Thermization process

Thermal processing plays a crucial role in ensuring the safety and quality of various food products, particularly in the dairy industry. Among the different techniques employed, pasteurization and sterilization are the two primary temperature categories used. However, there is another technique called thermization, or thermalization, which offers an alternative approach with distinct advantages.

Thermization is a heat treatment method that falls under the category of sub-pasteurization. In this process, milk is subjected to temperatures ranging from 62 to 65 °C for a duration of 10 to 20 seconds, followed by cooling. The objective of thermization is to maintain the properties of raw milk as closely as possible while significantly reducing the presence of bacteria, especially psychrotrophic flora.

Compared to pasteurization, thermization is considered a milder treatment. It is commonly employed to stabilize the quality of milk during extended storage periods or prior to cheesemaking. By applying thermization, the number of spoilage bacteria present in the milk is markedly reduced, thereby extending its shelf life. The advantage of this method lies in its ability to achieve significant bacterial reduction while minimizing collateral heat damage to the milk components. Furthermore, thermization does not result in any noticeable changes to the flavor of the milk, ensuring that its original taste and characteristics are preserved.

Typically, thermization is carried out at temperatures ranging from 62 to 68 °C for a duration of 15 seconds. This temperature range and time combination has been widely adopted within the industry, demonstrating its efficacy and reliability in achieving the desired outcomes.

In conclusion, thermal processing techniques such as pasteurization and sterilization are well-known methods for ensuring food safety. However, thermization provides an alternative approach that offers several advantages, including minimal alteration to the properties and flavor of milk while effectively reducing bacterial presence. By employing thermization at specific temperature and time parameters, the dairy industry can achieve the desired stabilization of milk quality for prolonged storage or in preparation for cheesemaking.
Thermization process

Food preservation: Fermentation

Fermentation is one of the oldest ways of preservation food products with desirable properties such as extended shelf-life and good organoleptic properties. It is an essential metabolic phenomenon that basically takes place in absence of oxygen (O2).

Fermented foods are staples of the human diet and usually have an improved microbial stability and safety. In addition, some can be stored even at ambient temperatures. Furthermore, there are several examples of fermentation processes which lead to an increase in nutritional value or digestibility.

Fermentation happens commonly in yeast and bacteria and also in oxygen-starved muscle cells, as in the case of lactic acid fermentation. Microorganisms are integral part of the processing system during the production of fermented foods. In terms of microbiologists, fermentation is a primary means of producing ATP by the degradation of organic nutrients anaerobically, in presence of suitable microorganisms.

Science of fermentation is called zymology. Research shows that fermentation processes have been developed in order to preserve foods for times of scarcity by preserving the food by organic acid and alcohols at the same time it imparts desirable flavor, texture to foods, reduce toxicity and decrease cooking time.

Fermentation is employed in the production of foods and its major roles including:
(1) Preservation of food through formation of inhibitory metabolites such as organic acid;
(2) improving food safety through inhibition of pathogens or removal of toxic compounds;
(3) improving the nutritional value and also makes the food palatable by enhancing its aroma and flavor.

Food preservation: Fermentation 

Process of bioconversion

Bioconversion processes generally take place in bioreactors, which may be operated in batch, continuous, or semi-continuous mode, among others. Moreover, different bioreactor configurations may be suitable depending on the specific application.

It is the process by which an organism or its enzyme bring out chemical changes on compounds that are not part of their metabolism and they result in the formation of novel or useful products.

Bioconversions also known as biotransformation, are preferred where the nature of some biochemical conversions in plant cells is complex and the type of reactions cannot be accomplished by synthetic routes.

A bioconversion technology project requires an ecological and economic performance evaluation at the conceptual phase of the project.

The technology may range from solid-phase bioconversion processes to gas-phase ones, besides aqueous phase bioprocesses. In any case, a given amount of moisture is generally needed, as this is required, in most cases, for optimal microbial activity.

The effectiveness of bioconversion projects may be estimated by the productivity of the bioreactor, taking into account the costs for thermostabilization and intensification of the fermentation process. The economic efficiency of investments in innovative, energy efficient bioconversion projects is determined by taking into account capital and operating costs for the proposed project.

Example of bioconversion industry:
*Waste conversion in the dairy industry
*Bioconversion of cellulosic wastes
*Hemicellulose conversion
*Bioconversion of starch wastes

Bioconversion processes and biorefineries are environmentally friendly alternatives to common chemical processes and conventional oil refineries. They allow the production of a wide range of products with cheap biocatalysts, usually under mild conditions.
Process of bioconversion

Food processing and technology: Definition and main objectives

Food processing is the set of techniques transformation a food substance to change its properties with the intention of preserving it, improving its quality, or making it functionally more useful through the application of scientific knowledge and technology.

