How To Reduce The Influence Of Oxygen On The Shelf Life Of Bakery Products?
Jan 20, 2021
Oxygen is the most widely distributed substance in nature and is essential for human survival. The so-called everything is a double-edged sword, and oxygen is no exception. Especially in the field of food processing, most foods are corrupted and deteriorated with oxygen. Related, such as the oxidative failure of nuts, the oxidative deterioration of fruits and vegetables, and so on.
The moldy and deterioration of bread and pastries are also related to oxygen, because most microorganisms need oxygen to reproduce, so today I will talk to you about the influence of oxygen on different microorganisms.
1. Obligate aerobic bacteria
This kind of microorganisms can only grow under the condition of molecular oxygen, have a complete respiratory chain, use molecular oxygen as the final hydrogen receptor, and cells contain superoxide dismutase (SOD) and catalase. Most fungi and many bacteria are obligate aerobic bacteria, such as Aspergillus oryzae, Acetobacter and so on.
2. Microaerobic bacteria
Microorganisms that can only grow normally under low oxygen partial pressure, pass through the respiratory chain and use oxygen as the final hydrogen acceptor to produce energy, such as Zymomorsas and Campylobacter.
3. Facultative aerobic bacteria
This type of microorganisms can grow and reproduce in aerobic or anaerobic environments, but they grow better under aerobic conditions. They rely on respiration capacity when they are aerobic, and receive fermentation or anaerobic respiration capacity when there is no oxygen; cells contain SOD and excess Catalase.
Such as yeast undergoing aerobic respiration in an aerobic environment, fermenting glucose under hypoxic conditions to produce alcohol and carbon dioxide, most pathogenic bacteria that cause disease to humans and animals, and many intestinal bacteria, such as E. coli.
4. Aerobic bacteria
Aerobic bacteria can live anaerobic in the presence of molecular oxygen. They do not need oxygen for their growth. Molecular oxygen is useless to them, but it is also harmless. It has no respiratory chain and depends on obligate fermentation to obtain energy. Known as aerobic tolerant anaerobes. The general lactic acid bacteria are mostly aerobic bacteria, such as Lactobacillus lactis, Streptococcus lactis, Leuconostoc mesenteroides, and Enterococcus faecalis.
5. Anaerobic bacteria
Bacteria grow better under anaerobic conditions than in an aerobic environment. Molecular oxygen is toxic to it. Short-term exposure to air will inhibit their growth and even kill them; in air or air containing 10% CO2, in solid medium It cannot grow on the surface, and can only grow under the deep anaerobic or low redox potential environment; the energy required for life activities is provided by fermentation, anaerobic respiration, cyclic photosynthetic phosphorylation or methane fermentation; the cells lack SOD and cells Most of pigment oxidases lack catalase. Anaerobic bacteria are widely distributed in nature, humans and animals. Non-spore anaerobes mainly exist in humans and animals, especially in the intestines, oral cavity, upper respiratory tract and urinary tract.
From the perspective of the above five types of microorganisms, obligate aerobic bacteria are the main cause of moldy and deterioration of bread and pastry, followed by facultative aerobic bacteria and aerobic tolerant bacteria. Therefore, controlling the demand for oxygen by microorganisms can effectively control the moldy and deterioration of products. .
1) Sealed packaging: automatic packaging machine or manual sealing machine to isolate outside oxygen from entering.
2) Use packaging materials with poor air permeability: especially for products with a long shelf life, reducing gas exchange inside and outside the packaging materials.
3) Use nitrogen-filled packaging: reduce the air content in the packaging and indirectly reduce the oxygen content.
4) Select the appropriate deoxidizer: absorb the oxygen in the air in the package to create an oxygen-free environment for microorganisms.
In addition to the control of oxygen, everyone should not be arbitrarily in the workshop environment management, personnel hygiene and the choice of preservatives. After all, anti-corrosion is a systematic project. Any problem in any link will affect the final product quality. Please learn more. Contact Guangzhou Baiqing Technical Department.
