Text: Bread Clip Knowledge
Edit|Bread Clip Knowledge
«——【Preamble】】 ——»
The Chinese round snail, commonly known as the snail and snail, is a mollusk of the family Snail family, which is endemic to the mainland.
The Chinese round snail has the advantages of fast growth, strong fecundity, high meat yield, and the meat is delicious, rich in nutrition, and has certain medicinal value, and is deeply loved by people.
Chinese round snail is one of the main raw materials of Liuzhou snail flour and fried snail, and its market demand is increasing year by year, and the breeding area and output in Guangxi are also increasing year by year.
The muscle quality of aquatic products is affected by factors such as bait, environment, water body, source, season, etc., and different breeding modes will also have an impact on muscle quality.
The research of Chinese round snail mainly focuses on bait, toxicity and breeding mode, and there is still a lack of systematic analysis of the germplasm characteristics of muscle nutritional quality in different breeding populations.
Based on the analysis of nutrient composition and quality evaluation of the muscles of three Chinese round snail breeding populations, the research on germplasm characteristics and other related studies was carried out, in order to provide reference for the resource utilization, germplasm innovation and improved seed breeding of Chinese round snail.
«——【Materials and Methods·】——»
Three Chinese round snail breeding groups were collected from the breeding bases of Luchuan County, Yulin City, Liujiang District, Liuzhou City, and Rongshui County, Guangxi Zhuang Autonomous Region, and the growth environment was basically the same, and the bait in the aquaculture water body was ingested.
A total of 180 Chinese round snails with intact shells, fresh vitality and no mechanical damage were selected from each group, and sampling began after fasting for 24 hours.
The Chinese round snails of each group were randomly divided into 3 groups, with 60 snails in each group, and the muscles were taken after shelling, washed and dried and stored at low temperature.
The water content in the muscle was determined by direct drying method (GB/T5009.3-2016), and the crude protein content was determined by Kjeldahl nitrogen determination method (GB/T5009.5-2016).
The crude fat content was determined by Soxhlet extraction method (GB/T5009.6-2016), the crude ash content was determined by the muffle furnace burning method (GB/T5009.4-2016), the amino acid content was determined by high-performance liquid chromatography (GB/T5009.124-2016), and the fatty acid content was determined by gas color.
SPSS25.0 software was used for one-way ANOVA and Duncan's method for multiple comparisons. The results were expressed as "mean ± standard error", and P<0.05 indicated significant differences.
«——【Results and Analysis·】——»
Comparison of the conventional muscle nutrients of the three Chinese round snail breeding populations (see Table 1) showed that the crude fat content of Chinese round snail in Luchuan County and Liujiang District was significantly higher than that in Rongshui County (P<0.05), and the crude protein content of Chinese round snail in Luchuan County was significantly higher than that in Liujiang District and Rongshui County (P<0.05).
Analysis of muscle amino acid composition of three Chinese round snail breeding populations (see Table 2~Table 4) From Table 2, it can be seen that there are 16 kinds of muscle amino acids in the three Chinese round snail breeding populations, and cystine (Cys) was not detected.
Among them, 7 essential amino spectroscopy methods (GB/T5009.168-2016) were used to determine the mineral and trace element content of muscle, and the content of mineral and trace elements in muscle was determined by inductively coupled plasma emission spectrometry (GB5009.268-2016).
The amino acid score (AAS), chemistry score (CS) and essential amino acid index (EAAI) were calculated according to the amino acid scoring standard model recommended by the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO) and the amino acid pattern of whole egg protein.
where: aa is the amino acid content in the muscle of the parmesan tassel; AA (FAO/WHO) is the content of the same amino acid in the scoring model; AA (Egg) is the content of the same amino acid in whole egg protein (mg/gpro).
a、b、c…… j为巴马拟缨鱼肌肉蛋白质的必需氨基酸含量（mg/gpro）；ae、be、ce…… je为全鸡蛋蛋白质的必需氨基酸含量（mg/gpro）。
The atherosclerosis index (IA) and thrombosis index (IT) were used to assess the effect of fatty acids in the muscles of the Chinese round snail on the risk of cardiovascular disease in the feeding population.
