taylor equation for multicomponent mixtures, and we found a minimum weight fraction of 0.67 (w/dw) maltodextrin required to obtain glassy asparagus powder for storing at ambient conditions.
Highlights
Asparagus (Asparagus officinalis) is a popular vegetable consumed all over the world
The moisture content of powder dried from a 2:1 asparagus solids to maltodextrin ratio was found to be higher than that of the 1:2 ratio sample
Increasing maltodextrin concentration resulted in spraydried powders with a lower moisture content, higher Tg and less unde sired agglomeration
Summary
Asparagus (Asparagus officinalis) is a popular vegetable consumed all over the world. Some aroma compounds of asparagus are lost during drying, whereas some other asparagus key odorants can be formed upon drying, including sulphur-containing compounds such as dimethyl sulphide (Nijhuis et al, 1998; Ulrich et al, 2001). Artificial flavouring agents are added to the asparagus powders These flavouring agents may not fit in a formulation targeted to be perceived as natural and healthy by consumers (Bearth et al, 2014; Eiser et al, 2002; Shim et al, 2011). To obtain asparagus powders with better aroma profile, new drying strategies need to be developed. These strategies include the selection of a drying method as well as the optimisation of this drying method
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
