Effect of Gaseous Ozone and Heat Treatment on Quality and Shelf Life of Fresh Strawberries during Cold Storage

Figures & data

Table 1. F, df and p values of the physicochemical parameters measured for all treatments

A. Weight loss
	F	df	p
Ctl vs. ctl + ht	−10.757	14	1.69x10^−14 < 0.05
Ctl vs. 0.5 ppm	−9.958	14	2.31x10^−13 < 0.05
Ctl vs. 1.0 ppm	−10.410	14	5.21x10^−14 < 0.05
Ctl vs. 1.5 ppm	−10.996	14	7.84x10^−15 < 0.05
Ctl vs. 0.5 ppm + ht	−11.185	14	4.29x10^−15 < 0.05
Ctl vs. 1.0 ppm + ht	−12.84	14	2.69x10^−17 < 0.05
Ctl – 1.5 ppm + ht	−11.086	14	5.87x10^−15 < 0.05
B. Firmness
	F	df	p
Ctl vs. ctl + ht	−8.457	99	3.85x10^−11 < 0.05
Ctl vs. 0.5 ppm	3.381	99	0.14 > 0.05
Ctl vs. 1.0 ppm	−4.292	99	83x10^−6 < 0.05
Ctl vs. 1.5 ppm	−5.927	99	0.303 > 0.05
Ctl vs. 0.5 ppm + ht	−0.559	99	0.579 > 0.05
Ctl vs. 1.0 ppm + ht	−10.216	99	9.85x10^−14 < 0.05
Ctl vs. 1.5 ppm + ht	2.532	99	0.15 > 0.05
C. Total soluble solids (TSS)
	F	df	p
Ctl vs. ctl + ht	−2.234	49	0.03 < 0.05
Ctl vs. 0.5 ppm	5.724	49	6.21x10^−7 < 0.05
Ctl vs. 1.0 ppm	7.434	49	1.41x10^−9 < 0.05
Ctl vs. 1.5 ppm	−3.174	49	0.151 > 0.05
Ctl vs. 0.5 ppm + ht	8.127	49	1.22x10^−10 < 0.05
Ctl vs. 1.0 ppm + ht	10.441	49	4.7x10^−14 < 0.05
Ctl vs. 1.5 ppm + ht	3.607	49	0.001 < 0.05
D. Titreatable acidity
	F	df	p
Ctl vs. ctl + ht	10.822	9	1.37x10^−14 <0.05
Ctl vs. 0.5 ppm	9.473	9	1.17x10^−12 < 0.05
Ctl vs. 1.0 ppm	13.429	9	4.82x10^−18 <0.05
Ctl vs. 1.5 ppm	9.28	9	2.26x10^−12 <0.05
Ctl vs. 0.5 ppm + ht	12.033	9	3.05x10^−16 <0.05
Ctl vs. 1.0 ppm + ht	12.133	9	2.24x10^−16 <0.05
Ctl vs. 1.5 ppm + ht	10.152	9	1.21x10^−13 <0.05
E. pH
	F	df	p
Ctl vs. ctl + ht	−3.296	9	0.17 > 0.05
Ctl vs. 0.5 ppm	−4.618	9	0.28 > 0.05
Ctl vs. 1.0 ppm	0.469	9	0.01 < 0.05
Ctl vs. 1.5 ppm	−2.672	9	0.17 > 0.05
Ctl vs. 0.5 ppm + ht	−4.003	9	0.212 > 0.05
Ctl vs. 1.0 ppm + ht	−2.513	9	0.015 < 0.05
Ctl vs. 1.5 ppm + ht	1.174	9	0.246 > 0.05
F. Color parameter L*
	F	df	p
Ctl vs. ctl + ht	4.139	49	0.137 > 0.05
Ctl vs. 0.5 ppm	1.021	49	0.312 > 0.05
Ctl vs. 1.0 ppm	−3.817	49	379x10^−6 < 0.05
Ctl vs. 1.5 ppm	0.508	49	0.614 > 0.05
Ctl vs. 0.5 ppm + ht	0.575	49	0.568 > 0.05
Ctl vs. 1.0 ppm + ht	1.474	49	0.147 > 0.05
Ctl vs. 1.5 ppm + ht	−4.481	49	45x10^−6 < 0.05
G. Color parameter a*
	F	df	p
Ctl vs. ctl + ht	5.03	49	0.7 > 0.05
Ctl vs. 0.5 ppm	−1.575	49	0.122 > 0.05
Ctl vs. 1.0 ppm	−6.102	49	1.63x10^−7 < 0.05
Ctl vs. 1.5 ppm	11.992	49	3.46x10^−16 < 0.05
Ctl vs. 0.5 ppm + ht	7.953	49	0.225 > 0.05
Ctl vs. 1.0 ppm + ht	3.022	49	0.4 > 0.05
Ctl vs. 1.5 ppm + ht	0.047	49	0.009 < 0.05
H. Color parameter b*
	F	df	p
Ctl vs. ctl + ht	6.021	49	2.17x10^−7 < 0.05
Ctl vs. 0.5 ppm	−2.062	49	0.045 < 0.05
Ctl vs. 1.0 ppm	−3.127	49	0.003 < 0.05
Ctl vs. 1.5 ppm	8.133	49	1.19x10^−10 < 0.05
Ctl vs. 0.5 ppm + ht	3.09	49	0.003 < 0.05
Ctl vs. 1.0 ppm + ht	3.09	49	0.003 < 0.05
Ctl vs. 1.5 ppm + ht	2.735	49	0.211 > 0.05

