"Crayfish are delicious, but they're too hard to peel." Entering the shrimp season, many crayfish lovers have the same troubles as Xiaowen. "Every time I finish eating shrimp shells, I pile up a table, I look at a lot, but I don't actually eat much meat."
This problem, which has plagued consumers for many years, has made new progress with the efforts of the Institute of Agricultural Products Processing and Nuclear Agricultural Technology of the Hubei Academy of Agricultural Sciences. Shi Liu, an associate researcher at the institute, told Jiupai News that the mainstream shrimp peeling technology on the market is manual shrimp peeling, and the enterprises she contacted had to employ more than 8,000 people during the peak period, and the daily salary of a skilled shrimp peeling worker was between 500 yuan and 600 yuan, and the cost of enterprise employment was high.
Last year, her team successfully developed a shrimp peeling machine that can directly peel raw shrimp into shrimp, "At present, its working efficiency is to peel 100 kilograms of shrimp per hour, and the shrimp of a crayfish accounts for 20% to 25% of the weight of the whole shrimp, which is equivalent to the machine can process 500 kilograms of crayfish per hour." And this value is equivalent to about 50 times that of manual labor.
In addition, the shells of crayfish are also highly nutritious. According to Shi Liu, the main components of crayfish shells are protein, calcium, and some minerals. Although it is currently mainly used as a feed raw material on the market, it may be used in the future to treat skin trauma, joint calcium deficiency and other diseases, and her team is also conducting research on this recently.
On May 10, Shi Liu, an associate researcher at the Institute of Agricultural Products Processing and Nuclear Agricultural Technology of Hubei Academy of Agricultural Sciences, was interviewed by Jiupai News. Photo/Jiupai News Qin Ke
[1] "One-click shrimp peeling", the texture of shrimp meat is not much different from that of a home kitchen
Jiupai News: What are the mainstream shrimp peeling techniques on the market now?
Shi Liu: We visited more than 10 large and medium-sized crayfish processing factories in Qianjiang and found that the mainstream shelling technology is still hot scalding, and then manual shelling. At present, the relevant machinery and equipment need to be strengthened, so at present, manual shrimp peeling is a more widely used technology.
Jiupai News: A brief introduction to the shrimp peeling machinery and equipment.
Shi Liu: This device was successfully developed last year, and it took more than two years before and after. It can peel 100 kg of shrimp per hour, and the peeling rate is more than 90.74%, and this value has increased recently. Our prototype has already been applied in two companies in Qianjiang, and it is still being further improved, so it has not yet been put into the market.
Its practical machine peeling shrimp, it not only has to complete the step of peeling shrimp, but also other steps need to be operated in the machine. Unlike the factory, when using the shrimp peeling machine, we use fresh shrimp, so we first dormant the shrimp to reduce their vitality and control the behavior of the shrimp, and then enter the corresponding channel for head and tail orientation, and then realize the separation of head and tail. Our separation mainly uses multi-roller extrusion to squeeze the shrimp tail, that is, the shrimp, out of the shrimp shell.
The crayfish and shrimp peeling machine developed by Shi Liu's team. Photo/Jiupai News Yang Zhen
Jiupai News: Is there a big difference in texture between the shrimp meat squeezed out by machine and the shrimp meat peeled by hand?
Shi Yanagi: As mentioned earlier, our machine uses raw shrimp to peel the shell directly, and the texture of this shrimp meat is similar to that of the shrimp we make by hand at home. The shrimp that are manually shelled in the factory are first blanched at high temperatures, and the protein is denatured, and then the shrimp are peeled by hand, so what they make is cooked shrimp. There is a certain difference between the two.
Jiupai News: What are the difficulties in researching shrimp peeling machinery and equipment?
Shiliu: The processing equipment for crayfish, or the large-scale processing equipment for freshwater products, is mainly improved on the basis of seafood processing equipment. But there is a major difference between crayfish and sea shrimp, that is, the shell of crayfish is very hard, and its head proportion is relatively large, and the proportion of shrimp tail is relatively small. So we first have to separate the head and tail, and then we have to peel the shrimp.
For example, the ultra-high pressure technology used in the research is mainly used to promote the separation of shrimp shell and shrimp meat, as well as the shape adjustment of shrimp tails in the machine, so as to achieve the purpose of improving the shrimp peeling rate.
Jiupai News: If the shrimp peeling technology can be improved in a large area, what changes will it bring to the crayfish industry chain?
Shi Liu: The shrimp peeling technology and equipment we are developing now are mainly used in crayfish processing enterprises, especially in the current momentum of prefabricated dishes, and the cooked semi-finished seasoned crayfish will enter more families and market entities.
In addition, it can reduce the labor cost of enterprises and greatly promote the scale of processing. Take Qianjiang, Hubei Province, for example, the factory will recruit a large number of processing workers, provide them with accommodation, and wages. I learned that during the peak period, a single shrimp peeling worker has to recruit more than 8,000 people, and the salary of each worker is billed by the hour or day, and the salary of a skilled worker is about 500 yuan to 600 yuan a day, which is a very huge expense for the enterprise.
