Antioxidant effects of lotus (Nelumbo nucifera) root and leaf extracts and their application on pork patties as inhibitors of lipid oxidation, alone and in combination

Figures & data

Table 1. Antioxidant properties of lotus root and leaf extracts

Properties	R50^1	R75	L50	L75	BHT
Extraction yield (%)	19.42 ± 1.61^a	14.05 ± 2.34^b	17.29 ± 1.64^ab	15.65 ± 1.08^b	-
IC50^2 on DPPH radical (g/L)	0.52 ± 0.01^b	0.71 ± 0.03^a	0.17 ± 0.01^c	0.13 ± 0.01^cd	0.09 ± 0.02^d
IC50 on chelating activity (g/L)	0.32 ± 0.03^b	0.31 ± 0.08^b	0.84 ± 0.02^a	0.85 ± 0.11^a	-

All values are mean ± standard deviation.

^a-dMeans within a row with different letters are significantly different (P < 0.05).

¹R50, extract of lotus root using 50% ethanol solvent; R75, extract of lotus root using 75% ethanol solvent; L50, extract of lotus leaf using 50% ethanol solvent; L75, extract of lotus leaf using 75% ethanol solvent; BHT, butylated hydroxytoluene.

²IC₅₀, concentration of extracts (g/L) to inhibit 50% DPPH radical or chelate metal ions.

Table 2. Quality properties of pork patties with lotus root and leaf extracts

Traits		Control^1	Additives
			LRE	LRE+LLE	LLE	BHT
Physicochemical properties	Moisture (%)	57.6 ± 1.26^ab	56.3 ± 1.03^b	56.9 ± 6.80^ab	56.2 ± 1.17^b	58.0 ± 1.45^a
	Fat (%)	19.2 ± 3.57	18.8 ± 3.14	18.8 ± 3.31	19.2 ± 1.55	19.8 ± 2.39
	Protein (%)	18.8 ± 0.33	19.6 ± 1.41	20.1 ± 0.57	20.9 ± 1.10	19.4 ± 2.41
	Ash (%)	2.1 ± 0.17	2.1 ± 0.19	2.1 ± 0.02	2.0 ± 0.14	2.1 ± 0.20
	Cooking yield (%)	66.2 ± 2.43	63.6 ± 3.60	64.7 ± 3.29	63.3 ± 3.56	66.2 ± 2.28
	pH	5.89 ± 0.10	5.88 ± 0.14	5.88 ± 0.13	5.89 ± 0.15	5.90 ± 0.12
Color	CIE L*	70.2 ± 0.93^b	70.6 ± 0.96^ab	68.4 ± 1.16^c	68.2 ± 2.58^c	71.6 ± 0.91^a
	CIE a*	3.8 ± 0.58^a	3.3 ± 0.70^bc	3.1 ± 0.39^c	3.1 ± 0.63^c	3.8 ± 0.64^ab
	CIE b*	11.6 ± 0.75^a	10.7 ± 0.75^b	11.6 ± 0.97^a	12.2 ± 0.76^a	11.6 ± 0.81^a

All values are mean ± standard deviation.

^a-cMeans within a row with different letters are significantly different (P < 0.05).

¹Control, no ingredient added; LRE, patties with 1% LRE; LRE+LLE, patties with 0.5% LRE and 0.5% LLE; LLE, patties with 1% LLE; BHT,

patties with 0.02% butylated hydroxytoluene (BHT).

Table 3. Thiobarbituric acid reactive substances (TBARS) values of pork patties depending on the addition level of lotus root and leaf extracts

Treatments	0% (Control)	0.1%	0.5%	1.0%	0.02% BHT
LRE^1	1.88 ± 0.04^a	1.13 ± 0.33^b	0.95 ± 0.29^Abc	0.84 ± 0.23^Ac	1.03 ± 0.19^bc
LLE	1.88 ± 0.04^a	1.14 ± 0.40^b	0.64 ± 0.17^Bc	0.33 ± 0.05^Bd	1.03 ± 0.19^b

All values are mean ± standard deviation.

^A-Bmeans within a column with different letters are significantly different (P < 0.05).

^a-dmeans within a row with different letters are significantly different (P < 0.05).

¹0%(Control), no ingredient added; LRE, patties with LRE; LLE, patties with LLE; BHT, patties with 0.02% butylated hydroxytoluene (BHT).

Figure 1. Reducing power of lotus root and leaf extracts. (□) R50, Lotus root extract extracted with 50% ethanol; (■) R75, Lotus root extract extracted with 75% ethanol; (○) L50, Lotus leaf extract extracted with 50% ethanol; (●) L75, Lotus leaf extract extracted with 75% ethanol; (−) BHT, 0.02% BHT (butylated hydroxytoluene). Error bars show the SD

Figure 2. Changes in peroxide value (POV) of pork patties containing lotus loot and leaf extracts during refrigerated storage. (×) Control, no ingredient added; (△) patties with 1% lotus root extract; (◇) patties with 0.5% lotus root extract and 0.5% lotus leaf extract; (▲) patties with 1% lotus leaf extract; (■) patties with 0.02% butylated hydroxytoluene (BHT). Error bars show the SD

Figure 3. Changes in thiobarbituric acid reactive substances (TBARS) of pork patties containing lotus root and leaf extracts during refrigerated storage. (×) Control, no ingredient added; (△) patties with 1% lotus root extract; (◇) patties with 0.5% lotus root extract and 0.5% lotus leaf extract; (▲) patties with 1% lotus leaf extract; (■) patties with 0.02% butylated hydroxytoluene (BHT). a-d means that column with different letters are significantly different (P < 0.05)

Table 4. Sensory evaluation of pork patties with lotus root and leaf extracts

Traits^1	Control^2	Additives
		LRE	LRE+LLE	LLE	BHT
Color	6.9 ± 0.65^a	6.6 ± 0.56^b	6.5 ± 0.54^b	6.6 ± 0.68^b	6.8 ± 0.62^ab
Flavor	6.7 ± 0.74^a	6.3 ± 0.67^b	6.8 ± 0.74^a	6.6 ± 0.91^a	6.8 ± 0.85^a
Tenderness	6.8 ± 0.60	6.9 ± 0.60	7.0 ± 0.67	7.0 ± 0.59	6.9 ± 0.66
Juiciness	6.8 ± 0.76^ab	6.7 ± 0.89^b	6.9 ± 0.71^ab	6.9 ± 0.76^ab	7.1 ± 0.79^a
Off-flavor	6.2 ± 0.80^c	6.7 ± 0.54^b	7.6 ± 0.68^a	7.0 ± 0.69^ab	6.8 ± 0.82^b
Overall acceptability	6.8 ± 0.61^ab	6.6 ± 0.71^b	7.1 ± 0.96^a	6.9 ± 0.88^ab	7.1 ± 0.87^a

All values are mean ± standard deviation.

^a-cMeans within a row with different letters are significantly different (P < 0.05).

¹Traits: color (1 = extremely undesirable, 9 = extremely desirable), flavor (1 = extremely undesirable, 10 = extremely desirable), tenderness (1 = extremely undesirable, 9 = extremely desirable), juiciness (1 = extremely undesirable, 9 = extremely desirable), off-flavor (1 = extremely undesirable, 9 = extremely desirable), and overall acceptability (1 = extremely undesirable, 9 = extremely desirable).

²Control, no added ingredient; LRE, patties with 1% LRE; LRE+LLE, patties with 0.5% LRE and 0.5% LLE; LLE, patties with 1% LLE; patties with 0.02% BHT (butylated hydroxytoluene).