Food analytical methods Flashcards
What are food analytical methods used for?
Characterize food composition, quality, and safety
They help determine nutritional value, detect contaminants, and ensure regulatory compliance.
What are the two main categories of analytical methods?
- Instrumental Methods
- Chemical Methods
Instrumental methods include techniques like chromatography and spectroscopy, while chemical methods involve wet chemistry techniques.
What does Gas Chromatography (GC) separate?
Volatile compounds in a gas phase
It is commonly used for flavor compounds and fatty acid derivatives.
What is High-Performance Liquid Chromatography (HPLC) used for?
Non-volatile compounds in a liquid phase
It is often used for analyzing proteins, vitamins, and antioxidants.
What does Fourier Transform Infrared Spectroscopy (FTIR) identify?
Functional groups in food components
It measures the absorption of infrared light to identify molecular bonds.
What is the purpose of Atomic Absorption Spectroscopy (AAS)?
Measures metal concentrations in food
It is used to analyze elements such as iron, calcium, and magnesium.
What is an Electronic Nose (E-nose) used for?
Sensory analysis of aroma
It detects volatile compounds to analyze food aroma.
What does Ion Chromatography (IC) separate?
Charged molecules like anions and cations
It is useful for measuring compounds like sodium, potassium, and chloride.
What is the role of sample preparation in food analysis?
- Homogenization
- Extraction
- Filtration & Centrifugation
- Drying & Concentration
Proper sample preparation enhances detection and ensures uniform composition.
Fill in the blank: The Partition Coefficient (K) describes how a compound distributes between two liquid phases in _______.
liquid-liquid extraction
The formula is K = C_upper / C_lower.
What do E-Tongue devices measure?
Taste compounds based on electrochemical sensors
E-Tongues are used in quality control for food and beverage industries.
What are the key aspects of method validation in food analysis?
- Accuracy
- Precision
- Limit of Detection (LOD)
- Limit of Quantification (LOQ)
These aspects ensure the reliability of analytical methods.
True or False: The Coefficient of Variation (CV) is calculated as Standard Deviation (SD) divided by Mean (X) and multiplied by 100.
True
CV = (SD / Mean) × 100.
What is Thin-Layer Chromatography (TLC) used for?
Separating small amounts of compounds on a coated glass plate
The Rf value helps identify compounds.
What does Near-Infrared Spectroscopy (NIR) analyze?
Moisture, protein, and fat
It is often used for routine quality control in food production.
What is chromatography used for?
To separate and analyze individual components in complex food mixtures.
What is the purpose of Gas Chromatography (GC)?
Separates and analyzes volatile and thermally stable compounds in food.
How does Gas Chromatography (GC) work?
The sample is vaporized and carried through a column by a gas mobile phase.
What are the pros of Gas Chromatography (GC)?
- High resolution and sensitivity for volatile compounds
- Detects compounds in small concentrations (ppm or ppb levels)
What are the cons of Gas Chromatography (GC)?
- Only works with volatile substances
- Requires derivatization for non-volatile samples
What is the purpose of High-Performance Liquid Chromatography (HPLC)?
Separates and analyzes non-volatile and thermally unstable compounds.
How does High-Performance Liquid Chromatography (HPLC) work?
The sample is dissolved in a liquid mobile phase and passed through a stationary phase column.
What are the pros of High-Performance Liquid Chromatography (HPLC)?
- Suitable for thermally unstable and non-volatile compounds
- Works for polar and non-polar substances
What are the cons of High-Performance Liquid Chromatography (HPLC)?
- Slower than GC
- More expensive due to specialized solvents and detectors
