Natural pectic substance in pectin, pectin and pectic acid form widely exists in plants, roots, stems and leaves, is a component of the cell wall, they are accompanied by cellulose and the existence of a neighboring cell layer of bonding material, the plant tissue tightly bonding together. Pectin is not soluble in water, but in acid and alkali, salt and other chemical reagents and enzymes, water decomposition into water soluble pectin. Pectin is essentially a polysaccharide polymer linear, containing hundreds to about 1000 dehydration of galacturonic acid residues, the average relative molecular mass of 50000~150000 corresponding.

pectin Structure

Chinese Name: pectin English Name: pectin English alias: 2,3,4,5-Tetrahydroxypentanal; 9000-69-5; pentoseCAS:9000-69-5EINECS:232-553-0 molecular formula: C5H10O5 molecular weight: 150.1299
 Pectin molecular graphs Pectin molecular graphs
Pectin (Pectin) is a group of Poly Galacturonic acid . In appropriate conditions, its solution can form Gel: Set & Match And part of the methoxy (methyl ester, is formed methanol Ester), its main component is part of the esterification of the alpha - 1,4 D polygalacturonic acid. The residual carboxyl unit to free acid form or the formation of ammonium, potassium sodium and calcium salt.
Its molecular formula: (C6H10O6) n

pectin Character

Pectin as coarse powder to fine powder with white or yellow or light grey, light brown, some odorless, taste slimy. Soluble in water for 20 times, the formation of white viscous colloidal solution is acidic. Strong heat resistance, almost insoluble in ethanol and other organic solvents. With ethanol, glycerol, sugar syrup and moist, or more than 3 times the sugar mixture can improve the solubility. In acidic solution than in alkaline solution is stable .

pectin Gel effect

Pectin can form an elastic gel, gel forming mechanism of pectin esterification degree is different, Gao Jiayang must be formed in the gel glue: low pH and high glucose concentration, the general requirements of pectin content <1%, sucrose concentration of 58%~75% and pH2.8~3.5. Because the pH2.0~3.5 can prevent the change of height of carboxyl carboxyl dissociation, hydration and charged to uncharged molecules, so that the intermolecular repulsion is reduced, reducing the hydration of the molecule, it is conducive to the formation of intermolecular binding and three-dimensional network structure. The sucrose concentration reached 58%~75%, because the sugar for water molecules, resulting in neutral pectin molecular solvation degree is greatly reduced, is conducive to the formation of molecular hydrogen bond and gel .

pectin source

Pectin is a plant cell wall One of the components that exist in the cell wall between adjacent cell layer, plays a role in cell will stick together. Different vegetables, fruit taste difference, is mainly decided by difference between them contain pectin and pectin molecules. citrus , lemon , grapefruit etc. peel Contains about 30% pectin, is the most abundant source of pectin. According to the composition of the pectin can have two types of homogeneous polysaccharide and polysaccharide: homogeneous type of pectin polysaccharides such as D- Galactosan Arabia L-, chitosan and D- chitosan galacturonic acid; heteropoly compound is the most common candy That is the galacturonic acid polysaccharide, galactan and Arabia chitosan Composition in different proportion, usually called Pectic acid . Different sources of pectin, the proportion is also different. Part of the esterification of pectic acid is called Pectic acid ester . About 20% ~ 60% carboxyl natural pectin by esterification, molecular weight From 20 thousand to 40 thousand. Crude pectin is yellowish white powder, soluble in water 20, forming a thick tasteless solution, negatively charged. Pectin is widely used food industry The amount of pectin can make. Ice cream , Jam Gelation and juice.
Pectin is a Natural polymer That has good gelling and emulsifying stability, has been widely used in food, medicine, daily chemical and textile industries. Pomelo peel is rich in pectin, its content reached around 6%, is the ideal raw material preparation of pectin. Fruit pectin sub liquid, fruit powder and low methoxyl pectin three, among which the most common application of fruit powder. Can be produced from pomelo fruit powder and low methoxyl pectin.

pectin application

According to China's "Hygienic Standards for uses of food additives" (GB2760-1996) provides that: pectin may be appropriate to all kinds of food according to production needs. Pectin can be used for making jam, jelly cake; prevent hardening; improve the quality of cheese; making juice powder. High fat pectin acid is mainly used for jam, jelly, jelly, candy stuffing and lactic acid drinks. Low fat pectin is mainly used for general or low sour jam, jelly, jelly, frozen dessert, salad sauce, ice cream, yogurt, etc. .

