Data from: Acrylamide in fried sweetpotato chips: The relationship with free asparagine and effects of asparaginase

Data Description

These data are ‘Bayou Belle’ sweetpotato raw and chip compositions and acrylamide contents of model sweetpotato systems. Raw composition includes dry matter, glucose, fructose, sucrose, free asparagine, and total nitrogen contents. Fried chip composition includes fat, acrylamide, asparagine, glucose, fructose, sucrose, maltose, and total nitrogen contents as well as chip color data. These data were used in the manuscript "Acrylamide in fried sweetpotato chips: The relationship with free asparagine and effects of asparaginase " by Allan, Thomas, Pecota, Yencho, and Johanningsmeier.

Objective

These data were utilized to investigate acrylamide formation in sweetpotato chips in relation to natural biological variability and determine if an asparaginase treatment could mitigate acrylamide formation.

Methods

‘Bayou Belle’ sweetpotatoes were grown for 2 years at 3 locations with varying soil and nitrogen regimens. Roots were harvested, cured, and stored for 5-6 months using conventional practices. Sweetpotato chips were produced by cutting into 1.5 mm slices then frying for 3 min at 149°C.

Asparaginase treated slices were blanched in water for 3.5 min at 85°C, cooled to ≈50°C, soaked for 20 min in a 0.2% (7480 u/L) asparaginase solution at 40°C, dried in a forced air dehydrator at 35°C for 10 min, then fried. The control chips underwent the same treatment but soaked in water instead of an asparagine solution.

Model sweetpotato solutions were A full factorial design (n = 48) with 4 levels of total reducing sugars (50, 100, 400, 800 μmol), 4 levels of asparagine (10, 25, 50, and 100 μmol), and 3 levels of other amino acids (1:3, 1:1, 3:1 total other amino acids to asparagine molar ratios). Other amino acids were equal molar ratios of alanine, aspartic acid, glutamic acid, glutamine, leucine, methionine, phenylalanine, serine, tyrosine, and valine. The concentrations represent μmol/g of dry sweetpotato. One mL solutions were prepared in 2 mL vials then heated for 1 h at 150°C.

The following are compositional analysis methods.

Moisture content: Data Support Company 50P moisture balance (Panorama City, CA, USA).

Fat content: Time domain nuclear magnetic resonance Bruker minispec mq-one seed analyzer (Bruker Corporation, Billerica, MA, USA).

Total nitrogen: Leco Corporation Series 928 Carbon/Nitrogen (St. Joseph, MI, USA).

Color: Konica Minolta CM-700d Spectrophotometer (Osaka, JP) colorimeter with an 8 mm aperture.

Sugar content: Sugars were extracted from 1g of freeze dried sweetpotato powder with 10 mL of 70°C 80% ethanol, mixed for 10 min, centrifuged at 6500 g for 10 min, decanted into a 50 mL volumetric flask, and repeating for a total of 3 extractions. Flask was brought to volume with ambient 80% ethanol, mixed, 200 µL of extract solution was pipetted into 2 mL tube, dried down, reconstituted with 2 mL of water, mixed thoroughly, then passed through a 0.45 µm nylon filter into an HPLC vial. Sugars were separated and quantified using anion exchange chromatography with a pulsed amperometric detector. Chromatography conditions were 200 mM NaOH at 1 mL/min with a CarboPac Pa-1 and guard column at 30°C.

Free asparagine: Free asparagine was extracted from 250 mg of freeze dried sweetpotato powder with 5 mL of water, mixed for 15 min, centrifuged at 6000 g for 10 min, decanted into a 250 mL volumetric flask, and repeated for a total of 3 extractions. Volumetric flask was brought to volume with water, mixed, then a portion was passed through a 0.45 µm nylon filter into an HPLC vial. Free asparagine was separated and quantified using anion exchange chromatography with a pulsed amperometric detector. Chromatography conditions were AminoPac PA-10 with guard column and a CarboPac Pa-1 guard column before it at 30°C using the following method: solvent A – 1 M sodium acetate, solvent B – water, solvent C – 250 mM NaOH; 0 to 2 min, 76% B and 24% C; 2 to 8 min, 76 to 64% B and 24 to 36% C; 8 to 11 min 64% B and 36% C; 11 to 12 min, 0 to 60% A, 64 to 0% B, and 36 to 40% C; 12 to 22 min, 60% A and 40% C; then 76% B and 24% A for 23 min.

Acrylamide content: Free asparagine was extracted from 1 g of ground, defatted chips using 9 mL of water and 1 mL of 200 ng/mL C₁₃ acrylamide internal standard, then mixed for 20 min. Tubes were centrifuged at 12500 g for 15 min, 1.5 mL of the aqueous phase was loaded onto a preconditioned 6 mL, 200 mg, OASIS HLB solid phase extraction column (Waters Corporation, Milford, MA, USA), washed with 0.5 mL of water, discarded this portion, then eluted with another 1.5 mL of water and collected. This was loaded onto a preconditioned 3 mL, 200mg, Bond Elut - Accucate solid phase extraction column (Agilent, Santa Clara, CA, USA), eluted with 1.5 mL, discarded first 0.5 mL, and collected the next 1 mL into HPLC vial for analysis. Acrylamide was separated and quantified using liquid chromatography with triple quadrupole mass spectrometry (LC-MS/MS). Chromatography conditions were isocratic 0.1% v/v formic acid in water at 0.3 mL/min with a Atlantis T3 (Waters Corporation) at 30°C.