Stability of encapsulated and non-encapsulated anthocyanin in yogurt produced with natural dye obtained from <i>Solanum melongena</i> L. Bark

Barretto, Flavia Jamille de Figueiredo Paes; Clemente, Heleni Aires; Santana, Andrea Lopes Bandeira Delmiro; Vasconcelo, Margarida Angélica da Silva

doi:10.1590/0100-29452020137

Abstract

This research evaluated the stability of non-encapsulated and spray-dried encapsulated anthocyanin from Solanum melongena L. bark as a natural dye in yogurts. Anthocyanin was extracted using 70% cereal alcohol acidified with citric acid at pH 2.0. Extract spray-drying was defined using the experimental design (22), with drying temperature (°C) and carrier concentration (Gum arabic) as independent variables. The response variable adopted was the total monomeric anthocyanin content. The following analyses were performed: color; total monomeric anthocyanins; total phenolic contents; antioxidant activity using the DPPH• (1,1-diphenyl-2-picrylhydrazyl) radical; pH; and acidity. Yogurt degradation constant, half-life, and color retention percentage of anthocyanin added to yogurt were calculated. The total monomeric anthocyanin value found in the extract was 67.21 mg 100g-1 of bark. Natural non-encapsulated and encapsulated dye extract were added to yogurt at concentrations of 1.0; 1.5; and 2 g extract/100 mL yogurt. Average pH values after addition of anthocyanin extract ranged from 3.60 to 3.87. Acidity was 1.04% in natural yogurt (time zero), while 1%; 1.5%; and 2% samples showed 1.4; 1.7; and 2.05% and 1.18; 1.29; and 1.47% acidity in non-encapsulated extract added to yogurt and encapsulated extract added to yogurt, respectively. Anthocyanin content decreased during storage using non-encapsulated extract, remaining constant in encapsulated extract added to yogurt. The three formulations showed increased L* at thirty days, with discoloration being related to decreased anthocyanin content. DPPH• radical scavenging activity decreased during the 30 days of storage. The content of phenolic compounds ranged from 106.01 to 239.90 mg GAE 100 g-1 of yogurt in non-encapsulated extract added to yogurt, and from 225.17 to 291.98mg GAE 100 g-1 of encapsulated extract added to yogurt. Extract encapsulation is indicated because it provides high anthocyanin stability.

Index terms
Anthocyanidins; dye; spray-drying; dairy products; eggplant

[TFN0201] ^*
Means in rows followed by the same letters do not differ statistically from each other using the Tukey test (p> 0.05).

Test	Temperature(°C)	Gum Arabic	Anthocyanin (mg/100g^-1 bark)
1	(-1) 130	(-1) 10	18.43
2	(+1) 180	(-1) 10	21.11
3	(-1) 130	(+1) 20	15.76
4	(+1) 180	(+1) 20	5.81
5			40.48
6			42.61
7			40.14
8			39.81

Analyses	Non-encapsulated extract	Encapsulated extract
Total phenolic compounds (mg GAE 100g¹)	487.50^a	460.87^a
DPPH antioxidant activity (%)at 60 minutes	91.68^a	91.25^a

Type	Test	Time
Type	Test	0 days	10 days	20 days	30 days
Non-encapsulated	Natural	1.04 a±0.00	1.04 a±0.01	1.10 a±0.01	1.11 a±0.05
	1.0%	1.49 a±0.01	1.54 ab±0.02	1.52 a±0.08	1.61 b±0.02
	1.5%	1.70 a±0.10	1.79 b±0.03	1.84 b±0.02	1.82 b±0.02
	2.0%	2.05 a±0.00	2.06 a±0.11	2.05 a±0.01	2.05 a±0.01
Encapsulated	Natural	0.98 a±0.01	0.99 a±0.33	1.03 a±0.01	1.07 a±0.01
	1.0%	1.18 a±0.01	1.19 a±0.04	1.41 b±0.04	1.21 a±0.02
	1.5%	1.29 a±0.01	1.28 a±0.02	1.30 a±0.01	1.33 a±0.01
	2.0%	1.47 a±0.03	1.48 a±0.01	1.48 a±0.01	1.49 a±0.00

Type	Test	Time
Type	Test	0 days	10 days	20 days	30 days
Non-encapsulated	1.0%	7.51 a±0.50	3.87 b±0.13	2.36 c±0.34	0.00 d
	1.5%	7.57 a±0.21	4.93 b±0.82	2.59 c±0.14	0.00 d
	2.0%	8.01 a±0.01	4.72 b±0.55	3.47 c±0.8	0.00 d
	1.0%	18.00a±0.20	17.81a±2.04	17.81a±0.76	17.79 a±0.27
	1.5%	19.37a±0.01	19.00ab±1.35	17.37ab±0.44	17.22 b±2.05
	2.0%	21.37a±0.62	21.59a±0.38	20.93a±1.01	19.15 b±1.02
Natural Yogurt	-	-	-	-	-

