Table 4.
Trueness (R’%) and precision (RSDr%) and Horwitz ratio value (HorRat) of the optimized method, based on four concentration levels (5, 25, 50, and 100 µg/g) of phenolic compounds spiked brewing spent grains.
| Phenolic Compounds | Concentration Level (µg/g) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 25 | 50 | 100 | |||||||||
| R’% (Mean ± SD) |
RSDr % |
HorRat | R’% (Mean ± SD) |
RSDr % |
HorRat | R’% (Mean ± SD) |
RSDr % |
HorRat | R’% (Mean ± SD) |
RSDr % |
HorRat | |
| 3,4,5-trihydroxybenzoic | 100 ± 1 | 0.9 | 0.1 | 101 ± 1 | 0.2 | 0.1 | 98 ± 2 | 1.0 | 0.1 | 93 ± 2 | 1.6 | 0.2 |
| 3,5-dihydroxybenzoic | 85 ± 1 | 0.8 | 0.1 | 98 ± 1 | 0.7 | 0.1 | 96 ± 2 | 1.0 | 0.1 | 90 ± 1 | 0.5 | 0.1 |
| 2,5-dihydroxybenzoic | 87 ± 1 | 1.3 | 0.1 | 89 ± 1 | 1.1 | 0.1 | 81 ± 4 | 1.2 | 0.4 | 85 ± 2 | 1.2 | 0.1 |
| 4- hydroxybenzoic | 85 ± 1 | 1.1 | 0.1 | 92 ± 1 | 0.6 | 0.1 | 86 ± 2 | 1.2 | 0.1 | 82 ± 1 | 1.1 | 0.1 |
| tyrosol | 93 ± 1 | 0.9 | 0.1 | 86 ± 2 | 2.3 | 0.2 | 89 ± 4 | 2.1 | 0.2 | 94 ± 1 | 0.9 | 0.1 |
| 2,6-dihydroxybenzoic | 92 ± 1 | 1.5 | 0.1 | 90 ± 1 | 0.9 | 0.1 | 97 ± 3 | 1.7 | 0.1 | 84 ± 1 | 0.8 | 0.1 |
| 3- hydroxybenzoic | 103 ± 1 | 1.0 | 0.1 | 101 ± 1 | 1.2 | 0.1 | 109 ± 4 | 1.9 | 0.2 | 102 ± 1 | 1.1 | 0.1 |
| vanillic | 88 ± 1 | 0.8 | 0.1 | 92 ± 2 | 1.7 | 0.1 | 90 ± 4 | 2.2 | 0.1 | 80 ± 1 | 0.3 | 0.1 |
| caffeic | 101 ± 1 | 1.1 | 0.1 | 100 ± 1 | 0.8 | 0.1 | 110 ± 3 | 1.2 | 0.1 | 104 ± 1 | 1.1 | 0.1 |
| chlorogenic | 97 ± 1 | 1.2 | 0.1 | 85 ± 2 | 2.1 | 0.1 | 93 ± 2 | 2.4 | 0.1 | 81 ± 1 | 1.0 | 0.1 |
| syringic | 88 ± 1 | 1.2 | 0.1 | 93 ± 2 | 1.6 | 0.1 | 89 ± 3 | 1.0 | 0.1 | 80 ± 1 | 0.6 | 0.1 |
| homovanillic | 107 ± 1 | 0.6 | 0.1 | 87 ± 1 | 1.5 | 0.1 | 86 ± 2 | 1.2 | 0.1 | 80 ± 1 | 0.2 | 0.1 |
| p-coumaric | 94 ± 1 | 1.4 | 0.1 | 86 ± 1 | 1.0 | 0.1 | 94 ± 3 | 1.6 | 0.1 | 81 ± 2 | 1.1 | 0.2 |
| salicylic | 90 ± 1 | 1.1 | 0.1 | 82 ± 1 | 1.4 | 0.1 | 93 ± 1 | 0.6 | 0.1 | 86 ± 1 | 1.1 | 0.1 |
| ferulic | 97 ± 1 | 2.0 | 0.1 | 92 ± 1 | 0.6 | 0.1 | 85 ± 3 | 1.9 | 0.2 | 80 ± 1 | 0.5 | 0,1 |
| m-coumaric | 97 ± 1 | 1.0 | 0.1 | 83 ± 2 | 2.3 | 0.2 | 84 ± 3 | 1.6 | 0.1 | 85 ± 1 | 1.1 | 0.1 |
| sinapic | 96 ± 1 | 1.5 | 0.1 | 80 ± 1 | 1.6 | 0.1 | 80 ± 1 | 0.4 | 0.1 | 84 ± 1 | 1.1 | 0.1 |
| o-coumaric | 104 ± 1 | 1.7 | 0.1 | 103 ± 1 | 0.2 | 0.1 | 93 ± 2 | 0.9 | 0.1 | 81 ± 1 | 1.2 | 0.1 |
Mean of ten replications. R’ = relative spike recovery; RSDr = relative standard deviations of repeatability; HorRat = Horwitz ratio value.