阅读说明：本技术 一种大米及其副产物体外消化能的检测方法 (Method for detecting in-vitro digestion energy of rice and byproducts thereof ) 是由 聂昌林 李黛淋 徐绍华 胡声迪 方伟 宋丹丹 周晓舟 吴茜茜 刘慧� 于 2019-11-14 设计创作，主要内容包括：本发明提供了一种大米及其副产物体外消化能的检测方法,属于食品检测技术领域。为了解决体外仿生消化法评估大米及其副产物等淀粉含量高的原料时存在的问题,本发明从原料消化和残渣烘干方面对传统的大米体外消化能检测方法进行创新,通过实验发现,本发明所提供的大米体外消化能检测方法测得的大米消化率和大米体内实际的消化率更相符,说明本发明的检测方法优于传统的检测方法。(The invention provides a method for detecting in-vitro digestion energy of rice and byproducts thereof, belonging to the technical field of food detection. In order to solve the problems existing in the evaluation of the raw materials with high starch content such as rice and byproducts thereof by the in-vitro bionic digestion method, the traditional detection method for the in-vitro digestion energy of the rice is innovated in the aspects of raw material digestion and residue drying, and experiments show that the rice digestibility measured by the detection method for the in-vitro digestion energy of the rice provided by the invention is more consistent with the actual digestibility in the rice body, which indicates that the detection method provided by the invention is superior to the traditional detection method.)

1. A method for detecting the in vitro digestion energy of rice and byproducts thereof is characterized by comprising the following steps:

(1) crushing rice and byproducts thereof, and sieving the crushed rice and byproducts through a test sieve;

(2) preparing a buffer solution in the gastric stage, a buffer solution in the front section of the small intestine and a buffer solution in the rear section of the small intestine;

(3) weighing 2g of crushed rice and byproducts thereof, uniformly mixing with 20ml of stomach simulated digestive juice added with digestive enzyme in the stomach stage, adding into a simulated digestive tube, placing on a single-stomach bionic digester, and performing simulated digestion in the stomach stage according to set stomach stage simulated digestion parameters;

(4) after the simulated digestion at the gastric stage is finished, adding a small intestine forepart buffer solution into a simulated digestion tube through a peristaltic pump, reacting for 30min, adding 2ml of small intestine forepart digestion solution containing trypsin, chymotrypsin, α -amylase, isoamylase and lipase into the simulated digestion tube, and performing small intestine forepart simulated digestion according to small intestine stage simulated digestion parameters;

(5) after the simulated digestion of the rear small intestine is finished, adding a rear small intestine buffer solution into the simulated digestion tube through a peristaltic pump, and performing the simulated digestion of the rear small intestine according to the set simulated digestion parameters of the large intestine stage;

(6) after simulated digestion is finished, washing the rice and the byproduct residues thereof in the simulated digestion pipe by using deionized water, then transferring the rice and the byproduct residues into a blast drying oven without damage, and drying the rice residues under a set condition until no water mark exists;

(7) transferring the rice without water marks and the byproduct residues thereof into a vacuum drying oven, drying for the second time, placing the culture dish into a dryer after drying, cooling to room temperature, and weighing;

(8) gently transferring the rice and the byproduct residues thereof in the culture dish into a crucible for a C2000 type energy instrument by using a sample residue scraping knife;

(9) measuring GE of rice and byproduct residues of the rice by using an IKA C2000 calorimeter, and calculating to obtain in-vitro digestion energy of the rice and byproducts of the rice, wherein the in-vitro digestion energy of the rice and the byproducts of the rice is calculated by the following formula: in vitro digestibility of rice and its by-products = total energy of rice and its by-products-total energy of residues after digestion of rice and its by-products.

2. The detection method according to claim 1, wherein the rice and its by-products comprise: rice, broken rice, rice wheat middling, rice flour and rice sugar residues.

3. The detection method according to claim 1, wherein in the step (1), the pore size of the test sieve is 0.28 mm.

4. The assay of claim 1, wherein in step (2), the gastric phase buffer is phosphate buffer, and the pH is 2.0; the small intestine forepart buffer solution is a phosphate buffer solution, and the pH value is 6.5; the buffer solution of the small intestine posterior segment is phosphate buffer solution, and the pH value is 7.9.

