First, what is cutting vegetables?
In recent years, a new type of vegetable processing product that is convenient, fast, and nutritious has emerged in the supermarkets and fast food industries in large and medium-sized cities in China. We call this cut vegetables, or semi-processed vegetables. It refers to the steps of cleaning, refurbishing, peeling and slicing of fresh fruit and vegetable raw materials. Finally, it is packed in plastic film bags or plastic trays and packed in plastic film for consumption by consumers immediately or in the food and beverage industry. Processed products. Cutting vegetables is a kind of comprehensive technical project, although it belongs to the category of clean dishes, but it requires more scientific and technological content than ordinary net dishes and combines vegetable preservation and processing techniques.
Second, cutting vegetables processing technology
The main types of cutting vegetables are onions, carrots, potatoes, lettuce, cabbage and so on.
Vegetables used for peeling must be easily cleaned and peeled, and the ingredients must be of good quality. Proper storage and careful dressing before processing are very important for good quality vegetable processing products.
But not all varieties are suitable
(I) Peeling and slicing
In industrial production, mechanical, chemical or high-pressure steam peeling is usually used, but the ideal method is manual peeling using a sharp cutting tool, because mechanical peeling, steam peeling and caustic peeling will seriously damage fruits and vegetables. The cell wall causes a large amount of cell juice to flow out, increasing the possibility of microbial growth and enzyme browning, thus impairing product quality.
In addition, the cutting size also has an impact on the quality of the product. For example, leaf lettuce is cut into 1 mm and 3 mm sizes and stored at 2°C for 11 days. The quality of the former is much worse than the latter. The more broken the cut, the greater the surface area of ​​the cut vegetables, and the unfavorable preservation.
Cutting tools and pads used for cutting need to be disinfected (eg with 1% hypochlorite solution). The cutting machine must be firmly installed because the vibrating machinery can damage the surface of the vegetable slices.
(b) Cleaning, washing and draining
In general, washing should be performed after peeling or slicing. If cabbage and cabbage are shredded, they must be washed once more. Washing water must meet drinking water standards and the temperature should preferably be less than 5°C. Adding some additives such as citric acid, sodium hypochlorite, etc. in the washing water can reduce the amount of microorganisms and prevent the enzyme reaction, thus improving the shelf life and the sensory quality of the product. According to reports, before or after peeling or slicing, when the amount of chlorine in the washing water or citric acid is 100 mg/L to 200 mg/L, the shelf life can be effectively extended. However, after the chlorine treatment, the vegetable raw materials should be cleaned to reduce the chlorine concentration to the drinking water standard, otherwise it will lead to the product's failure and wilting, and the odor with residual chlorine.
After washing vegetables, if they are not treated with water, they are more likely to be corrupt than those that are not washed. If the water-removed vegetables are also accompanied by more than 1% of water, they are usually removed using a centrifugal dehydrator.
In the case of vegetables, such as peeled potatoes, the main quality issue is browning, and browning causes a poor appearance. Traditionally, sulfites are generally used to inhibit browning, but the use of sulfites can have some adverse effects on the human body. The combination of citric acid and ascorbic acid is likely to become a sulfite substitute.
The final operation in cutting vegetable production is packaging. When preparing fresh vegetables, the most used packaging method is map. That is, a gas environment with a composition of 2%-5% of carbon dioxide, 2%-5% of oxygen, and the balance of nitrogen is obtained.
(3) Storage, distribution and retail
In general. Temperature is the main factor affecting the shelf life. After cutting vegetables, they should be stored in cold storage immediately. The storage temperature must be ≤5°C to obtain sufficient shelf life and ensure food safety. During storage, the packaging pouch should be placed in a flat shape, otherwise the center of the product is not easy to cool, especially when it is stored in a cardboard box.
Use a freezer or cold storage vehicle when distributing. On the one hand, it should be noted that the doors of refrigerated trucks should not be opened or closed frequently to avoid fluctuations in product temperature, which is higher than 5°C, which is not conducive to the maintenance of product quality. On the other hand, the retractable insulated containers and coolant (such as ice) are used to solve the door. Product temperature fluctuations caused by frequent opening and closing, such as cutting cabbage with a 0.04 mm polyethylene bag and placing in a polystyrene foam container, all the gaps filled with ice, at 30 °C environment, after 12 hours, product temperature Can stay below 25°C.
At the time of retail, in order to maintain product quality, cold storage facilities such as refrigerators should be provided, and the storage temperature should be ≤ 5°C.
As a commodity, vegetables are also no exception to certain packaging. This is an important part of the commercialization of vegetables and plays an important role in ensuring the quality of vegetable products. With the development and circulation of vegetable products, the demand for packaging has become more and more urgent. Reasonable packaging can reduce the mechanical damage during storage and transportation, reduce the spread of disease and moisture evaporation, and ensure the quality of goods. Packaging is generally divided into two categories: one is transport packaging; the other is product packaging. At present, there are many types of transport packaging in China, including crates, bamboo baskets, plastic boxes, cartons, sacks, straw bags, and nylon mesh bags. The commodity packaging of vegetables is generally conducted at the place of production and the wholesale market, and some are also conducted at retail stores. The packaging material is mainly plastic film. Implementing commodity packaging prevents moisture from evaporating and keeps vegetables fresh. It can also beautify the appearance, improve the quality of goods, and facilitate consumers to carry it. Vegetable packaging should generally follow the following points: First, the quality of vegetables is good, and the weight is accurate; Second, as far as possible so that customers can see the situation of the packaging of vegetables inside; Third, avoid the use of colored packaging to confuse the color of the vegetable itself; four is Some rare vegetables should have their nutritional value and instructions for their consumption. Plastic film packaging is generally poor in air permeability, and some small holes should be made to exchange the internal and external gases in order to reduce the decay of vegetables.
Diagnostic reagents can be divided into two categories: in vivo diagnostic reagents and in vitro diagnostic reagents. It is mostly a reagent for detection by the reaction between antigen and antibody.
A: Classification of in vitro diagnostic reagents:
1. In vitro biodiagnostic reagents managed as drugs include:
1. Blood type and tissue type reagents;
2. Microbial antigen, antibody and nucleic acid detection reagents;
3. Tumor marker reagents;
4. Immunohistochemistry and human tissue cell reagents;
5. Human genetic testing reagents;
6. Biochips;
7. Allergy diagnostic reagents.
2. In vitro reagents managed as medical devices include:
1. Clinical basic test reagents;
2. Clinical chemistry reagents;
3. Blood gas and electrolyte determination reagents;
4. Vitamin determination reagents;
5. Cell histochemical stains;
6. Autoimmune diagnostic reagents;
7. Microbiological test reagents.
B: According to medical test items, clinical diagnostic reagents can be roughly divided into clinical chemical test reagents, immunology and
Serological testing reagents, hematological and cytogenetic testing reagents, microbiological testing reagents, body fluid excretion
Detection reagents, genetic diagnosis reagents, etc. Among them, the market share of clinical chemistry
The largest, close to 34%; followed by the immunology market, accounting for about 29%. Novel immunodiagnostic reagents and genetic diagnostic tests
The reagent was developed in the late 1980s, and it is the most common diagnostic reagent for all current diagnostic reagents, regardless of technology or market.
The fastest growing product.
Urine Rapid Test Kit,Rapid Test Kit 6-Panel,Toxoplasma rapid test kits,Fecal Occult Blood Test
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