-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
- Cosmetic Ingredient
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
Introduction
and hydrolysing are the main sources of dry sausage flavor formation in China, producing more than 80% of the volatile flavor compounds. During processing, moderate oxidation can produce pleasant flavors, while excessive oxidation can lead to unpleasant flavors and even affect consumer health. Therefore, in the process of Chinese dry sausage processing, it is very important to regulate the degree of lipid oxidation, not only to control the quality, but also to protect the health of consumers. Lipid oxidation and hydrolysing are common reactions in the processing of cured meat products. Lipid hydrolysing promotes lipid oxidation. During processing and storage, although the content of triglycerides did not change significantly, there were significant changes in in-muscle phospholipids. Intracerine phospholipids, as the main flavor prescultural, produce polyunsaturated fatty acids (PUFA) with flaxic acid, flaxic acid and peanut tyrenic acid as the main components through the hydrolyzing of lipase and microbial activity. Unstable double bonds are easily oxidized and produce a series of oxidizing products such as aldehyde, ketones and alcohols. The detection of oxidation products in primary and secondary stages is the most common method for evaluating the degree of lipid oxidation. Level 1 lipid oxidation products are usually evaluated by peroxide value (POV) and iodine. Thiodebic acid reactants (TBARS) are mainly used to evaluate the degree of lipid dioxide, mainly reflecting the content of acetaldehyde compounds formed by lipid oxidation, and therefore used to evaluate the degree of oxidation and degeneration of food.
the lipid oxidation of Chinese dry sausage can be influenced by some external process factors, such as processing temperature, time and NaCl content, but the flavor formation mechanism of Chinese dry sausage still needs to be clarified. NaCl is an important ingredient in meat processing, especially cured meats. NaCl gives the product a good flavor, inhibits the growth of microorganisms, promotes lipid oxidation, and affects the activity of lipid oxygenase and lipid hydrolyzyme. Different studies have different opinions on the effect of NaCl content on lipid hydrolysaling, some studies have suggested that increased NaCl content can promote lipid hydrolysaling, and others have suggested that NaCl content has little effect. Excessive sodium intake is thought to induce cardiovascular diseases such as high blood pressure, so it is necessary to study the effects of NaCl levels on lipid oxidation in Chinese dry sausages. However, the mechanism of the effect of NaCl content on protein oxidation, fat oxidation and hydrolysing has not been explored.
Bing Zhao and Shunliang Zhang of the China Meat and Food Research Center tested the effects of NaCl content on protein oxidation, lipid hydrolysing and oxidation, and their relationship during the processing of Chinese dry sausages. This will help to study the mechanism by which NaCl content regulates protein and lipid changes and improve the quality of dry sausage products.
changes in the activity of lipases during results and discussion
processing
changes in the activity of neutral lipases during processing
hydrolyzing of glycerides is mainly carried out by neutral lipases. Changes in neutral lipase activity during Chinese dry sausage processing are shown in Figure 1. Neutral lipase activity showed significant changes in the processing process (
P
<0.05), reaching maximum value after the marinating stage, and the activity of neutral lipase decreased rapidly in the latter two groups. The neutral lipase activity of LS group (2% (
m
/
m
) NaCl) and HS group (4% (
m
/
m
) NaCl were 5.66 U/g and 7.48 U/g proteins, respectively, in the marinating phase. The activity of the LS group samples was significantly lower than that of the HS group samples (
P
<0.05), indicating that the NaCl content affected the neutral lipase activity content and the appropriate NaCl concentration contributed to the increase of neutral lipase activity.
Figure 1 Changes in neutral lipase activity during dry sausage processing in China
Changes in acidic lipase activity during processing
Figure 2 summarizes the activity of acidic lipase in dry sausage processing in China. Acid lipase activity showed significant changes in the processing process (
P
<0.05), reached maximum after the marinating stage, decreased rapidly in the later stage, and the trend of acidic lipase activity in both groups was similar, with similar trends to changes in neutral lipase activity. The lipase activity of the LS and HS groups was 4.50 U/g and 8.39 U/g proteins, respectively, during the curing phase, with significant differences (
P
<0.05) throughout the process. This result is similar to other studies, indicating that proper NaCl concentrations can help increase the activity of acidic lipases and speed up lipid and hydrolyzing.
Figure 2 Changes in acidic lipase activity during dry sausage processing in China
Changes in phospholipase activity during processing
Changes in phospholipase activity during the processing of dried sausages in China are shown in Figure 3. The activity level of phospholipase showed significant changes in the processing process (
P
<0.05), the maximum value was reached after drying 5 d, and the activity of phospholipase decreased rapidly in the latter two groups. The activity of phospholipidase after drying 5 d in LS group and HS group was 3.05 U/g protein and 3.50 U/g protein, respectively, indicating that the appropriate NaCl concentration helps to increase the activity of phospholipase, which is the main endogenous enzyme that forms free fatty acids. Changes in phospholipase activity were associated with changes in neutral lipids, free fatty acids and phospholipid content during the processing of the two groups. Therefore, the change of phospholipidase activity reflects the corresponding change of free fatty acid and phospholipid content.
