Stability of spray-dried microencapsulated anthocyanins extracted from culinary banana bract

Figures & data

Table 1. Independent variables and their levels employed in a central composite design for the optimization of culinary banana bract extract for anthocyanin content.

Variables	Low	Centre	High
Solvent: solute ratio	5	10	15
Ethanol concentration (ml/100ml)	40	50	60
Sonication temperature (°C)	40	50	60

Table 2a. Experimental design of three factors and one response central composite design and the total anthocyanin content of ultrasonic-assisted banana bract extract.

Run	X1, Solvent: solute	X2, Solvent Conc (ml/100ml)	X3, Sonication Temp (°C)	Y, Anthocyanin Content (mg/100g)
1	5	40	40	40.27
2	15	40	40	51.61
3	5	60	40	46.11
4	15	60	40	54.12
5	5	40	60	42
6	15	40	60	49.54
7	5	60	60	51.5
8	15	60	60	57.49
9	1.59	50	50	42.66
10	18.40	50	50	55.2
11	10	33.18	50	45.51
12	10	66.81	50	51.42
13	10	50	33.18	53.72
14	10	50	66.81	49.72
15	10	50	50	56.74
16	10	50	50	56.08
17	10	50	50	53.5
18	10	50	50	55.01
19	10	50	50	56
20	10	50	50	53.8

The parameter X₁ shows the varying amount of solvent (5–15 ml) as the solute amount was kept constant (0.5 g) during experiment.

Table 2b. Estimated optimum condition for predicted and experimental values of responses.

Factor (Independent variables)	Optimal condition	Predicted Value, anthocyanin(mg/100g)	Experimental value Anthocyanin (mg/100g)
Solvent: Solute	15:0.5
Ethanol Concentration (ml/100ml)	53.97	57.29	56.98
Sonication Temperature (̊C)	49.39

Figure 1. Effect of a) ethanol concentration and solvent solute ratio, b) sonicated temperature and solvent solute ratio, and c) sonicated temperature and ethanol concentration on the yields of total anthocyanin from culinary banana bract.

Figure 2. Identification of compounds for anthocyanin pigments extracted from culinary banana bract.

Table 3. The properties of encapsulated pigment powders.

Hygroscopicity (%)	Solubility (%)	Encapsulation efficiency (%)
28.89 ± 0.09	84.10 ± 0.20	96.15 ± 0.31

(Values represent as mean± SD).

Figure 3. SEM micrographs of anthocyanin-encapsulated spray-dried powder: a) 2000X and b) 5000X.

Table 4a. Effect of storage of encapsulated pigment powders on anthocyanin content, DPPH radical scavenging activity (%), and moisture content.

Time (days)	Anthocyanin (mg/100g)	DPPH radical scavenging activity (%)	Moisture content (%)
0	57.64 ± 0.71^d	67.08 ± 0.22^c	5.72 ± 0.30^a
7	52.41 ± .93^c	65.73 ± 0.46^b	7.12 ± 0.10^b
14	36.97 ± 0.79^b	61.76 ± 0.37^a	13.42 ± 0.51^c
21	32.30 ± 0.31^a	61.44 ± 0.01^a	20.26 ± 0.45^d

Mean with different superscript letters in the same column represent a significant difference at p < 0.05, values represent mean ± SD; n = 3.

Table 4b. Effect of storage of encapsulated pigment powder on colour characteristics.

Days	L*	a*	b *	C*	H ̊
0	61.38 ± 3.44^b	21.53 ± 2.0^b	–0.08 ± 0.23^a	21.52 ± 2.0^c	0.19 ± 0.01^a
7	60.16 ± 1.11^b	20.26 ± 0.29^b	0.64 ± 0.05^b	20.3 ± 0.26^b	1.79 ± 0.15^b
14	59.15 ± 0.16^b	19.56 ± 0.39^b	0.69 ± 0.01^b	19.57 ± 0.39^b	2.01 ± 0.04^b
21	55 ± 1.50^a	16.63 ± 0.61^a	1.06 ± 0.03^c	16.46 ± 0.62^a	3.69 ± 0.20^c

Mean with different superscript letters in the same column represent a significant difference at p < 0.05, values represent mean ± SD; n = 3.