Sugars and Sugar product-Food microbiology

Food microbiology

1. VIVEKANANDHA ARTD AND SCIENCE COLLEGE FOR WOMEN VEERACHIPALAYAM sangagri salem dt. Tamilnadu india . Department of Microbiology Subject : Food Microbiology Topic: sugars and sugar products SUBJECT INCHARGE SUBMITTED BY Dr. DINESH KUMAR, K. KANMANI , ASSISTANT PROFESSOR, III- BSc. MICROBIOLOGY, DEPARTMENT OF MICROBIOLOGY, VIVEKANANDHA ARTS AND SCIENCE, VIVEKANANDHA ARTS AND SCIENCE COLLEGE COLLEGE FOR WOMEN FOR WOMEN SANGAGIRI, SALAM. VEERACHIPALAYAM SANGAGIRI, SALAM .

2. Sources of microorganisms Production process of raw sugar Equipment, packaging Raw materials Storage condition Distribution

3. Spoilage of high sugar products Yeasts : Torula sp ,.Zygosaccharomyces sp ,. Leuconostoc mesenteriodes Bacteria: Bacillus, Micrococcus, Flavobacterium , Alcaligenes Enterobacter . Fungi: Aspergillus , stemphylium , sterigmatocystis , cladosporium , and Monilia . U contamination Sucrose The raw juice expressed from sugarcane may become high in microbial content unless processing is prompt.

4. The relevant microorganisms are those from the sugarcane and the soil contaminating it and therefore comprise slime producers, such as species of Leuconostoc and Bacillus: representstives of the genera Micrococcus, Flavobacterium , Alcaligenes , Pseudomonas: a variety of yeast, chiefly in the genera Saccharomyces, Candida, and Pichis : and a few molds . Much contamination may come from debris or fine particles on the sides or joints of troughs at the plant. If organisms grow to any ectent , inversion of sucrose or even destruction of sugar may take place. Activity of the orgsnisms continues from cutting of the cane through extraction to clarification of juice, a process which kills yeasts and vegetative cells of bacteria. Bacterial spores are present from then on, through sedimentation, filtration, evaporation, crystallization, and centrifugation, but may be refuced in numbers by these processes, although spores of thermophils may be added from equipment.

5. Bagging of the raw sugar also may add some microorganisms. During the the refining of the raw sugars, contamination may come from equipment, and organisms are added during bagging. In the manufactute of beet sugar, cleaned beets are sliced into thin slice and the sugar is removed by a diffusion process at 60 to 85C. Thermophiles may grow in the latter up to 70C. Contamination also may take place during refining and bagging of the sugar. Granulated sugar now on the market is very low in microbial content for the most part, containing from a few to several hundred organisms per gram, mostly bacterial spores. Maple Syrup Sap of the sugar maple in the vascular bundles is sterile or practically so but becomes contaminated from outside sources in the tapholes and by the spout, plasstic tubing, and buckets or other collection vessels.

6. If a period of unusual warmth occurs before the sap is collected, considerable growth of yeasts and bacteria may take place in the sap. Microorganisms entering sap between its flow from the tree and being boiled and concentrated are mostly psychrotrophic , gram – negative rodes of Pseudomonas, Alcaligenes , and Flavobacterium , plus yeasts and molds . Paraformaldehyde taphole pellets are inserted into the driled hole to prevent microbial growth from blocking the flow. Bacteria counts in sap are usually less then 10,000 per millilitre, but higher numbers, can develop as a result of warmer temperatures near the end of the season and poor sanitation.

7. Honey The chief sources of microorganisms in honey are the nectar of flower and the honeybee. Yeast have been shown to come from the nectar and from the intestinal content of the bee bacteria also come from the latter source. Honey rarely contains staphylococci or enteric bacteria. Common isolates are usually acidophilic and glycolytic yeasts, which can damage the product. Honey has been found to contain losozyme , an enzyme with a bacteriostatic as well as a lytic effect on most gram positive bacteria. The use of antibiotics such as neomycin and streptomycin is wide spread in beekeeping, and these antibiotics have been found in the honey obtained have an effect on its microbial flora.

8. Honey is the one of the suspected food vehicles for the sources of C. Botulinum spores in cases of infant botulism. About 10 percent of the suspected honey samples contained viable spores. A study by Ruiz- Argueso and Rodriguez- Navarro (1975) suggested that Gluconobacter and Lactobacillus are the two main groups of bacteria present during maturation of nectar to honey.

