J Food Bioact

Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online

Journal website www.isnff-jfb.com

Original Research

Volume 20, December 2022, pages 29-39

Identification, quantitation and sensory elucidation of off-taste compounds in wheat bran

Figure 2. MPLC chromatogram with collected fractions and determined TDA values.

Figure 3. HPLC chromatogram with collected fractions and determined TDA values.

Figure 4. Excerpt of HMBC NMR experiment of distinctive singlet of alkyl resorcinols resonating at 6.01 ppm.

Figure 5. Heatmap of identified off-taste compounds in commercially available wheat bran showing DoT-factors.

**Table 1.** Taste profile analysis of wheat bran fibre and extracts
Taste intensity of	Wheat bran	Fractions
A = n-pentane, B = ethyl acetate, C = methanol/water (7/3, v/v) and methanol.
Bitter	1.8	1.0	1.7	1.1
Astringent	1.5	1.1	1.3	0.9
Sweet	0.7	0.7	0.7	1.2
Salty	0.3	0.2	0.3	0.3
Sour	0.9	0.5	0.6	0.6
Burning	0.4	0.3	0.4	0.4

Table 1. Taste profile analysis of wheat bran fibre and extracts

Taste intensity of

Wheat bran

Fractions

A = n-pentane, B = ethyl acetate, C = methanol/water (7/3, v/v) and methanol.

Bitter

1.8

1.0

1.7

1.1

Astringent

1.5

1.1

1.3

0.9

Sweet

0.7

1.2

Salty

0.3

0.2

0.3

Sour

0.9

0.5

0.6

Burning

0.4

0.3

0.4

**Table 2.** MRM transitions of alk(en)yl resorcinols
Analyte	MRM 1	MRM 2
NA: no further transition available.
9	m/z 347.4 → 305.3	m/z 347.4 → 81.0
10	m/z 375.2 → 333.4	NA
11	m/z 403.2 → 361.7	m/z 403.2 → 81.0
12	m/z 431.2 → 489.5	m/z 431.2 → 81.0
13a/b	m/z 373.2 → 333.4	NA
14a-c	m/z 401.2 → 359.7	NA
15	m/z 379.4 → 337.6	NA

Table 2. MRM transitions of alk(en)yl resorcinols

Analyte

MRM 1

MRM 2

NA: no further transition available.

m/z 347.4 → 305.3

m/z 347.4 → 81.0

m/z 375.2 → 333.4

m/z 403.2 → 361.7

m/z 403.2 → 81.0

m/z 431.2 → 489.5

m/z 431.2 → 81.0

13a/b

m/z 373.2 → 333.4

14a-c

m/z 401.2 → 359.7

m/z 379.4 → 337.6

**Table 3.** Concentration, standard deviation, taste quality, taste recognition thresholds [µmol/kg] and dose-over-threshold-factors (DoT)
Compound	Conc. [µmol/kg]^a	Taste quality	Taste threshold [µmol/kg]	DoT
^aConcentrations were determined by LC-MS/MS and were calculated as the mean of duplicates; ^bTaste recognition threshold concentrations were taken from literature (Lainer, 2019).
Palmitic acid (1)^b	7,080 ± 406	Bitter, scratchy	807	8.8
Stearic acid (2)^b	534 ± 67	Bitter, scratchy	810	0.7
Oleic acid (3)^b	5,787 ± 155	Bitter, scratchy	981	5.9
Linoleic acid (4)^b	10,885 ± 286	Bitter, scratchy	931	11.7
Linolenic acid (5)^b	1,068 ± 186	Bitter, scratchy	280	3.8
E-9,10,13-trihydroxyoctadec-11-enoic acid ( (6)^b	565 ± 81	Bitter, scratchy	80	7.1
(10E,12Z)-9-Hydroxyoctadec-10,12-dienoic acid (7)^b	259 ± 19	Bitter, scratchy	354	0.7
(9Z,11E)-13-Hydroxyoctadec-9,11-dienoic acid (8)^b	233 ± 27	Bitter, scratchy	787	0.3
5-Heptadecylresorcinol (9)	98 ± 10	Bitter, astringent	20	32	4	3
5-Nonadecylresorcinol (10)	1,604 ± 89	Bitter, astringent	12	47	56	111
5-Heneicosylresorcinol (11)	2,890 ± 268	Bitter, astringent	30	15	96	193
5-Tricosylresorcinol (12)	481 ± 46	Bitter, astringent	57	8
(Z)-5-Nonadec-12/14-enylresorcinol (13a/b)	1,158 ± 115	Bitter, astringent	86	14
(Z)-5-Heneicos-12/14/16-enylresorcinol (14a-c)	250 ± 5	Bitter, astringent	255	1

Table 3. Concentration, standard deviation, taste quality, taste recognition thresholds [µmol/kg] and dose-over-threshold-factors (DoT)

Compound

Conc. [µmol/kg]^a

Taste quality

Taste threshold [µmol/kg]

DoT

Bitter

Astringent

Bitter

Astringent

^aConcentrations were determined by LC-MS/MS and were calculated as the mean of duplicates; ^bTaste recognition threshold concentrations were taken from literature (Lainer, 2019).

Palmitic acid (1)^b

7,080 ± 406

Bitter, scratchy

807

8.8

Stearic acid (2)^b

534 ± 67

Bitter, scratchy

810

0.7

Oleic acid (3)^b

5,787 ± 155

Bitter, scratchy

981

5.9

Linoleic acid (4)^b

10,885 ± 286

Bitter, scratchy

931

11.7

Linolenic acid (5)^b

1,068 ± 186

Bitter, scratchy

280

3.8

E-9,10,13-trihydroxyoctadec-11-enoic acid ( (6)^b

565 ± 81

Bitter, scratchy

7.1

(10E,12Z)-9-Hydroxyoctadec-10,12-dienoic acid (7)^b

259 ± 19

Bitter, scratchy

354

0.7

(9Z,11E)-13-Hydroxyoctadec-9,11-dienoic acid (8)^b

233 ± 27

Bitter, scratchy

787

0.3

5-Heptadecylresorcinol (9)

98 ± 10

Bitter, astringent

5-Nonadecylresorcinol (10)

1,604 ± 89

Bitter, astringent

111

5-Heneicosylresorcinol (11)

2,890 ± 268

Bitter, astringent

193

5-Tricosylresorcinol (12)

481 ± 46

Bitter, astringent

(Z)-5-Nonadec-12/14-enylresorcinol (13a/b)

1,158 ± 115

Bitter, astringent

(Z)-5-Heneicos-12/14/16-enylresorcinol (14a-c)

250 ± 5

Bitter, astringent

255