Volume 168, 1 February 2015, Pages 561–565
Key volatile aroma compounds of three black velvet tamarind (Dialium) fruit species
Highlights
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- Application of aroma extract dilution analysis on tamarind extracts obtained by SAFE yielded 19 odorants of importance.
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- Results of OAVs and sensory analysis revealed significant differences in odour profiles between species.
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- The differences were mainly caused by linalool, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, limonene, (Z)-3-hexenal and nonanal.
Abstract
Nineteen
odour-active compounds were quantified in three black velvet tamarind
fruit species. Calculation of the odour activity values (OAVs)
of the odorants showed that differences in odour profiles of the
tamarinds were mainly caused by linalool, limonene,
4-hydroxy-2,5-dimethyl-3(2H)-furanone, nonanal, and (Z)-3-hexenal. On the basis of their high OAVs, cis-linalool
oxide (furanoid), geranyl acetone, and cinnamyl acetate were identified
as other potent odorants in the three tamarinds. Sensory studies
revealed very distinct aroma profiles, which are characteristic of these
types of fruits. While the Dialiumguineense elicited floral, flowery, caramel-like notes, the other two species were dominated by leaf-like, caramel, and green notes.
Keywords
- Black velvet tamarind fruits;
- Aroma-active compounds;
- Stable isotope dilution assay;
- Odour activity values
Chemical compounds studied in this article
- (E)-2-dodecenal (PubChem CID: 5283361);
- Acetic acid (PubChem CID: 176);
- Geraniol (PubChem CID: 637566);
- Cinnamyl acetate (PubChem CID: 5282110);
- (Z)-3-hexenal (PubChem CID: 643941);
- 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (PubChem CID: 19309);
- Benzyl alcohol (PubChem CID: 244);
- Linalool (PubChem CID: 6549);
- Nonanal (PubChem CID: 31289);
- cis-Linalool oxide (furanoid) (PubChem CID: 6428167)
1. Introduction
Cultivation
and the interest in wild edible fruits such as black velvet tamarind
have grown due to their comprehensive protective effects, especially
their antioxidant activity (Adepoju, 2009). Black velvet tamarind is a common name for several trees in the genus Dialium, and may refer to the following: Dialium guineense; Dialium indum, and Dialium cochinchinense. D. cochinchinense and D. indum are native to southeast Asia, while D. guineense is found in Africa. D. guineense is a tall (30 m), fruit-bearing tree. It belongs to the Fabaceae
family, and produces fruits that are enclosed in a brittle shell. The
seed is embedded in a dry brownish sweet slightly sour edible pulp. The
fruiting period is usually between the months of March and May but may
be earlier and sometimes persist longer. Black velvet tamarind is
commonly present in humid dense forests of west Africa, and central
Africa. Its native range includes Benin Republic, Burkina Faso,
Cameroon, Central African Republic, Chad, Côte d’Ivoire, Equatorial
Guinea, Ghana, Nigeria and Senegal ( Ajiwe, Okeke, Agbo, Ogunleye, & Ekwuozor, 1996). The fruits are consumed for their sweetly edible pulp which is rich in vitamin C (35.7 mg/100 g) ( Achoba, Lori, Elegbede, & Kagbu, 1992), and β-carotene (362 μg/100 g) ( Adepoju, 2009) respectively.
The genus Dialium comprises of five species in Africa with three of them commonly found in Nigeria. The three species are D. guineense, Dialiumdinklagel and Dialiumpackyphyllum ( Ogu & Amiebenomo, 2012).
The pleasant organoleptic properties of these fruits explain its
increasing popularity in west Africa. It is worth mentioning that the
world production and trade of fresh tropical fruits are expected to
expand over the next few years. Presently, developing countries account
for about 98% of total production, while the developed countries account
for 80% of the world import trade ( FAO Corporate Document Repository., 2013). This fact shows that there is a growing demand for healthy food like tropical fruits.
Fruit
aroma is one of the most appreciated characteristics that attract
consumers. In addition, aroma can be used to define maturity stage or
distinguish different fruit types (Ong et al., 2008). Volatiles responsible for the D. guineense characteristic aroma note, such as alcohols, alkanes, acids and aldehydes were earlier described by Pelissier, Haddad, Marion, Milhau, and Bessiere (2001). However, there has been no systematic study aimed at identifying the key aroma compounds in black velvet tamarind.
The aim of the present study was to identify and quantify the aroma volatile compounds in three different tamarinds (D. guineense, D. dinklagel and D. packyphyllum). In addition, correlation between their volatile constituents and sensory properties were evaluated.
