Mold Is Repeated Again And Again, What Should Food Factories Do?

All parts of the country have entered the hot and rainy season. There are many "microbial pollution sources" in the processing of bread and cakes. How to prevent product contamination is absolutely the first task. Micro-pollution sources include bacteria, molds, yeasts, viruses and other spoilage bacteria, and mold is just one of them. If it is not controlled, it will inevitably affect the shelf life of bread and cakes. How to control mold contamination to products?

 To control mold pollution, we must first understand the types of molds, growth habits, and various conditions and growth environments that contaminate products. Only on this basis can we propose reasonable and practical prevention and control methods to improve the quality and safety of products.

1. What are the common molds?

1. Aspergillus

It is widely distributed in nature. It uses soil or air as a medium to cause mildew and deterioration of food, grains, fruits and vegetables, and some can produce carcinogenic aflatoxins. The mold hardly dies during the storage of raw materials. Because of its strong resistance to drying, it is often isolated in some dry foods, and sugar and shell processing plants are often contaminated by such molds. Bakery products are also often contaminated by Aspergillus due to raw materials such as sugar, peanuts, oil, and rice.

Color is an important basis for the classification of Aspergillus. Aspergillus fumigatus is cotton-like, beginning to be white, turning green after 2-3 days, and dark green after a few days; Aspergillus flavus is powdery and yellow; Aspergillus flavus is powdery and black; colored mold is fluffy , Wooly, from green to red and green.

2. Penicillium

Like Aspergillus, it is widely distributed in nature and has the same ecology. However, Aspergillus grows at moderate to high temperature, while Penicillium is mainly moderately temperature. The representative species is Penicillium griseus, which is easily separated from soil or air. The spores of Penicillium have strong heat resistance, and the bacteria reproduce at a low temperature. The sour agents commonly used in bakery products such as tartaric acid, malic acid and citric acid are its favorite carbon sources, which often cause mildew in these products, which is dry The main mold in the processing plant of sexual shell products. Its harmfulness is to cause spoilage of fruits, vegetables, meat, clothing and footwear, produce mycotoxins and induce allergies.

It is also a common polluting bacteria. Strengthening ventilation, lowering temperature, and reducing air relative humidity can greatly reduce the harm of penicillium. Winter and spring are the peak periods of Penicillium growth. The front of the colony has cyan, blue-green, yellow-green and gray-green, and there are obvious light-colored edges around.

3. Mucor

Mucor is also called black mold and Mucor longum. Mucor exists in the environment such as soil, manure, grass and air. It grows well under conditions of high temperature, high humidity and poor ventilation. In factories with high humidity, poorly ventilated environments and places with significant temperature differences (such as wet floors and ceilings), this mold often exists.

The colony is flocculent, initially white or off-white, with a gray aftertaste. The hyphae of Mucor are mostly white, the sporangia are black or brown, and most of the sporangia spores are colorless or light blue, depending on the species.

4. Rhizopus

    Rhizopus nigricans, also known as Rhizopus stolonifera, is widely distributed and often appears on moldy foods. The rot of fruits and vegetables during transportation and storage and the soft rot of sweet potatoes are all related to it. Rhizopus nigricans is a microbial species commonly used in the fermentation industry. It can saccharify starch, convert sucrose, and produce lactic acid, fumaric acid and trace alcohol. The optimum growth temperature of Rhizopus nigricans is about 2~8℃, and it will not grow more than 32℃.

Amorphous colony, white in the initial stage, grayish brown or black after mature. The spores are spread by air currents, favoring moderate temperature, high temperature and acidic conditions.

5. Alternaria alternata

Alternaria spp. is a moderately mild and hygroscopic mold, which is easy to cause decay, putrefaction and allergies. In high-humidity factory environments (such as pastry, fish, aquatic processing and meat processing environments), the black mold on the ceiling, wall and floor, and water distribution pipes is almost the fungus or Cladosporium.

The colonies are fluffy, mostly gray-black to black.

6. Fusarium

Fusarium is a worldwide distribution of fungi. It can not only live through the winter and summer in the soil, but also infect a variety of plants (food crops, cash crops, medicinal plants and ornamental plants), causing root rot and stems of plants. There are more than 100 kinds of host plants, such as rot, stem base rot, flower rot and ear rot. Fusarium toxin can be produced. Eating moldy food can cause illness and death. Certain strains can induce human skin and corneal ulcers. The occurrence of malignant tumors may be related to some strains.

The colors are generally yellow, white, purple, red, green, etc. The shape of sclerotia is mostly spherical, solitary or clustered.