(EA) (EA) 䉌(NEAA) (NEA)
以及谷氨酸（Glu）、精氨酸（Arg）和天门冬氨酸（Asp）含量较高，组氨酸（His）和蛋氨酸（Met）含量较低。
The contents of amino acids in the muscles of the S. sinensis population in Luchuan County were significantly higher than those in the other groups (P<0.05), and the TAA, EAA and FAA in the muscles of the S. sinensis population in Luchuan County were significantly higher than those in the other groups (P<0.05).
It can be seen from Tables 3 and 4 that the AAS of the muscles of the three Chinese round snail breeding populations was between 0.33~2.06, the first limiting amino acid was methionine + cystine, and the second limiting amino acid was valine.
The CS range of Chinese round snail muscle was 0.25~1.72, the first limiting amino acid was methionine + cystine, and the second limiting amino acid was phenylalanine + tyrosine. The amino acid index of the aquaculture population in Liujiang District reached the highest, which was higher than that of other groups.
It can be seen from Table 5 that 21, 23 and 23 fatty acids were detected in muscle fat in the three Chinese round snail breeding populations in Luchuan County, Liujiang District and Rongshui County, respectively.
Among them, 8 kinds of saturated fatty acids and 13 kinds of unsaturated fatty acids were detected in Luchuan County, including 9 kinds of highly unsaturated fatty acids. Eight saturated fatty acids and 15 unsaturated fatty acids were detected in Liujiang District and Rongshui County, including 10 highly unsaturated fatty acids.
The content of saturated fatty acids in Liujiang District was significantly higher than that in Luchuan County and Bama County (P<0.05), the content of unsaturated fatty acids, polyunsaturated fatty acids and EPA+DHA in Luchuan County was significantly higher than that in Liujiang District and Rongshui County (P<0.05), and the IA and IT indices were significantly lower than those in Liujiang District and Rongshui County (P<0.05).
The results showed that the contents of myristic acid, mountain acid and hexadecaenoic acid in the muscle of Chinese round snail were low, and the contents of palmitic acid, linoleic acid and stearic acid were high.
Table 6 showed that the concentrations of Ca, Mg and Mn in Rongshui County were the highest, which were significantly higher than those in Luchuan County and Liujiang District (P<0.05). The P content of Rongshui County was significantly higher than that in Liujiang District (P<0.05).
The Fe content in Luchuan County was significantly higher than that in Liujiang District and Rongshui County (P<0.05), the Cu content in Liujiang District was significantly higher than that in Luchuan County and Rongshui County (P<0.05), and the Zn and Se contents in Liujiang District were significantly higher than those in Rongshui County (P<0.05).
«——【Discussion·】——»
Analysis of the nutritional composition of Chinese round snail muscleThe main components of muscle include protein, fat and water, which can be used as an important indicator of the nutritional value of meat.
The crude protein content and crude fat content of the muscles of the three Chinese round snail breeding populations were 11.29%~15.35%, and the crude fat content was 0.27%~0.42%, and the results were consistent.
The protein and fat content of some common shellfish is 9.42% crude protein and 0.69% crude fat content of spinnaker mussels.
The crude protein content and crude fat content of freshwater clams in China were 9.30%, 1.00%, 7.00% and 1.40% respectively, and 10.40% and 0.96% respectively.
The crude protein content of Shih Tzu tongue was 11.18%, the crude fat content was 0.53%, and the crude protein content of clams was 10.7%, and the crude fat content was 1.15%.
Compared with other shellfish, the muscle content of Chinese round snail is higher in protein and lower in fat, indicating that the muscle of Chinese round snail is a high-protein and low-fat meat, and Chinese round snail is a high-quality aquaculture species.
For example, the analysis of amino acid composition and content in the muscle of the Chinese round snail In this study, it was found that the muscles of the three Chinese round snail breeding populations were rich in amino acids, and the content of the 16 detected amino acids was the highest, followed by Arg and Asp. His and Met were the lowest, and the results were similar.
Glu is not only an important umami amino acid, but also a major source of energy for tissues such as the liver, intestines, muscles, and kidneys, and it plays an important role in regulating fish metabolism, gene expression, and immunity.
