The course is now open: the variety of lychees and the identification method
It's the season to eat lychees again ~ There are many varieties of Chinese lychees, more than a hundred kinds, the most common of which are guiwei, concubine laughter, glutinous rice fins, etc., but you certainly don't know that there are many varieties of lychees ~ teach you to identify them for a second, whether it is forced by people or to prevent being deceived, it is a good skill
Maturation: Late April - late May
March red
Because it ripens in late March of the lunar calendar, it is called March Red. It is the earliest mature species.
Maturation: Late May to early June
The concubine laughed
Generally the most common is the concubine smile in the morning, which looks large, full, and the color contrast is particularly obvious, often a lychee is red and green, like a concubine hiding her face and smiling. The core is small, juicy and sweet, but it will have a sour taste when collected too early.
Maturation: late May to mid-June
White sugar poppies
White sugar poppy, also called bee poppy, means to have a honey flavor. This is a variety often used by profiteers to counterfeit glutinous rice fins, the fruit body is relatively large, flat, eccentric in shape, the core is not large, but not as small as glutinous rice fins, the tip cone type, less juice, the taste is passable. In short, each point is like glutinous rice fin but not as good as glutinous rice fin.
Maturation: early June to mid-June
Ash and black leaves
Both are core juicy, but very sweet, and the black leaves are even sweeter, sweeter than glutinous rice and cinnamon flavor, sweet and sad. The picture above is white wax, the fruit is heart-shaped, medium in size, the skin is reddish with yellow wax, thick and brittle, and the cracks are smooth.
The black leaves are characterized by a dark red color with a very bright skin background, and the skin protrusions are dark light green, as shown above.
Maturation: late June - early July
Hang green
Zengcheng hanging green, just like that love is not what you want to buy, you can buy it, the original tree tens of thousands of hundreds of thousands of grains do not say, the external fourth generation of hundreds of dollars a pair, it is better to eat two eggs. The fruit is as large as a chicken print, the core is as small as a pea, the skin is dark red and green, the cracks are flat, the suture line is obvious, the meat is thick and crisp, thick and sweet and juicy, and the entrance is fragrant.
Maturation: mid-June - early July
Cinnamon flavor
Cinnamon is actually the easiest to identify by appearance, which is very different from other lychees, that is, the fruit body is fuller, and the peel has a sharp edge. Cinnamon flavor, juice is no more and no less, the flesh tastes refreshing, sweet but not greasy, the core is generally very small pointed cone type, there are also knots that are not good is the large core.
Maturation: Mid-June to early July
Glutinous rice fin
The shape of the fruit is partial to the heart, crooked handle, the fruit shape is larger, the color is bright red and waxy yellow, the skin and spine are not obvious, the meat is milky and translucent, the meat is rich, the taste is tender and smooth, the taste is extremely sweet, the core is thin, and the natural sugar content is high. The reason for the crooked stem is that glutinous rice fins are generally one stalk and two fruits, but one of the fruits is stunted. Fruit vendors often on the street are the varieties with the highest unit price.
The above are the more common varieties. Many people evaluate whether lychees are delicious or not, but they are limited to whether they are sweet or not, in fact, the most important thing about lychees is the taste of the lychees, which cannot be said (just like the taste of mangoes and pineapples). And this smell of lychees, only fresh lychees will have, after a long-distance transport of frozen lychees, although it can be as sweet as fresh, but the smell of lychees disappeared without a trace.
Lychee is not good or not, and the edible rate is an important indicator. The edible rate of lychee varieties in Guangdong is about 75% on average, and the edible rate of more than 80% of the varieties is more than 70%, of which glutinous rice fin, white wax, concubine smile, etc. are all varieties with high juice yield and edible rate.
Compare one to the other
Which lychee has the most meat?
Eat lychees, if you like a big one, you must say "Lychee King" - Hainan Purple Niangxi, one can weigh up to 80 grams, to know that everyone's favorite cinnamon flavor is only 18.5 grams on average, even if it is glutinous rice fins, it takes 3 and a half to catch up with The Purple Niangxi.
The sugar content of lychee pulp is usually 20%-22%, if it is less than 18%, it is not sweet enough. At the same time, lychee is also a fruit with low acidity, and acid is directly related to the freshness of lychee. The acid content of black leaves is 0.375, which is relatively high, while the acid content of white sugar lychee is 0.05, which is relatively low. In addition, the content of folic acid in lychees is also high, and pregnant women know this very well.
