SPME-MS-MVA as an electronic nose for the study of off-flavors in milk.

Journal of agricultural and food chemistry (1999-11-24)
R T Marsili
ABSTRACT

A new technique using solid-phase microextraction, mass spectrometry, and multivariate analysis (SPME-MS-MVA) was developed for the study of off-flavors in milk. The analytical column of a GC/MS system was replaced with a 1-m deactivated fused-silica column, which served as a transfer line to deliver volatiles extracted from milk samples with a Carboxen-SPME fiber to the mass spectrometer. Mass fragmentation data resulting from the unresolved milk volatile components were subjected to MVA. Principal component analysis based on SPME-MS-MVA provided rapid differentiation of control reduced-fat milk (2% butterfat content) samples from reduced-fat milk samples abused by light, heat, copper, and microbial contamination. The three psychrotrophic bacteria studied included Pseudomonas fluorescens, Pseudomonas aureofaciens, and Pseudomonas putrefaciens. SPME-MS-MVA is rapid and offers significant advantages over commercial electronic nose instruments currently being used as quality assurance tools to differentiate normal-tasting food and beverage samples from those containing off-flavors and malodors.

MATERIALS
Product Number
Brand
Product Description

Supelco
Tenax® TA / Carboxen® 1018, glass TD tube, preconditioned, O.D. × L 1/4  in. × 3 1/2  in., Sealed with (Swagelok® End-Fittings), pkg of 10 ea
Supelco
Carboxen®-1010 PLOT Capillary GC Column, L × I.D. 30 m × 0.53 mm, average thickness 30 μm
Supelco
Carboxen® Adsorbent, matrix Carboxen® 569, 20-45 mesh, bottle of 10 g
Supelco
ORBO 78 HBr on Carboxen® 564 specially cleaned (20/45), 400/200 mg, W,W,W separators, O.D. × L 6 mm × 110 mm, pkg of 25 ea
Supelco
Carboxen®-1006 PLOT Capillary GC Column, L × I.D. 30 m × 0.53 mm, average thickness 30 μm
Supelco
Carboxen® Adsorbent, matrix Carboxen® 1000, 60-80 mesh, bottle of 10 g
Supelco
ORBO 90 Carboxen® 564 (20/45), 160/80 mg, W,F,F separators, O.D. × L 6 mm × 75 mm, pkg of 25 ea, for analyte group MEK (methylethyl ketone)
Supelco
Carboxen®-1010 PLOT Capillary GC Column, L × I.D. 30 m × 0.32 mm, average thickness 15 μm
Supelco
Carboxen® Adsorbent, matrix Carboxen® 569, 20-45 mesh, bottle of 500 g
Supelco
Carboxen®-1006 PLOT Capillary GC Column, L × I.D. 30 m × 0.32 mm, average thickness 15 μm
Supelco
Carboxen® Adsorbent, matrix Carboxen® 1003, 40-60 mesh, bottle of 10 g
Supelco
Carboxen® Adsorbent, matrix Carboxen® 1000, 40-60 mesh, bottle of 50 g
Supelco
Carboxen® Adsorbent, matrix Carboxen® 563, 20-45 mesh, bottle of 10 g
Supelco
Carboxen® Adsorbent, matrix Carboxen® 564, 20-45 mesh, bottle of 10 g
Supelco
Carboxen® 1000 Reversible SPE Tube, 200 mg/mL, pk 30
Supelco
Carboxen® 572 for Tobacco Smoke, Adsorbent Bed Wt: (300 mg), cartridge volume 3 mL, pkg of 10 ea
Supelco
ORBO-93 Sorbent Tube, matrix Carboxen® 1000, ORBO tube I.D. × L 6 mm × 95 mm, Bed B 90 mg, Bed A 180 mg, 60/80 mesh, pkg of 25 ea
Supelco
SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), df 75 μm (CAR/PDMS), for use with manual holder, needle size 24 ga
Supelco
SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, for use with manual holder
Supelco
Carboxen® 569, O.D. × L 1/4  in. × 3 1/2 , glass TD tube, fritted, Sealed with Brass Endcaps, preconditioned, pkg of 10 ea
Supelco
Carboxen® 572 for Tobacco Smoke, Adsorbent Bed Wt: 300 mg, cartridge size 3 mL, pkg of 50 ea
Supelco
SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), df 75 μm (CAR/PDMS), needle size 23 ga, for use with manual holder
Supelco
SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, StableFlex, for use with manual holder/autosampler
Supelco
Carboxen® 569, glass TD tube, fritted, O.D. × L 1/4  in. × 3 1/2  in., preconditioned, pkg of 10 ea
Supelco
Carboxen® Adsorbent, matrix Carboxen® 564, 20-45 mesh, pack of 144 × 290 mg
Supelco
SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), df 75 μm (CAR/PDMS), needle size 24 ga, for use with autosampler
Supelco
SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, StableFlex, for use with autosampler
Supelco
SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), df 75 μm (CAR/PDMS), needle size 23 ga, for use with autosampler
Supelco
SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 23 ga, StableFlex, for use with manual holder/autosampler, fiber L 2 cm
Supelco
SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), df 85 μm (CAR/PDMS), needle size 24 ga, for use with manual holder, StableFlex fiber