Now our crayfish peeling machine can peel shrimp, at present its working efficiency is to peel 100 kg of shrimp per hour, and the shrimp of a crayfish accounts for 20% to 25% of the weight of the whole shrimp, according to 20%, it is equivalent to the machine can process 500 kg of crayfish per hour. And a skilled worker can peel 1.5 kg to 2 kg of shrimp in an hour. Therefore, one set of shrimp peeling machine is equivalent to about 50 people.
[2] Shrimp shells are mainly used for aquatic feed, and can also be used for wound recovery and calcium supplementation
Jiupai News: How many of the shells of crayfish can be recycled?
Shi Liu: According to our survey results, there are two main sources of recycled shrimp shells, one is factories and the other is catering; The proportion of household consumption is small, and the difficulty of investment is relatively large, so we do not consider it.
We have basically achieved 100% utilization of the by-products recovered from the factory, whether it is shrimp head shell or shrimp tail shell. This kind of product has high nutritional value, but the technology of using shrimp shells for intensive processing is not mature, and the most reuse is to use them as aquatic feed. This operation is also very simple, after recycling, dry and crush, and then classify, and it is completed.
The shrimp shells recovered from the catering industry are also mainly used for feed, but the non-feeding parts of them need to be removed, such as plastic bowls and chopsticks, and then applied uniformly.
Jiupai News: What other recycling can shrimp shells make?
Stone willow: The main components of crayfish shells are protein, calcium, polysaccharides, and some minerals. Calcium is an essential element of the human body, and this aspect can be made into basic calcium supplements, such as repairing human joints.
Crayfish also contains a lot of polysaccharides, which can be processed into chitosan and chitin. From the food aspect, it is a good preservative and can also adjust the texture of the food. In medicine, it can also be used for skin regeneration, such as applying it to the wound after a burn to promote the growth rate of new skin.
In addition, I also learned some reports about the shrimp shells woven into clothes, which is the use of electrospinning technology to make shrimp shells, and then multi-layer compounding to achieve the effect of type fabric. Because it has relatively strong toughness, it also has a bulletproof function.
Shrimp shell powder made from crayfish shells. Photo/Jiupai News Yang Zhen
Jiupai News: In this way, the utilization value of crayfish shells is very high, why are there fewer finished products on the market?
Shi Liu: There is a certain degree of difficulty in the research on the deep processing of crayfish by-products, and the progress is still in the initial stage, mainly to make low-value fishing feed.
One of the projects we are working on is to extract the active ingredients from crayfish shells and explore their applications in food and medicine.
Crayfish shell still has great application prospects, the current development momentum of crayfish industry in Hubei Province is getting better and better, mining the economic value of crayfish by-products, and more work needs to be done in the future.
[3] Refuting rumors of "stinky ditch" shrimp farming, wild shrimp can not meet market demand
Jiupai News: What are the main crayfish products sold on the market now?
Shiliu: There are three main types, in terms of morphology, including whole shrimp, shrimp balls (also called shrimp tails), and shrimp. Whole shrimp is more commonly used in braised prawns, seasoned shrimp, etc., and shrimp tails are processed semi-finished products, which are often used in catering and making snack foods. Shrimp can be used to make pâtés or in fast food products such as burgers and pizzas.
Jiupai News: It seems that it is rare to see crayfish and shrimp directly sold on the market?
Shiyanagi: As far as I know, a considerable part of crayfish shrimp is used for export. For example, in the United States and Europe, their acceptance of such ingredients that still need to be processed on the table is different from that in China, so shrimp is mainly supplied for export.
Jiupai News: So to say that the so-called "foreigners don't eat crayfish" is also false?
Shi Yanagi: Yes, foreigners eat crayfish, and in 2010, I saw crayfish products in supermarkets in the United States. Our Chinese cuisine only needs to be properly modified in combination with the local diet, and the popularity of foreigners is still very high.
Shiliu's unit produces crayfish products that are guided and participated in the research and development, and the products marked with English characters on the right are mainly used for export. Photo/Jiupai News Yang Zhen
Jiupai News: There have always been rumors that crayfish grow in stinky ditches and the growing environment is not clean, is this really the case?
Stone willow: The so-called "stinky ditch" culture mostly refers to wild shrimp. If we push the crayfish industry back twenty or thirty years, this phenomenon may exist. But in the past decade, the vast majority of shrimp have been farmed in two ways, one is shrimp-rice co-cropping, that is, shrimp growing in rice fields. The other is standardized pond culture. Crayfish bred in both environments, they grow within a controlled environment.
Wild shrimp is far from enough for the huge demand for food and beverages, and basically does not appear on the table of the public.
Jiupai News reporters Yang Zhen, Wen Yanli, Li Yang, reported from Qianjiang, Hubei
Edited by Wang Jiaqing and Ren Zhuo
Please contact the reporter on WeChat: linghaojizhe
[Source: Jiupai News]
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