Food preservation methods have recently become one of the most frequently discussed issues. One of these preservation methods is microbiological inactivation. Various heat treatment techniques such as pasteurization, sterilization, freezing, drying and thickening are used to ensure the microbiological safety of food. However, these techniques cause loss of food in terms of taste, smell, texture, aroma and vitamins. Cold sterilization methods have been developed in which the freshness and naturalness of the food can be preserved without disturbing the quality of the food. Cold plasma technique, which is one of these methods, is more advantageous than other cold sterilization methods. This is because it minimizes the mentioned losses and ensures less energy consumption.
Plasma technology is a new alternative surface sterilization and disinfection process since it can inactivate both vegetative cells and bacterial spores in a short time at ambient temperature. A good conductor (conducts electricity and heat well), interacts with electric and magnetic fields, has a high rate of chemical reactions, high temperature and energy density. This technology was first discovered by Irving Langmuir in 1928. Plasma is formed by applying energy to a gas to rearrange the electrical structure of atoms and molecules and to produce excited species and ions.
The mechanism of action of plasma technology: Direct degradation of genetic materials of microorganisms by UV rays. As a result of the ‘etching’ effect, the microorganism is eroded at the atomic level. It is used only in modifications of heat-resistant inorganic materials (metals, metal oxides, etc.) since it is increased to 1000K in hot plasma, which is divided into hot and cold plasma types. Cold plasma is used for sterilization and preservation of foods. The cold plasma temperature is between 300–400K. The ion temperature is close to room temperature. For this reason, it is called cold plasma.
Labne is a fermented dairy product. This product is made by standardization of fat and dry matter and using yoghurt culture. It has a slightly acidic flavor. Its color is milky white and its structure is soft, smooth and creamy. Labne is mainly consumed in Lebanon, Syria, Morocco and Iraq and Middle East countries.
Labne has a longer shelf life than yoghurt and is widely consumed. It is generally consumed by spreading on bread and adding olive oil. In one study, 25 different dry matter, 9.08% protein, 11.87% fat, 0.63% ash and 4.23 pH values were determined in labne production using two different methods. In the labne samples produced by ultrafiltration method, they determined between 22.65-23.95% dry matter, 7.80-8.31% protein, 10.59-11.33% fat, 0.67-0.70% ash and 4.17- 4.23 pH values.
Main methods used in industry; to make standardization of dry matter by centrifugation after fermentation in mechanical separation method, using milk powder in reconstitution method and pressure and temperature application in ultrafiltration method. In a study, the traditional method, before and after fermentation ultrafiltration, before and after fermentation obtained by the reverse osmosis methods consistency and microstructures of labne samples examined as a result of the traditional way produced 23.31% dry substance, 9.18% fat, 9.20% protein, 4.16% fat lactose and ash was reported to be 0.79%.
The choice of starter culture is important to produce quality labne. Different starter cultures are used. The most effective mixture of Streptococcus thermophilus and Lactobacillus delbrueckii spp. bulgaricus. When used as a mixture of coagulation time, it was found to be more effective than using one by one. In a study, labne produced using probiotic Lactobacillus acidophilus culture instead of yoghurt culture as a culture has been turned into a healthier product thanks to probiotic microorganism and it has been found that it does not bring additional cost to production.
I was preparing aonla RTS ( Ready to serve ) using Stevia which is my Hands on training project report of graduation. Usually we prepare RTS from table sugar then it is easy to maintain 15°Bx TSS but while we use stevia it becomes sweet but I’m not able to maintain 15°Bx TSS.