Vinegar is a sour flavoring agent produced by various fermentations, chemical formula: CHthreeCOOH is a weak electrolyte.Rice orHigh beamIs the raw material.Appropriate fermentation can use carbohydrate (sugarstarch）Of liquid intoalcoholWith carbon dioxide, alcohol is formed by combining with oxygen in the air under the action of some bacteriaacetic acidAnd water.Therefore, the process of vinegar making is the process of further oxidation of alcohol to acetic acid.Vinegar is sour and mellow, fragrant and soft. It is an essential condiment in cooking, and its main ingredients are acetic acid, high-gradealcoholsEtc.Currently used vinegar mainly includes "rice vinegar", "smoked vinegar", "special vinegar", "sweet vinegar", "wine vinegar", "white vinegar", etc. According to different varieties of originacetic acidThe amount of acetic acid is also different, generally between 5% and 8%. The acidity intensity of vinegar is mainly determined by the amount of acetic acid contained in it.for exampleShanxi aged vinegarHas a strong sour taste, andZhenjiang vinegarIts sour taste is soft in acid, but not strong.
Vinegar, the ancient Chinese characters for "Zuo", also for "acyl".According to the record of "acyl palms and acyl compounds" in the Rites of Zhou Dynasty, it can be confirmed that Chinese vinegar had existed in the Western Zhou Dynasty. Jinyang (today's Taiyuan) is one of the birthplaces of our vinegar. It is said that there were vinegar workshops in Jinyang in the 8th century BC, which spread throughout the urban and rural areas during the Spring and Autumn Period. By the Northern Wei Dynasty, Qimin Yaoshu had recorded twenty-two vinegar making methods, such as sorghum sorcery and sorghum sorcery sorcery.Since the Tang and Song Dynasties, due to the progress and development of microorganisms and starter making technology, there had been Daqu, Xiaoqu and Hongqu in the Ming Dynasty. Shanxi vinegar took Hongxin Daqu as the high-quality vinegar Daqu, which integrates various beneficial microbial populations such as Daqu, Xiaoqu and Hongqu.
The earliest record of vinegar is in West Asia, between the Tigris River and the Euphrates River, and at the southern end of Mesopotamia, which is equivalent to the area from Baghdad, the capital of Iraq, to the Persian Gulf. In 5000 BC, this area has entered the Bronze Age. Using the lunar calendar, it started damming to block floods, irrigated agriculture, and produced bread from barley and double grain wheat, and squeezed oil from sesame seeds.It is said that in 5000 BC, Babylonia had the oldest vinegar record, making wine with the juice and sap of date and raisins, and then producing vinegar with wine and beer.Jujube is the fruit of coconut trees. Jujube juice can produce high-quality vinegar.
Our country is avinegar As a big country of production and consumption, vinegar making has a long history, and many people have the habit and hobby of eating vinegar.With the improvement of people's living standards and the further revelation of the functional characteristics of vinegar by scientific research, the use of vinegar is becoming more and more extensive, and the demand for vinegar and its derivatives is growing.The use of vinegar is not only limited to traditional cooking, but also increasingly favored by more and more people as a nutritional drink, health care products, etc.
Great changes have taken place in China's vinegar manufacturing industry. The vinegar manufacturing process using self-priming deep fermentation indicates that China's traditional vinegar industry has entered into industrial production.According to the Zhiyan Data Research Center, there is still a big gap between China and developed countries in terms of independent research, development and application of vinegar production equipment, which also indicates that there is still considerable room for development.The technological advantages of foreign food machinery products are mainly reflected in the high automation of equipment, high efficiency of production, high utilization of food resources, high energy saving of products and the practicality of high-tech.High and new technologies popularized and applied in food machinery abroad include microelectronic technology, photoelectric technology, vacuum technology, membrane separation technology, extrusion technology, microwave technology, ultra micro crushing technology, supercritical extraction technology, ultra-high pressure sterilization technology, low-temperature sterilization technology, intelligent technology, etc. These high and new technologies all contribute to the modernization of vinegar industry.Food machinery equipped with high-tech equipment has improved production efficiency, reduced energy consumption, increased yield, reduced waste, maintained food nutrition and flavor, and improved food quality.Therefore, China's vinegar industry cannot go global without the joint efforts of a large number of food professional and technical talents and related technical talents.
classification
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brief introduction
There is no unified classification method for vinegar due to different brewing materials and technological conditions and different flavors.