Variables		L* Parameter	L* Parameter in the non-encapsulated extract	L* Parameter in the encapsulated extract
Type	Encapsulated	85.38 a
Type	Non- encapsulated	83.30 b
Test	Natural	85.70 a	84.66 a	86.73 a
	1.0%	84.56 b	82.94 b	86.18 a
	1.5%	83.91 bc	83.29 b	84.54 b
	2.0%	83.19 c	82.30 b	84.08 b
Time	0	83.06 b	82.01 b	84.12 c
	10	83.74 b	82.55 b	84.93 bc
	20	84.98 a	83.90 a	86.06 ab
	30	85.57 a	84.72 a	86.42 a

Brasil

Brasil

Stability of encapsulated and non-encapsulated anthocyanin in yogurt produced with natural dye obtained from Solanum melongena L. Bark

Avaliação da estabilidade das antocianinas em iogurte elaborado com corante natural obtido da casca de Solanum melongena L.encapsulado e não encapsulado

Abstract

Variables		a*Parameter	a* Parameter in the non-encapsulated extract	a* Parameter in the encapsulated extract
Type	Encapsulated	-6.41 a
Type	Non- encapsulated	-2.90 b
Test	Natural	-5.40 d	-3.79 d	-7.02 c
	1.0%	-4.74 c	-3.09 c	-6.40 b
	1.5%	-4.47 b	-2.56 b	-6.39 b
	2.0%	-4.01 a	-2.19 a	-5.83 a
Time	0	-4.16 b	-1.68 b	-6.64 c
	10	-3.96 a	-1.43 a	-6.50 b
	20	-4.11 b	-2.01 c	-6.21 a
	30	-6.40 c	-6.50 d	-6.30 a

Variables		b*Parameter	b* Parameter in the non-encapsulated extract	b* Parameter in the encapsulated extract
Type	Encapsulated	10.65
Type	Non- encapsulated	8.30
Test	Natural	9.55 a	7.95 a	11.14 a
	1.0%	9.42 a	7.84 a	11.00 a
	1.5%	9.54 a	9.01 a	10.08 a
	2.0%	9.38 a	8.40 a	10.36 a
Time	0	7.33 d	5.50 c	9.17 b
	10	8.18 c	6.40 c	9.97 b
	20	10.39 b	9.11 b	11.66 a
	30	11.99 a	12.19 a	11.80 a

Yogurts*	Degradation constants	Half-life time (t_1/2) days	Color retention (%)
Extract 1%	K= 0.0583	11.89	31.02
Extract 1.5%	K= 0.0536	12.93	32.10
Extract 2%	K=0.0418	397.92	43.32
Powder 1%	K= 0.0003	2.310.49	98.83
Powder 1.5%	K= 0.0039	177.73	88.90
Powder 2%	K=0.0037	187.34	89.61

Type	Test	Time
Type	Test	0 days	10 days	20 days	30 days
Non- encapsulated	1.0%	207.52 a±7.20	203.26 a±2.05	177.29 a±7.36	106.01 b±5.67
	1.5%	235.60 a±14.87	203.14 ab±4.27	177.38 b±3.02	172.46 b±3.37
	2.0%	239.90 a±8.81	209.00 ab±5.36	184.57 b±4.06	172.32 b±6.27
Encapsulated	1.0%	270.02 a±5.00	263.34 a±8.96	238.40 b±3.10	225.17 b±2.67
	1.5%	286.97 a±5.50	283.40 a±6.24	271.55 a±2.37	269.09 a±11.66
	2.0%	291.98 a±9.32	286.41 a±10.00	285.20 a±3.23	281.97 a±10.86

Type	Test	Time
Type	Test	0 days	10 days	20 days	30 days
Non-encapsulated	Natural	24.76a±0.76	24.77a±0.76	22.72ab±0.30	19.75b±0.25
	1.0%	35.70a±0.20	33.55a±0.50	28.22b±0.16	22.48c±0.10
	1.5%	49.78a±0.35	39.00b±1.04	38.39b±0.28	29.05c±0.33
	2.0%	51.27a±0.55	43.07b±1.37	42.27b±0.21	34.85c±0.23
Encapsulated	Natural	24.77a±0.10	24.77a±0.40	22.73a±0.34	19.75b±0.01
	1.0%	53.56a±0.42	51.90a±0.36	48.90b±0.19	44.16c±0.51
	1.5%	64.64a±0.02	61.04b±0.20	52.93c±0.37	47.56d±0.33
	2.0%	68.93a±0.30	55.2 b±0.08	51.47c±0.21	50.00c±0.02