pectin Production method

pectin Fruit powder

Production process: raw materials, pretreatment, extraction, decoloration, concentrating and drying to obtain the product.
 pectin pectin
1 of the raw material and processing of fresh or dry skin saved naringin can be used as raw materials. Fruit leather should be timely treatment, so as not to produce raw materials pectinase class hydrolysis The effect of gelling of pectin production or decreased. First peel crushed to a particle size of 2 ~ 3mm, placed in steam or boiling water treatment in 5 ~ 8min. passivation Pectinase activity. The raw material after enzyme killing again in the water clear bubble 30min, and heated to 90 DEG 5min, the pressure to the juice, rinse with water several times, as far as possible to remove the bitter taste, pigment and soluble impurities. Squeeze the juice for recovery Naringin . Dry skin re soaked in warm water after taking over the same reserve.
The 2 is usually extracted by acid extraction. Place the peel into the interlayer pot, add water for 4 times, and for industrial use hydrochloric acid The pH adjusted to 1.5 ~ 2, heated to 95 DEG C, keep constant temperature under constant agitation in 60min. Hot filtering pectin extraction Liquid. To be cooled to 50 DEG C, adding 1% ~ 2% starch Enzyme to decompose the starch enzyme, at the end, and then heated to 80 DEG C to kill enzyme. Then add 0.5% ~ 2% activated carbon, stirring 20min at 80 DEG C, filtering to obtain filtrate decolorization.
Because of calcium and magnesium in Pomelo Peel Ion Higher content of these ions are closed on the role of pectin, effect of pectin into water-soluble pectin, but also because of high levels of skin impurities, while the impact of gels, so acid extraction rate is low, poor quality. In order to solve the above problems, Southwest Agricultural University College of food (1995) of acid extraction were improved in acid on the basis of the method by adding 5% to 732 weight of dry skin cation exchange resin Or to extract weight adding 0.3% ~ 0.4% six phosphoric acid Sodium, the former pectin yield can be increased by 7.2% ~ 8.56%, gel strength increased by more than 30%, and the yield increased by 25.35% ~ 35.2%, the degree of gelation was 180 + 3.
3 concentrated by vacuum concentration method, in 55 ~ 60C, the extract pectin content increased to 4% ~ 6.5% after the subsequent processing. Recently, the author and other domestic research shows that can be used for ultrafiltration of pectin solution concentration, such as molecular weight cut tube is 50 000U poly propylene Nitrile membrane ultrafilter, at a temperature of 45 DEG C, pH3.0, 0.2MPa under pressure ultrafiltration The pectin, concentration Concentrated to 4.21%, and the content of impurity and regular production costs were only concentrated in vacuum 1/5 and 1/2 ~ 1/3.
4 dry deposition drying method commonly used methods, namely 95% alcohol Or aluminum, copper and other metal salts to precipitate pectin. By alcohol precipitation of pectin to take the best quality. The method is: adding 1.5% weight in pectin in the concentrated solution Industrial salt Acid, stir well, then slowly adding the same amount of 95% alcohol, while stirring, the pectin precipitation. Then 80% of the alcohol washing, removing alcohol soluble impurities. Then with 95% alcohol acid washed 2 times with screw press press, the pectin into the vacuum dryer at 60 deg.c until the water content is below 10%, the pectin porphyrized, sealed packaging of finished powder results. Pectin precipitation with metal salts, the impurity content is higher, is less used.
Until 2013 most of foreign pectin by spray drying drying, using spray drying, the concentrated liquid in the feed temperature 150 to 160 DEG C, discharge temperature 220 ~ 230 degrees under the conditions of dry, continuous operation can continue to get powder products. Southwest Agricultural University College of food by ultrafiltration and spray drying test solution, the results show that the method is feasible, the pectin quality conforms to the national standards.