3 Changes in phospholipase activity during the processing of dried sausages in China
the results show that NaCl promotes the activity of lipase, possibly because high levels of NaCl accelerate the oxidation of fatty acids. Enzymes, as a protein, dissolve more easily in a certain concentration of NaCl solution than in pure water. Due to diffusion differences, the NaCl content in the muscle is higher than that of adipose tissue, but may still have some beneficial effects on endogenetic enzyme systems. NaCl's activation of lipase activity may also be associated with water content, water activity and pH.
the peroxide value during processing
lipid oxidation is a free-based chain reaction that occurs during processing. The product of early oxidation is peroxide, peroxide is very unstable, easy to be oxidized, and produce some small harmful compounds, such as aldehyde, ketones and so on. Therefore, the peroxide value is mainly used to evaluate the amount of hydrogen peroxide produced by lipid oxidation. If hydrogen peroxide is generated at a rate less than its decomposition rate, the peroxide value begins to decrease. In general, the peroxide value increased to a certain extent and gradually decreased, so that the harm of lipids increased.
of peroxide during the processing of Chinese dry sausages is shown in Figure 4. Peroxide values showed sharp fluctuations throughout the processing process, with an upward trend at the beginning and a downward trend in the later stages. Both groups of dried sausages showed significant changes in peroxide values (
P
<0.05) during processing, reaching maximum value after fermentation and rapid decline in the latter stages. After fermentation, the peroxidation values of LS group and HS group are 0.06 meq/kg and 0.08 meq/kg, respectively, indicating that the appropriate NaCl concentration can promote the formation of peroxide value, leading to the increase of peroxide value and speed up the rate of lipid oxidation. As a result, the peroxidation value of the HS group is still significantly higher than that of the LS
P
<0.05).
Figure 4 Changes in peroxides during dry sausage processing in China
Changes in the value of
TBARS
during processing
TBARS values assess the amount of aldehyde produced by lipid dioxide, the representative compound is acetaldehyde (MDA). The TBARS value also reflects the degree of lipid oxidation. Figure 5 summarizes the changes in the value of TBARS during the processing of dried sausages in China. The trend of change in TBARS values is to go up and down first, with no significant change during pickling, fermentation and drying of 5 d. The trend of change of TBARS value is similar to the trend of change of peroxide value, and there are still significant differences between the two groups at the same stage (
P
<0.05) throughout the process.
Figure 5 Changes in TBARS values during dry sausage processing in China
both groups of TBARS values changed significantly in the processing process (
P
<0.05), reached maximum value after fermentation, and decreased rapidly in the latter stages. In general, if peroxide lipids are just produced, the TBARS value reaches a maximum later than the peroxide lipids reach a maximum because they test different substances. However, the maximum value of TBARS and peroxide occurs simultaneously, possibly due to the reaction of propylene due to the possible reaction of propylene due to free amino acids and other small molecular products in the form of dual-phenolic group compounds during processing. As a result, TBARS values show a downward trend in the later stages. The TBARS values of raw meat and sausages at different stages of processing are shown in Figure 3. The TBARS values of the LS and HS groups reached a maximum of 0.27 mg/100 g and 0.32 mg/100 g, respectively, after fermentation.
in the process
Changes in
of LOX
Figure 6 shows LOX activity of raw meat and sausages during different processing periods. Changes in LOX activity are similar to TBARS values. LOX activity in cured meat is maximized and then decreases rapidly, but LOX activity in raw meat samples is much higher than in cured meat. This is mainly due to the structure of LOX, which is a non-hemoglobin iron protein. The catalytic activity of LOX is closely related to the presence of iron ions. LOX is inactive when the iron ion is Fe
2 plus
, and is activated when Fe
2 plus
is converted to Fe
3 plus
. In raw meat, iron mainly exists in the form of Fe
2 plus
, making LOX inactive and less active, while in the process of marinating, when hydroxide is formed, Fe
2 plus
is converted into Fe
3 plus
, LOX is quickly significantly activated.(SH-group) stabilizes LOX activity, hydrogen peroxide oxidizes the SH-group, causing LOX inferation.
6 Changes in LOX activity during the processing of dried sausages
Conclusion
study shows that The content of NaCl pickled salts has a significant effect on protein oxidation, lipid oxidation and lipolyticity in dry sausage production in China, and adjusting NaCl concentrations can increase enzyme activity and ultimately lipid hydrolyzing and oxidation. 4% of the protein oxidation of the NaCl group, the activity of phospholipase, neutral lipase and acidic lipase, and POV, TBARS, LOX values were higher than 2% of the NaCl group. Adjusting the concentration of NaCl to regulate the activity of enzymes is of great significance to the quality and flavor control of Chinese dry sausages. For the future development prospects, the relationship between protein oxidation, lipid oxidation and lipolytic and flavor compound formation in the production of Chinese dry sausages will be further studied.
Changes of protein oxidation, lipid oxidation and lipolysis in Chinese dry sausage with different sodium chloride curing salt content
。 Bing Zhao, Huimin Zhou, Shunliang Zhang*, Xiaoqian Pan, Su Li, Ning Zhu, Qianrong Wu, Shouwei Wang, Xiaoling Qiao, Wenhua Chen
China Meat Research Centre, Beijing Academy of Food Sciences, Beijing, 100068, China
*Corresponding.
E-mail address: 270157988@qq.com
。 Abstract
The effect of sodium chloride (NaCl) curing salt content on protein oxidation, lipid oxidation and lipolysis of Chinese dry sausage was investigated. Two groups Chinese dry sausages with 2% and 4% (m/m) salt content were studied. The degree of protein oxidation increased during the processes in two groups sausages, while the content of phospholipids decreased, neutral lipids and free fatty acids increased. The degree of protein oxidation, lipid oxidation and lipolysis in 4% NaCl content group was higher than those in 2% NaCl content group, while 4% NaCl content group has higher lipase activity. In conclusion, 4。