Processing method for improving bioavailability of nutrients in sesame

Abstract

The application discloses a processing method for improving the bioavailability of nutrients in sesame, and belongs to the field of food processing. The effects of different processing methods, including steaming, microwave, baking and ultra-high pressure, on the digestion and release rates of calcium and vitamin E in sesame are compared through in-vitro simulation digestion, and it is found that the method of using ultra-high pressure and baking has good effects on processing and treating sesame. The application also compares the digestion and release rates of calcium and vitamin E in different sesame varieties, thereby providing technical support for better application of sesame as a nutrient fortification raw material in food production.

Description

TECHNICAL FIELD

[0001] The present application relates to a processing method for improving the bioavailability of nutrients in sesame, belonging to the field of food processing. BACKGROUND

[0002] Sesame, soybean, peanut and rapeseed are the four major traditional edible oil crops in China. Sesame is rich in minerals, with the highest content of calcium, reaching 8 mg / g, followed by phosphorus, magnesium, iron and zinc. However, due to the presence of large amounts of oxalic acid, phytic acid and indigestible crude fiber as well as pigments in the skin and seeds of sesame, and the fact that a large amount of calcium in sesame exists in the form of calcium salt, the bioavailability of calcium in the human body is not high.

[0003] Phytic acid is negatively charged under physiological conditions and strongly chelates with metal ions, especially calcium, forming insoluble complexes in the gastrointestinal tract. Due to the lack of intestinal phytase, the human body cannot directly digest or absorb calcium. Studies have found that the sesame oil extraction process increases the content of anti-nutritional factors, such as phytic acid, from 2% to 5%, and crude fiber from 5.3%; the dehulled seeds still retain a large amount of fiber (4-4.5%) as well as phytic acid and oxalic acid (usually more than 2% and 3%, respectively). In addition to calcium, sesame is also rich in fat-soluble components such as vitamin E, sesamin, etc. Suitable processing methods not only help to retain active fat-soluble components in sesame, but also promote the release and absorption of its nutritional components by changing the "oil path" of the cells.

[0004] Therefore, the present application studies the effects of different processing methods on the bioavailability of nutrients in sesame through in vitro simulated digestion, thereby providing theoretical guidance for the use of sesame as a nutrient fortification material, especially a calcium supplement, in the food production industry. SUMMARY

[0005] The purpose of the present application is to provide a processing method for improving the bioavailability of nutrients in sesame, so that sesame can better play a role in nutrient fortification.

[0006] The above-mentioned purpose is achieved by the following technical solutions:

[0007] A processing method for improving the bioavailability of nutrients in sesame, which compares the effects of different processing methods including cooking, microwave, baking and ultra-high pressure on the digestion and release rate of nutrients in sesame through in vitro simulated digestion, and selects the use of ultra-high pressure and baking to process sesame.

[0008] Preferably, the pressure of the ultra-high pressure is 250-500 Mpa, the temperature is 20-50℃, and the time is 5-30 min.

[0009] Further preferably, the pressure of the ultra-high pressure is 380 Mpa, the temperature is 30℃, and the time is 15 min.

[0010] Preferably, the baking temperature is 120-180℃, and the time is 10-30min.

[0011] The nutrient is calcium and vitamin E.

[0012] The beneficial effects of the present application are:

[0013] The present application screens the sesame processing method which is more beneficial to human body absorption, and the ultra-high pressure processing and baking method is obviously superior to the cooking and other processing methods. The present application provides important scientific support for the updating and upgrading of traditional products and promotes the upgrading of the industry; and provides a new idea and method for the utilization of by-products of traditional oil crops.

[0014] Compared with the cooking and other pretreatments, the baking treatment can destroy macromolecular proteins, plant fibers and other substances which hinder the dissolution of nutrients, and release minerals combined with anti-nutritional factors. The ultra-high pressure technology treatment process is instantaneous, efficient, uniform, safe and energy-saving, and can reduce the content of anti-nutritional factors, reduce the combination of amino acids, minerals and other nutrients, release more amino acids and minerals to improve the physiological function and bioavailability of nutrients. At the same time, the ultra-high pressure can retain the active lipid-soluble components in sesame, and promote the release and micellization absorption by changing the cell "oil path". DETAILED DESCRIPTION

[0015] In order to better understand the present application, the present application will be further described in detail below in conjunction with specific examples, but those skilled in the art will understand that the following examples are not a limitation on the scope of protection of the present application, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application shall be regarded as equivalent replacement methods and shall be included in the scope of protection of the present application.

