Spoilage natural fermentation

The starter cultirre for cucumber fermentation usually consists of the normal mixed microbial flora of cucumbers, including Lb. mesenteroides. Enterococcus faecalis, Pediococcus cerevisiae. Lb. brevis, and Lb. plantarum. Of these, the pediococci and Lb. plantarum are the most involved, with Lb. brevis being undesirable because of its ability to produce gas. Lb. plantarum is the most essential species in pickle production, as it is for sauerkraut production. The natural fermentation of cucumbers, though in practice for many years, can lead to pickle spoilage and thereby serious economic loss. A controlled fermentation of cucumbers brined in bulk has been developed, and this process not only reduces economic losses but also leads to a more uniform product over a shorter period of time (10-12 days). This method employs a chlorinated brine of 25° salinometer, acidification with acetic acid, the addition of sodium acetate, and inoculation with P. cerevisiae and Lh. plantarum or with Lb. plantarum only. 

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Propyl alcohol [71-23-8J, 1-propanol, CH2CH2CH2OH, mol wt 60.09, is a clear, colorless liquid having a typical alcohol odor it is miscible ia water, ethyl ether, and alcohols. 1-Propanol occurs ia nature ia fusel oils and forms from fermentation and spoilage of vegetable matter (1). 

Among Pasteur s many contributions to the wine industry were several simple methods of wine analysis, and his research has had a permanent influence on the wine industry. As a well-trained chemist he was certain that chemical analysis would reveal the nature of the process of alcoholic fermentation and the type and degree of spoilage related to it. In both cases he was correct. 

Biogenic amines (BAs) are organic bases of low molecular weight occurring naturally in food and beverages. Their amount increases during microbial fermentation or spoilage (1-11) as a result... 

It could be said that freshly pressed fruit juice provides the truly natural answer to all the requirements of a soft drink thirst quenching, fresh, healthy, flavour-some, nutritional and, of course, natural. So why should it have been necessary to look any further towards the creation of different flavour types and the myriad of drink var ieties that has appealed over the years in beverage markets around the world Necessity, being the mother of invention, has been the driving force in all this. In the early years of the industry there was a real necessity for soft drinks manufacturers, in order to stay in business, to control a major threat to their trade, that of microbial fermentation and spoilage of the bottled product. 

Brettiness". "Volatile phenols can be considered as natural components in wines and beer, or as spoilage compounds when present in excessive amounts" (84). Brettanomyces species can produce both mousiness and, at low concentrations of volatile phenolics, also "a distinct aroma described variously as cider-like, spicy, dove-like or phenolic... formed toward the end of fermentation" (84). The ethyl phenols produced can exceed the sensory threshold 16-fold (85), producing wines, at high concentrations of volatile phenolics, with distinct "barnyard", "stable", and "animal" phenolic odors (85-87). Wines with high concentrations of phenolic odors are deemed "Bretty" by tasters. 

Antibiotic residues may occur in foods in several ways. Antibiotics can be added either directly to foods to retard spoilage and extend shelf life, or can be added indirectly through contamination from the immediate environment, through animals treated with antibiotics for medical and prophylactic purposes or animals given antibiotic treated feeds for growth. Conversely, during fermentation, certain lactic cultures synthesize "natural" antibiotics which may remain in the food. These compounds include Nisin produced by Streptococcus lactls, Diplococcin from cremoris, "Antibacterials" from... 

Some winemakers and coimnentators believe that the ambient yeast population in the vineyard and winery constitnte part of the characteristics of a natural wine (Lewin, 2010). They believe that the uniqne contributions of diverse yeast species -including non-Saccharomyces species - confer a complexity upon wine not seen in inoculated ferments. This might be tme (Varela et al., 2009), but it comes with the risk of spoilage. There is also an increased risk that the fermentation will become stuck (Martini, 1993) - i.e. the ferment will stop and be difficult to restart. In addition. 

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