The transformation of cakes and breads is the result of mold reproduction. The transformed cakes and breads are easy to cause food poisoning and are inedible. Therefore, the preservation of cakes and breads is very necessary.
(1) Strictly abide by the selection of raw materials: resolutely do not use raw materials that are changed, moth-eaten, or rancid.
(2) Strictly abide by the baking customs: Baking is a necessary measure to mature cakes and breads, as well as a necessary means to inactivate mold. Cakes and breads must be baked thoroughly, and the center of the cakes and breads can reach a certain temperature to kill the mold spores in the cakes, but they should not be quickly baked to avoid burning on the outside.
(3) Strictly abide by the packaging customs
①Basic requirements for packaging: environment, secondary dressing room, special packaging room, ultraviolet germicidal lamp, special room disinfection, operating table or packaging machinery disinfection; personnel must be in three whites, that is, white and clean work clothes, caps and masks; cakes, breads Packing or packaging must be done after cooling. If cakes and breads are packed while they are hot, moisture will accumulate in the box, and the increased humidity will create conditions for mold growth.
②Special packing method: pump oxygen and nitrogen. Fill packaging is to fill the package with a proportion of inert gas, the purpose is similar to that of vacuum packaging. By destroying the conditions for the survival and reproduction of microorganisms, reducing the oxygen content inside the package, and filling with a quantitative inert gas can slow down the biochemical deterioration of packaged food.
Nitrogen is an ideal inert gas, which generally does not chemically interact with food. If the nitrogen concentration in the packaging is increased, the oxygen concentration will be relatively reduced, which has the effect of inhibiting the growth of bacteria and preventing the oxidation of food.
(4) Precautions
①Different varieties have different baking temperatures and times. Fruit cakes with heavy oil and sugar have a lower oven temperature than clear cakes and take longer to bake.
②The size of the same variety of products is different, and the baking temperature and time are different. The larger the block is, the lower the oven temperature is, and the longer the baking time is.
③ Pay attention to the proper spacing of the green bodies in the baking pan.
2. Add preservatives
(1) The mechanism of action of food preservatives
The standard for selecting food preservatives is "high efficiency and low toxicity". High efficiency means that the inhibitory effect on microorganisms is good, and low toxicity means that there is no observable toxicity to the human body. Generally, various substances enter the cells directly through the cell membrane for reaction, and any substances that interfere with their physiological metabolism can interfere with the growth of microorganisms. Therefore, many substances do not have any adverse effects on the human body, but have a great impact on the growth of microorganisms. Since different types of microorganisms have different structural characteristics and metabolic methods, the same preservative has different effects on different microorganisms.
The mechanism of preservatives inhibiting or killing microorganisms is very complex. The currently used preservatives are generally believed to have the following effects on microorganisms:
① Acts on the cell membrane, resulting in an increase in the permeability of the cell membrane and the outflow of intracellular substances, thereby causing the cells to lose their activities, such as benzoic acid and phenolic substances.
②Inactivation of enzymes necessary for cell activities, many antibacterial agents are achieved by inhibiting the activity of enzymes or the synthesis of enzymes in cells. These enzymes can be either basal metabolic enzymes or enzymes that synthesize important components of cells, such as enzymes for protein or nucleic acid synthesis.
③ Destroy the genetic material in the cytoplasm or make it lose its function.
After adding an effective concentration of antibacterial agents to food, some molds can be killed over a certain period of time. However, the addition of antibacterial agents is used to keep mold numbers in food below spoilage levels rather than a post-mold remedies for mold blooms caused by poor sanitation in food production, transportation and storage. This requires grasping the timing of addition in actual production. Generally, when the number of food molds is small, that is, when the molds are still in the lag period, anti-corrosion measures are taken, so that they can play an effective role at a lower dosage and grow until the After the period, even if the dosage is very high, it will not be able to meet the requirements.
(2) Commonly used cake and bread preservatives: acid has a strong antiseptic effect. In fact, most of the effective and widely used preservatives are various acids, such as sorbic acid, malic acid, and propionate, to name a few. These preservatives are more effective at low pH than at high pH, with only polylysine and paraben being effective at near neutral pH.
①Sorbic acid: The inhibitory effect of sorbate on the spore germination of Clostridium botulinum and Bacillus cereus has been confirmed in the medium. As an additive, sorbic acid antibacterial agent has not been found to be toxic to the human body, and the antibacterial spectrum is very broad, and it can be used in almost all foods with a pH value below 6.0. Although sorbic acid is not as widely used as propionic acid in baked goods, it is still useful because of its stronger fungal inhibitory effect than propionic acid, and it is still effective at higher pH values. Just pay attention in use, like cakes and sweets should be added as soon as possible to make it evenly distributed. The dosage of sorbic acid in baked goods is 0.03%-0.3%.
②Propionic acid Propionic acid is a colorless and transparent liquid with a pungent odor and is miscible with water. Its calcium salt and sodium salt are white powder with good water solubility and smell similar to propionic acid. Both propionic acid and propionate are easily absorbed by the human body and participate in the normal metabolic process of the human body. They have harmful effects and are safe food additives for workers in many countries in the world. The antibacterial effect of propionic acid is not as strong as that of sorbic acid and benzoic acid. Propionic acid mainly has an inhibitory effect on mold. Products produced by chemical starter should generally use sodium propionate, because calcium ions will affect the effect of starter. It is best to use calcium propionate in bread, because calcium can enhance the nutrition of the product and should not exceed 0.32%.
③ Parabens: This acid is a white crystalline powder with a slightly narcotic odor. Parabens can be quickly absorbed in the human stomach and intestines, hydrolyzed in the liver and kidneys to produce parahydroxybenzoic acid which is directly excreted or converted into p-hydroxy hippuric acid and glucuronic acid ester and then excreted without accumulation in the body. , so it is also a safe food additive. Parabens can damage mold cell membranes and denature intracellular proteins. Its antibacterial effect is stronger than other types of antibacterial agents. The inhibitory effect on fungi is the best, and the inhibitory effect on bacteria is stronger than that of sorbic acid, and it can kill Langerhans positive bacteria.
④Polylysine: a biological preservative protein polypeptide substance, with broad-spectrum antibacterial effect and remarkable fresh-keeping effect. Can be used both internally and externally, an alternative to chemical preservatives.
Yoatbio is a China based bio preservatives manufacturer for Nisin Natamycin Polylysine and other bio&chemical preservatives, feel free to ask us for samples.
Our line: samlui@yotabio.com, samlui@yotabio.cn