[0016] The related detection methods involved in the following examples are as follows:

[0017] (1) Atomic absorption spectrophotometry for determining the calcium ion content of the sample

[0018] Accurately weigh 0.2g-3g (accurate to 0.001g) of solid sample or accurately transfer 0.500mL-5.00mL of liquid sample into a digestion tube with scale, add 10mL of nitric acid and 0.5mL of perchloric acid, and digest on an adjustable electric heating furnace (reference conditions: 120℃ / 0.5h-120℃ / 1h, rise to 180℃ / 2h-180℃ / 4h, rise to 200℃-220℃). If the digestion solution is brown, add more nitric acid and digest until white smoke is generated, and the digestion solution is colorless and transparent or slightly yellow.

[0019] The calcium standard series solution is introduced into the flame atomizer in order of low to high concentration, and the absorbance value is measured. The mass concentration of calcium in the standard series solution is taken as the abscissa, and the corresponding absorbance value is taken as the ordinate to make a standard curve. Under the same experimental conditions as the determination of the standard solution, the blank solution and the sample to be tested are introduced into the atomizer, and the corresponding absorbance value is measured and compared with the standard series for quantitative determination. The specific steps are shown in GB 5009.92-2016.

[0020] (2) Determination of the content of vitamin E by high performance liquid chromatography

[0021] Take 5 mL of the sample and add 10 mL of n-hexane, vortex for 30 min, centrifuge (4000 rpm, 10 min), take the supernatant, nitrogen blow, then add 1 mL of n-hexane for redissolution, pass through a 0.2 μm filter membrane, and measure in a brown sample bottle. Liquid chromatography analysis conditions: LC-6AD high performance liquid chromatography, mobile phase is n-hexane: isopropyl alcohol = 99.5:0.5 (V / V), flow rate is 1 mL / min, injection volume is 20 μL, and temperature is 30℃.

[0022] (3) In vitro simulated digestion test

[0023] Add 2 g of sesame sample to 20 mL of simulated gastric juice and mix evenly (the concentration of pepsin solution is 10 mg / ml, and the pH of deionized water solution is adjusted to 2.0 before adding pepsin), adjust the pH of the mixed sample to 2.0, and incubate in a 37℃ constant temperature oscillator for 120 min to simulate the human gastric digestion environment. Then adjust the pH of the sesame digestion solution after 120 min of gastric digestion to 7.0, add 20 mL of intestinal digestion solution (the concentration of trypsin solution is 10 mg / ml), adjust the pH of the mixed sample to 7.4, and incubate in a 37℃ constant temperature oscillator for 120 min to simulate the human intestinal digestion environment. Finally, place the sample in a boiling water (97±2℃) bath for 10 min, quickly cool to room temperature with ice water after the water bath is completed, and centrifuge at 10000 x g for 30 min, and collect the supernatant as the sesame digestion solution.

[0024] Example 1: Ultra-high pressure treatment of sesame and optimization of process parameters

[0025] Take 500 g of raw sesame seeds, place them in a vacuum bag, vacuumize, then place them in the container cavity of the ultra-high pressure device, use water as the pressure medium, increase the pressure in the container cavity to 200-600 Mpa at 20-50℃, maintain the pressure for 5-20 min, then release the pressure, take out the vacuum bag, and store it in the refrigerator for standby. Perform in vitro simulated digestion test on the stored sesame seeds, and calculate the release rate of calcium and vitamin E according to the content in the digestion solution and the raw material.

[0026] Based on the pre-experiment, a number of different process parameters were set, and the effect of ultra-high pressure treatment on the digestibility and release rate of calcium and vitamin E in sesame was investigated. The results are shown in Table 1 and Table 2.

