Comparative Analysis of Flavor, Taste, and Volatile Organic Compounds in Opossum Shrimp Paste during Long-Term Natural Fermentation Using E-Nose, E-Tongue, and HS-SPME-GC-MS

Abstract

The present study focused on the determination of color, flavor, taste, and volatile organic compounds (VOCs) changes of shrimp paste fermented for 1, 2, 3, and 8 years by E-nose, E-tongue, and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). During fermentation, the color of shrimp paste turned dark brown with decreases in L*, a*, and b* values. Inorganic sulfide odor was dominant in all fermented samples. The umami, richness, and aftertaste-B reached a maximum in year 3 of fermentation. A total of 182 volatiles, including long-chain alkanes, esters, aldehydes, olefins, ketones, acids, furans, and pyrazines, were detected. Sixteen VOCs including dimethyl disulfide, methional, trimethyl-pyrazine, (E,E)-2,4-heptadienal, benzeneacetaldehyde were selected as flavor markers. Correlation analysis showed that 94 VOCs were related to saltiness while 40, 17, 21, 22, and 24 VOCs contributed to richness, umami, aftertase-B, sourness, and bitterness, respectively. These novel data may help in optimizing fermentation duration to achieve target flavor indicators in opossum shrimp paste production.

Keywords: HS-SPME-GC-MS; correlation analysis; flavor substances; orthogonal partial least square discriminate analysis (OPLS-DA); sensory evaluation; shrimp paste.

Figure 1

Appearance of shrimp paste at fermented for 1, 2, 3, and 8 years.

Figure 2

Distribution of volatile compound species in shrimp paste samples during 1 (a), 2 (b), 3 (c), and 8 (d) years of fermentation, using an E-nose sensor.

Figure 3

The PCA of all shrimp paste samples fermented for 1, 2, 3, and 8 years based on taste composition identified by E-tongue.

Figure 4

The classification and amount of VOCs in shrimp paste samples fermented for 1, 2, 3, and 8 years.

Figure 5

The number of peak VOCs in shrimp pastes fermented for 1, 2, 3, and 8 years.

Figure 6

The PCA analysis of the whole groups (A), between two groups (C–E) and cluster analysis (B) of VOCs in all shrimp paste groups fermented for 1, 2, 3, and 8 years.

Figure 7

The OPLS-DA analysis (A1,B1,C1), between-group comparative analysis (A2–A5,B2–B5,C2–C5) of VOCs in all shrimp paste samples fermented for 1, 2, 3, and 8 years.

Figure 8

Correlation network between saltness (A) and richness, umami, aftertaste-B and bitterness (B) wiht the VOCs in shrimp paste samples fermented for 1, 2, 3, and 8 years.