. 2020 Nov 25;10(12):1599. doi: 10.3390/biom10121599

Table 4.

The amounts of aroma compounds (higher alcohols, esters, fatty acids and terpenes) in sour beer produced during subsequent lactic acid and alcoholic fermentation of brewers’ wort depending on the initial concentrations of magnesium (Mg.1 Mg.2) and zinc (Zn.1 and Zn.2) ions. REF-beer obtained from wort without supplementation.

		Sample [µg/L]
	LRI ²	REF	Mg.1	Mg.2	Zn.1	Zn.2	Sig. ¹
Esters
Ethyl acetate	614	2716 ^a	3224 ^a	2740 ^a	4099 ^b	2733 ^a	*
Butanoic acid, ethyl ester ³	789	0.3 ^b	0.4 ^b	0.5 ^c	0.0 ^a	0.0 ^a	***
1-Butanol, 3-methyl-, acetate	872	16.7 ^d	9.5 ^c	6.6 ^b	3.7 ^a	2.7 ^a	***
Hexanoic acid, ethyl ester	986	2.8 ^b	2.5 ^b	2.1 ^ab	1.6 ^a	1.9 ^ab	*
Octanoic acid, ethyl ester	1180	34.6 ^a	53.6 ^b	61.9 ^b	54.6 ^b	57.9 ^b	*
Octanoic acid, 2-methyl-, ethyl ester ³	1209	69.3 ^b	33.4 ^a	26.3 ^a	30.6 ^a	30.1 ^a	***
Acetic acid, 2-phenylethyl ester	1228	64.2 ^c	63.2 ^c	46.8 ^b	37.4 ^ab	30.5 ^a	***
Decanoic acid, ethyl ester	1397	11.8 ^b	11.4 ^b	11.7 ^b	7.9 ^ab	6.9 ^a	*
Dodecanoic acid, ethyl ester	1581	6.3 ^a	8.1 ^b	6.2 ^a	6.0 ^a	4.7 ^a	*
Benzyl Benzoate	1750	1.3 ^a	3.8 ^b	3.8 ^b	10.7 ^c	13.2 ^d	***
Tetradecanoic acid, ethyl ester ³	1790	0.8 ^a	2.6 ^ab	3.5 ^b	12.6 ^c	14.7 ^d	***
Hexadecanoic acid, ethyl ester ³	1990	0.6 ^a	2.0 ^a	2.6 ^a	12.2 ^b	14.7 ^c	***
Higher alcohols
1-Propanol, 2-methyl-	617	433.6 ^a	699.2 ^b	725.5 ^b	977.8 ^c	1046.8 ^c	***
1-Butanol, 3-methyl-	723	13,787 ^a	21,007 ^bc	19,298 ^b	24,456 ^c	29,083 ^d	***
1-Butanol, 2-methyl-	740	4984 ^a	6818 ^b	5173 ^a	6093 ^ab	7235 ^b	***
2,3-Butanediol	768	1663 ^bc	1861 ^c	1322 ^b	838 ^a	553 ^a	***
1-Hexanol	865	23.7 ^a	36.0 ^b	25.8 ^a	24.9 ^a	23.8 ^a	*
2-Furanmethanol ³	880	48.8 ^a	130.1 ^c	73.1 ^ab	75.4 ^b	73.3 ^{a b}	***
Isomaltol ³	975	48.5 ^a	104.4 ^c	72.1 ^ab	77.3 ^b	146.0 ^d	***
2-Ethyl-1-hexanol ³	1020	99.9 ^b	97.3 ^b	78.1 ^a	73.2 ^a	64.5 ^a	***
Furaneol ³	1057	35.8	43.3	41.2	40.1	42.3	ns
1-Octanol ³	1070	19.9	21.5	16.9	14.7	13.6	ns
Phenylethyl Alcohol	1084	3320.3 ^a	4966.0 ^b	3233.5 ^a	3193.6 ^a	5582.0 ^b	***
1-Decanol ³	1272	192.3 ^a	179.6 ^a	312.3 ^c	244.2 ^b	159.3 ^a	***
1-Undecanol ³	1374	44.2	59.0	56.3	57.5	73.3	ns
Fatty acids
Hexanoic acid	982	2.7 ^a	7.2 ^b	6.9 ^b	19.7 ^c	27.6 ^d	***
Octanoic acid	1160	62.2 ^a	173.5 ^a	184.2 ^a	584.3 ^b	1102.2 ^c	***
n-Decanoic acid	1368	3.9 ^a	9.5 ^a	11.2 ^a	30.7 ^b	36.8 ^b	***
Dodecanoic acid	1568	0.6 ^a	2.0 ^b	1.4 ^ab	4.3 ^c	6.8 ^d	***
Terpenes
α-Terpineol	1171	13.0 ^a	28.6 ^ab	50.3 ^b	96.8 ^c	159.1 ^d	***
Geraniol	1257	27.6 ^a	59.2 ^ab	91.5 ^b	201.1 ^c	248.0 ^d	***
β-Damascenone ³	1386	29.2	30.6	32.6	31.6	30.5	ns
Lactones
Butyrolactone ³	916	79.7	72.0	80.9	73.3	42.9	ns
γ-Nonalactone ³	1360	64.4	75.2	62.2	54.2	57.4	ns
Other compounds
Benzothiazole ³	1186	247.8 ^a	437.2 ^b	592.8 ^c	586.1 ^c	772.4 ^d	***
Benzophenone ³	1610	5.2	6.5	4.9	4.8	5.0	ns

Inline graphic The colours (from light to dark) indicate increasing values within the same volatile compound. ¹ Sig.: significance; * and *** indicate significance at the 5, 1 and 0.5% levels by least significant difference; ns: not significant. Values with different superscript roman letters (^a–d) in the same row are significantly different according to the Duncan test (p < 0.05) ² LRI: Linear retention index ³ Determined semi-quantitatively by measuring the relative peak area of each identified compound, according to the NIST database, and comparing it to that of the internal standard.