pectin Low methoxyl pectin

Production method of low methoxyl pectin are mainly alkaline, acid method and enzyme method 3. This paper introduces two kinds of alkali method and enzyme method.
 Low methoxyl pectin Low methoxyl pectin
1 the alkali concentrate in pectin Stainless steel pot In addition, ammonium hydroxide is adjusted to pH 10.5, 15 C 3h. Add an equal volume of 95% alcohol and the amount of hydrochloric acid, the pH dropped to about 5. Stirring 1H, leaching precipitation pectin, dry, respectively by 50% and 95% of the alcohol washed 1 times, dry after the share in the pan, drying at 65 DEG C in vacuum dryer, take grinding and packaging to get the finished product. About 90% of the yield of pectin.
2 pectin esterase enzyme that is fat with low methoxy pectin extraction. Guangdong Institute of Pomology Cai Changhe (1996) has been successfully developed using enzymatic low-fat industrialized production technology of extracting pectin from pomelo peel. Compared with the traditional alkali and acid, the process is easy to control, high product quality, save energy and cost advantages and reduce, is to make a brief introduction to the method, the process is as follows:
Peel, crushing, washing, degreasing, gel extraction, precipitation, filtration, filter, desalting alcohol washing, drying, crushing, finished, press.
Raw materials: raw minced pieces and stir 3 ~ 5mm size.
Washing: 50 C water immersion 30min, centrifugation, and then rinse with water to 2 ~ 3 times, until the eluate was colorless.
Skim Adding carbonic acid Sodium to activate the endogenous PE Enzyme Peel, degreasing. The process conditions of temperature 50, time 1H, pH7.0, sodium carbonate 7g/kg fresh skin (25g/kg dry skin) combination is the best.
Gel extraction with hydrochloric acid (ph1.7: 2) gel extraction at 95 DEG C.
Precipitation: adding an appropriate amount of pectin CaCl2 precipitation.
In addition to alcohol wash: the hydrochloric acid salt, oxalate According to the ratio of 1:3 mix in alcohol solution in salt, and after repeated alcohol wash,
Drying and crushing: at 60 DEG C, vacuum drying, pectin drying after crushing fruit powder. The yield of pectin was 3.5% ~ 4% fresh peel, dry peel is 12% ~ 15%, the gels of 100 + 5, aliphaticity reached less than 50%. U.S.A The quality standard of fcc.

pectin Use value

pectin Speed high ester pectin

(1) technical indicators
Gelation degree: 150 degrees - 5 degrees (US--SAG)
Ester value: 65%-70%
Galacturonic acid: >65%
Appearance: white to light yellow powder
PH (1% aqueous solution) 2.8 + 0.2%
Water <12%
Ash <3%
Acid insoluble ash: <0.5%
Size: <60.
Sulfur dioxide <5ppm
The heavy metal <0.5ppm
(2) the amount of reference purposes.
Jam, jelly, jelly : from gelation, exquisite, elasticity and toughness, increase the aroma, so smooth refreshing taste, the amount of reference: 0.3%-0.6%.
Popsicle, ice cream: emulsification Stable, refined and delicate taste, smooth. The amount of reference: 0.1%-0.2%
Yogurt , lactic acid Bacteria, fruit juice : stability, thickening effect, extend the product shelf life, with natural fruit flavor, the amount of reference: 0.1%-0.3%
Baked food: improve dough permeability, enhance the taste, extend shelf life. The amount of reference: the amount of flour 0.3%-0.8%
(3) using the method:
The pectin and 3---4 times the fine sugar mix, add 80 degrees of pure water through stirring, concentration of dissolved 2.5%-4%, dissolved after the proportion of adding a variety of products.

pectin low ester pectin

(1) technical indicators:
Gelation degree 100: 5 degrees (US-SAG)
The degree of esterification : 25%-35%
Galacturonic acid : >65%
Appearance: light yellow powder
PH (1% aqueous solution): 2.8 - 0.2
Water <12%
Ash <5%
Acid insoluble ash <1%
Mesh size <60
Sulfur dioxide <5ppm
heavy metal <0.5ppm
(2) use, dosage reference
Jam, jelly, from gelation for low sugar food, low ester pectin Made of jelly, can stomach, increase appetite, relieve lead poisoning That is the children's health food products.
Reference to the amount of 0.3%-0.8%
Lili and with a pulp orange drink, have a stabilizing effect, solve the capsules and orange pulp suspension containing drinks layered, sticking to the wall, so that the pulp evenly distributed in the drink, and good taste.

