8 Flashcards
Yeast fermentation
Yeast breads, alcoholic beverages and vinegars. Saccharomyces cerevisiae is often used. Main source of energy= sugar, but can use honey, molasses or corn syrup.
Fermentation of Bread
Bread: warm liquid to activate yeast, mixing to distribute evenly, kneading to develop gluten, proofing to help yeast to produce enzyme to break down sugars to release alcohol and co2. Yeast fermented product
Wine and alcoholic beverages
Wine: from grapes, honey, fruits, dandelions. Sulfur dioxide (SO2) or potassium bisulfite to inhibit growth of unwanted microbe growth. Held in anaerobic conditions up to 4weeks in oak barrels or stainless steel tanks and then aged in barrels (when CO2 production stops)
Beers barley, bourbon corn, rum sugar cane/molasses, brandy wine or fermented juice, liqueurs/cordials have a brandy base + sugar and flavorings. Yeast fermentation product
Lactic acid fermentation
Type of bacterial fermentation. Produces also bi-products of acetic acid, formic acid and CO2.
Sauerkraut
Sauerkraut is cabbage in brine salt and water. Salt controls water activity and pulls water with dissolved sugar to surface and bacteria feed on the sugars and release lactic acid. Bacterial fermentation
Pickles and other fermented veggies
Cucumbers are heated in a spiced vinegar solution, refrigerating in acid brine OR fermented with lactic acid bacteria. Commercial pickling involvhttps://www.facebook.com/es washing cucumbers in chlorine solution and placed in a Lactobacillus brine. Other vegetables like watermelon rinds, beets, cauliflower, okra, onions and eggs.
Olives
Washed in lye solution to remove any bitter flavor compound (phenols), lactic acid neutralizes any remaining lye and sugar is added to start fermentation process. Green/Spanish olives are picked before being ripe, then cured, pitted and stuffed. Black are picked at ripe stage. Bacterial fermentation
Fermentation of Meat
Lactic acid fermentation is used to make dry and semi dry sausages. Fermentation tenderization, tart flavor. We add sugar for food for bacteria and spices and salt for flavor. Bacterial fermentation (lactic acid)
Cultured dairy products
Sour cream, yogurt, buttermilk.
Streptococci are the fastest lactic acid producers, which enables milk to acidify quickly, thus reducing prep time and contamination risk. Leuconostoc and lactobacilli are added to produce flavors.
Milk is pasteurized and bacteria is added (and rennin). They ferment lactose to lactic acid, which denatures proteins and causes them to coagulate. Coagulation is also affected by T, pH, fermentation time and added enzymes used (cooling stops the process). After curds are formed, they are separated into smalll cubes and heated to help whey separate from casein. Curds are rinsed and salted (added cream for cottage cheese and put in presses and wax for aged cheese). Different bacteria and molds are responsible for flavor of cheese, which is called sharpness.
Mold fermented products
Antibiotics, flavor compounds, enzymes.
Soy sauce is soybeans and wheat
Tempeh is cooked mashed soybeans inoculated with Rhizopus molds wrapped in banane leaves.
2-step fermentation
Lactic acid
Cheese, soy sauce and sourdough bread require lactic acid and other microbes
Cheese: lactic acid to form product and microbes to develop flavor and textures
Sourdough: lactic acid to ferment the yeast starter and then yeast ferments the bread
Acetic acid
Yeast release alcohol and acetic acid fermentation begins because of Acetobacter which releases acetic acid from alcohol
Also candied citron from citron lemons for baked goods. Cacao beans to chocolate.
Nutritional changes in fermentation
Changes depend on microbes used, ingredients added and impact of fermentation on bioavailability. Higher fat and calcium in cheese than milk. More salt in brined-pickled products.