Formulation
The aim of product development is for a company to increase sales and remain competitive. A logical basic sequence of steps to produce an acceptable, attractive, marketable and quality food product from raw materials. Processing method enhance the appearance of food and it make food more appetizing and tastier.

Most of the time, processing of foods adds value to the resultant product by increasing storability, portability, palatability and convenience.

Time economy
A cohesive plan that combines the science of production and manual labor to reduce the time needed to produce the product. It also provides employment to a large population.

Improve consistency and texture
Application of modern science and technology to assure the consistency of each batch of products.

Food processing can boost the shelf life of the products. The processing can prevent food contamination. The concepts associated with food processing are reducing/eliminating microbial activity and other factors that influence food spoilage. The principal microorganisms that cause food spoilage are bacteria, fungi, yeasts and moulds.

Product safety
The government and the manufacturers work closely to make sure that the product is safe for consumption. Food processing and preservation are required to preserve food in edible and safe form. Methods by which food is preserved from spoiling after harvesting or slaughtering date back to prehistoric times. Among the oldest methods were sun drying, controlled fermentation, salting/pickling, candying, roasting, smoking, baking and using spices as preservatives.

Processing softens the fiber, gelatinizes the starch denatures protein, at the same time makes food easier to digest.

Food convenience
Processing and packaging technologies reduce time-constraints by providing a range of convenient foods: ready meals, bagged salads, sliced and canned fruits and vegetables.
Food processing and technology: Definition and main objectives

Industrial microwave

Microwave ovens are mainly used for heating and reheating of foods; however, trends show that they are used increasingly also for cooking and defrosting.

Industrial scale microwave processing units have been developed for drying, precooking of meat, pasteurization of ready meals, and tempering of meat and fish. Microwave processing is generally characterized by uniform heating on a macroscopic scale and rapid heating rates, as opposed to conventional processing.

Microwave heating talks place throughout the volume of the product. This volumetric heat delivery leads to a much higher rate of heating than conventional methods, limited by the heat penetration from the heated surface to the bulk of the material.

Microwave processing is used in various industrial application:
*Pasteurization of liquid and viscous in the food industry
*Sterilization of liquid products on food/pharmaceutical sector
*Drying of casings in sausage production
*Heating of minced meat mixtures after the extruder for flashing
*Preheating of viscous products before spray dryers or vacuum dryers
Industrial microwave

Manufacturing of grape fruit juice

The grapes are washed in acid or alkaline solutions, then in water to remove spray residues. Grapes are then conveyed to a stemmer/ crusher, which then remove residual stems, leaves and petioles form the fruit.

Once the stemmed/crushed grapes are separated from the vines, the grapes are heated to about 180 °F (82.2 °C) to extract pigment from the skins, after which the heated material is subjected to mechanical pressure while enclosed in cotton press cloths. Hot pressing is appropriate for deeply pigmented grapes where maximum color extraction is desired.

Whereas, the immediate or cold press procedure is necessary to maintain the initial color of light colored grapes.

The juice is then filtered pasteurized by heating to 170 °F (76.7 °C) and stored in bulk in covered tanks at about 40 °F (4.4 °C). This provides for the separation of tartaric acid salts.

Tartrates must be precipitated. Otherwise, it will settle out upon cooling or even when filtered juice is refrigerated.

This juice is then siphoned off from the tartrate and treated with enzymes, which break down pectins, or with casein for purposes of clarification. Typically, 50-100 ppm of pectinase enzymes is sufficient for the de-pectinization prices at this stage.

The juice is then filtered and bottled. The bottles are capped and then pasteurized by heating in water at 170 °F (76.7 °C) for 30 min.
Manufacturing of grape fruit juice

Stainless steel equipment for food process

Stainless steel is doubtless the most suitable material for the construction of the equipment that contacts food.

Stainless steel has become a widely used material for the construction of food process equipment because of its mechanical and it is also non-corrosive and easily sanitised. A special stainless steel may be required for areas controlled by chlorides, such as those occurring in sea water or brine.

The corrosion environment often involves moderately to highly concentrated chlorides on the process side often mixed with significant concentration of organic acids.

Most vats and vessels used in the food industry are made of stainless steel. Since products do not stay long in such equipment, usually AISI 304 stainless steel is sufficient.

Stainless steel can be produced in various grades depending on their chemical composition in iron, chromium and nickel. The most commonly used grade in the food industry is AISI 304 with 18% chromium and 9% nickel.

Other elements may be improved anti-corrosive properties, like molybdenum in AISI 316, often used in dairies. Type 316 is suitable in situations where alkalis, acids, etchants and various fermentation by-products lead to more corrosive situation.
Stainless steel equipment for food process