Dr. Syed S H Rizvi

Editor in Chief

Professor

Department of Food Science

Cornell Univeristy, USA

Tel: 607-327-1082

Fax: 607-254-4868

Editorial Board Member

Syed S H Rizvi is International Professor of Food Process

Engineering and has served as Director of Graduate Studies at

the Cornell Institute of Food Science. He has a Ph.D. from Ohio

State University, a M. Eng. (Chemical Engineering) from the

University of Toronto, and a B. Tech. from Panjab University,

India. He teaches courses devoted to engineering and

processing aspects of food science and related biomaterials. He

has also serves as a Jefferson Science Fellow and Senior Science

Adviser in the U.S. Department of State, 2007-2008.

Biography

• Bio separation processes, Physical and engineering properties,

Supercritical fluids, Extrusion, Rheology and international

developments.

Research Interest

Publications• Sikin AM, Zoellner C, Rizvi SS (2013) Current Intervention

Strategies for the Microbial Safety of Sprouts.. Journal of Food Protection. 76:2099-2123.

• Paraman I, Wagner ME, Rizvi SS (2012) Micronutrient and protein-fortified whole grain puffed rice made by supercritical fluid extrusion. Journal of Agricultural and Food Chemistry. 60:11188−11194.

• Manoi K, Rizvi SS (2010) Physicochemical characteristics of phosphorylated cross-linked starch produced by reactive supercritical fluid extrusion. Carbohydrate Polymers. 81:687-694.

Book• Rizvi SS (2010) Separation, extraction and concentration processes

in the food, beverage and nutraceutical industries.. p. 665 Syed S.H. Rizvi (ed.), Wood head Publishing, Oxford, U.K.

Publications and Books

Food Rheology

Food Rheology a study of deformation and flow of matter (especially

interesting in agricultural and biological materials).

We encounter rheology in our daily life! 

We eat breakfast, perhaps using a range of spreads for toast, or perhaps

we eat yoghurt with pieces of fruit suspended in it. 

We all have squeezed toothpaste tubes, kneaded bread dough or tried to

rub skin lotion on our leg. 

Rheology is simply one way of describing those sensations!!

Importance of Food Rheology

• Food rheology is important in quality control during food

manufacture and processing

• Long food can be stored

• The study of food rheology is more complicated than study in

fields such as the rheology of polymers.

Rheology in Daily Life

• We normally take for granted a lot of things in life and

these include some of the “rheological events”.

• The pictures show the different roles of rheology in

food and nonfood products.

Examples of Rheological Properties

• Viscosity

• Elasticity

• Peanut butter in the jar

• Ketchup is commonly used an example

• The textural properties of a peanut butter and jelly sandwich

• Cheese

• Cheese is a nutritious Food made mostly from Cow’s milk.

• Curded by Lactic Acid Bacteria

• It is a source of protein and calcium

• Containing additional nutrients

Types of Cheese

• Asiago Cheese

• Bleu Cheese

• Goat Cheese

• Cream Cheese

• Vegetarian Cheese

Rheological and Functional Properties in Cheese

Three categories

• Empirical- supply basic single point information

• Imitative-try to imitate the forces and deformations associated with

a specific process

• Fundamental- gives information as to the element properties of a

material

Rheological Tests

Rheological Methods

Small Strain• Used to define both the elastic and the viscous nature of

cheese.• Cheese is a time dependent material • Useful in understanding mechanisms of some endues

functions. • Used to determine changes caused by processing and storage

parameters of cheesesLarge Strain• Used to determine cheese texture • These measurements occur outside of linear viscoelastic region • Characterize the non linear and fracture properties of the

material • Relate well to sensory properties since mastication is a large

strain action

Factors affecting Rheological and Functional Properties

• Can be categorized as below • Properties of milk • Cheese composition • Cheese making procedures • Post manufacturing processes

• Responsible for any formulation, production, appearance, usage, and

finally affect stability

• Affects final cost of product

• If a material is pumped, sprayed, extended, extruded, molded,

coated, mixed, chewed, swallowed, rubbed, transported, stored,

heated, cooled, aged …Rheology is important

Industrial Aspect of Rheology

Foods

• Emulsions (mayonnaise, ice cream)

• Foams (ice cream, whipped cream)

• Suspensions (mustard, chocolate)

• Gels (cheese)

Bio fluids

• Suspension (blood)

• Gel (mucin)

• Solutions (spittle), etc.,

Examples of Complex Fluids

Thank You..!