Analysis of volatile flavour components by dynamic headspace analysis/gas chromatography-mass spectrometry in roasted pistachio extracts using supercritical carbon dioxide extraction and sensory analysis

Figures & data

Figure 2. Descriptive analysis of the pistachio extract.

Table 1. Flavouring attributes selected for DSA.

Attribute*	Characteristics
Sweet	Taste of candy
Salty	Taste of sodium chloride
Pistachio oil	Oily taste of extracted pistachio
Pistachio	Characteristic taste of pistachio
Bitter	Taste of caffeine solution
Shell	Woody mouthfeel
Roasted	Taste of roasted nut
Raw	Taste of nonroasted pistachio
Oxidized	Taste of rancidity and old fat

*Flavouring attributes were selected by tasting the roasted pistachio extract.

Table 2. Different process parameters for SC-CO₂ extraction.

Method	Feed amount (g)	Pressure (Bar)	Temperature (°C)	CO2 flow rate (gCO2/min)	Time (min)
1	100	300	60	100	120
2	150
3	200
4	250
5	300
6	200	150	60	100	120
7		200
8		250
9		350
10		400
11		450
12	200	350	50	100	120
13			70
14			80
15	200	350	70	50	120
16				75
17				125
18	200	350	70	75	40
19					60
20					90
21					180

Table 3. The flavouring compounds detected in the pistachio extracts by DHA-GC/MS.

Compounds	Area %
Isobutyraldehyde	0.48
Isovaleraldehyde	46.66
Diacetyl	0.19
Tricylene	0.36
α-Pinene	24.47
Camphene	1.61
Hexanal	0.31
Pinene 2-β	1.42
Delta-3-carene	1.04
β-Myrcene	0.52
Limonene D	2.25
Isoamyl alcohol	0.41
β-Ocimene	0.15
P-cymene	0.20
α-Terpinolene	5.70
Acetoin	0.31
2.5-Dimethyl pyrazine	0.18
2.6-Dimethyl pyrazine	0.26
Nonanal+2-Ethyl-6-methyl pyrazine	0.21
α-para-dimethyl styrene	0.13
Acetic acid	9.32
Furfural	0.18
Benzaldehyde	0.23
2.3-Butanediol	4.09
ɣ-Butyrolactone	0.76
1.8-Menthadiene-4-ol	0.23
P-Cymene-8-ol	0.09
Octanoic acid	0.11
Decanoic acid	0.11
Palmitic acid	1.24

Italic values are the primary flavouring compounds which give the characteristic odour and taste of pistachio.

Table 4. The fatty acid composition (%) of the pistachio extract.

Fatty acid composition	% total
Methyl myristate	0.16
Methyl palmitate	9.86
Methyl palmitoleate	0.69
Methyl heptadecanoate	0.06
Methyl stearate	1.78
Methyl oleate	67.51
Methyl linoleate	17.85
Methyl linolenate	0.31
Methyl arachate	0.14
Methyl docosanoate	Not detected
Methyl-10-octadecenoate	Not detected

Figure 1. Concentration (%) of the flavouring compounds (α-pinene, β-myrcene, limonene-D and α-terpinolene) in the pistachio extracts obtained by SC-CO₂ extraction under the different process parameters. A: feed amount, B: process pressure, C: process temperature, D: CO₂ flow rate, E: process time.