Choice and validity of methods. Compositional analysis of food: moisture, crude fat, carbohydrate and protein. Analytical methods to verify the conformity of food characteristics to law requirements: milk and derivatives, olive oil, wine, bread and pasta. Understanding chemical principles that underlie relationships between the composition of food and functional, nutritional and sensory properties. Laboratory experience aimed to provide knowledge of methods and equipment used in food analysis
Analisi dei Prodotti Alimentari
P. Cabras e C.I.G. Tuberoso
Piccin Editore 2014
Chimica degli alimenti
P. Cabras e Martelli
Piccin Editore, 2004
Food Analysis,
Susan Nielsen
Kluver Academic, Plenum Publisher, New York, 2003
Learning Objectives
Knowledge of chemical composition of food products and relevant analytical methods
Competence for characterizing raw material and food product in terms of chemical and physical parameters
Competence in defining of relationships between chemical and physical parameters of food products and their compliance to law requirements and process specifications.
• Ability in defining an appropriate analytical method on the basis of protocol of official method of analysis and scientific publications
• Ability in applying an analytical method, to interpret instrumental response and to write a technical report
General part
Compositional analysis of food:
Moisture and Water activity. Moisture determination: oven drying methods, distillation procedures, chemical methods.
Crude fat analysis: solvent extraction methods: continuous, semi-continuous, discontinuous. Elevated pressure/temperature solvent. Non solvent wet extraction methods: Gerber and Babcock. Introduction at IR and NMR techniques for fat content determination.
Carbohydrate analysis: total carbohydrate and total reducing sugar. Enzymatic methods for determining glucose content.
Protein analysis: Kjeldhal method, colorimetric assay: Biureto, Lowry, Coomassie. UV absorption.
Fat characterization: determination of physical chemical indices. Lipid peroxidation. Measuring oxidation state: peroxide value, conjugated dienes and trienes. Lipid composition: principles of chromatography for characterization of lipid fraction.
Protein separation and characterization procedure: separation by differential solubility, principles of chromatography for characterization of protein fraction. Separation by electrophoresis.
Special
Milk components and their physical state. Evaluation of milk thermal treatments by means of enzymatic indicators (alkaline phosphatase and lactoperoxidase). Maillard reaction. Physical chemical indices: density, pH, acidity, cryoscopic index.
Phenolic composition and sensory properties of wine. Anthocyanins and wine colour. Assessment of functional properties of tannins: Phenolic and technical grape maturity indices.
Olive oil composition: triglycerides, fatty acids, minor polar fraction. Chemical physical characteristics of natural fatty acids: determination of fatty acid in 2-monoglicerides. Assessment of conformity to botanical origin. UV-VIS assay. Determination of eritrodiol and uvaol content in rectified oils. Determination of elaidinc acid content. Phenolic compounds and olive oil stability and sensory properties.
Laboratory
Protein content determination by using a reference curve. Determination of milk pH and acidity and protein for milk quality assessment.
Classification of olive oil samples by peroxide values, total acidity and UV-VIS parameters determination.
Determination of anthocyanin content by means of SO2 bleaching method. Evaluation of red wine color
Assaying total sugar content (glucose and fructose) by using an enzymatic kit in fruit jams
Evaluation of common wheat in pasta product by means of immunochemical assay.