Table 2.

Changes in physical attributes of RBO during frying/heating at vacuum and atmospheric pressure

Parameters		Fresh	Samples name	Frying/heating cycles
				1	2	3	4	5	6	7	8
Color	L* value	4.13 ± 0.07	VFO	4.26 ± 0.08aA	4.33 ± 0.05abA	4.4 ± 0.06abA	4.48 ± 0.06bcB	4.59 ± 0.05cdBC	4.75 ± 0.06deC	4.96 ± 0.06fC	4.88 ± 0.04efB
			VHO	4.16 ± 0.08aA	4.21 ± 0.06abA	4.28 ± 0.05abcA	4.36 ± 0.05bcdA	4.41 ± 0.05cdeA	4.48 ± 0.04defAB	4.53 ± 0.04efA	4.61 ± 0.04fA
			AFO	4.29 ± 0.07aA	4.36 ± 0.06aA	4.45 ± 0.07abA	4.58 ± 0.04bcB	4.72 ± 0.06cdC	5.01 ± 0.06eD	4.88 ± 0.06deC	4.73 ± 0.06cdAB
			AHO	4.21 ± 0.05aA	4.28 ± 0.07abA	4.35 ± 0.06abA	4.44 ± 0.05bcAB	4.53 ± 0.05cdAB	4.62 ± 0.05deB	4.71 ± 0.05efB	4.79 ± 0.04fB
	a* value	− 0.58 ± 0.04	VFO	− 0.41 ± 0.05aAB	− 0.06 ± 0.04bAB	0.21 ± 0.04cA	0.36 ± 0.06dBC	0.51 ± 0.04eB	0.66 ± 0.04fB	0.75 ± 0.04fgB	0.84 ± 0.04gB
			VHO	− 0.43 ± 0.05aA	− 0.14 ± 0.04bA	0.08 ± 0.05cA	0.16 ± 0.05cdA	0.26 ± 0.06deA	0.37 ± 0.05efA	0.42 ± 0.05fA	0.49 ± 0.04fA
			AFO	− 0.14 ± 0.05aC	0.15 ± 0.04bC	0.34 ± 0.03cB	0.49 ± 0.05dC	0.68 ± 0.06eC	0.92 ± 0.04fC	1.07 ± 0.06gC	1.14 ± 0.05gC
			AHO	− 0.26 ± 0.05aBC	0.09 ± 0.06bBC	0.17 ± 0.05bcA	0.28 ± 0.04cAB	0.42 ± 0.05dAB	0.57 ± 0.05eB	0.63 ± 0.06eB	0.70 ± 0.05eB
	b* value	1.37 ± 0.12	VFO	1.84 ± 0.12aB	2.26 ± 0.16bBC	2.53 ± 0.12bcBC	2.87 ± 0.13cdB	3.24 ± 0.13deC	3.61 ± 0.15efC	3.72 ± 0.12fC	3.76 ± 0.16fB
			VHO	1.97 ± 0.15aB	2.42 ± 0.10bC	2.92 ± 0.14cC	3.33 ± 0.11dC	3.65 ± 0.14deD	3.87 ± 0.13efC	4.06 ± 0.13fC	4.17 ± 0.14fC
			AFO	1.42 ± 0.16aA	1.5 ± 0.13abA	1.85 ± 0.11bcA	2.04 ± 0.12cdA	2.27 ± 0.15deA	2.56 ± 0.15efA	2.72 ± 0.13fA	2.94 ± 0.16fA
			AHO	1.63 ± 0.14aAB	2.04 ± 0.15bB	2.35 ± 0.12bcB	2.63 ± 0.12cdB	2.82 ± 0.13deB	3.04 ± 0.14efB	3.28 ± 0.12fgB	3.42 ± 0.14gB
Viscosity		71.31 ± 0.18	VFO	72.62 ± 0.10aB	73.71 ± 0.16bB	74.34 ± 0.25cB	74.99 ± 0.20 dB	75.74 ± 0.26eB	76.89 ± 0.14fB	78.25 ± 0.22gB	79.83 ± 0.19hB
			VHO	72.03 ± 0.09aA	72.49 ± 0.14aA	73.05 ± 0.21bA	73.44 ± 0.25bA	74.36 ± 0.25cA	75.15 ± 0.14dA	75.87 ± 0.19eA	76.95 ± 0.20fA
			AFO	73.85 ± 0.21aC	75.87 ± 0.17bD	78.57 ± 0.10cD	81.42 ± 0.09dD	84.00 ± 0.20eD	87.26 ± 0.20fD	90.56 ± 0.22gD	94.25 ± 0.18hD
			AHO	72.89 ± 0.25aB	74.36 ± 0.21bC	75.92 ± 0.16cC	76.81 ± 0.14dC	77.73 ± 0.19eC	79.03 ± 0.15fC	80.23 ± 0.17gC	82.36 ± 0.18hC

^*The first different superscript letters (a–h) shows the values are significantly different at p < 0.05 in a row

^*The second different superscript letters (A–D) shows the values are significantly different at p < 0.05 in a column