The "Big Mac" in Lychee
The most complete lychee preservation and storage Dafa
We all know that the surface of the lychee has a layer of armor-like shell (peel), in fact, it is very "fragile". Lychees are actually one of the least resistant fruits to storage. Lychee is not easy to store and has a certain relationship with its structure and growth environment. Those shells that seem to be very hard, in fact, they are not only thin but also have a lot of gaps between their internal tissues.
Lychee peel is composed of three layers of tissue: the outermost layer is anthocyanin-containing grid tissue cells with many pores in the tissue; the middle layer is a sponge-like tissue with a large cell space, accounting for most of the peel; and the innermost layer is a very thin layer of parenchymal cells. This structure is crisp and thin, and the moisture is very easy to escape through the gap, accelerating the dehydration of the lychee.
Lychees are also easily contaminated by various microorganisms. Lychee is produced in tropical and subtropical regions, mature in the summer of high temperature and high humidity, this season is also very suitable for the production of microorganisms and pests, therefore, lychee is very prone to decay and deterioration after harvesting. Microbial infestation is not only one of the causes of browning in lychee storage, but also causes lychee to rot and deteriorate. Therefore, if there is no antiseptic preservation treatment on lychees, many people will not be able to eat lychees at all.
Storage method of lychee
At present, the preservation and storage methods of lychee are:
1. Low temperature storage
Temperature management is one of the most effective ways to extend the storage life of fresh fruits, mainly because low temperatures can reduce the physiological and metabolic response of fruits. Respiration depletes the nutrients accumulated during fruit development and reduces the quality of the fruit. For every 10 ° C decrease in storage temperature, respiratory activity is reduced by 2-4 times. Therefore, low temperature refrigeration is the simplest and most efficient way to increase the storage life of lychee and control fruit browning. Generally, the recommended storage temperature of lychee is 2-4 ° C. However, some studies have also pointed out that the storage of 0 °C can be stored for about 3 weeks, but after experiments, some lychees are stored at 0 °C. About 2 weeks, the peel appeared cold infestation.
2. Pre-cooled with ice water
Harvested fruits are more sensitive to moisture loss and temperature changes than before harvest. The heat energy generated by respiration increases the temperature of the fruit. After lychee harvest, the temperature will quickly cool down to 3 °C. Stored at low temperatures (5°C), it can reduce the sensitivity to water dispersion loss and disease. Studies have shown that the use of ice water precooling can quickly reduce fruit temperature and physiological response. It also significantly increases the storage life of lychees and delays the browning of the epidermis of lychees.
3. Impregnation treatment
Acid immersion treatment can effectively inhibit the activity of brown peel enzymes, delay the anthocyanin interpretation and pathogenic microbial growth. Using the soaking of organic acids, non-free acids are provided to enter the cell through the cell membrane through osmotic action, forming intracellular free acids, increasing the content of intracellular acids, and reducing the pH value in cells. According to current research reports, citric acid, tartaric acid and oxalic acid can all inhibit the browning reaction of lychee peel. However, the treatment effect of different acids varies depending on the concentration and soaking time.
Different concentrations of acidity and case of lychee peel
4. Chemical treatment
Before, in the circle of friends, Weibo circulated such news everywhere, rumors of what lychee bubble medicine and so on. Regarding the news of lychee soaking medicine, the source does not know where it came from. But when the rumors came out, it actually hurt the growers very much. This is the face of an unreasonable price reduction for lychees. In fact, in the picking process of lychees, foaming with chemical reagents is a very conventional treatment method. Moreover, there are provisions in China's agricultural standards that longan and lychee can be cleaned with bleaching powder solution after picking, and can also be soaked with fungicide, as long as the fungicide residue meets China's agricultural standards. Similarly, the standard lychee stored at ice temperature also allows soaking lychee with bleach powder and fungicide. The aim is to moisturize, preserve and inhibit browning reactions
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5. Packaging handling method
Packaging treatment reduces peel dehydration, avoids mechanical damage and maintains fruit quality. Gas-changing packaging (map) is a technology that can extend the life of fresh fruit products by means of gas components around the covered fruit in the packaging method. The effects of map on fruit products include reducing respiration and reducing the loss of respiratory mechanism, inhibiting the production and effect of ethylene, and delaying the post-ripening effect of fruits. It is currently used in post-harvest preservation technology.
6. Room temperature preservation method
The shelf life of this method is short (2-3 days), and it is only suitable for close sales;