Potential of Szechuan pepper as a saltiness enhancer

Figures & data

Table 1. Descriptive attributes of Szechuan pepper A.

Attribute	Definition	Reference	Intensity^a
Aroma
Woody	Aroma sensation with dry wood or bark	1 g of Ice cream wooden stick	12
Camphor	Aroma sensation with camphor which obtained from camphor tree or pine	1 g of 100% Camphor powder	12
Citrus peel	Aroma sensation with peel of citrus fruit	1 g of fresh-cut kaffir lime peel	12
Clove	Aroma sensation with dried clove bud	0.5 g of Clove powder (Cooking for Fun; Central Food Retail Co., Ltd., Thailand)	11
Taste
Salty	Taste sensation associated with sodium chloride	5 mL of NaCl aqueous solution (Prungthip; Thai Refined Salt Co., Ltd., Thailand)
		0.20% (w/v)	4
		0.35% (w/v)	7
		0.50% (w/v)	10
Bitter	Taste sensation associated with caffeine	5 mL of Caffeine aqueous solution (Sigma-Alrich, MO, USA)
		0.05% (w/v)	2
		0.08% (w/v)	5
		0.15% (w/v)	10
Flavor
Astringent	Shrinking or puckering of the tongue surface and associated with tea	5 mL of Tea (2 g of tea soaked in 100 mL hot water for 1 h) (Lipton; PT Unilever Indonesia Tbk, Indonesia)	8
Numb	Impermanent loss of sensation or lack of feeling	5 mL of Clove powder in water (0.2 g/100 mL) (Nguan Soon; Artchit International Pepper and Spice Co., Ltd., Thailand)	9
Cooling	Cool sensation in the mouth produced by substances associated with menthol or mint	A piece of chewing gum (1.7 g) (Double Mint; William Wrigley Jr., Thailand)	9
Burnt-aftertaste	Burning aftertaste sensation in the mouth associated with black pepper	5 mL of Grounded black pepper in water (0.02 g/100 mL) (Nguan Soon; Artchit International Pepper and Spice Co., Ltd., Thailand)	3

^aRated on a 15-cm line scale: 0 = none and 15 = extreme (n = 10).

Figure 1. Flavor profile of Szechuan pepper A from descriptive sensory analysis on 15-cm line scale (n = 10).

Table 2. Flavor intensities of various food samples with and without the addition of Szechuan pepper A.

	Intensity^a
Food sample	Without	With	p-Value
Fried potato sticks	3.77 ± 1.30	5.00 ± 1.55	0.001
Chicken broth	4.53 ± 1.52	5.93 ± 1.39	< 0.001
Creamy chicken soup	3.20 ± 1.79	5.53 ± 1.48	< 0.001
Pasta sauce	4.23 ± 1.41	6.17 ± 1.26	< 0.001

^aUsed a 9-point category scale: 0 = none, 2 = light, 4 = moderate, 6 = strong and 8 = extreme (n = 30).

Table 3. Panel response on the salty and saltiness enhancing properties of Szechuan pepper A in fried potato sticks.

Fried potato sticks with	Selection of saltier sample^a (%)	p-Value
Salty property
Unseasoned	36.67	0.144
1% Szechuan pepper	63.33
Saltiness enhancing property
1% salt	26.67	0.011
1% salt and 1% Szechuan pepper	73.33

^aAccessed by 2-alternative forced-choice test (n = 30).

Figure 2. Relationship between saltiness intensities and salt concentrations added to fried potato sticks (n = 11).

Table 4. Taste qualities and taste dilution factors of saltiness enhancing subfractions in Szechuan pepper A.

Subfraction number^a	Taste quality	Taste dilution factor^b
11	Bitter	4
12	Salty, umami	8
13	Salty, umami, sweet	32
14	Extremely salty, umami	107
15	Salty, sour	8
16	Salty, bitter	2
43	Bitter	4
47	Tasteless	2
55	Tasteless	2
56	Tasteless	1
60	Tasteless	2
82	Tasteless	2
83	Tasteless	2
84	Tasteless	9
92	Tasteless	5
93	Tasteless	1
94	Tasteless	8
95	Slightly umami	21
96	Slightly umami	21
97	Tasteless	3

^aReferred to the order of subfractions collected by GPC from water-soluble fraction.

^bAveraged from three trained panelists.

Table 5. Salt concentrations in Szechuan peppers obtained from different manufacturers.

Source	Sample	NaCl (mg/g Szechuan pepper)^a
Thailand	A	65.03 ± 4.38a
	B	63.66 ± 1.47a
	C	56.57 ± 5.32b
	D	18.49 ± 1.16c
China	E	17.73 ± 5.75c
	F	12.16 ± 3.04c

^aMean ± standard deviation followed by different letter was significantly different (p ≤ 0.05).

Table 6. The content of sodium, potassium and chloride ions in Szechuan pepper A.

Ion	Mass (mg/g Szechuan pepper)	Molar mass (g/mol)	Content (mmol/g Szechuan pepper)
Na^+	40.2 ± 0.2	22.99	1.76
K^+	9.9 ± 0.0	39.09	0.25
Cl^−	59.3 ± 3.2	35.45	1.67

Table 7. Panel response on the salty taste of seasoned fried potato sticks having equivalent concentration of NaCl.

Fried potato sticks with	Selection of saltier sample^a (%)	p-Value
1% salt and 1% Szechuan pepper A	53.33	0.715
1.1% salt^b	46.67

^aAccessed by 2-alternative forced-choice test (n = 30).

^bThe additional 0.1% salt was adjusted to the same NaCl content in 1% Szechuan pepper A.