5. The detection method according to claim 1, wherein in the step (3), the gastric mimic digestive juice is pepsin digestive juice, and the content of pepsin is 2.19 x 10^-3g/ml; in the step (3), the stomachThe stage simulation digestion parameters are digestion time of 4 hours and digestion temperature of 41 ℃.

6. The detection method according to claim 1, wherein in the step (4), the content of trypsin is 4.12X 10^-3～5.26×10^-3g/ml, the content of the chymotrypsin is 2.03 multiplied by 10^-3～2.96×10^-3g/ml, the content of the α -amylase is 1.67 multiplied by 10^-1～2.15×10^-1g/ml, the content of the isoamylase is 4.610^-2～7.7×10^-2g/ml isoamylase, wherein the content of the lipase is 1.123-1.487 multiplied by 10^-1g/ml lipase.

7. The detection method according to claim 1, wherein in the step (4), the digestion parameters of the small intestine stage simulation are digestion time of 7.5 hours and digestion temperature of 41 ℃.

8. The detection method according to claim 1, wherein in the step (5), the large intestine stage simulated digestion parameters are digestion time of 7.5 hours and digestion temperature of 41 ℃.

9. The detection method according to claim 1, wherein the set condition in the step (6) is 55 ℃.

10. The detecting method according to claim 1, wherein in the step (7), the conditions of the secondary drying are as follows: the vacuum degree is minus 0.08Mpa, the drying temperature is 55 ℃, and the drying time is 4 hours.

Technical Field

The invention relates to the technical field of food detection, in particular to a method for detecting in-vitro digestion energy of rice and a byproduct thereof.

Background

Currently, a monogastric animal bionic digestion system (SDS-II type) is mainly adopted for digestion test for evaluating the in-vitro digestion energy of feed raw materials, then digested residues are transferred to a clean culture dish, dried by a blast drying oven at 65 ℃ until no water mark exists, and then dried, weighed and analyzed at 105 ℃ for the nutrient content in the residues. However, the existing bionic digestion method has certain problems in measuring in-vitro digestion energy, has good effect on raw materials of grain and cake meal, but cannot evaluate the raw materials with high starch content such as rice and byproducts thereof (rice, rice wheat middling, rice flour, rice sugar residue) and the like. The traditional detection method has the defects of incomplete starch digestion, Maillard reaction in the drying process and the like. Therefore, a detection method capable of effectively measuring the in vitro digestion energy of the rice and the byproducts thereof is urgently needed at present.

Disclosure of Invention

In order to solve the problems existing in the process of detecting the digestion energy of the rice and the byproducts thereof, the invention provides a novel method for detecting the in-vitro digestion energy of the rice and the byproducts thereof.

In order to achieve the aim, the invention provides a method for detecting the in vitro digestion energy of rice and byproducts thereof, which is characterized by comprising the following steps:

(1) crushing rice and byproducts thereof, and sieving the crushed rice and byproducts through a test sieve;

(2) preparing a buffer solution in the gastric stage, a buffer solution in the front section of the small intestine and a buffer solution in the rear section of the small intestine.

(3) Weighing 2g of crushed rice and byproducts thereof, uniformly mixing with 20ml of stomach simulated digestive juice added with digestive enzyme in the stomach stage, adding into a simulated digestive tube, placing on a single-stomach bionic digester, and performing simulated digestion in the stomach stage according to set stomach stage simulated digestion parameters;

(4) after the simulated digestion at the gastric stage is finished, adding a small intestine forepart buffer solution into a simulated digestion tube through a peristaltic pump, reacting for 30min, adding 2ml of small intestine forepart digestion solution containing trypsin, chymotrypsin, α -amylase, isoamylase and lipase into the simulated digestion tube, and performing small intestine forepart simulated digestion according to small intestine stage simulated digestion parameters;

(5) after the simulated digestion of the rear small intestine is finished, adding a rear small intestine buffer solution into the simulated digestion tube through a peristaltic pump, and performing the simulated digestion of the rear small intestine according to the set simulated digestion parameters of the large intestine stage;

