|Title||Contribution of microwaves or ultrasonics on carvone and limonene recovery from dill fruits|
|Author(s)||Esveld, D.C.; Chemat, S.|
|Source||Innovative Food Science and Emerging Technologies 17 (2013). - ISSN 1466-8564 - p. 114 - 119.|
|Department(s)||FBR Food Technology|
|Publication type||Refereed Article in a scientific journal|
|Abstract||The objective of this study is to investigate alternative preparation techniques such as microwave and ultrasound
for the recovery and evaluation of carvone and limonene from flaked dill fruits (Anethum graveolens L.).
The study indicates that microwave-assisted extraction using hexane is highly recommended to reveal the correct
amount of carvone and limonene in dill fruits. In this respect,when hexane is used, microwave-assisted system
gives a better carvone yield of 29.96 mg/g compared to 24.54 and 23.49 mg/g for ultrasound and
maceration (control) methods respectively. Furthermore, systems using hexane are able to recover high
amount of limonene as opposite to systems using water where extracts are characterised by an absence of
free fatty acids and a high abundance of carvone translated by high carvone/limonene ratio especially in microwaves
(22.88) and ultrasound (6.55). These findings suggest that the intervention of microwaves or ultrasonics
enhances extraction selectivity for carvone but have no great effect on limonene recovery.
Although the recovered quantity of carvone in water extracts is much lower than the system using hexane due
to low solubility of carvone inwater, the advantages of using a GRAS solvent such as water are evident. It allows
extracts to be readily available for spray application on potatoes' storage. In addition, the proposed enhancement
involving ultrasound pre-treatment has helped in increasing carvone yield and has the advantage to be
easily implemented on existing extraction processes.
Industrial relevance: Our study shows that newtechnologies such as ultrasound andmicrowaves offer important
advantages over conventional methods, such as shorter extraction time, energy saving and selectivity. Furthermore,
the pretreatment of samples with ultrasound stands an intelligent tool to enhance extraction yields without
jeopardising selectivity. Those aspects are of primary importance for industry to reduce cost and bring
greener routes to their established processes.
In another aspect, the application of the proposed tandem method involving ultrasonics and water as a solvent
would contribute to the creation of a niche market for hydrocarbon-free products, which are very sought
after from exigent clients.
In addition, the results indicate also that water gives valuable advantages in terms of safety, cleanliness and adoption
if we decide to generalise its use at an industry scale for carvone recovery. On top of that, usingwater as solvent
inmicrowaves or ultrasound systems produces extracts rich in carvone, offering a product thatmay be used on potato
storage on products for example having Bio or Organic labels without hindering their stringent regulations. Furthermore,
the use of the produced carvone directly as a spray would not influence the perception of people as
carvone represents also the major compound on the widely used condiment Carum carvi L.