1. If classified according to the vinegar production process, it can be divided into brewing vinegar and synthetic vinegar.Brewing vinegar can also be divided intoGrain vinegar(made of grain and other raw materials)Sweet and sour(withmaltose, sucrose, sugar raw materials), wine vinegar (made from edible alcohol and wine tail).Grain vinegarAccording to different processing methods, it can be divided into smoked vinegarSpecial vinegar、aromatic vinegar, bran vinegar, etc.Synthetic vinegar can also be divided into colored vinegar andvinegar(White vinegar can be further divided into ordinary white vinegar and vinegar essence).Vinegar is better to brew vinegar, among whichGrain vinegarIt is better.
2. If classified according to the raw material processing method, the grain raw materials are directly used to make vinegar without cooking and pasting treatment, which is called raw vinegar;The vinegar brewed after steaming and gelatinization is called clinker vinegar.
3. If classified according to saccharified koji used for vinegar making, there are bran koji vinegar and old method koji vinegar.
5. If vinegar is classified according to its color, it can be divided into strong color vinegar, light color vinegar and white vinegar.
6. If classified by flavor,mature vinegarThe vinegar flavor of;The smoked vinegar has a special burnt flavor;Sweet vinegar is added with Chinese medicinal materials, plant spices, etc.
Flavor classification
The brewing of vinegar in China has a long history of more than 2000 years and has a wide variety. Due to the different geographical environment, raw materials and technology of brewing, there are many different regions and different flavors of vinegar.With people's understanding of vinegar, vinegar has developed from a simple condiment tocookType, catering type, health care type andDrinksType, etc.
Cooking type: This kind of vinegar has a acidity of about 5%, strong taste, mellow fragrance, and has the function of eliminating fishy smell, removing mutton smell, and helping freshness.For cooking fishmeatAnd seafood.If brewed white vinegar is used, the original color of the dishes will not be affected.
Catering type: This kind of vinegar has a acidity of about 4% and tastes sweet. It is suitable for mixingCold DishesDip in, such as cold cucumber, dim sum, fried food, etc., it has a strong role in helping fresh.This kind of vinegar hasroseRice vinegar, brewed rice vinegar and table vinegar, etc.
Health care type: this kind of vinegar is low, generally about 3%.The taste is good. It is better to take 1 spoon (10 ml) every morning and evening or after meals, which can strengthen the body and prevent diseases. This kind of vinegar includes Kangle vinegar, Hongguo fitness vinegar, etc.The vinegar used to make vinegar egg liquid is also a kind of health care vinegar, with a high acidity of 9%.This kind of vinegar has more obvious health care effect.
Beverage type: This kind of vinegar is only about 1%.Sucrose and fruit are added in the fermentation process to form a new type of acetic acid beverage called the fourth generation beverage (the first generation is citric acid beverage, the second generation is cola beverage, and the third generation isLactic acid beverage）。It has the functions of preventing heatstroke, producing saliva and thirst, improving appetite and eliminating fatigue. This kind of beverage type rice vinegar still hassweet and sourModerate, refreshing and non sticky, which is liked by people.This kind of beverage includes hawthorn, apple, honey pear, thorn pear and other thick juice, which will become a beverage with better taste after being mixed with ice water and carbon dioxide.[1]
Raw material classification
The raw materials for vinegar production include rice, wheat, sorghum, millet, bran, sugary fruits, etc.There are many famous vinegar produced in China: for example, Shanxi aged vinegar with sorghum as raw material;Made from branSichuan bran vinegar；Zhenjiang balsamic vinegar with glutinous rice as raw material;Jiangbo rose rice vinegar with rice as raw material;Dandong tower vinegar made from liquor;With glutinous riceMonascusPineapple vinegar and banana vinegar made from sesame.There are also many stores in foreign countriesalcoholVinegar, wine vinegarapple vinegar, grape vinegar, malt vinegar, distilled white vinegar, etc.Here are some of them.