Figure 1. Effect of ozone and treatment on weight loss percentage of strawberries during cold storage

Figure 2. Effect of ozone and heat treatment on firmness of strawberries during cold storage

Figure 3. Effect of ozone and heat treatment on TSS content of strawberries during cold storage

Figure 4. Effect of ozone and heat treatment on titratable acidity of strawberries during cold storage

Figure 5. Effect of ozone and heat treatment on pH of strawberries during cold storage

Table 2. Effect of ozone and heat treatment on the color parameter L* of strawberries during cold storage

Days of storage	Control	Control + HT	0.5 ppm ozone	1.0 ppm ozone	1.5 ppm ozone	0.5 ppm ozone + HT	1.0 ppm ozone + HT	1.5 ppm ozone + HT
0	26.64^1a±0.35	26.64^1a±0.35	26.64^1a±0.35	26.64^1a±0.35	26.64^1a±0.35	26.64^1a±0.35	26.64^1a±0.35	26.64^1a±0.35
4	27.11^2a±0.41	26.53^1b±0.43	27.56^2c±0.36	29.52^2d±0.52	27.89^2e±0.79	28.63^2f±0.53	27.63^2g±0.43	29.29^2h±0.39
8	28.09^3a±0.49	26.30^1b±0.40	27.80^3c±0.59	28.68^3d±0.58	27.60^2e±0.59	27.89^3e±0,65	27.23^3f±0.43	28.70^3g±0.49
12	29.05^4a±0.39	26.36^2b±0.41	27.69^3c±0.75	27.83^4c±0.65	27.66^2c±0.55	27.16^4d±0.56	27.00^3d±0.61	28.24^4e±0.54
16	26.20^5a±0.80	27.32^3b±0.52	26.84^4c±0.54	27.93^4d±0.90	27.03^3e±0.51	26.26^5f±0.46	27.35^4g±0.55	27.46^5g±0.56

Note. Mean values followed by different letters, in the same row, differ significantly (P < 0.05). Mean values followed by different exponents, in the same column, differ significantly (P < 0.05).

Table 3. Effect of ozone and heat treatment on the color parameter a* of strawberries during cold storage

Days of storage	Control	Control + HT	0.5ppm ozone	1.0ppm ozone	1.5 ppm ozone	0.5 ppm ozone + HT	1.0 ppm ozone + HT	1.5 ppm ozone + HT
0	42.95^1a±0.75	42.95^1a±0.75	42.95^1a±0.75	42.95^1a±0.75	42.95^1a±0.75	42.95^1a±0.75	42.95^1a±0.75	42.95^1a±0.75
4	44.95^2a±0.55	42.72^1b±0.42	45.66^2c±0.46	45.95^2c±0.95	44.33^2d±0.53	44.54^2e±0.44	45.46^2f±0.66	45.48^2f±0.48
8	44.60^3a±0.49	42.50^2b±0.39	44.70^3c±0.80	45.30^3d±0.40	43.70^3e±0.50	43.96^3f±0.46	44.10^3f±0.59	44.42^3f±0.62
12	44.32^3a±0.72	42.36^2b±0.66	43.97^4c±0.67	44.71^4d±0.51	43.06^4e±0.60	43.42^4f±0.42	42.80^4g±0.61	43.45^4h±0.55
16	42.34^4a±0.64	43.60^3b±0.51	42.17^5c±0.57	42.29^5c±0.49	41.46^5d±0.61	40.42^5e±0.52	42.44^5f±0.64	42.85^5g±0.75

Note. Mean values followed by different letters, in the same row, differ significantly (P < 0.05). Mean values followed by different exponents, in the same column, differ significantly (P < 0.05).

Table 4. Effect of ozone and heat treatment on the color parameter b* of strawberries during cold storage

Days of storage	Control	Control + HT	0.5ppm ozone	1.0ppm ozone	1.5 ppm ozone	0.5 ppm ozone + HT	1.0 ppm ozone + HT	1.5 ppm ozone + HT
0	25.72^1a±0.55	25.72^1a±0.55	25.72^1a±0.55	25.72^1a±0.55	25.72^1a±0.55	25.72^1a±0.55	25.72^1a±0.55	25.72^1a±0.55
4	26.65^2a±0.60	24.97^2b±0.80	28.48^2c±0.70	28.88^2d±0.59	26.33^2e±0.53	27.86^2f±0.56	27.85^2f±0.65	28.02^2f±0.42
8	27.06^3a±0.56	24.56^2b±0.61	27.87^3c±0.69	28.33^3d±0.51	25.55^3e±0.75	26.45^3f±0.45	25.83^3g±0.63	26.77^3h±0.57
12	27.31^3a±0.51	24.22^3b±0.42	26.72^4c±0.41	27.60^4d±0.41	24.37^4e±0.57	25.87^4f±0.67	24.79^4g±0.59	25.92^4h±0.69
16	24.56^4a±0.55	25.43^4b±0.40	23.91^5c±0.65	23.38^5d±0.61	23.31^5d±0.45	23.10^5d±0.70	24.12^5e±0.39	24.41^5f±0.55

Note. Mean values followed by different letters, in the same row, differ significantly (P < 0.05). Mean values followed by different exponents, in the same column, differ significantly (P < 0.05).

Figure 6. (a) Effect of ozone and heat treatment on the appearance of strawberries during cold storage. (b) Effect of ozone and heat treatment on the taste of strawberries during cold storage. (c) Effect of ozone and heat treatment on the odor of strawberries during cold storage