Slowly digestible whole grain food, and processing method and application thereof
Technical Field
The invention relates to a slowly digestible whole grain food, a processing method and application thereof, belonging to the technical field of modern food processing.
Background
With the rapid development of national economy, the living standard of people is obviously improved, but the prevalence rate of abnormal carbohydrate metabolism and metabolic syndrome related to diet also presents a continuously increasing situation. The international diabetes alliance publishes the latest global diabetes map, the number of diabetics in China is ranked first in the global ranking, the total number of diabetics is about 1.2 hundred million, and the global diabetes map accounts for one fourth of the total number of diabetics in the global. And China is also the country with the most number of the elderly with diabetes. The threat of diabetes to health has become a prominent problem in modern society. The daily staple food of residents in China is a rice-flour product, but the physiological activity and the nutritional value of the rice-flour product are low, and chronic diseases such as diabetes and the like and metabolic syndrome are easily caused. The government of China releases the strategy of 2030 healthy China, and the health level of the whole people is improved through dietary nutrition intervention.
Starch is the most main component of cereal food and also the most main source of metabolic energy of the body, wherein the slowly digestible starch nutrition fragments have the advantages of continuously slowly releasing energy and maintaining the postprandial blood sugar steady state, and the health effect value of the slowly digestible starch proposed by the European Union food safety bureau is more than 40%. Currently, common cereal foods in China are mainly digestible starch, glucose is quickly released after the common cereal foods are ingested, and metabolic syndromes such as insulin resistance, energy balance disorder and the like are easily caused. Therefore, there is a need to develop a method for processing a slowly digestible whole grain food to solve the above problems.
Disclosure of Invention
In order to solve the problems, the invention provides a processing method of slow digestion whole grain food, which has the characteristics of simple process, controllable process, environmental protection, low processing cost and the like. The slowly digestible whole grain food product disclosed by the invention is rich in slowly digestible starch, has the health effects of maintaining postprandial blood glucose steady state and the like, and can be used as a novel health food product such as functional food, special medical food, nutritional meal replacement and the like.
The invention aims to provide a processing method of slowly digestible whole grain food, which takes whole grains as raw materials and prepares the slowly digestible whole grain food by a component conditioning auxiliary extrusion molding technology, and mainly comprises the following steps:
(1) crushing the whole grain particles to 120-mesh 500-mesh powder, then uniformly mixing the grain powder and a proper amount of water by mass, and adjusting the water content to 10-35 wt%;
(2) the extruder is taken as a processing unit, the temperature of the three sections of sleeves for uniformly mixing, kneading and molding materials is respectively 60-90 ℃, 105-150 ℃, 80-100 ℃, the screw rotation speed is 80-200r/min, the unit mechanical energy consumption is 150-300kJ/kg, and then the slow digestion whole grain food can be prepared by the screw die head according to the general rice and flour food molding process.
As an embodiment of the invention, the whole grain comprises one or more of brown rice, wheat, oat, sorghum, moss, millet, grain amaranth, coix seed, quinoa, buckwheat, royal cereal, highland barley and corn, wherein the starch content is 40-70% and the protein content is 10-20%.
As an embodiment of the invention, the extruder is a twin-screw extruder, and the length-diameter ratio of the screws is 20-60: 1.
As an embodiment of the invention, the slowly digestible whole grain food has a proportion of slowly digestible starch fragments in the total starch amount of more than 40%, an amorphous structure in the total structure of the grain food of more than 85%, and a GI index of less than 55.
As an embodiment of the present invention, the general rice and flour food forming process includes one or a combination of several of noodle, reconstituted rice, instant porridge and puffed food forming processes.
As an embodiment of the present invention, the general rice and flour food molding process is a rice and flour food molding process in Principles of Cereal Science and Technology, published by the American International Association of Cereal chemists.
It is a second object of the present invention to provide a slowly digestible whole grain food product having a slowly digestible starch fraction of more than 40% and an amorphous structure fraction of more than 85% produced by the aforementioned process.
The third purpose of the invention is to provide the application of the slow-digestion whole grain food in the fields of functional food, special medical food and nutritional meal replacement.
The invention has the following beneficial effects:
(1) the raw materials of the invention are grain crops which are commonly sold in domestic markets, have wide sources, are not limited by production places and seasons, and are easy for industrial production.
(2) The invention adopts the component tempering auxiliary extrusion molding technology, can realize continuous production, has simple process and is easy to automatically control.
(3) The slowly digestible whole grain food product has the functions of preventing and treating glycometabolism disorder and further maintaining the health of the organism, and can meet the diet requirements and special medical food standard requirements of special populations such as diet-related glycometabolism disorder and metabolic syndrome patients (GI <55, see general rules of formula food for special medical use GB 29922-2013). The slowly digestible whole grain food product has wide market prospect and obvious economic and social benefits.
(4) The invention develops the high-nutrition quality whole grain food by utilizing the abundant whole grain resources in China, accords with the strategic development plan of China's health, and has important significance for the high-quality development of modern food industry.
Drawings
FIG. 1 is a 13C CP/MAS NMR spectrum of the slowly digestible whole grain food product obtained in example 1.
Detailed Description
And (3) measuring the content of slowly digested starch:after hydrolysis of 200mg of slowly digested whole grain food with 10mL of enzyme-mixed solution (pancreatic. alpha. -amylase 290U/mL and glucoamylase 15U/mL) in a water bath at 37 ℃ for 20min and 120min with shaking at 160r/min under conditions simulating in vitro intestinal digestion (pH5.2) according to the classical Englyst method, 0.5mL of supernatant was taken and glucose content was determined by GOD-POD colorimetry.