Shanxi aged vinegar
Shanxi aged vinegar is the most famous vinegar in northern China.It uses high-quality sorghum as the main raw material, through the process of cooking, saccharification, wine, and other processes, and then quickly acetifies at high temperature,Warm fireIt is made by roasting fermented vinegar and sunning and water aging.
This kind of Shanxi aged vinegar is black and purple in color, clear in liquid, rich in sour fragrance, soft in taste, mellow without astringency.And it is not moldy, and the winter is not strong frozen. The more you put it, the more fragrant it will be, and the longer you put it, the less rotten it will be.
Zhenjiang vinegar
Zhenjiang aromatic vinegar takes high-quality glutinous rice as the main raw material, adopts unique processing technology, and goes through three major technological processes, including wine making, fermented grains making, and vinegar pouring. It takes more than 40 processes and 50-60 days before and after brewing.
Zhenjiang balsamic vinegar is famous at home and abroad for its "sour but not astringent, fragrant but slightly sweet, strong color and strong taste".This kind of vinegar has five characteristics of "color, aroma, taste, mellow and thick", and is popular with the people, especially in the south of the Yangtze River.
Sichuan bran vinegar
The bran vinegar produced by Baoning is the most famous one in Sichuan.This kind of bran vinegar is fermented with bran and wheat rice as the main raw materials for vinegar making. It is also fermented with more than 70 kinds of rare Chinese medicinal materials, such as Amomum villosum, Eucommia ulmoides, Hua Ding, Bai Kou, Mu Ding, etc., which can strengthen the spleen and protect the stomach. It also uses clean and sweet spring water, which contains a variety of mineral components and is helpful for vinegar making.
This vinegar is dark brown in color and has a strong sour taste.
Henan Special Vinegar
Henan Laobieyi Special Vinegar is a typical representative of ancient vinegar brewing in Central Plains.Its brewing technique is a "living cultural relic" in the vinegar industry of Henan Province, which embodies the essence of traditional folk techniques and contains rich scientific, historical, humanistic and social values.
Henan Laobianyi Special Vinegar combines the essence of vinegar making technology in the north and south. It takes wheat and sorghum as the main materials, more than 30 rare Chinese medicinal materials to make koji, and Daqu and Xiaoqu are fermented together. After more than 50 processes, it takes more than six months to carefully brew.She has a strong and mellow fragrance, a long aftertaste, a prominent flavor, a little sweet but not astringent, a long life without decay, and the more stale, which is loved by people in the vast areas of the Central Plains.
Jiangsu and Zhejiang rose rice vinegar
Jiangsu and Zhejiang rose rice vinegar is a unique rice vinegar brewed from high-quality rice.The biggest feature of Jiangsu Zhejiang rose rice vinegar is that the color of vinegar is bright and transparent rose red, with a strong special fragrance that can promote appetite, and the content of acetic acid is not high, so the vinegar taste is not strong, very palatable, especially suitable for condiments of cold dishes and snacks.
Fujian Red Koji Vinegar
Fujian Red Koji Vinegar is made from high-quality glutinous rice and red koji sesame by adding them in batches, liquid fermentation and aging for many years (more than three years).
This kind of vinegar is characterized by its dark brown color, sour but not astringent, sweet in sour, and a pleasant aroma.This kind of vinegar has a unique and attractive aroma because it is seasoned with sesame.
Pineapple vinegar
Pineapple vinegar is ChineseTaiwanIt is a kind of famous vinegar in Hunan Province.This kind of vinegar is made from pineapple produced in Taiwan as the brewing material.It is characterized by clear vinegar color, sour but not strong, and sweet in sour.
apple vinegar
Apple vinegar is made from apple juice.Apple juice is first fermented by alcohol and then by acetic acid to produce apple vinegar.In addition to acetic acid, cider vinegar also contains citric acid, malic acid, succinic acid, lactic acid, etc.
Grape vinegar
It is made of wine, grape juice and grape flavor agent as raw materials.The prepared grape vinegar is mainly used forsaladIt can be used as sauce and hot soy sauce.
