MICROBIOLOGY Study Guide - 2012

The confectionery industry produces a wide range of products, which are generally divided into sugar-based and flour-based confections. The former include candies, marmalade, marshmallow, zefir, fudge, oriental sweets (such as turkish delight, sherbet, creamy log, and nut-containing caramel masses), and others. Flour-based confectionery products (FCP) include sponge cakes with and without fillings, various cakes and pastries, wafers, cookies, gingerbread, and more.

Microorganisms generally play a detrimental role in confectionery manufacturing, with the exception of *Saccharomyces* Yeasts, which are used in the preparation of muffins and hardtack.

The primary sources of microorganisms in confectionery production are raw Materials and semi-finished products. The safety and shelf-life of finished confections depend directly on their quality. All confectionery products undergo thermal Processing and pose no epidemiological risk provided that high-quality raw materials and semi-finished products are used. Product contamination with microorganisms typically occurs during manual operations such as decoration, packaging, transport, and retail. Cream-based confectionery products are of particular concern regarding food poisoning and infections, though contamination by bacterial and viral pathogens in other sugar-based products cannot be ruled out.

Confectionery production utilizes a diverse array of raw materials and semi-finished products, including granulated sugar, honey, starch treacle, whole and condensed milk, cream, butter, flour, eggs, liquid egg melange, egg powder, cocoa, pectin, fruit and berry preps, nuts, oilseeds, colorants, flavor extracts, acids, and spices.

Granulated sugar. Beet or cane sugar is used in confectionery manufacturing. Total microbial contamination of sugar depends on storage conditions. At a standard moisture content of 0.15%, 1 g of sugar may contain from 10 to 1,000 microbial Cells. Osmophilic yeasts (Saccharomyces, Torulopsis), spores of thermophilic (B. stearothermophilus, B. coagulans) and mesophilic Bacteria (B. subtilis, B. mycoides), slime-forming bacteria (Leuconostoc mesenteroides), as well as mold spores, have all been isolated from sugar. Using sugar with elevated microbial counts can lead to spoilage in finished products. Gas-producing bacteria and osmophilic yeasts cause Swelling and cracking in candies, while marshmallows, zefir, and marmalades are particularly susceptible to spoilage. These same microorganisms promote Fermentation and souring in fruit semi-finished products such as purees, preserves, jams, and jellies.

Honey. The microflora of honey may include osmophilic yeasts of the genus Zygosaccharomyces, which can induce Alcoholic Fermentation in unripe or diluted honey. Bacteria and Molds are present in small quantities. Identified bacteria include Sarcina lutea, B. subtilis, B. megatherium, and others. Due to high sugar concentration and the presence of bactericidal compounds, natural honey has a long shelf-life. The initial microflora introduced by bees (bacilli, osmophilic yeasts, and molds) does not present a significant hazard. However, secondary contamination can pose epidemiological risks. Despite the bacteriostatic activity of honey resulting from its high sugar content and phytoncides, pathogenic bacteria may occasionally be detected. For instance, infant botulism cases in California have been linked to honey consumption.

Whole milk and cream serve as rich nutrient media for various groups of microorganisms. The most frequently encountered are lactic acid bacteria, enterococci, coliforms, and putrefactive spore-forming bacteria of the genus Bacillus (B. subtilis, B. mycoides, B. cereus, B. polymyxa). Pathogenic bacteria may also be present in these products; while they are destroyed by pasteurization and sterilization, or killed during the boiling of chocolate mass and butter fillings, they can survive the preparation of certain creams.

The microflora of sweetened condensed milk and butter is discussed in Section 15.1.

The microflora of eggs, egg melange, and egg powder is discussed in Section 15.3.

Fruit and berry semi-finished products. Various microorganisms capable of surviving adverse conditions—such as high-Temperature processing, high sugar concentrations, acidity, and preservatives—can multiply in fruit and berry preps during storage. Fruit purees are especially prone to spoilage, supporting the growth of Saccharomyces yeasts (causing alcoholic fermentation), acetic acid bacteria (Acetobacter aceti, which accumulate acetic and other volatile acids), and lactic acid bacteria (genera Lactobacillus, Lactococcus, causing souring). A surface film is sometimes observed on purees due to the growth of imperfect yeasts (Candida, Monilia), alongside mold layers (Penicillium, Aspergillus, Mucor).

Fruit preserves (povidlo) are less susceptible to microbial spoilage because they are boiled down after sugar addition. Nevertheless, microbiological processes can occur due to the proliferation of osmophilic yeasts, introduced via sugar, contaminated containers, or air. Molds can also cause surface spoilage. Preservatives are commonly used to protect fruit and berry semi-finished products from microbial deterioration.

Cocoa beans serve as the raw material for cocoa powder and cocoa butter, which are used to manufacture chocolate, chocolate candies, chocolate creams, and other confectionery products. To enhance flavor, cocoa beans undergo fermentation, drying, and roasting. Roasting destroys the majority of microorganisms. Secondary contamination of cocoa beans occurs during prolonged storage under high-humidity conditions. Spoilage may be caused by molds, yeasts of the genus Candida, and others. To prevent molding, cocoa beans must be stored in dry, well-ventilated areas.