Analysis and testing of pecan nutritional components

The analysis and detection of pecan (i.e. walnut) nutrients involves a variety of methods and techniques to ensure the accuracy and reliability of its nutrients. The following are some commonly used methods for analyzing and detecting pecan nutrients:

1. Sample preparation
Collection and preservation:
Select representative pecan samples for collection.
Ensure that the samples are not contaminated during collection, transportation and storage, and are kept moisture-proof and light-proof.
Pretreatment:
Wash the samples and remove surface impurities.
Crush and grind the samples to an appropriate particle size for subsequent analysis.
2. Moisture and ash detection
Moisture detection:
The moisture content in the sample is determined by drying or Karl Fischer titration.
The drying method is to dry the sample at a specified temperature to a constant weight and measure the weight change to calculate the moisture content.
The Karl Fischer titration method uses the Karl Fischer reagent to react with water and determine the moisture content by the titration end point.
Ash detection:
The sample is burned at high temperature to a constant weight, and the mass of the residue is measured as the ash content.
The ash content reflects the content of inorganic matter in the sample.
3. Protein detection
Kjeldahl method:
Based on the relatively stable nitrogen content in protein, nitrogen is converted into ammonia through chemical reactions.
The amount of ammonia is determined by titration, and then the protein content is calculated.
Other methods:
Such as ultraviolet spectrophotometry, near-infrared spectroscopy, etc., these methods can also be used for rapid protein determination.
4. Fat detection
Soxhlet extraction method:
The fat in the sample is extracted using organic solvents (such as ether).
The fat content is calculated by weighing.
This method is simple and fast, and is suitable for rapid detection of large batches of samples.
Other methods:
Such as Rozs-Gottli method, gas chromatography, etc., can also be used for fat determination.
5. Fiber detection
Weight method:
Soluble substances and starch in the sample are removed by acid hydrolysis or enzymatic hydrolysis.
The remaining substance is the fiber component, and the fiber content is calculated by weighing.
Colorimetry:
The principle of color reaction between certain chemicals and fiber components is used.
The fiber content is determined by measuring the color depth.
6. Vitamin and mineral detection
Vitamin detection:
High performance liquid chromatography (HPLC): high sensitivity and good resolution, suitable for the determination of trace vitamins in complex samples.
Fluorescence spectrophotometry, ultraviolet spectrophotometry, etc. can also be used for the determination of vitamins.
Mineral detection:
Atomic absorption spectrometry (AAS): determine the content by measuring the degree to which metal ions in the sample solution absorb light of a specific wavelength.
X-ray fluorescence spectrometry (XRF): use X-rays to excite elements in the sample to produce characteristic fluorescence, and quantify by detecting the fluorescence intensity.
Inductively coupled plasma mass spectrometry (ICP-MS) and other methods can also be used for the determination of minerals.
7. Antioxidant detection
Pecans are rich in antioxidants, such as flavonoids and anthocyanins. These antioxidants help reduce free radical damage and protect body cells from damage. Commonly used antioxidant detection methods include high performance liquid chromatography (HPLC), spectrophotometry, etc.

8. Other tests
Pesticide residue detection:
High performance liquid chromatography (HPLC), gas chromatography (GC), etc. can be used for the determination of pesticide residues.
Ensure that the pesticide residue in pecans meets the standard to protect the health of consumers.
Heavy metal detection:
Use highly sensitive analytical methods such as atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS).
Accurately determine the content of heavy metals in pecans to ensure that they meet food safety standards.
Microbial detection:
Common microbial detection methods include PCR and culture methods.
It can detect whether there is bacterial contamination in pecans and determine whether it meets food safety standards.
IX. Data processing and result analysis
Data recording:
Record the various data in the experimental process in detail, including instrument parameters, sample processing process, measurement results, etc.
Data analysis:
Perform statistical analysis on the measurement results, compare theoretical values ​​with measured values, and determine whether the nutrients in the product reach the expected level.
Result report:
Write a detailed test report, including experimental methods, measurement results, data analysis, etc. In summary, the analysis and detection of pecan nutrient components involves a variety of methods and technologies. By comprehensively applying these methods and technologies, we can fully and accurately understand the nutrient content and quality characteristics of pecan nutrient components, and provide strong support for product development and quality control.