Malt vinegar
Malt vinegar, as its name implies, is a special kind of vinegar brewed from malt.Its nutritional value is higher than other vinegar, and its taste is more pure and refreshing.
distilled vinegar
Distilled white vinegar is a colorless and transparent vinegarFranceIt's a kind of famous vinegar.When using this kind of distilled white vinegar, attention should be paid to the control of the amount to prevent the excessive sour taste from affecting the original taste of the dishes.Distilled white vinegar is the sour seasoning used for cooking natural color dishes and light color dishes.
Nutritional composition
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The main component of vinegar is acetic acid. It also contains rich calcium, amino acids, succinic acid, grape acid, malic acid, lactic acid, B vitamins and salts and other nutrients beneficial to the body.
Production
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Production method
(1) Traditional Chinese vinegar making materials, south of the Yangtze RiverGlutinous riceAnd rice (japonica rice), and sorghum andmilletMainly.Most of them are broken riceCorn, sweet potato, dried sweet potatoPotato, dried potato, etc.The raw materials are first digested, gelatinized, liquefied and saccharified tostarchConvert to sugar and reuseyeastFermentethanol, and thenAcetobacterUnder the action of, acetic acid is fermented and ethanol is oxidized to acetic acid.
(2) Vinegar made from sugar containing raw materials can be usedGrape, apple, pear, peach, persimmon, jujube, tomato, etc.They only need to go through two biochemical stages: ethanol fermentation and acetic acid fermentation.
(3) Using ethanol as raw material, acetic acid bacteria were added to ferment acetic acid for only one biochemical stage.For example, withLow alcohol liquorOr use edible alcohol and water to dilute as raw materials, and use fast brewing method to make vinegar. It only takes 1 to 3 days to get wine vinegar.
(4) Make white vinegar with edible glacial acetic acid and water, and then addflavoring, spices, colors, etc., to make it a vinegar with a similar flavor to brewing vinegar.
Production process
Solid state method
There are three traditional solid state vinegar brewing processes.
1. UseDaqusystemVinegar: Take sorghum as the main raw material, use the enzymes secreted in Daqu to carry out low-temperature saccharification andalcohol fermentationAfter that, put half of the mature vinegar fermented grains in the fumigation fermented grains tank, heat them with a gentle fire, and then add the vinegar liquor from the other half of the mature vinegar fermented grains to soak them, and then pour out the new vinegar.At last, the new vinegar is processed into vinegar with black color, thick texture, mellow sour taste and special fragrance through the aging process of three volt winter sun drying solution and ice.Shanxi is famous for its aged vinegar.
2. UseDittyVinegar production: With glutinous rice and rice as raw materials, first use microorganisms such as rhizopus and yeast in Xiaoqu (also known as liquor medicine) to conduct solid culture on rice grains, and ferment while saccharifying.Add water andyeastContinue saccharification and alcohol fermentation.Then mix it in the mashbranPut it into the vat in solid state, add high-quality vinegar fermented grains as seeds, adopt solid layered fermentation, and gradually expand the propagation of acetic acid bacteria.After aged vinegar is brewed, the vinegar juice is poured out by the method of douching, mixed with fried beige and white sugar, clarified, heated and boiled to obtain balsamic vinegar.The famous one is Zhenjiang balsamic vinegar.
3. With bran as the main material, glutinous rice and wine or polygonum hydropiper juice were used to make vinegar mother for acetic acid fermentation. The fermented grains were aged for one year to produce bran vinegar with unique flavor.The famous ones areSichuanBaoning (todayLangzhong County）Bran vinegar and SichuanQu CountySanhui Special Vinegar.
