Effects of zein-nisin edible coating on physicochemical and microbial load of ‘Granny Smith’ apple after long term storage

Figures & data

Figure 1. Effects of zein and zein-nisin coating and storage duration on the weight loss of “Granny Smith” apple stored for 15°C for 21 days. Mean values (n = 3) with standard deviation bars. Different lower-case letters represent significantly different mean (p ≤ .05).

Table 1. Effects of zein and zein-nisin coating and storage duration on the total soluble solid (TSS), titratable acidity, colour attributes and texture of “Granny Smith” apples stored at 15°C for 21 days.

Quality parameters	Sampling days	Treatments
		CONTROL	ZEIN	ZEIN-NISIN
TSS (°Brix)	Day 0	13.1 ± 0.00a^A	13.1 ± 0.00a^A	13.1 ± 0.00a^A
	Day 7	12.6 ± 0.44a^A	12.7 ± 0.55a^A	12.5 ± 0.50a^B
	Day 14	12.8 ± 0.06b^A	13.1 ± 0.15a^A	12.7 ± 0.42a^B
	Day 21	12.8 ± 0.40a^A	13.0 ± 0.06a^A	12.8 ± 0.55a^A
TA (g 100 mL^−1, malic acid)	Day 0	1.04 ± 0.00a^A	1.04 ± 0.00a^B	1.04 ± 0.00a^B
	Day 7	1.2 ± 0.07a^A	1.0 ± 0.01b^B	1.2 ± 0.06a^A
	Day 14	1.2 ± 0.02a^A	1.2 ± 0.09a^A	1.1 ± 0.04b^A
	Day 21	0.8 ± 0.06a^A	0.9 ± 0.05a^A	0.8 ± 0.07a^A
Hue angle (h°)	Day 0	155.7 ± 0.00a^B	155.7 ± 0.00a^A	155.7 ± 0.00a^B
	Day 7	129.3 ± 0.25a^A	114.7 ± 0.94b^B	128.4 ± 2.60a^A
	Day 14	117.2 ± 0.61b^B	115.6 ± 0.64b^B	128.9 ± 0.64a^A
	Day 21	114.7 ± 0.83a^A	112.3 ± 0.66a^A	111.7 ± 0.77a^A
Chroma (C*)	Day 0	44.4 ± 0.00a^A	44.4 ± 0.00a^A	44.4 ± 0.00a^A
	Day 7	43.4 ± 0.38a^A	44.1 ± 1.67a^A	42.5 ± 3.44a^A
	Day 14	42.9 ± 0.59a^A	41.9 ± 0.58a^B	42.5 ± 3.45a^A
	Day 21	44.7 ± 0.87a^A	37.8 ± 3.25b^C	21.9 ± 3.48c^B
Lightness (L*)	Day 0	55.92 ± 0.00b^A	55.92 ± 0.00b^A	55.92 ± 0.00c^A
	Day 7	58.70 ± 0.27aA^A	59.46 ± 0.59a^A	61.24 ± 1.70a^A
	Day 14	58.42 ± 1.08b^A	58.75 ± 0.87a^A	57.40 ± 0.96b^A
	Day 21	53.79 ± 1.07c^C	57.59 ± 1.03a^B	63.25 ± 0.33a^A
Firmness (kg)	Day 0	7.1 ± 0.00a^A	7.1 ± 0.00a^A	7.1 ± 0.00a^A
	Day 7	7.7 ± 0.23a^A	7.7 ± 0.09a^A	7.4 ± 0.26a^B
	Day 14	7.5 ± 0.16a^B	7.8 ± 0.21a^A	7.4 ± 0.03a^B
	Day 21	7.6 ± 0.04b^B	8.0 ± 0.20a^A	7.8 ± 0.12b^A

Mean values (n = 3), Different superscript upper case letters in a raw and lower-case letter in column represent statistically significant differences based on Duncan’s Multiple Range Test at p ≤ .05 on quality of apple at different treatment and storage duration.

Figure 2. Effects of zein and zein-nisin coating and storage duration on the respiration rate (a) and ethylene production rate (b) of “Granny Smith” apple stored for 15°C at 21 days. Mean values (n = 3) with standard deviation bars. Different lower-case letters represent significantly different mean (p ≤ .05).

Figure 3. Effects of zein and zein-nisin coating and storage duration on the aerobic mesophilic bacteria (a) and the yeast and mould counts (b), on the surface of “Granny Smith” apple stored for 15°C for 21 days. Mean values (n = 9 plates) with standard deviation bars. Different lower-case letters represent significantly different mean (p ≤ .05).