Normal Microbiological Quality of Foods and Its Significance ◾ 47
Soft Drinks, Fruit and Vegetable Drinks, Juices, and Bottled Water
Soft drinks are nonalcoholic beverages containing water, sweeteners, acids, flavoring, coloring and
emulsifying agents, and preservatives. Some may contain fruit juices and be carbonated or noncarbonated and have a pH of 2.5–4.0. Fruit juices (100%) have a pH of 4.0 or below. Vegetable juices
(e.g., tomato) can have a pH of 4.5 or above. Bottled water is obtained from either natural springs
or drilled wells and handled under conditions that prevent contamination.
Soft drinks can have different types of microorganisms, but only aciduric microorganisms,
such as molds, yeasts, lactic acid bacteria, and acetic acid bacteria, can multiply. 11 In carbonated beverages, some yeasts are microaerophilic and can grow; in beverages with fruit juices,
Lactobacillus and Leuconostoc species can grow. In noncarbonated beverages, molds (Geotrichum)
and Acetobacter and Gluconobacter spp. can also grow. Most of these come from the processing
environment and equipment. In fruit juices, molds, yeasts, Lactobacillus spp. (Lactobacillus fermentum, Lactobacillus plantarum), Leuconostoc spp. (Leu. mesenteroides), and acetic acid bacteria can
grow. Spoilage of fruit juices by acid-resistant spore-forming species from genus Alicyclobacillus has
currently been recognized. Some pathogens (e.g., acid-tolerant Salmonella and Esc. coli O157:H7
strains in orange juice and apple cider) can remain viable for a long time (≥30 days) in the acid
products. 11 Vegetable juices can have molds, yeasts, and lactic acid bacteria along with Bac. coagulans, Clo. butyricum, and Clo. pasteurianum.
Bottled water should not contain more than 10–100 bacteria and >10 coliforms/100 mL. The
indigenous flora are mainly Flavobacterium, Alcaligenes, and Micrococcus. They may also have some
Pseudomonas as contaminants from outside. They should not have pathogens unless produced
under poor sanitation.
Mayonnaise and Salad Dressings
Water-in-oil emulsion products formulated with oil, water, vinegar (approximately 0.25% acetic
acid) or lemon juice, sugar, salt, starch, gum, egg, spices, and vegetable pieces, such as mayonnaise
and salad dressings, have a pH between 3.5 and 4.0. Some low-calorie and less sour products containing less acid, less oil, and more water may have a pH of 4.5 or above.
Microorganisms are introduced into the products through ingredients, equipment, and air.
However, except for aciduric microorganisms, most others die, especially when stored for a long
time at room temperature. 12 Among aciduric microorganisms, molds (Geotrichum and Aspergillus
spp.), yeasts (Saccharomyces spp.), and several species of Lactobacillus (Lab. fructivorans, Lab. brevis)
and some Bacillus spp. (Bac. subtilis, Bac. mesentericus) have been isolated. Normally, their numbers should not exceed 10/g. If pathogens are introduced (e.g., Salmonella through eggs), they are
expected to be killed rapidly; however, they may survive longer in low-calorie, high-pH products
kept at refrigerated temperatures.
Spices and Condiments
Spices are plant products (seeds, flowers, leaves, bark, roots, or bulbs) used whole or ground, singly
or mixed. The top 12 spices used in the United States include dehydrated onion/garlic, mustard
seed, red pepper, sesame seeds, black pepper, paprika, cinnamon, cumin seeds, white pepper,
oregano, poppy seeds, and ginger. Other spices include allspice, anise, basil, bay leaves, cloves,
Soft Drinks, Fruit and Vegetable Drinks, Juices, and Bottled Water
Soft drinks are nonalcoholic beverages containing water, sweeteners, acids, flavoring, coloring and
emulsifying agents, and preservatives. Some may contain fruit juices and be carbonated or noncarbonated and have a pH of 2.5–4.0. Fruit juices (100%) have a pH of 4.0 or below. Vegetable juices
(e.g., tomato) can have a pH of 4.5 or above. Bottled water is obtained from either natural springs
or drilled wells and handled under conditions that prevent contamination.
Soft drinks can have different types of microorganisms, but only aciduric microorganisms,
such as molds, yeasts, lactic acid bacteria, and acetic acid bacteria, can multiply. 11 In carbonated beverages, some yeasts are microaerophilic and can grow; in beverages with fruit juices,
Lactobacillus and Leuconostoc species can grow. In noncarbonated beverages, molds (Geotrichum)
and Acetobacter and Gluconobacter spp. can also grow. Most of these come from the processing
environment and equipment. In fruit juices, molds, yeasts, Lactobacillus spp. (Lactobacillus fermentum, Lactobacillus plantarum), Leuconostoc spp. (Leu. mesenteroides), and acetic acid bacteria can
grow. Spoilage of fruit juices by acid-resistant spore-forming species from genus Alicyclobacillus has
currently been recognized. Some pathogens (e.g., acid-tolerant Salmonella and Esc. coli O157:H7
strains in orange juice and apple cider) can remain viable for a long time (≥30 days) in the acid
products. 11 Vegetable juices can have molds, yeasts, and lactic acid bacteria along with Bac. coagulans, Clo. butyricum, and Clo. pasteurianum.
Bottled water should not contain more than 10–100 bacteria and >10 coliforms/100 mL. The
indigenous flora are mainly Flavobacterium, Alcaligenes, and Micrococcus. They may also have some
Pseudomonas as contaminants from outside. They should not have pathogens unless produced
under poor sanitation.
Mayonnaise and Salad Dressings
Water-in-oil emulsion products formulated with oil, water, vinegar (approximately 0.25% acetic
acid) or lemon juice, sugar, salt, starch, gum, egg, spices, and vegetable pieces, such as mayonnaise
and salad dressings, have a pH between 3.5 and 4.0. Some low-calorie and less sour products containing less acid, less oil, and more water may have a pH of 4.5 or above.
Microorganisms are introduced into the products through ingredients, equipment, and air.
However, except for aciduric microorganisms, most others die, especially when stored for a long
time at room temperature. 12 Among aciduric microorganisms, molds (Geotrichum and Aspergillus
spp.), yeasts (Saccharomyces spp.), and several species of Lactobacillus (Lab. fructivorans, Lab. brevis)
and some Bacillus spp. (Bac. subtilis, Bac. mesentericus) have been isolated. Normally, their numbers should not exceed 10/g. If pathogens are introduced (e.g., Salmonella through eggs), they are
expected to be killed rapidly; however, they may survive longer in low-calorie, high-pH products
kept at refrigerated temperatures.
Spices and Condiments
Spices are plant products (seeds, flowers, leaves, bark, roots, or bulbs) used whole or ground, singly
or mixed. The top 12 spices used in the United States include dehydrated onion/garlic, mustard
seed, red pepper, sesame seeds, black pepper, paprika, cinnamon, cumin seeds, white pepper,
oregano, poppy seeds, and ginger. Other spices include allspice, anise, basil, bay leaves, cloves,