Foods – dynamic systems Structure variation –Storage –Distribution –Preparation Factors –Composition –Acidity –Internal pressures –Interacting phases –Environmental conditions (RH,P,T) Modeling and optimization of engineering properties –Computing power, understand underlying phenomena

Properties Particle size (size, shape, surface toughness, density, hardness, adsorption properties) Size distribution among particles Bulk density, porosity (compressibility) Flowability – ease of flow through chute or hopper Chemical and mechanical interaction Segregation – unwanted separation

Storage of Biological Products Handling methods Moisture Management Storage of Biological Products Transport of biomaterials Augers Pneumatic Conveyors Sizing a Pneumatic System.

Handling methods Assessment of moisture content ( water activity) Field Crops ( Corn, Rice, bean) In the field before harvest (Ripening stages  possible to dry in field  a function of whether ( rain or shine) and field condition (wet or dry)  harvesting time ( Night or day). At farm after harvest, for sale or storage Moisture varies with harvesting stages, field handling

Moisture management Grains, ( %,generally about 12%) Fresh vegetable, fruits, ( Maintenance freshness and turgidity  cool and humid)  control atmosphere  refrigeration Dry fruits  Cool and dry, air tight Processed food  In control environment (Frozen, Salt or Sugar solution, Air tight bag)

Moisture Management Assessing moisture in Biomaterial Keeping Biomaterial moisture content ( water activity) at equilibrium point where water migration of water from Biomaterial to ambient air is minimum. Objectives: Keeping low water activities so that biological, chemical and physical properties remain stable/ or as desired, for storage purpose

MOISTURE MEASUREMENT Experience (touch, ocular, smell) Direct measurement: Moisture meter electronic (probes with sensors) Sampling from bulk ( Sampler) Oven dry ( wet basis) Moisture meter

Why must we know the moisture contents for Biomaterials Marketing  Sale purpose (Weight of actual products, at transaction time, ) Buyer and seller mutual agreement Storage purpose ( eg. Grains)  will cause the buyer to keep the grains at desired storage moisture content.

Research into food structure Behavior of properties under different processing conditions can be explained and different structure-property relationships determined Engineer’s task – translate structural characterization in relation to engineering properties Qualitative through microscopic perspective Quantitative characterization of interacting forces and energies involved still being studied.

Future Advances Genetic engineering and biotechnology Naturally synthetic components and raw biomaterials with modified properties fabricated at molecular and microstructural level Application of nanotechnology allow manufacture and positioning of specific molecules or functional groups within biomaterial or food microstructures