FAA accounted for 40.43%~42.10% of TAA in the muscles of the three Chinese snail farming populations, which was higher than that of marine fish such as rainbow trout (36.77%~39.08%), grouper (35.83%~36.01%) and Ussuri whitefish (28.95%), and also higher than that of freshwater fish such as herring (37.53%), grass carp (37.69%), carp (37.94%) and crucian carp (38.47%).
It was comparable to some marine shellfish such as Omi oyster (42.16%), nine-hole abalone (40.15%), and clam (40.98%~42.73%), indicating that the Chinese round snail had a higher edible flavor and delicious taste.
According to the ideal model of FAO/WHO, the protein quality of ΣEAA/ΣTAA is about 40% and ΣEAA/ΣNEAA is more than 60%.
IN THIS EXPERIMENT, THE ΣEAA/ΣTAA OF THE MUSCLES OF THE THREE CHINESE ROUND SNAIL BREEDING POPULATIONS WERE 32.87%, 32.87% AND 33.49%, RESPECTIVELY, AND THE ΣEAA/ΣNEAA WERE 59.58%, 59.50% AND 61.24%, RESPECTIVELY, WHICH WERE RELATIVELY CLOSE TO THE STANDARD OF ESSENTIAL AMINO ACID BALANCE MODEL FORMULATED IN FAO1973.
The FAA and EAA contents of S. sinensis muscle in Luchuan County were the highest, but the EAAI of S. sinensis was the highest in Liujiang District (83.06), indicating that the nutritional value of S. sinensis muscle in Luchuan County and Liujiang District was relatively high.
As one of the main components of cell membrane, fatty acids play an important role in the metabolism of organisms.
In this study, 21, 23 and 23 amino acids were detected in muscle fat in the three Chinese round snail breeding populations, respectively, and palmitic acid had the highest content in FA, which could induce lipid precipitation in skeletal muscle cells.
Among UFAs, Luchuan County had the highest DHA content, and Liujiang District and Rongshui County had the highest oleic acid content. High levels of PUFAs enhance odor and, to a certain extent, serve as one of the indicators of the juiciness of the muscles.
In this experiment, the PUFA content of the three Chinese round snail breeding populations was quite different, and the total PUFA content of the population in Luchuan County was the highest (62.88%), which may be caused by the different population sources, ages, genders, temperature and tissues of the breeding groups, or it is also possible that the lipids ingested are directly transferred to body lipids and are rarely modified.
The IA of the three Chinese round snail breeding groups were 0.24, 0.38 and 0.42, respectively, and the IT was 0.28, 0.53 and 0.76, respectively, which were much lower than those of pork (IA0.60, IT1.37), beef (IA0.72, IT1.06) and mutton (IA1.00 and IT1.58).
Analysis of the composition and content of mineral elements in the muscle of the Chinese round snail The inorganic salt elements required by the human body must be obtained from food, and the muscle of the Chinese round snail is rich in inorganic salts, among which the content of P and Ca is the highest among the inorganic salts detected.
Guangxi is a typical karst landform, and the bedrock in the karst habitat is mostly soluble salts such as CaCO3, and the Ca in the soil infiltrates into the water body.
However, the soil erosion and vegetation degradation in the karst rocky desertification area of Guangxi are serious, the soil available phosphorus content is low, and P element is enriched in the water body in large quantities.
It may cause the Ca and P content in the muscle of Chinese round snail to be higher than that of other trace elements. Inorganic salts are an important component of the body, and insufficient or excessive intake can damage the body.
The composition characteristics of inorganic salts in the muscles of Chinese round snails were consistent with the ecological environment where the breeding sites were located, which was consistent with the results of the study of inorganic salts in fish.
«——【·Conclusion·】——»
The results of this study showed that the crude protein content, crude fat content, umami amino acid and unsaturated fatty acid content were higher in the muscle of the three breeding groups.
This also shows that the Chinese round snail is a high-quality high-protein, low-fat food source, and the nutritional value and flavor of the muscle muscle of the Luchuan County group are better than those of other groups.