Slowly digestible starch content of (G120-G20) × 0.9/W
Wherein G20- -the amount of glucose (mg) produced after 20min of hydrolysis; g120- -amount of glucose (mg) produced after 120min of hydrolysis; w- -amount of sample to be tested (mg).
Amorphous structure determination:refer to the 13C CP/MAS NMR method. The slow digestion state whole grain food is placed on a 4mm MAS probe for scanning more than 2400 times, the cycle interval time is 5s, the resonance frequency is 150.9MHz, the rotating speed is 10000KHz, the contact time is 1ms, and then the proportion of the amorphous structure in the sample is calculated through peak separation fitting.
Glycemic index GI assay:the blood glucose concentration is obtained by calculating the area amplification under a postprandial blood glucose response curve caused by 50g of food eaten by a human body, wherein the blood glucose concentration is measured by adopting a GOD-POD colorimetric method.
The present invention will be further explained with reference to examples, but the present invention is not limited to the examples.
Example 1
Pulverizing whole grain oat particles (starch content 53%, protein content 15%) to 300 mesh, then mixing oat powder and appropriate amount of water by mass, and adjusting to moisture content of 20 wt%; an extruder (the length-diameter ratio of a screw is 50:1) is used as a processing unit, the temperatures of three sections of sleeves for uniformly mixing, kneading and molding materials are respectively 60 ℃, 120 ℃ and 80 ℃, the rotating speed of the screw is 100r/min, and the unit mechanical energy consumption is 170kJ/kg, and then a screw type die head is used for preparing the slow-digestion whole-grain food according to a general noodle molding process.
The slowly digestible whole grain food obtained in example 1 was determined to have a proportion of slowly digestible starch fragments of 56% of the total starch. The 13C CP/MAS NMR spectrum of the slowly digestible whole grain food product obtained in example 1 is shown in FIG. 1. As can be seen from the analysis of fig. 1, the amorphous structure accounts for 92% of the total structure of the cereal, and the large amount of low disordered stacking structure causes a significant decrease in the enzyme digestion rate, GI index 42.
According to the determination, the untreated oat particles of the same batch are prepared into the whole grain food according to the general noodle forming process, wherein the slowly digestible starch fragment accounts for 12% of the total starch amount, the amorphous structure accounts for 69% of the total structure of the grain food, and the GI index is 69.
Example 2
Crushing whole grain wheat grains (starch content 62%, protein content 18%) to 500 mesh, then uniformly mixing the grain powder with a proper amount of water by mass, and adjusting the water content to 15 wt%; an extruder (the length-diameter ratio of a screw is 35:1) is used as a processing unit, the temperatures of three sections of sleeves for uniformly mixing, kneading and molding materials are respectively set to be 70, 150 and 100 ℃, the rotating speed of the screw is 80r/min, the specific mechanical energy consumption is 250kJ/kg, and then the slowly digestible whole grain food can be prepared by a screw die head according to a general recombinant rice food molding process.
According to the determination, the slowly digestible starch fragment accounts for 45% of the total starch amount, the amorphous structure accounts for 86% of the total structure of the cereal food, and the GI index is 48 in the slowly digestible whole cereal food.
According to the determination, the untreated wheat grains in the same batch are prepared into the whole grain food according to the general recombinant rice food forming process, wherein the slowly digestible starch fragment accounts for 8% of the total starch amount, the amorphous structure accounts for 76% of the total structure of the grain food, and the GI index is 72%.
Example 3
Crushing whole grain millet particles (with the starch content of 42 percent and the protein content of 14 percent) into 150 meshes, uniformly mixing the millet powder and a proper amount of water by mass, and adjusting the water content to be 30 percent by weight; an extruder (the length-diameter ratio of a screw is 60:1) is used as a processing unit, the temperatures of three sections of sleeves for uniformly mixing, kneading and molding materials are respectively 90 ℃, 120 ℃ and 90 ℃, the rotating speed of the screw is 140r/min, the specific mechanical energy consumption is 150kJ/kg, and then the slow digestion whole-grain food can be prepared by a screw die head according to the general instant porridge food molding process.
According to the determination, the slowly digestible starch fragment accounts for 51 percent of the total starch amount, the amorphous structure accounts for 89 percent of the total structure of the cereal food, and the GI index is 51 in the slowly digestible whole cereal food.
According to the measurement, the untreated millet particles in the same batch are prepared into the whole grain food according to the general instant porridge food forming process, wherein the slowly digestible starch fragment accounts for 14% of the total starch amount, the amorphous structure accounts for 80% of the total structure of the grain food, and the GI index is 68.
From examples 1-3, it can be seen that the slowly digestible whole grain food of the present invention has a total starch content of more than 40% by weight, an amorphous structure content of more than 85% by weight, and a GI index of less than 55. Therefore, the slowly digestible whole grain food product can meet the dietary requirements and the special medical food standard requirements (GI <55, see the general rules of formula food for special medical applications GB29922-2013) of specific people such as patients with abnormal glucose metabolism and metabolic syndrome related to diet, and has the functions of preventing and treating glucose metabolism disorder and maintaining the health of organisms. Therefore, the slowly digestible whole grain food product has wide market prospect and obvious economic and social benefits.
In addition, the raw materials of the slowly digestible whole grain food adopt grain crops which are commonly sold in domestic markets, have wide sources, are not limited by production places and seasons, and are easy for industrial production. The invention adopts the component tempering auxiliary extrusion molding technology, can realize continuous production, has simple process and is easy to automatically control. The invention develops the high-nutrition quality whole grain food by utilizing the abundant whole grain resources in China, accords with the strategic development plan of China's health, and has important significance for the high-quality development of modern food industry.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.