The solid vinegar method is used to brew vinegarnatureWild microorganisms, so the fermentation cycle is long. Fermented grains need to be turned during acetic acid fermentation, so the labor intensity is high.distiller 's yeast, alcohol fermentation, and then pure culture of acetic acid bacteria made of vinegar mother, acetic acid fermentation to produce vinegar.Enzymatic liquefaction, ventilation and reflux method are also used to soak raw materials with water, and then add bacteriaα-The amylase is heated and liquefied, and then saccharified with bran koji. The saccharified mash is cooled, and then added to the yeast foralcoholFor fermentation, after the alcohol fermentation is completed, the wine mash, bran, rice husk and vinegar mother are fully mixed, and then sent to the acetic acid fermentation tank with a false bottom. There is a ventilation hole under the false bottom, which can allow the air to enter naturally. Natural ventilation and vinegar reflux are used to replace the turning of fermented grains, and the fermentation temperature of fermented grains is uniform until maturity.The yield, vinegar yield and labor productivity of enzymatic liquefaction ventilation reflux method are higher than those of traditional method.
Liquid method
There are many traditional liquid vinegar brewing processes.
1. With rice as raw material, it will naturally mildew in the wine jar after steaming, then add water to form a liquid state, and ferment at room temperature for 3-4 months.After the vinegar mash is mature, it is pressed, clarified, sterilized, and the finished product is bright in color, fragrant in smell, not pungent in sour taste, and mellow in taste.The famous Jiangxi rose rice vinegar.
2. With glutinous rice, red kojisesameAs the raw material, the product is prepared by natural liquid fermentation with batch addition method, aging for 3 years, and finally adding white sugar.The famous ones areFujianRed koji vinegar.
3. It is made from diluted liquor by acetic acid fermentation in a packed fast brewing tower, such as Liaoning ProvinceDandongvinegar.
The new technology of deep fermentation is gradually adopted in the production of vinegar by liquid fermentation.After liquefaction, saccharification and alcohol fermentation of starchy raw materials, the wine mash is sent into the fermentation tank, and the pure culture and gradually expanded acetic acid bacteria liquid are introduced to control the product temperature and ventilation rate, and accelerate theethanolIt can be oxidized to produce acetic acid and shorten the production cycle.There are many types of fermentation tanks, and now Cifou uses self-priming aerated fermentation tanks.It wasFederal GermanyFirst used in vinegar production, calledFringsAcetic acid fermentation tank, which was patented in 1969.Japan, European countries have adopted.It has been used in China since 1973.
Main efficacy
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Vinegar can digest fat and sugar: properly drinking vinegar can not only reduce weight, but also promote the burning of nutrients in the body and improve the utilization of heat energy, and promote health;Vinegar can reduce the intake of salt: for people who like to eat salt, they may as well add a little vinegar to the food, more vinegar and less salt;Vinegar can inhibit and reduce the formation of lipid peroxide in the process of aging, reduce age spots, and delay aging;Vinegar has diuretic effect and can prevent urinary retention, constipation and various stone diseases;Vinegar can reduce blood pressure, soften blood vessels, reduce cholesterol accumulation and urine sugar content, and prevent cardiovascular disease and diabetes;Vinegar is rich in K, Na, Ca, Mg and other alkaline earth metal elements, which are alkaline after entering the stomach. It can regulate the acid-base balance of the blood, maintain the relative balance of the human body environment, and reduce atherosclerosis, hyperlipidemia, hyperglycemia, hyperuricemia and other diseases caused by acidification of body fluids.[2]
Edible Guide
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Edible method
1. Insomnia - Insomniacs pour a cup of cold boiled water before going to bed, and then add a spoonful of vinegar. After drinking it, they will fall asleep quickly.Rub the soles of feet with warm old vinegar before going to bed, and you will easily fall asleep.
2. Sprain - Mix the flour and boil it into a paste, add proper amount of old vinegar, smear it on paper or gauze, and stick it on the affected part.After drying, gently uncover and change another piece.Repeated application can eliminate the burning and pain of the sprain.This method has curative effect on bone and joint dislocation, falls and other injuries.
3. Rhinitis - Put about 5ml of aged vinegar into a 1000ml detergent to clean the nasal cavity, and wash twice a day to treat rhinitis.
4. Feet numbness - heat 1 liter of old vinegar and pour it into a bucket, then soak both feet for 20 minutes each time.The numbness symptom can be relieved after soaking for 4-5 times.
5. Scald - according to the principle of acid-base neutralization, vinegar is made into a 5 degree solution to wash burns, especially for lime burns.Or apply gauze soaked in vinegar on the scalded part, which can also be effective.
