food processing and preservation

food processing and preservation

- heat

- cold

- dehydration

- food additives

- food packaging

princples/goals

- addition of heat

- removal of heat

- removal of moisture

protection

protection

- all the principles/goals will be undone if the food is not properly protected

- achieved by the best packaging resources

preservation principle/goals

- prevention or delay of microbial decomposition

- killing the microorganisms -> if you kill all microorganisms there will be no nutritional value left in the food

- prevention or delay of self-decomposition

- prevention of damage

hurdle technology

- suitable combination of lethal agents

- a method of combining multiple mild preservation techniques to control or eliminate microorganisms and spoilage in food

importance of hurdle technology/preservation

- increases shelf-life of foods

- increases availability

- variety and convenience

- adding value

- providing (supplementing) nutrients

food processing

- transform animal, plant, and arine materials into intermediate or finished value-added food products

- broad scope involving different unit operations (steps) that occur after harvest or raw materials until they are processed into food products (packaged and shipped for retailing) -> scientific, knowledge, machinery, labor, energy

- primary processing

- secondary processing

primary processing

- processing of foods that occur after harvest or slaughter to make food ready for consumption or use in other food products

secondary processing

- turns primary processed food or ingredients into other food products

food and beverage manufacturing

- accounted for 16% of the value of shipments in the US in 2015

- 14.1% of value added in all manufacturing

- mainly located in california

unit operations

- food materials may be combined with a number of ingredients to formulate the product and these ingredients are subjected ot different steps (unit operations) to produce the final product

heat transfer

- heat exchange between a product and its surrounding medium

- the rate of heat transfer is dependent on the temperature difference between the food and its surroundings

- the larger the temperature difference the quicker the heat transfer

mass transfer

- migration of constituent of fluid or a component of mixture in or out of a food product

- ex: evaporation of water in beef jerky

fluid flow

- transporting fluid food through pipes during processing

- how fluids flow from one system to another

- the thickness/density of the product determines how much fluid will be transported or processed

mixing

- used to evenly distribute each ingredient during manufacturing of a food product

size adjustment

- food is either reduced into smaller pieces or in some instances increase in size is also possible

- usually results in production size

- ex: gelatin

- agglomeration (instant coffee)

separation

- separation and recovery of targeted food components from a complex mixture of compounds

- distillation

- membrane filtration (whey - the liquid byproduct of cheesemaking that is separated from solid curds)

factors to consider

- raw material handling

- cleaning and sanitation

- engineering properties of food, biological and packaging material

- acidity and water activity

- microbiological considerations

- reaction kinetics

raw material handling

- quality and the way the material is handled

cleaning and sanitation

- cleaning: the physical act of removing foreign material

- sanitation: making sure wholesome foods are produced

- sanitization: the process of making something sanitary, which involved cleaning to reduce germs (the application of chemical agents)

acidity and water activity

- most important factor is th pH 4.6

- high acid: pH < 4.6 -> ex: fruit juices

- low acid: pH > 4.6

- if water activity is < 0.86 it means that the food product is generally considered shelf-stable and protected against the growth of major foodborne pathogenic bacteria (staphylococcus aureus)

biological reaction kinetics

- microbial inactivation

chemical reaction kinetics

- enzyme reactions, color, nutrient dehydration

emerging issues and sustainability in food processing

- feeding the world

- overcoming the negative perceptions about "processed foods"

- obesity