Invasion of Foodborne Yeast and Mold

Baliseafoodlab.com, Yeast and Mold Testing in Alcoholic Beverages.

Yeast and mold are used in fermentation process the alcoholic beverages, but if the numbers are over the safe limit, they can potentially cause quality deterioration in them. The samples tested were outstanding commercial alcoholic beverages in Denpasar, Bali, i.e vodka, whisky, arak, wine and beer. From the result in table above, we can see that there are no yeast and mold content in the samples. They show that the alcoholic beverages in the market, especially in the Denpasar, Bali are meet the National Standards of Indonesia. Usually, alcoholic beverages producer, do yeast and mold testing in fruit pulp, before use for raw material and in the end product. If any excessive yeast and mold content in the fruit pulp, it will be affecting the fermentation process, and there is a big possibility we can not get the specification that we expected first. Furthermore, it may not safe to consume it. Both yeast and mold can cause deterioration or decomposition of foods. Moreover, the odor, flavor, and color can be indicator if any of alcoholic beverages deterioration.

• INTRODUCTION

Alcoholic beverages are defined as beverages that contain ethanol (C2H5OH). This ethanol is almost always produced by fermentation – the metabolism of carbohydrates by certain species of yeast under anaerobic or low-oxygen conditions.

According to National Standard of Indonesia (SNI) 7388: 2009 for Maximum Limit of Microbe Contaminant in Food, the quality requirements for alcoholic beverages, including likely-free alcohol or low alcohol beverages are Total Plate Count 2×102 col/ml, Coliform (MPN) 20/ml, Escherichia coli <3/ml,  Salmonella spp. negative/25 ml, Staphylococcus aureus negative/ml and Yeast and Mold 1×102 col/ml.

Yeast and mold are used in fermentation process the alcoholic beverages, but if the numbers are over the safe limit, they can potentially cause quality deterioration in them. Therefore, we do yeast and mold testing in the end product of alcoholic beverages to ensure that the alcoholic beverages are meet the standards.

• MATERIAL AND METHODS

This research used test kit 3M Petrifilm Yeast and Mold Count Plate. This kit identifies foodborne yeast and mold in food products and food processing environment. Yeast are easily differentiated from mold on the plate. Result will obtained in 3-5 days with three easy steps; inoculate, incubate and enumerate. Yeast are typically indicated by small, blue-green colonies with defined edges and no foci. Molds are indicated by large, variably-colored colonies with diffuse edges and center foci.

The samples tested were outstanding commercial alcoholic beverages in Denpasar, Bali, i.e vodka, whisky, arak, wine and beer.

• RESULT

• DISCUSSION

Yeast are type of fungi. Yeast are commonly found on plants, grains, fruits and other foods containing sugar. They are present in soil, in the air, on the skin, and in the intestines of animals and in some insects. They are transferred from place to place by people, equipment or food and air currents. Yeast cause food to spoil and do not cause foodborne illness.

Yeast and Mold

Molds are microscopic fungi that can live on plants and animals. Most molds spoil foods. Some form toxins that can cause illness. Molds can grow in a wide range of foods. Unlike bacteria, mold can grow in foods that are high acid and low moisture. Freezing does not destroy molds. Molds also need air to grow.

Food borne yeast and molds (fungi) are a large and diverse group of microorganisms that comprise several hundred species.  The ability of therse organisms to attack many foods is largely due to their versatile environmental requirements.

• The majority, but not all, require free oxygen for growth
• Their pH requirement is broad, ranging from pH 2 to pH 9
• Their temperature range is also broad, ranging from 10O to 35OC (50O-95OF).
• Moisture requirements for mold are quite low (water activity of 0.85 or less), with yeast requiring a slightly higher water activity.

From the result in table above, we can see that there are no yeast and mold content in the samples. They show that the alcoholic beverages in the market, especially in the Denpasar, Bali are meet the National Standards of Indonesia.

Usually, alcoholic beverages producer, do yeast and mold testing in fruit pulp, before use for raw material and in the end product. If any excessive yeast and mold content in the fruit pulp, it will be affecting the fermentation process, and there is a big possibility we can not get the specification that we expected first. Furthermore, it may not safe to consume it.

Both yeast and mold can cause deterioration or decomposition of foods. Abnormal flavors and odors may be produced. The food may become slightly or severely blemished and slime, white cottony mycelium or highly colored mycelium may develop. Virtually any type of food product may be affected- from raw products such as nuts, beans, grains or fruits to processed foods. Contamination of foods by yeast or mold can result in substantial economic losses to the producer, the processor and the consumer.

Several foodborne molds, and possibly yeast, may also be hazardous to human health. Some molds have the ability to produce toxic metabolites known as mycotoxins. Most mycotoxins are stable compounds that are not destroyed during food processing or home cooking. Even though the generating organisms may not survive heat treatment, the performed toxin may still be present.

Other foodborne yeast and molds may elicit allergic reactions or may cause infections. Although most are not infectious, some species can cause infection, especially in immuno-compromised individuals, such as the aged or debilitated, HIV-infected individuals or persons receiving chemotherapy or antibiotic treatment.

The best way to prevent yeast and mold arising in the alcoholic beverages is ensure of using of high quality raw ingredients. Proper sanitation and handling practices are also required in the production process, because it will affect their quality. Moreover, the odor, flavor, and color can be indicator if any of alcoholic beverages deterioration.

• REFERENCES

http://datcp.wi.gov/uploads/Food/pdf/YeastAndMold.pdf
http://en.wikipedia.org/wiki/Yeast
http://lordbroken.wordpress.com/2010/06/14/pembuatan-wine/
http://www.botany.hawaii.edu/faculty/wong/BOT135/Lect14.htm
http://www.foodsafetysite.com/resources/pdfs/EnglishServSafe/ENGSection2.pdf
Standar Nasional Indonesia SNI 7388: 2009 Batas maksimum cemaran mikroba dalam pangan
http://www.umm.edu/patiented/articles/000557.htm