6. Antitussive - After soaking garlic in aged vinegar for 15 days, you can eat 1-2 pieces of pickled garlic every morning on an empty stomach, and drink some vinegar juice. After taking it for 10-15 days, you can stop cough, relieve asthma, detoxify and remove stasis, reduce blood pressure and lipid, and prevent infectious diseases and tumors in the elderly.
7. Reduce blood pressure - soak 500g peanuts in aged vinegar for more than 7 days and stir them once a day. Chew 3-5 capsules every night before going to bed. Take them for 7 days to relieve arteriosclerosis.
8. Beauty - soak 250 grams of Job's tears in 500 millilitersmature vinegarAfter 10 days of sealing, take a spoonful of vinegar every day to make your skin white, tender and pigmented.
9. Treatment of gastritis - 100g of ginger is washed and cut into thin filaments, sealed in 250ml of aged vinegar for 3 days, and 10ml is taken every morning on an empty stomach to treat chronic gastritis.
10. Car Sickness - For those who are prone to carsickness and seasickness, drinking a cup of warm water with aged vinegar before departure will be very comfortable.
11. Relieve fatigue - When you are tired on the journey, add a little old vinegar in the bath water to make your skin smooth, relax your muscles, and eliminate fatigue.
12. Stop bleeding - plug your nostrils with cotton dipped in aged vinegar to stop nosebleed.
13. Influenza prevention - "flu" season.The room is fumigated with vinegar to disinfect the air and prevent colds;Fried with aged vinegar and salt can also stop vomiting and diarrhea.
14. Treatment of arthritis - use the aged vinegar, wheat bran and iron sand in a certain proportion to put them into the gauze belt after being mixed evenly, and use a new hot brick to put on the gauze belt to iron the affected part or related acupoints, which can treat arthritis, hyperosteogeny, etc.
15. Treatment of parotitis - use aged vinegar to add a little lime to evenly smear the affected part, which can cure parotitis.
16. Cure dermatitis - use the aged vinegar to smear the affected part three times a day to treat neurodermatitis.
17. Detumescence - bruise, blood stasis, redness (not broken, not injured bones and muscles) Apply warm old vinegar to the affected area three times a day to reduce swelling and dissipate blood stasis.
Suitable crowd
Edible
Vinegar is suitable for people with chronic atrophic gastritis, gastric acid deficiency, influenza, epidemic cerebrospinal meningitis, diphtheria, measles, kidney stones, ureteral stones, bladder stones, cancer, hypertension, children's biliary ascariasis, infectious hepatitis and other diseases, and also suitable for people who are allergic to fish and crabs, have rubella, and are drunk.
Avoid food
It is not suitable for patients with spleen and stomach dampness, flaccid arthralgia, muscle and vein contracture, excessive gastric acid, acid water vomiting, bronchial asthma, severe gastric and duodenal ulcer.
Food Precautions
Sour and sweet
It is easy to weaken the relationship between them and other seasonings.For example, sweet taste is added to vinegarSeasoningAfter (granulated sugar), the sour taste will be weakened. If a small amount of vinegar is added to the granulated sugar solution, the sweet taste will be weakened.
Sour and salty
When a small amount of salt is added to vinegar, the sour taste will be weakened, but when a small amount of vinegar is added to the salt solution, the salty taste will be enhanced.
Sour and delicious
If a high concentration of fresh soup is added to the vinegar solution, it can increase the taste. So if you need to improve the taste of dishes flavored with vinegar, you should add fresh soup instead of addingmonosodium glutamate。
In addition, rice vinegar is usually used for cooking.But it's also good to use vinegar when making sea fish.The best way to eat dumplings and steamed buns is to use aged vinegar and sweet vinegar.saladIt is better to use mature vinegar than rice vinegar.White vinegar must be put into Korean cold noodles.The best way to eat crabs and shrimps is to use vinegar.
Food Therapy Prescription
Ginger and vinegar water
Ingredients: 200g ginger, 200ml vinegar.
Preparation and usage: Fried water, hot drink.
Efficacy: It can relieve nausea and vomiting.
