Fruit By-Product Processing and Bioactive Compounds
Table 1
Means of total flavonoid content (TFC, mg/100 g), total phenolic content (TPC, mg/100 g), reducing power (FRAP <0.1 g/100 ml), and DPPH inhibition (IC50, %) of avocado peel, avocado seeds, kiwi fruit, orange peel, pineapple peel, and pomegranate skin during processing.
Fruit by-product
TRT
TFC (mg/100 g)1
TPC (mg/100 g)
FRAP (0.1 mg/100 ml)
IC50 (%)
Avocado peel
Dried
136.9a
1,017.2b
93.6d
14.5c
Blanched
63.1b
359.1d
169.0a
11.1d
Frozen
20.6c
1,000.5c
128.3c
55.6b
Fresh
14.4d
2,466.8a
149.2b
76.6a
Avocado seed
Dried
54.1a
5,973.0a
152.2a
52.5a
Blanched
45.4b
4,958.6b
147.9b
21.6c
Frozen
33.8d
1,268.6d
128.2d
28.2b
Fresh
39.8c
2,036.6c
142.7c
17.8d
Kiwi fruit
Dried
10.6a
4,571.9a
59.9b
32.1b
Blanched
1.3b
852.6b
93.6a
43.2a
Frozen
0.0c
324.2c
32.1c
30.0c
Fresh
1.3b
331.8c
28.5d
20.2d
Orange peel
Dried
380.0a
4,232.3a
177.7a
27.7b
Blanched
194.4b
2,445.5b
133.9b
38.8a
Frozen
56.9c
828.5c
49.3c
26.1b
Fresh
54.4c
756.5c
47.7d
26.2b
Pineapple peel
Dried
18.8a
1,342.8
42.6a
15.0b
Blanched
13.1b
733.4b
32.3b
19.8a
Frozen
1.3c
152.4c
6.5c
9.9c
Fresh
18.8a
95.0d
0.6d
6.5d
Pomegranate skin
Dried
862.5a
6,138.2c
93.6d
39.8c
Blanched
405.6d
5,346.8d
106.3c
45.3b
Frozen
478.8c
6,454.4b
173.5a
47.8a
Fresh
504.4b
6,909.8a
166.6b
20.0d
1Flavonoids content ((quercetin equivalents (mg/100 g)), phenolic compounds (gallic acid equivalents (mg/100 g)), FRAP (ascorbic acid equivalent (0.1 g/100 ml)), and IC50 (i.e., concentration of extract (mg/ml) needed to scavenge 50% of the DPPH radicals (mg/ml)) within the same fruit by-product and different treatment having different letters are significantly () different according to the LSD.