# Effects of Process Parameters on the Quality of Suantang Beef
## 3 Results and Discussion
### Quality Analysis of ST Beef and Boiled Beef
#### 3.6.3 Volatile Compounds in ST Beef and Boiled Beef
Benzaldehyde was found to provide floral and almond flavors in dry-cured foal sausage [58], not from lipid oxidation but the metabolism of aromatic amino acids [59]. The results show that ST both adds flavor and retains the characteristic aroma substances of beef. It is worth noting that the sulfide concentration increased from 0 \(\upmu\)g/100 g to 184.782 \(\upmu\)g/100 g after cooking in ST, no sulfide was detected in the beef, and the sulfide concentration increased after cooking in the ST. The high concentrations of diallyl disulfide and OAV in the ST beef correspond to the high concentrations of diallyl trisulfide and diallyl disulfide in the ST, which are due to the addition of garlic to the ST for fermentation. And one of the precursors of garlic flavor is s-(2-properly)-l-cysteine sulfoxide [60]. This compound is synthesized several times in the presence of the enzyme allinase to form sulfide flavoring substances. [PERSON], et al. [57] found that the detection of sulfide in sausage samples may be related to the use of garlic as the ingredient of the meat product. The concentration of ketones in beef decreased from 323.152 \(\upmu\)g/100 g to 238.984 \(\upmu\)g/100 g after being boiled in ST. It is worth noting that although the concentration of ketones in beef decreased after ST cooking, the types of ketones in ST beef increased, in which 2-nonanone, 2-undecanoneand acetoin showed OAV \(>\) 1. [PERSON], et al. [61] found that 2-nonanone contributes to a dry-cured ham aroma with floral/fruity/blue cheese aroma. In addition, beef after ST cooking presented significantly decreased concentration of 2,3-octanedione, which was related to the formation of a rotten odor of 2,3-octanedione [62]. There are not many phenols and acid compounds in various products. It is worth noting that phenols are not detected in ST. These substances only exist in beef and ST beef. The concentration of eugenol increased from 19.108 \(\upmu\)g/100 g to 21.323 \(\upmu\)g/100 g after ST cooking, and the OAV was very high. Cloves generally bring eugenol with a similar and spicy aroma. It provides aroma and taste and increases beef's mellow thickness [63]. Eugenol is considered one of the main contributors to the aroma of ST beef. Low-chain organic acids have an essential effect on the characteristic aroma of meat products because of their low odor threshold [64]. ST produced three kinds of acids by microbial fermentation; the concentration was 42.654 \(\upmu\)g/100 g. The acid concentration of beef after ST cooking increased from 5.965 \(\upmu\)g/100 g to 14.122 \(\upmu\)g/100 g; among them, the acetic acid concentration increased significantly, corresponding to the decrease in pH value of ST beef. Some studies have found that acetic acid has a vinegar flavor and contributes to a mature aroma [65], which plays a vital role in developing the typical aroma of fermented sausage [64;66]. For other kinds of compounds, high concentrations of 4-allylanisole and cis-anethole were detected in both beef groups. The concentration of 4-allylanisole annua increased significantly from 40.087 \(\upmu\)g/100 g to 349.339 \(\upmu\)g/100 g after ST cooking. 4-allylanisole annua is the main volatile component of the fennel plant, which can provide aroma [50]. The OAV value of 4-allylanisole annua is also very high, which can be considered one of the main contributors to the aroma of ST beef. It is worth noting that 2-pentylfuran decreased after the meat was cooked with ST. Rancidity is associated with valeraldehyde and 2-pentylfuran (metal, green, soil, legumes) [67].