Hs100 autosampler

The analysis of the volatile fraction of vegetable oils was conducted using ultra-fast chromatography device Heracles II equipped with HS100 autosampler (Alpha M.O.S., Toulouse, France). The gas chromatograph is equipped with two chromatography columns arranged in parallel. These chromatographic columns are: MXT-5, with crossbond diphenyl dimethyl polysiloxane stationary phase (10 m × 0.18 mm × 0.40 µm) and MXT-1701 with crossbond cyanopropylphenyl polysiloxane stationary phase (10 m × 0.18 mm × 0.40 µm) (Restek Corporation, Bellefonte, US). Hydrogen was used as a carrier gas. Detectors utilized in this device were two flame ionization detectors (μFIDs). Detailed information regarding the ultra-fast GC parameters is listed in Table 2.Table 2

Ultra-fast GC-FID parameters used in the research

Autosampler
Incubation time/s	Incubation temperature/°C	Syringe temperature/°C		Flushing time/s	Agitation speed/rpm
1200	40	100		90	500

Injector
Injection volume/mm3	Injection speed/mm3/s		Injector temperature/°C		Vent/cm3/min
2500	250		200		30

Sorbent trap
Trapping temperature/°C		Split/cm3/min		Trapping duration/s
40		1		20

Oven and detector
Initial oven temperature/°C	Initial time/s	Rate/°C/s	Terminal temperature/°C	Terminal time/s	FID detectors temperature/°C
70	2	2.0	270	18	270

Headspace analysis of meat samples was performed using an ultra-fast gas chromatography unit Heracles II equipped with the HS100 autosampler (Alpha M.O.S., Toulouse, France). The device was equipped with two parallel 10-m columns packed with MXT-5 and MXT-1701 stationary phases, respectively, and with two flame ionization detectors (μFID). Samples were incubated at 40 °C for the duration of a single analysis (90 s) Hydrogen was used as carrier gas. AlphaSoft 12.4 software was used to process the data.

The e-nose employed (a Fox 4000, Alpha MOS, Toulouse, France) was furnished with an HS100 autosampler (Alpha MOS), 18 metal oxide sensors, and propriety data processing software (Alpha Soft v8.0) and was used to analyze the volatile compounds from the bacon. The 18 sensors specifically used are referred to as LY2/AA, LY2/G, LY2/gCT, LY2/gCTL, LY2/GH, LY2/LG, P10/1, P10/2, P30/1, P30/2, P40/1, P40/2, PA/2, T30/1, T40/2, T70/2, T40/1, and TA/2.
Minced samples (3.0 g) were placed in a 10 mL glass vial. The headspace generation were incubated at 50 °C for 10 min. Headspace gas (2000 μL) was pumped into the sensor chamber for 10 s at a constant rate of 150 mL min⁻¹. The injection volume was 800 μL and the injected speed syringe was 2500 mL min⁻¹. The sensor-response data were acquired for 120 s and the time between injections was set to 600 s.
On each sampling point (0, 7, 15, 22, 30, and 45 days), samples were withdrawn in triplicate for the sub-sequent analyses, each sample was analyzed in three times. A total of ninety samples were tested in experiments. Based the data of the triplicate and three replications, the average results were used for PCA analysis to obtain a stable result. The software was used to calculate the discrimination index—the higher the index, the better the difference [71 ].