9. Candy Candies from retails markets contain from 0 to2 million bacteria per piece, but most pieces harbor no more than a few hundred. Few coliform bacteria are found. The candies receive most of their contamination from their ingredients, although some contamination may be added to unwrapped pieces by air, dust, and handling. The several thousand types of candies and confections can be divided into two categories for microbiological consideration: (1) cold- processed and (2) hot- processed confection. Molded chocolate and chocolate coating for creamed centers fall into the first category. Temperature during processing may only approach pasteurization temperature. Examples of the second category include hard candy, jellies, caramels, and fudges. Processing temperatures for these items very, but they all are exposed to a more severe heat treatment than are items in the first category. Candies are infrequently associated with food- poisoning outbreak, but chocolate candies have been incriminated in cases of salmoneosis . The problem appears to be one of cross contamination in the plant between raw and roasted cocoa beans, with the raw beans or environmental isolates serving as the source of contamination. Although temperature of 60C for 10 hr are not uncommon during processing and blending of milk chocolate, the low moisture content or the dryness of the chocolate apparently protects the salmonellae from heat. .

10. Preservation Like cereals, sugars normally have a low that microorganisms cannot grow. Only when moisture has been absorbed is there any chance for microbial spoilage. Storage conditions should be such that vermin are kept out and the sugar remains dry. The recommended storage temperature is similar or to that for cereals. Cane or sugar beets may be stored in a controlled atmosphere. Fungal growth is inhibited by 6 percent carbon dioxide and 5 percent oxygen. During the manufacturing of raw sugar and the subsequent refining process the numbers of microorganisms present, which may have been large during extraction from cane or sugar beet, are reduced by most subsequent processes, e. g,.clarification , evaporation, crystallization, gentrification, and filtration. Chemical preservatives used in sugar refining.

11. Numbers may be reduced by irradiation with UV/ heat+ H2O2. Chocolate bursting – prevented by a uniform, thick chocolate coating & use of fondant/ other filling. Sirups and molasses- stored at cool temperature. The boiling process kills the important spoilage organisms. Honey crystallization : heat to at 71 C, hold there for 5 minutes, and cool promptly to 32.2 to 38 C. Molasses & sirups : high osmotic presure . Mold growth prrvented by complete filling of container & reduced bytheir periodic mixing. Spoilage in the time by osmophilic yeasts. Commercially distributed honey usually pasteurcially at 71-77 C for few minutes. A recommended treatment of heat is 71 C hold for 5 min and cool promptly to 32.2 to 38 C.

12. Spoilage The spoilage of sugar or concentrated solution of sugars is limited to that caused by osmophilic or xerotolerent microorganisms. Certain yeasts, especially those of the genus, Saccharomyces and certain molds would be the principle spoilage flora. Some species of bacteria have also been suggested as possible spoilage problems, including species of Bacillus and Leuconostoc . As the sugar concentrations decrease, increasing numbers of kinds of organisms can grow, so that sap from a maple tree would show types of spoilage that maple sirup could not. Sucrose During the manufacture of sugar, the original cane or beet juice becomes more and more purified toward sucrose and the concentration of sugar in solution becomes greater and greater until finally crystalline sugar is attained plus molasses that is high in sugar.

13. The purer the product, the poorer it becames as a culture mediam for microorganisms the more cocentrated it gets, the fewer kinds of organisms can grow in it. Raw Juice The raw cane or beet juice is not high in sugar and contains a good supply of accessory foods for microorganisms It therefore is readily deteriorated by the numerous organisms present if sufficient time is allowed. Until clarification, gum and slime may be formed, e.g., dextran by Leuconostoc mesenteroides or L. dextranicum and levan by Bacillus spp. Or, less commonly, by yeasts or molds .

14. Sugar in storage Liquid sugar with sugar content as high as 67 to 72 brix will support the growth of yeasts and molds which may enter from the air. Dilution by absorption of moisture at the surface may result in growth of Microorganisms and hence deterioration of the product. This can be prevented by circulation of filtered sterile air across the top of the storage tank or exposure to ultraviolet lamps. Honey Honey is variable in composition but must contain no more than 25 percent moisture. Because of its high sugar content, 70 to 80 percent, mostly glucose and levulose , and its acidity, pH 3.2 to 4.2, the chief cause of its spoilage is osmophilic yeasts species of Zygosaccharomyces , such as Z. Mellis , richteri , or nussbaumeri , or Torula mellis .

15. Most molds do not grow well on honey, although species of penicillium and mucor have developed slowly. Candy Most candies are not subject to microbial spoilage because of their comparatively high sugar and low moisture content. Exception are chocolates with soft centets of fondant or of inverted sugar which under certain conditions burst or explode. Yeasts growing in these candies develop a gas pressure which may disrupt the entire candy or more often will push out some of the sirup or fondant through a weak spot in the chocolate coating. Often this weak spot is on the poorly covered bottom of the chocolate, where a cylinder of fondant squeezes out. The defect is prevented by using a filling that will not support growth of the gas formers and by coating the candy with a uniformly thick and strong layer of chocolate.

16. Thank you😍