Appunti (Advanced food analysis) (1)
1. Introduction to Advanced Food Analysis
Techniques for determining substance presence in food.
Ensuring robust and sensitive data for product quality and authenticity.
2. Food Quality
Definition: Food is genuine if healthy, unaltered, and free from contaminants.
Composition must be known to attest to genuineness.
2.1 Example with Extra Virgin Olive Oil
Genuine EVO oil: made only from mechanically processed olives at low temperatures.
Analysis must confirm parameters align with genuine EVO oil.
2.2 Sample Preparation Effects
e.g., Vitamin D in milk affected by cows' diet (grass rich in polyunsaturated fats leads to higher fat levels in spring milk).
Vitamin D is fat-soluble; accumulation linked to fat and calcium content.
3. Extraction Techniques
Non-thermal extraction methods (e.g., ultrasonics) for heat-sensitive compounds.
Use of specific solvents and methodologies for optimal yield without degradation (like Vitamin D).
4. Critical Thinking in Exams
Emphasis on reasoning over rote memorization (e.g., understanding analysis types vs. column names).
Example question: "How can fat be calorie-free?" - Discuss lipid metabolism by lipases.
Example health risks of non-absorbable fats (e.g., digestive issues).
5. Oleogel
Composition: water and trapped oil droplets in a reticular network.
Used to reduce saturated fat in foods while providing elasticity.
Techniques involve using waxes or emulsifiers to stabilize oils in gel form.
6. Plant-Based Foods
Proteins replace fats; need for textural modifications to maintain organoleptic properties.
Commonly used ingredients: modified starches and binders.
7. Analysis Types
7.1 Targeted Analysis
Focuses on known substances with established reference materials.
7.2 Untargeted Analysis
Investigates unknown substances, often utilizing ohmic techniques.
8. Rheology and Texture Analysis
Texture analysis quantifies attributes like hardness or crunchiness using instruments like texture analyzers.
Statistical analysis for accurate representation of food texture.
9. Importance of Food Analysis
Ensures food safety and quality standards.
Government regulations on nutrition labeling and product quality standards (e.g., PGI).
10. Research and Development
Essential for developing new food products; monitoring quality throughout the food chain.
10.1 By-products Management
By-products must be stabilized and analyzed for safety (e.g., cocoa shells' mycotoxin levels).
10.2 Quality Control
Analytical methods must be consistent across the supply chain (raw materials to products).
11. Methods of Quality Assessment
APCI & ESI for sensitive ionization practices; standard selections for compound identification.
12. Sampling Methods
Importance of representative sampling based on product homogeneity.
12.1 Analysis of EVO Oil
Sensory evaluation required for genuine EVO oil standards.
13. Common Extraction Methods
13.1 Soxhlet Extraction
Continuous extraction for complete analyte recovery.
13.2 Countercurrent Extraction
Efficient solvent-use via continuous flow, ideal for separating analytes.
14. Chromatography Overview
14.1 GC vs HPLC
GC advantages for volatile compounds; HPLC for liquid-soluble analytes without degradation.
14.2 Types of Columns
Packed versus capillary columns: efficiency vs capacity and analyte separation speed.
15. Detector Types in Chromatography
15.1 Thermal Conductivity Detector (TCD)
Universal, but limited linearity; ideal for gas compositions.
15.2 Flame Ionization Detector (FID)
High sensitivity, wide linear range for organic compounds; common in food analyses.
15.3 Electron Capture Detector (ECD)
Sensitive to halogenated compounds, primarily used for pesticides.
16. Mass Spectrometry Basics
16.1 Mass Analyzer Types
Various types include quadrupole, ion trap, and time-of-flight for m/z determination.
16.2 Sample Preparation and Analysis
Standard creation essential for proper spectral comparison and identification (relative abundances in mass spectrometry).
16.3 Fragmentation Patterns
Unique framment patterns aid in the identification of analytes based on their mass spectra.
Overall Practice
Successful food analysis relies on method selection, sample integrity, and proper data interpretation for safety and quality assurance.