Bread: Mold Contamination

Mold is a term commonly employed to characterize the fuzzy growth that emerges on damp or decaying organic matter due to fungal proliferation. This growth of mold can lead to diverse types of food spoilage, encompassing off-flavors, toxins, discoloration, rot, and the generation of pathogenic or allergenic spores.

The majority of molds are acknowledged as saprotrophs, reproducing by releasing spores that settle on decomposing organic material. They acquire nutrients by utilizing digestive enzymes to break down large molecules into smaller components before absorbing them.

An estimated 1-5% of bread production is thought to be impacted by fungal activity. In the context of bread, the contamination by mold not only induces changes in color and taste but also results in a deterioration of food quality due to the potential formation of mycotoxins.

The color of mold on bread can range from white, golden yellow to green-gray, depending on the species and the extent of sporulation.

Molds require moisture to thrive and typically disseminate spores in damp or moist settings. In general, most molds thrive in conditions with high water potential (aw values > 0.8), whereas a few xerophilic molds prefer to grow at lower aw values, dropping as far as 0.65.

The manifestation of moldiness is linked to external contamination of bread after the baking process, as the spores present in flour during a standard technological process lack favorable conditions for multiplication and are eliminated during baking.

Bread contamination with molds may occur during transportation, cooling, storage, or optional cutting and packing procedures.

Molds, mold spores, and mold fragments can negatively impact an individual's health, causing minor irritations such as a runny nose or itchy, watery eyes, and progressing to more severe health issues like breathing difficulties, asthma attacks, infections, fever, and notable skin irritations.
Bread: Mold Contamination

The mold in blue cheese

Molds are a type of fungus that produces spores. They’re transported through air, insects, and water and can be found everywhere in the environment, including your refrigerator — though they grow best in warm, moist conditions.

Blue cheese is a fermented cheese renowned for its strong flavor and blue marbled coloring. Cheesemakers create blue cheese using Penicillium roqueforti mold cultures. which is responsible for its distinct taste, smell, and appearance.

Cheesemakers mix the mold spores with milk to begin the fermentation process. After the cheese forms into a solid shape, the cheesemaker pierces it with stainless steel needles to create pathways for air to flow.

Penicillium roqueforti strain has been specifically chosen for cheese because it adds flavor. These penicillin moulds are completely harmless in cheese making because unlike other types of mold, the types of Penicillium used to produce blue cheese do not produce mycotoxins and are considered safe to consume.

Penicillium roqueforti produces enzymes that release amino acids, which quickly break down the cheese's proteins (casein). Called proteolysis, this makes the cheese creamy, particularly near where the amino acids are most active — the gray, blue veins.

As the blue veins develop, they enhance the flavor of the cheese. Penicillium roqueforti itself (and the enzymes it releases) aggressively breaks down the fat and protein in the cheese to give the texture, flavour and aroma associated with blue cheese: sharp, strong and piquant.
The mold in blue cheese

Black mold

Black mold otherwise known as “Aspergillus niger” often occurs on fruits that have become moist on the surface or broken; or it may occur on other products occasionally. Aspergillus niger is the thermophilic organism; hence it occurs most frequently in hot regions.

It does not produce a moldy taste or odor; it is much less prevalent and is easier to control than is the blue mold. This disease is most prevalent in subtropical and tropical production areas where high temperatures favor its development. While black mold can cause some problem in the field most losses occur in storage.

The spore of the organism seem to be present everywhere, but they are able to infect fruit such as grapes only when there are skin breaks or punctures, or when the ripening grapes are wet – as, by rain or sprinkler irrigation during maturing. 

 

This disease causes unsightly, black, dusty fungal growth on and between the bulb scales. The entire surface of the bulb may be turned black in several cases, and a bulb rot may follow.
Black mold

Mouldy food

Moulds are visible but other organisms that cause food to decay such as bacteria are not. Since many micror0gansm release large quantities of spores into the air and some people are allergic to these, mouldy foods should be kept in closed plastic bags or other closed containers.

Moulds are fungi composed of many cells. Most of them have a thread-like structure, live on plant or animal material and thrive in a warm, humid conditions.

Under a microscope they look like narrow mushrooms, with root threads which can extend very deeply into the food, and a stalk rising above the food.

The presence of mould has a major impact on the quality of grain for example. Nobody wants to eat mouldy food. Mould-contaminated grain is often discarded, is certainly difficult to sell, and will either cause grain to be rejected or at best downgraded with a loss in value.

However, mouldy grain is usually retained for brewing beer or is fed to livestock.
Mouldy food

Subsurface mold growth in food

Mold is a fungus that produces a fuzzy, cobweblike growth on moist materials, including food.  Black bread mold, Aspergillus niger, is one of the most familiar molds. Molds are found nearly everywhere in the environment.  When present in fresh or processed foods, molds may grow and cause an unsightly appearance and off-flavors.

In addition, some molds are capable of producing mycotoxins which are hazardous to human health. Most products will allow only mold growth due to low aw. Molds must have a warm, moist environment, oxygen, some light and food to produce their spores.

Most molds grow well on starchy foods (bread), the rind of some fruit such as lemons and oranges.

Sulfur dioxide is broadly effective again yeasts and molds. It is used extensively to control growth of undesirable microorganism in fruits, fruit drinks, wines, sausages, fresh shrimp and pickles.
Subsurface mold growth in food

Benzoic acid as food preservative

Benzoic acid is not only present in food and flavors but is also endogenous in the human body.

Benzoic acid is used in food as antimicrobial agent, flavoring agent and preservative. It is usually used in the form of its sodium salt, sodium benzoate, long has been used as antimicrobial additive in foods.

The benzoates are used as preservatives to inhibit the growth of yeast and moulds and have been used since the early 1900s.

They are often synergistic with other preservatives, such as sorbates, and are used in conjunction with sulfur dioxide which inhibits enzymes action and browning.

Benzoic acid (0.05-0.1%) is often used in combination with other preservatives and on the basis of its higher activity at acidic pH’s, it is for preservation of sour food, carbonated and still beverages, fruit salads, syrup, fruit cocktails, marmalades, mince meat, relishes, jellies, margarine, paste, fillings and pickled sour vegetable. 

Benzoic acid esters are also commonly used as food preservatives, particularly in marinated fish product. 

Benzoic acid is able to directly lower the cytoplasmic pH whereas the benzoic acid esters must first de-esterified by microbial cytoplasmic esterases to release benzoic acid.
Benzoic acid as food preservative