(6) after simulated digestion is finished, washing the rice and the byproduct residues thereof in the simulated digestion pipe by using deionized water, then transferring the rice and the byproduct residues into a blast drying oven without damage, and drying the rice residues under a set condition until no water mark exists;

(7) transferring the rice without water marks and the byproduct residues thereof into a vacuum drying oven, drying for the second time, placing the culture dish into a dryer after drying, cooling to room temperature, and weighing;

(8) gently transferring the rice and the byproduct residues thereof in the culture dish into a crucible for a C2000 type energy instrument by using a sample residue scraping knife;

(9) measuring GE of rice and byproduct residues of the rice by using an IKA C2000 calorimeter, and calculating to obtain in-vitro digestion energy of the rice and byproducts of the rice, wherein the in-vitro digestion energy of the rice and the byproducts of the rice is calculated by the following formula: in vitro digestibility of rice and its by-products = total energy of rice and its by-products-total energy of residues after digestion of rice and its by-products.

Preferably, the rice and its by-products include: rice, broken rice, rice wheat middling, rice flour and rice sugar residues.

Preferably, in the step (1), the pore size of the test sieve is 0.28 mm.

Preferably, in the step (2), the gastric stage buffer solution is phosphate buffer solution, and the pH value is 2.0; the small intestine forepart buffer solution is a phosphate buffer solution, and the pH value is 6.5; the buffer solution of the small intestine posterior segment is phosphate buffer solution, and the pH value is 7.9.

Preferably, in the step (3), the weighed rice and the by-product thereof are pepsin digestion liquid, and the content of pepsin is 2.19 × 10^-3g/ml; in the step (3), the simulated digestion parameters of the stomach stage are digestion time of 4 hours and digestion temperature of 41 ℃.

Preferably, in the step (4), the content of the trypsin is 4.12X 10^-3～5.26×10^-3g/ml, the content of the chymotrypsin is 2.03 multiplied by 10^-3～2.96×10^-3g/ml, the content of the α -amylase is 1.67 multiplied by 10^-1～2.15×10^-1g/ml, the content of the isoamylase is 4.610^-2～7.7×10^-2g/ml isoamylase, wherein the content of the lipase is 1.123-1.487 multiplied by 10^-1g/ml lipase.

Preferably, in the step (4), the digestion parameters of the small intestine stage simulation are digestion time of 7.5 hours and digestion temperature of 41 ℃.

Preferably, in the step (5), the simulated digestion parameters of the large intestine stage are digestion time of 7.5 hours and digestion temperature of 41 ℃.

Preferably, in the step (6), the set condition is 55 ℃.

Preferably, the conditions of the secondary drying are as follows: the vacuum degree is minus 0.08Mpa, the drying temperature is 55 ℃, and the drying time is 4 hours.

The invention has the beneficial effects that:

1. the in vitro digestibility of rice measured by the detection method of the invention is 81.01%, while the in vitro digestibility of rice measured by the traditional method is 88.73%. According to animal metabolism experiment research, the in-vivo digestibility of the rice is about 82%, which is similar to the result of the detection method, and the digestibility of the rice measured by the detection method is more consistent with the actual digestibility of the rice.

2. The traditional method leads to loss of part of rice due to Maillard reaction because of higher drying temperature, thus leading to inaccurate evaluation result.

3. The amylase used in the traditional method can not completely digest starch in rice and byproducts thereof, so that the digestion energy measured by the traditional method is inaccurate, the invention uses a mixed enzyme group of α amylase and isoamylase to replace the traditional single α -amylase, and the applicant of the invention finds that when the single α -amylase is simply added, 15.56% of starch in residues is still digested, and the starch content in the residues adopting the mixed enzyme group is only 1.42%, so that the accuracy of the detection method can be greatly improved.

4. In the traditional method, the rice residue needs to be degreased by absolute ethyl alcohol before the digestion energy of the residue is measured, but in practical tests, the inventor finds that in the process of degreasing by the absolute ethyl alcohol, the rice residue and the absolute ethyl alcohol react to produce jelly-shaped substances, so that subsequent tests cannot be carried out. The invention uses lipase to replace absolute ethyl alcohol, and successfully solves the problems.

Drawings

FIG. 1 shows the results of Maillard reaction assay.

Detailed Description