Introduction to Food Process Engineering PDF

06/16/2023 Food Process Engineering LEARNING OBJECTIVES At the end of the topic, students should be able to: Discuss the importance of the course. Explain the scope of Food Process Engineering...

06/16/2023 Food Process Engineering LEARNING OBJECTIVES At the end of the topic, students should be able to: Discuss the importance of the course. Explain the scope of Food Process Engineering 1  06/16/2023 OVERVIEW OF AGRICULTURAL PROCESS ENGINEERING DEFINITION OF TERMS 2  06/16/2023 DEFINITION OF TERMS DEFINITION OF TERMS MILK COFFEE SUGAR 3  06/16/2023 2. POSTHARVEST LOSSES FOR GRAINS AND OTHER AB MATERIALS 4  06/16/2023 POSTHARVEST LOSSES A decline in the availability, utility and saleable weight is known as quantitative loss. A decline in acceptability by the consumer is called qualitative loss. A change in chemical constituents, appearance or nutritive value can decrease edibility and acceptability. In general, a loss that cannot be translated in economic terms is not considered a loss, especially when considering improvements in handling procedures. POSTHARVEST LOSSES Losses can occur during harvesting, all along the handling route and up to the consumer’s level. Often, losses occur because the materials for the container used are of inferior quality. In fact, in the 1980’s, containerization was already considered the weakest link in the distribution chain and it is still true today. High temperatures during transit, storage and distribution during the day and lack of facilities; the predominance of rough roads; irresponsible drivers and delays in distribution; and absence of grading, all contribute to increase in losses (Pantastico 1980). Losses in leafy vegetables during the hot wet period, June to November, are higher than during the dry cool months, December to March. "It will only be considered a loss if it is not used at all" 5  06/16/2023 Nature of losses Mechanical – loss due to unintentional damage sustained by the commodity (e.g., abrasion, punctures) Biological – loss due to disease organisms and insects Physico-chemical – loss due to faster rate of inherent processes in the produce or abnormalities in such processes (e.g., weight loss) 6  06/16/2023 Source: Dela Cruz & Calica, 2016 Source: Dela Cruz & Calica, 2016 7  06/16/2023 CAUSES OF POSTHARVEST (PH) LOSSES OF FRESH PRODUCE 8  06/16/2023 3. UNIT OPERATIONS INTRODUCTION This course is designed to give AB engineers an understanding of the engineering principles involved in the processing of food products. They may not have to design process equipment in detail, but they should understand how the equipment operates. With an understanding of the basic principles of process engineering, they will be able to develop new food processes and modify existing ones. This course discusses the basic engineering principles and shows how they are important in and applicable to, every food industry and every food process. 9  06/16/2023 The Food Process Literally, a ‘ process ’ is defined as a set of actions in a specific sequence, to a specific end. A manufacturing process starts with raw materials and ends with products and by- products. ‘Actions’ that constitute a process may be grouped into a relatively small number of operations governed by the same basic principles and serving essentially similar purposes. These operations, are called UNIT OPERATIONS The Food Process The study of food process engineering is therefore an attempt to combine all forms of physical processing into a small number of basic operations, which are called unit operations. 10  06/16/2023 UNIT OPERATIONS Using a material balance and an energy balance, a food engineering process can be viewed overall or as a series of units. Each unit is a unit operation. BY- PRODUCTS RAW Previous Unit Futher Unit PRODUCT MATERIAL Operation Unit Operation Operation WASTE ENERGY CAPITAL LABOR ENERGY CONTROL The Feed Mill SCADA 11  06/16/2023 CONSERVATION OF MASS The principle of conservation of mass states that: "Mass can be neither created nor destroyed. However, its composition can be altered from one form to another" -Antoine Laurent Lavoisier Even in the case of a chemical reaction, the composition of mass of a reactant and the product before and after the reaction may be different, but the mass of the total system remains unaltered. When the chemical reactions are absent, the composition of a system as well as its mass remains the same for a closed system. We can express the conservation of mass principle as an equation written in words as: Rate of mass entering through Rate of mass exiting through Rate of mass accumulation the boundary of the system the boundary of the system within the system CATEGORIES OF PROCESSING OPERATIONS Category I. Consolidation, mixing to produce a formulated product Minimal mass transfer, may need heat transfer; examples are emulsification, foaming, coating process Category II. Preservation of packaged material Minimal mass transfer, some heat transfer; computations involved energy balances examples are heating or cooling Category III. Convert raw materials to product ingredients Washing, peeling, sorting by size or quality, size reduction; minimal mass transfer (leaching) Category IV. Simultaneous heat, mass transfer blanching, baking, drying, evaporation; actual testing required to confirm assumptions and computations 12  06/16/2023 CLASSIFICATIONS OF OPERATIONS Batch Operations 2. Semi-batch Operations 3. Continuous Operations Village type rice mill Batch type dryer Semi-batch type for continuous for mushroom dryer operations Source: https://www.directindustry.com/ Source: https://rice-processing.com/ Unit operations of the food processing industry 13  06/16/2023 Unit operations of the food processing industry Continued… Unit operations of the food processing industry continued… Unit operations of the food processing industry Continued… 14  06/16/2023 MOST IMPORTANT UNIT OPERATIONS Important unit operations in the food industry are FLUID FLOW, HEAT TRANSFER, DRYING, EVAPORATION, CONTACT EQUILIBRIUM PROCESSES (which include distillation, extraction, gas absorption, crystallization, and membrane processes), MECHANICAL SEPARATIONS (which include filtration, centrifugation, sedimentation and sieving), SIZE REDUCTION and MIXING. 3.3 UNITS AND DIMENSIONS 15 06/16/2023 16 06/16/2023 17 06/16/2023 18 06/16/2023 19 06/16/2023 20 06/16/2023 21 06/16/2023 22 06/16/2023 23 06/16/2023 24 06/16/2023 25 06/16/2023 26 06/16/2023 27  06/16/2023 Example 3 The heat loss through the walls of an electric oven is 6500 BTU/h. If the oven is operated for 2 h, how many kilowatt-hours of electricity will be used just to maintain the oven temperature (heat input = heat loss)? 28 06/16/2023 29