Table 4. Surface color of potatoes packaged with PBAT-based film and control films over 6 days

Variety	Day	Packaging material¹⁾	L	a	b	ΔE
Eunsun	0	Without film	72.15±2.23^2)ab3)	−3.70±0.83^e	25.47±1.24^b
	3	Without film	69.49±3.06^bc	−7.60±2.82^cd	25.52±1.79^b	6.19±1.59^bc
		HDPE	69.34±3.75^bc	−7.73±1.65^cd	25.82±1.18^b	5.97±2.29^bc
		Neat PBAT	69.81±2.07^abc	−6.98±2.49^cd	25.27±1.94^b	5.02±2.06^cd
		PBAT/CuONPs	72.42±1.51^a	−5.65±1.47^de	23.49±1.66^c	3.70±0.79^d
	6	Without film	64.19±2.09^d	−11.58±0.97^a	27.53±0.88^a	11.55±1.40^a
		HDPE	63.86±2.25^d	−10.81±2.77^ab	27.61±1.87^a	11.57±2.56^a
		Neat PBAT	67.37±2.43^c	−9.08±3.76^bc	25.73±2.81^b	8.11±3.51^b
		PBAT/CuONPs	67.34±4.81^c	−6.46±2.69^d	24.87±1.70^bc	7.10±3.38^bc
Duback	0	Without film	71.50±2.09^a	−4.63±0.33^f	21.53±1.84^d
	3	Without film	65.84±3.26^bc	−9.25±2.14^c	27.22±1.60^b	9.52±3.48^c
		HDPE	61.59±1.95^d	−10.54±0.97^b	27.29±0.78^b	12.99±1.61^b
		Neat PBAT	65.21±2.51^c	−9.07±1.39^c	27.07±1.05^b	9.59±2.66^c
		PBAT/CuONPs	67.67±2.72^b	−6.63±1.24^e	24.96±1.01^c	5.88±2.32^d
	6	Without film	61.13±1.86^d	−11.34±1.06^ab	27.92±1.11^ab	14.38±1.13^ab
		HDPE	60.99±1.75^d	−11.95±1.05^a	29.02±0.85^a	14.91±1.52^ab
		Neat PBAT	59.69±1.89^d	−11.82±0.84^a	27.91±1.36^ab	15.35±1.36^a
		PBAT/CuONPs	67.58±3.26^b	−7.77±1.38^d	25.82±1.60^c	7.08±2.79^d
Superior	0	Without film	64.68±1.52^a	−1.24±0.91^e	22.54±1.51^d
	3	Without film	60.54±1.51^cd	−13.48±1.01^ab	29.10±0.42^a	14.55±1.24^a
		HDPE	60.42±3.22^cd	−13.14±0.73^ab	28.63±0.95^ab	14.34±1.40^a
		Neat PBAT	64.14±1.86^ab	−11.71±1.04^c	28.23±0.84^ab	12.05±1.33^b
		PBAT/CuONPs	64.98±1.68^a	−9.35±1.15^d	25.79±1.20^c	8.93±1.31^c
	6	Without film	58.74±2.76^d	−12.26±0.67^bc	27.19±0.63^b	13.33±0.85^ab
		HDPE	61.51±1.44^bc	−12.59±0.89^abc	28.28±0.57^ab	13.16±0.75^ab
		Neat PBAT	62.03±1.30^bc	−13.88±0.47^a	29.18±0.48^a	14.56±0.34^a
		PBAT/CuONPs	65.76±0.42^a	−12.85±1.25^abc	29.45±1.03^a	13.56±1.57^ab

Without film, non-packaging potatoes; HDPE, high-density polyethylene film; Neat PBAT, neat poly(butylene adipate-co-terephthalate) film; PBAT/CuONPs, poly(butylene adipate-co-terephthalate) composite film with 0.08 g copper oxide nanoparticles.
All values are mean±SD (n=3).
Values with different superscript letters (^a-f) in the same column are significantly different at p<0.05 by Duncan’s multiple range test.