# Effects of Pretreatment on the Volatile Composition, Amino Acid, and Fatty Acid Content of Oat Bran
## 3 Results and Discussion
### HS-SPME-GC-MS Analysis of Volatile Compounds of Oat Bran
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Serial** & **Volatile Compound** & **Retention Time** & **CAS** & **Molecular** & \multicolumn{3}{c}{**Relative Content/(°C)**} & \\
**Number** & & **(min)** & **Cash** & **Formula** & **OB** & **S-OB** & **M-OB** & **HA-OB** \\ \hline VFC46 & Pyridine-2-carboxylic acid & 2.5 & 98-98-6 & C6 HENO2 & ND & ND & 0.25 \(\pm\) 0.01 & ND \\  & Total & & & & 1.10 \(\pm\) 0.04 & 0.34 \(\pm\) 0.02 & 0.25 \(\pm\) 0.01 & 0 \\ Anines(4) & (IR)-1- & & & & & & \\ VFC47 & Cyclohexylethanolamine & 1.02 & 5913-13-3 & C8H17N & 0.82 \(\pm\) 0.02 & 1.16 \(\pm\) 0.07 & 1.21 \(\pm\) 0.06 & ND \\  & 2- & & & & & & \\ VFC48 & Hydroxypropanamide & 1.11 & 2045-43-8 & C3H7N02 & 0.22 \(\pm\) 0.01 & 0.43 \(\pm\) 0.02 & 0.11 \(\pm\) 0.01 & ND \\ VFC49 & meshylethanolamine & 1.09 & 124-40-3 & C2H7N & ND & ND & ND & 0.15 \(\pm\) 0.05 \\ VFC50 & 1-Methyloxypora-2- & 1.44 & 3713-54- & C4H11 NO & ND & ND & ND & 0.30 \(\pm\) 0.01 \\  & amine & & 7 & C4H11 NO & ND & ND & ND & 0.30 \(\pm\) 0.01 \\ Alkanes(11) & & & & & & & \\ VFC51 & 2-Pertydiox & 5.32 & 5063-65-0 & C7H14O & 0.33 \(\pm\) 0.01 & ND & 0.36 \(\pm\) 0.02 & 0.45 \(\pm\) 0.02 \\ VFC52 & Dodecane & 13.61 & 112-40-3 & C12H26 & 0.67 \(\pm\) 0.02 & ND & 0.86 \(\pm\) 0.08 & ND \\ VFC53 & Tridecane & 16.37 & 629-50-5 & C13H28 & 0.80 \(\pm\) 0.02 & 1.83 \(\pm\) 0.14 & 0.53 \(\pm\) 0.01 & ND \\ VFC54 & Hexadecene & 21.48 & 544-76-3 & C16H34 & 0.16 \(\pm\) 0.01 & ND & ND & ND \\ VFC55 & Phenoxyoxybenzene & 28.3 & 104-66-5 & C14H14O2 & 1.70 \(\pm\) 0.08 & 1.25 \(\pm\) 0.11 & 0.79 \(\pm\) 0.02 & 0.31 \(\pm\) 0.01 \\ VFC6 & 2.4,6-Trimethyloctane & 13.6 & 62016-37- & C11H24 & ND & 2.47 \(\pm\) 0.15 & ND & 0.48 \(\pm\) 0.02 \\ VFC7 & 2.3-Dimethyloxitrane & 1.36 & 3266-23-7 & C4 HBO & ND & ND & 0.24 \(\pm\) 0.01 & ND \\ VFC88 & Penitycyclopropate & 9.87 & 2511-91-3 & C8H16 & ND & ND & 2.00 \(\pm\) 0.14 & ND \\ VFC99 & 3,7-Dimethyldodecane & 8 & & & & & \\  & 2-Oixiran-2- & & 8 & & & & \\ VFC60 &ylmethyl3-3-l- & 52338-90- & C10H16O3 & 0.27 \(\pm\) 0.01 & ND & ND & ND \\ VFC61 & 3,3-Dimethylhexane & 16.34 & 563-16-6 & C8H18 & ND & ND & ND & 0.29 \(\pm\) 0.01 \\ Pyrazines(2) & Total & & & & & 3.93 \(\pm\) 0.15 & 5.55 \(\pm\) 0.40 & 5.33 \(\pm\) 0.29 & 1.53 \(\pm\) 0.06 \\ VFC62 & 2,5-Dimethylyxrazine & 5.5 & 123-32-0 & C6H8N2 & 0.52 \(\pm\) 0.03 & 0.96 \(\pm\) 0.02 & 0.39 \(\pm\) 0.02 & ND \\ VFC63 & dimethylvyrazine & 10.13 & 13925-07- & C8H12N2 & ND & 0.85 \(\pm\) 0.04 & 0.49 \(\pm\) 0.01 & ND \\ Total & & & & & 0.52 \(\pm\) 0.03 & 1.81 \(\pm\) 0.06 & 0.88 \(\pm\) 0.03 & 0 \\ VFC64 & 2-Pentylfuran & 7.61 & 3777-69-3 & C9H14O & 1.28 \(\pm\) 0.12 & 2.40 \(\pm\) 0.17 & 3.05 \(\pm\) 0.11 & 2.37 \(\pm\) 0.13 \\ Total & & & & & 1.28 \(\pm\) 0.12 & 2.40 \(\pm\) 0.17 & 3.05 \(\pm\) 0.11 & 2.37 \(\pm\) 0.13 \\ \hline \end{tabular} MS: Identification based on the NIST 14 (Department of commerce, USA) mass spectral database. a: The relative contents are the means of three repetitions \(\pm\) standard deviation. b: OB, OT bar; S-OB, Steamed oat bran; M-OB, Microwaved oat bran; HA-OB, Hot air dried oat bran. c: ND: Not detected.  
\end{table} 
Table 2: _Cont._the HA-OB had the lowest content (5.96%), which indicated that the content of alcohols decreases with higher heating temperature. The content of esters in oat bran with different treatments was less (\(<\)10%). Among the 12 kinds of esters detected, S-OB had the highest content (7.56%), followed by the OB (5.25%), which may be related to the thermal degradation and oxidation of fat or fatty acid. [PERSON] et al. studied that the majority of oat volatile compositions were produced by heating and cooked oat porridge showed more volatiles [41]. The OB contained two kinds of ketones (1.82%), S-OB produced five kinds of ketones (5.34%), mainly including (2,5-dioxopyrrolidin-1-yl) benzoate(1.70%), and (E)-oct-3-en-2-one(1.40%), M-OB produced three kinds of ketones(2.97%), and HA-OB one kind of ketone (0.63%).