Chinese wolfberry white vinegar
Ingredients: 1L rice vinegar, 1kg Chinese wolfberry and white rice.
Preparation and usage: Boil medlar and white skin with rice vinegar, take 500g and gargle;Or use 200g of mature vinegar and 10g of Chinese prickly ash.Pan fry, remove pepper and gargle.
Efficacy: It can cure tooth pain.
Dietetic culture
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When purchasing vinegar, its quality should be identified from the following aspects: First, look at the color.There are two kinds of vinegar: red and white. High quality red vinegar is required to be amber or reddish brown.High quality white vinegar should be colorless and transparent.Second, smell the fragrance.High quality vinegar has sour aroma and no other smell.Third, taste.High quality acetic acid is high, but it has no irritation, mild acidity, slightly sweet taste, no astringency, and no other odor.In addition, high-quality vinegar should be transparent and clear, with proper concentration, and free of suspended solids, precipitates, and mold floating film.The bottled vinegar shall be free from mildew, floating film and other deterioration within three months from the time of delivery.
The color of real vinegar is brownish red or colorless and transparent, shiny, with incense or ester fragrance or mellow fragrance;Soft sour, slightly sweet, not astringent, long aftertaste;The concentration is appropriate and there is no sediment.Fake vinegar is mostly made by mixing industrial acetic acid directly with water, with light and dark color;When opening the bottle, the sour gas hits the eyes, without fragrance;The taste is thin, with obvious bitter and astringent taste except for sour taste;There are sediment and suspended solids.
preservation
The bottle containing bulk vinegar must be clean and waterless.Add a few drops of liquor and a small amount of vinegar into the bottlesalt, mix well and place it, which can make vinegar fragrant, not easyLandrace Film, can be stored for a long time.A little sesame oil can also be added to the bottle containing vinegar to cover the surface with a thin oil film to prevent the vinegar from mildewing and deterioration.
Put a section of onion white and a few garlic cloves in the vinegar bottle, which can also play the role of mold prevention.In addition, vinegar should not be placed in copper vessels because copper will react with acetic acidCupric acetateSuch substances are bad for health.[3]
Rapid determination of total acid in vinegar
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Acids exist in fruit and vegetable products, beverages, dairy products, wine, bee products, starch products, cereal products and condiments.Total acid refers to the amount of hydrogen ions that can be released finally, which is a fixed number;PH represents the ability of the substance to release hydrogen ions (or hydroxyl radicals) in the solution, which involves the balance of H+in a solution and can release more or less H+with the change of the concentration of the substance.
This method is suitable for the rapid detection of total acid in vinegar.
Detection principle
The main component of vinegar is acetic acid, which contains a small amount of other organic acids. Titrate it with sodium hydroxide standard solution, and show the end point with an indicator to get the total acid content in the sample.
Test material
Dripping bottle containing 0.1mol/L sodium hydroxide standard solution, indicator.
test method
Take 1.0mL of sample into a 10mL colorimetric tube, add water to the scale of 10.0mL, cover and mix evenly, take 1.0mL from it and put it into another colorimetric tube or test tube, add 4 drops of indicator, titrate with sodium hydroxide standard solution, shake a few times after each drop of solution, and stop titration when the solution turns purple red (dark vinegar turns brown red).At the same time, do a reagent blank test (that is, take 1.0mL of water and titrate it with sodium hydroxide standard solution).
Result analysis
Each drop of sodium hydroxide standard solution is equivalent to 0.36% g of total acid under the condition of constant sampling amount.The total acid content can be calculated according to the number of drops of sodium oxide standard solution used.
matters needing attention
1. Pay attention to the verticality of the dropping bottle during titration to reduce errors.
2. If the result measured by this method is only 1 drop different from the value specified in the national standard or the value marked on the sample label, the existence of field operation error should be taken into account. The unqualified samples should be sent to the laboratory for accurate quantification.
Reagent quality control
1. The concentration of sodium hydroxide standard solution shall be kept at 0.1008 ± 0.0008moL.
2. The number of drops in the emitter shall be kept at 0.060 ± 0.002 mL/drop.[4]
