Journal of Food Quality

Research Article

Effects of Pitaya Peel Supplementation on Nutritional Quality, Overall Sensory Acceptance, In Vitro Glycemic Index, and Antioxidant Release from Fiber-Enriched Cookies

Table 1

Proximate composition, antioxidant activity, and overall acceptability of cookie samples supplemented with different pitaya peel levels.


Ratio of pitaya peel powder (% of the total weight of pitaya peel powder and wheat flour)	0	10	15	20	25

Lipid (% dw)	24.15 ± 0.13^a	24.20 ± 0.15^a	24.44 ± 0.35^a	24.26 ± 0.11^a	24.34 ± 0.42^a
Protein (% dw)	7.97 ± 0.02^a	7.66 ± 0.16^b	7.60 ± 0.04^b	7.40 ± 0.02^c	7.39 ± 0.05^c
Ash (% dw)	0.87 ± 0.03^e	1.59 ± 0.05^d	1.93 ± 0.04^c	2.47 ± 0.06^b	2.78 ± 0.02^a
Starch (% dw)	47.63 ± 1.65^a	42.33 ± 0.74^b	40.99 ± 0.92^bc	39.28 ± 0.04^cd	37.61 ± 0.79^d
Total fiber (% dw)	1.44 ± 0.18^e	4.93 ± 0.01^d	6.73 ± 0.06^c	8.83 ± 0.37^b	10.21 ± 0.20^a
Insoluble fiber (% dw)	0.91 ± 0.12^e	3.20 ± 0.03^d	4.41 ± 0.02^c	5.82 ± 0.28^b	6.71 ± 0.18^a
Soluble fiber (% dw)	0.52 ± 0.06^e	1.73 ± 0.02^d	2.32 ± 0.04^c	3.01 ± 0.10^b	3.50 ± 0.03^a
Ratio of insoluble fiber/soluble fiber	1.75 ± 0.06^b	1.85 ± 0.03^ab	1.90 ± 0.03^a	1.93 ± 0.05^a	1.92 ± 0.04^a
Total carbohydrate (% dw)	67.01 ± 0.10^a	66.57 ± 0.31^a	66.03 ± 0.30^b	65.87 ± 0.14^bc	65.49 ± 0.43^c
Betacyanins (mg/kg dw)	—	27.00 ± 1.07^d	31.30 ± 1.38^c	35.58 ± 1.14^b	45.43 ± 3.36^a
Total phenolics (mg GAE/100g dw)	113.46 ± 2.74^e	201.34 ± 4.03^d	265.81 ± 8.87^c	299.92 ± 11.67^b	345.40 ± 7.57^a
Antioxidant capacity by the DPPH assay (μmol TE/100 g dw)	49.80 ± 1.90^e	160.63 ± 5.20^d	251.24 ± 8.32^c	326.25 ± 9.59^b	397.35 ± 11.68^a
Antioxidant capacity by the FRAP assay (μmol TE/100 g dw)	77.42 ± 3.09^e	234.36 ± 8.01^d	288.21 ± 5.43^c	399.48 ± 7.45^b	491.43 ± 12.79^a
Overall acceptability	6.47 ± 0.5^a	6.33 ± 0.48^a	6.32 ± 0.47^a	5.98 ± 0.34^b	5.15 ± 0.36^c

Values with different subscripts in the same row are significantly different ( < 0.05); dw: dry weight; GAE: gallic acid equivalent; DPPH: 2, 2-diphenyl-1-picrylhydrazyl; TE: trolox equivalent; FRAP: ferric reducing antioxidant power.