[0027] Table 1 Process parameters of ultra-high pressure

[0028] Pressure (Mpa) Temperature (°C) Time (min) Group 1 450 25 8 Group 2 320 35 12 Group 3 260 45 20 Group 4 500 20 5 Group 5 380 30 15

[0029] Note: The pressure value fluctuates by no more than 10 MPa, and the temperature fluctuates by no more than ±3℃.

[0030] Table 2 Effect of ultra-high pressure treatment on the digestibility and release rate of calcium and vitamin E

[0031] Release rate of calcium (%) Bioavailability of vitamin E (%) Group 1 7.7±1.1* 87.9±5.0* Group 2 11.3±2.1** 88.2±0.33* Group 3 10.5±1.6** 87.5±1.9* Group 4 9.4±1.3* 78.1±4.9 Group 5 13.6±2.2** 91.3±8.3* Blank group 5.1±0.86 76.1±2.85

[0032] Note: The blank group is sesame kernel without any treatment, and all data are repeated three times; compared with the blank group, *P<0.05, **P<0.01.

[0033] Through the above experiments, it was found that the calcium release rate and vitamin E bioavailability of sesame after ultra-high pressure treatment were improved. The reason may be that the ultra-high pressure treatment destroyed the plant fiber, limited the chemical bonds of protein molecules, reduced the generation of phytic acid and its chelation with calcium ions, under the action of strong pressure, the "oil path" of plant cells was opened, thereby increasing the release and absorption of related nutrients.

[0034] Comparative Example Comparison of the effect of ultra-high pressure treatment with other treatment methods

[0035] Steaming treatment: sesame was immersed in boiling water at a ratio of 1:5, and after boiling and soaking at about 97℃ for 30 min, it was taken out and dried.

[0036] Microwave treatment: sesame was placed in a microwave oven, and the microwave oven was operated at a frequency of 2450 MHz and a power of 700 W for 6 min.

[0037] Table 3 Effect of conventional treatment methods on the digestibility and release rate of calcium and vitamin E

[0038] Release rate of calcium (%) Bioavailability of vitamin E (%) Boiling 4.3±0.06 63.2±4.3 Microwave 5.5±0.28* 82.1±5.9 Blank group 5.1±0.86 76.1±2.85

[0039] Compared with the blank group, *P<0.05.

[0040] The results showed that the digestibility of calcium and vitamin E decreased after cooking treatment. The starch in sesame was gelatinized by cooking, and the high molecular weight pectin and fat were dissolved from the cells and enriched in the inner layer of the peel to form a protective layer, thus preventing the digestion and release of nutrients. Microwave treatment had a certain promoting effect on the release of nutrients. The rapid heating of water molecules rubbing against each other inside the sesame caused the internal water to diffuse to the surface, making the sesame quality become crisp and beneficial to the release of internal ingredients. At the same time, the local high temperature caused by microwave heating also led to a series of changes in the chemical composition and flavor substances in sesame, which might have an adverse effect on the processing and release of ingredients.

[0041] Example 2 Sesame roasting treatment and optimization of its process parameters

[0042] 200 g whole sesame seeds were placed in an aluminum foil tray and then placed in an air oven for roasting, followed by in vitro simulated digestion test. The release rates of calcium and vitamin E were calculated based on the contents in the digestion solution and the raw material.

[0043] Table 4 Effect of roasting treatment on the digestion release rate of calcium and vitamin E

[0044]

[0045] Note: The blank group is sesame seeds without any treatment, and all data are repeated three times; compared with the blank group, *P <0.05.

[0046] The results showed that roasting treatment could significantly improve the bioavailability of calcium, and the difference between the four groups was not too large. Roasting could also promote the rupture of cell walls and the loosening of sesame structure, promoting the migration of vitamin E in oil bodies. The biggest difference between roasting and microwave treatment was that the heating process of roasting was more gentle and uniform, and the slow heating process could effectively reduce the complex chemical reactions and loss of flavor substances caused by local high temperature.

Claims

1. A process for improving bioavailability of nutrients in sesame characterized in that: The sesame is processed by using ultrahigh pressure, the pressure of the ultrahigh pressure is 380Mpa, the temperature is 30 DEG C, the time is 15min, and the nutrients are calcium and vitamin E.

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