pectin Pharmaceutical pectin

(1) technical indicators:
 Pharmaceutical pectin Pharmaceutical pectin
Gelation degree: >97 degree (US-SAG)
Ester value: 52-58%
Product description
Galacturonic acid >85%
Appearance: This product is white to light yellow powder or granule.
PH (1%) aqueous solution of 2.8 + 0.2
Water <8%
Ash <5%
Acid insoluble ash <1%
Mesh size <60
Sulfur dioxide <5ppm
The heavy metal <5ppm
(2) use, dosage reference
Pectin secret for pharmaceuticals, and for lowering blood sugar, blood ester, remove lead poisoning, hangover agent of health care products.

pectin Special low ester pectin

Technical indicators:
The gels of >100% (US-SAG)
Ester value: <10%
Galactose Acid acid >80%
Appearance: light yellow powder
PH (1%) >4 water solution
Water <10%
Ash <5%
Mesh size <60
The heavy metal <5ppm
Used in diapers, can protect the infant skin for wound post, can accelerate wound healing, for Cosmetics That can prevent ultraviolet radiation. For the ink, writing smooth, stable precipitation.

pectin Related applications

As the era of technological progress, is not a simple bread made of flour, salt, yeast And water mixture manufacturing. The nature of many different types of baking ingredients are often used for improving bread. One of the most common is some fat glyceride Emulsifier . and Vitamin C or its bromide and calcium salts may be added as an improver. In recent years, the rapid development of baking raw materials, some new baking ingredients are also gradually attention. Enzymes used in the past few years has been taken seriously, and pectic gel material with special properties and applications were also widely used in the baking industry. This report is mainly used for special applications in the application of modified pectin bread volume and sale time frame.
The increase of volume and other characteristics
The volume of bread has been an important indicator of quality. But due to the production of flour is mostly in the production of the main considerations for the quality requirements of the less. Therefore, the flour quality problems are often caused by the occurrence, also caused the bread is not good, suitable for different processing conditions is not enough. For the above problems, the latest and effective solution is to use high methoxy pectin. Pectin is from A mandarin orange The extraction of natural raw material, in the food industry has long been widely used. As an active research and development, the special nature of the pectin products have gradually been successfully developed. Recent research results include a series of Grease Alternative products and used in baking products of high methoxylated pectin products. It can effectively increase the volume of bread, but also because of the strong adsorption of water, can also increase the amount of dough. For the dough freshness, hardness and stability have obvious help.
Reduce the use amount of flour
Basically, the dough is made from flour, water and yeast mixture. In the process of mixing flour gluten will be re aligned and even part of the commencement of the formation of a viscoelastic three-dimensional network structure, which is called the dough. For the dough, ductility and expansion of the absolute relationship for the formation of the dough volume during fermentation. If the dough extensibility is not enough, is produced during fermentation. Carbon dioxide Can not effectively put the dough leavening. Therefore, the dough containing pectin can provide an effective extension of results of dough required, and thus can improve the final baking of bread volume. For the bread, due to the increase of consumer preferences and the volume of bread, the bread industry will naturally profitable. with Hamburger Bread, for example, can reduce the use amount of pectin 30% flour in maintaining the existing conditions of the volume of bread.
Extended shelf life
Many factors affect the length of bread rack sold, but the main reason lies in the starch Crystal Or aging. In fact, we all know that the bread began to harden in the moment will be released, but after a few days later, most of the bread will become inedible. Changes of bread can be soft and hard texture analyzer using simple measured test showed that pectin can effectively prolong the shelf time of bread, emulsifier and high methoxyl pectin bread after storage for 6-7 days, the control group will achieve the hardness, that is to say, pectin can be longer than that of the control group for 5 days time frame. Adding pectin bread another advantage is that in the normal frame on sale time (after baking 2 -3 days), the hardness of bread compared with the control group, the other was soft. Hardness is one of the indexes of bread rack sold the length of time, another indicator is the freshness of bread, including bread volume elasticity and taste, hardness.
The addition of pectin for the impact of the volume of bread is very obvious, therefore, although there is no direct relationship between the volume of bread and rack sold the length of time, but for the love to measure the volume of bread consumers, but have enough difference. By the experimental data show that the soft bread than the control group. Although the determination of size and hardness, and can not be used to predict
Bread staling flavor, but the study found that adding pectin bread tasting scores than the control group, high flavor, and after storage for seven days than the control group still fresh.

Science China