The Composition, Rheological and Thermal Properties of Tajonal (Viguiera Dentata) Mexican Honey

Figures & data

Table 1 Physicochemical parameters, sugar content and rations describing crystallization of Tajonal honey ^a/ .

Parameter	Sample 1	Sample 2	Sample 3	Sample 4	ECH ^1
Moisture (%)	16.3 ^a ± 0.07	17.6 ^b ± 0.05	18.6 ^c ± 0.05	20.6 ^d ± 0.06	21*
Ash (%)	0.15 ^a ± 0.04	0.26 ^b ± 0.06	0.15 ^a ± 0.04	0.15 ^a ± 0.03	0.6*
pH	3.64 ± 0.15	3.79 ± 0.09	3.61 ± 0.11	3.67 ± 0.10
Free acid (meq/kg)	19.6 ^a ± 0.7	24.8 ^b ± 1.2	18.8 ^a ± 0.8	19.2 ^a ± 0.9	40*
Conductivity (mS/cm)	0.22 ^a ± 0.05	0.36 ^b ± 0.03	0.19 ^a ± 0.03	0.22 ^a ± 0.04	0.7*
Hydroxymethylfurfural (mg/kg)	3.7 ^a ± 0.6	6.8 ^c ± 0.7	5.2 ^b ± 0.4	2.8 ^a ± 0.6	40*
Diastase activity (U.Schade)	31.7 ^c ± 1.0	16.2 ^b ± 0.8	9.0 ^a ± 0.7	12.3 ^ab ± 0.7	8**
Invertase activity (NI)	22.5 ^c ± 0.8	17.4 ^b ± 0.5	15.9 ^b ± 0.5	12.2 ^a ± 0.3	10**
Glucose + Fructose (%)	78.2 ^b ± 1.2	76.5 ^a ± 0.8	76.1 ^a ± 0.9	76.9 ^a ± 1.0
Glucose (%)	36.8 ^b ± 0.9	35.2 ^a ± 0.7	35.3 ^a ± 0.5	36.5 ^b ± 0.8
Fructose (%)	41.4 ^b ± 1.0	41.3 ^b ± 0.8	40.8 ^ab ± 0.5	40.4 ^a ± 0.6
Sucrose (%)	0.04 ^a ± 0.01	0.25 ^b ± 0.05	0.03 ^a ± 0.01	0.04 ^a ± 0.01
Maltose (%)	1.17 ^a ± 0.2	1.82 ^b ± 0.3	1.13 ^a ± 0.2	1.11 ^a ± 0.2
Glucose/water	2.26	2.00	1.90	1.77
Fructose/glucose	1.13	1.17	1.16	1.11
(Glucose-water)/fructosa	0.50	0.43	0.41	0.39

Figure 1 Crystallization “nuclei” from sample 1 (1000X).

Figure 2 Evolution of the crystal habit in sample 1 (16.3% moisture) during storage. a) 4 weeks (1000X); b) 6 weeks (1000X); c) 8 weeks (400X); and d) 10 weeks (200X).

Figure 3 Tajonal honey crystal size distribution a) 4 weeks; b) 6 weeks; c) 8 weeks; d) 10 weeks of storage.

Table 2 Flow behavior index and consistency index for Tajonal honey (16.3% moisture content) along storage.

Storage weeks	Consistency index (k) (Pa.s)*	Flow behavior index (n) (Dimensionless)	(r^2)
0	3.5	1.00	0.989
2	3.6	1.01	0.988
4	3.7	1.03	0.975
6	3.5	1.01	0.991
8	4.5	1.06	0.983
10	4.5	1.04	0.992
12	17.0	0.69	0.998

Figure 4 Crystal images before and after viscosity test. a) Image before test; b) Crystals from central part; c) Peripheral crystals.

Figure 5 DSC thermogram of sample 1 showing: A) Tg; B) Tg; and C) Sugar Fusion Temperature.

Table 3 Glass transition temperatures (Tg') for Tajonal honey at different moisture contents ^a/ .

		Tg ^1 (°C)
Simple	Moisture (%)	Tgi	Tgm	Tgf
1	16.3%	−40.6 ^a ± 1.9	−37.9 ^a ± 0.6	−36.9 ^a ± 2.0
2	17.6%	−43.6 ^a ± 0.6	−43.3 ^b ± 0.6	−39.7 ^b ± 1.6
3	18.6%	−43.4 ^a ± 4.8	−41.6 ^b ± 1.2	−38.1 ^a ± 2.1
4	20.6%	−55.5 ^b ± 2.1	−47.6 ^b ± 0.1	−48.0 ^b ± 0.1

Table 4 Heat fusion (J/g) Tajonal honey during storage ^a/ .

Weeks of storage	Sample 1	Sample 2	Sample 3	Sample 4
0	325 ± 13.1 ^b	296 ± 5.3 ^a	291 ± 6.0 ^a	336 ± 12.6 ^b
2	333 ± 11.4 ^b	283 ± 7.5 ^a	283 ± 6.3 ^a	364 ± 9.3 ^b
4	347 ± 9.2 ^b	280 ± 8.2 ^a	301 ± 10.1^a	361 ± 4.7 ^b
6	394 ± 10.2 ^b	268 ± 12.7 ^a	280 ± 9.8 ^a	342 ± 7.1 ^b
8	368 ± 7.9 ^b	278 ± 5.5 ^a	327 ± 3.0 ^a	387 ± 10.3 ^b
10	360 ± 8.7 ^b	286 ± 4.2 ^a	286 ± 7.1 ^a	381 ± 11.1 ^b
12	345 ± 15.1 ^b	272 ± 9.7 ^a	294 ± 8.3 ^a	362 ± 13.0 ^b

Figure 6 Differences between initial and final fusion temperatures along storage.