Introductory Chapter: Food Processing

1. Introduction

Evidence suggests that the earliest food processing was undertaken in human history, using the heating process to make raw foodstuffs more palatable. When agricultural activities are started, the need for storage and preservation of raw food materials arose by 3000–1500 BC. Drying under sunlight, fermenting plant-based foods, grinding cereals, and baking bread in oven were the earliest attempts of food processing techniques. Exchanging of foods in trade and explorers-oriented technologies resulted in the change of food processing techniques in distinct food products (e.g., dairies, bakery, fermented foods). All the efforts brought today’s reached point [1].

In today’s world, food processing is a part of manufacturing industry. What we consume as foods are produced from plant-based or animal-based raw materials, in the meantime called as agricultural sources. Apart from directly consumed foods (e.g., raw eaten fruits) at postharvest term, the raw materials are required to be processed for a healthy consumption, as intermediate or finished value-added food products. Energy, equipment, labor-ship, science are used for a step (unit operation) or a series of steps (process) to produce a marketable product. For example, exposing milk to a heat source could be given as a simple example for a unit operation in terms of heat treatment (pasteurization or sterilization) in the case of milk processing at dairy industry. Therefore, from starting commercial sterilization the way what we observed up to now shaped the food industry [1, 2].

To meet the needs (e.g., shelf life stabile, nutritive, and variety in convenience with diet) of the global market, postharvested raw materials are processed in different ways. To serve a marketable food product, there are a number of intrinsic and extrinsic parameters that determine specific processing design of each product. Raw materials as sources of foods to be used for processing are complex substances. As intrinsic parameters the content of foods, carbohydrates, proteins, fats, vitamins, minerals along with water are first accounted. However, biological, chemical, and physical properties might be classified both in intrinsic and extrinsic parameters. The content and surrounding atmosphere (e.g., in-pack conditions, storage room conditions) of foods vary for almost each food product. Biological (bacteria, yeast and molds, viruses, parasites), chemical (pesticide, fungicide, allergens, mycotoxins), and physical (stones, dirt, metal, glass, insect fragments, hair) hazards should be controlled for a safe, nutritious, and wholesome consumption.

The basic processing steps consist of raw material harvesting, pretreatment (e.g., washing, separation,), basic unit operations (e.g., heat treatment, freezing, drying), and packaging. There are currently a number of different ways of processing technologies being applied in different ways at industrial scale. It is clear that almost every food types need different processing conditions to be an optimal product in its distinctive package. An overall view to food processing is presented in Table 1.

Unit operations in food processing	Thermophysical properties, microbial aspects, other considerations	Common food preservation/processing technologies	Other food processing/preservation technologies
Heat transfer	Raw material handling	Processes using addition or removal of heat (pasteurization and blanching, thermal sterilization, aseptic processing, sous-vide cooking, microwave heating, ohmic heating, drying, refrigeration and freezing)	Fermentation
Fluid flow	Cleaning and sanitation	Nonthermal food processing and preservation (irradiation, high-pressure processing, pulsed electric field processing, ultrasound)	Extrusion
Mass transfer	Engineering properties of food, biological, and packaging material		Baking
Mixing	Microbiological considerations		Hurdle technology
Size adjustment	Role of acidity and water activity in food safety and quality		Packaging
Separation	Reaction kinetics

Table 1.

An overview to food processing. Adapted from Park et al. [2].

However, both thermal and nonthermal food processing technologies are up-to-date widely used, alternative food processing technologies are now involved in the field. Some examples for these thermal technologies, microwave, radiofrequency, infrared heating, pressure-assisted thermal sterilization, and sous-vide processing, could be given. Whereas, nonthermal technologies in generally apply high hydrostatic pressure, irradiation, ultrasound, pulsed electric field, pulsed light technologies, and 3D printing. Nanotechnology (e.g., bio-sensing, packaging, agro-chemical production) is being started to implement besides these traditional processing techniques. The novel nonthermal or cold-pasteurization technologies provide less energy and water usage than traditional processing technologies, to sustain the scarce resources in globally. These technologies in sum serve for better quality, more healthful, minimally processed, traceable, and safer foods. Beyond product performance, the expectation of consumers is to consume safe foods that are produced under hygienic and sanitary conditions [3, 4, 5].

The food industry ensures food safety with the rise of pasteurization and sterilization techniques and food security with modern agricultural practices at reasonable prices. Meanwhile, the main problem still seems to be the issue of hunger and insufficient food, and the demand for food for the growing world population is still under discussion. Moreover, to meet the dynamic conditions and consumer-oriented needs, synchronized innovative solutions in food processing technologies should be found and applied.

So far all the time, the urgent need was to feed the world, by growing sufficient raw material and producing food products (e.g., wheat flour, dairies, meat products, aqua culture products, etc.) at reasonable prices. However, in today’s world, the climate crisis threatens sustainable food production, whereas sustainability concern has now become a real endangering issue. The United Nations defined “the needs of the present without compromising the ability of future generations to meet their own needs” for sustainable development [6]. From starting this end, a food production should ensure secure, environmentally sustainable, and healthy supply. The food industry produces more accessible and convenient foods, in terms of having reasonable price and remaining stable in predetermined shelf life periods. However, the quality of the foods, mainly snacks or on-the-go food or beverages, should be questioned for quality aspects. These types of foods and beverages containing carbohydrates, lipids, sugar, and food additives, which are increasing day by day and are purchased relatively cheaply, should be discussed for their unhealthy conditions. For the case of this concern in food industry, a high amount of negative perception on processed foods has become among consumers. The rate of literate people, social media, TV programs, magazines have all contributed to aforementioned negative concern on foods in pack.

To overcome current negative conditions, efficient and economic use of scarce resources (water, land, energy, air), environmental protection, and waste (food and non-food) management are requiring innovative attempts, unless carrying no suspicion on health concern of consumers.