Food and Beverage Industry 2017-18 PDF

APPLIED MICROBIOLOGY Food Microbiology MICR1010: INTRODUCTION TO MICROBIOLOGY AND MOLECULAR BIOLOGY Learning Outcomes 2  State the properties of useful industrial microorganism  Describe the steps involved in the making of Yogurt ...

APPLIED MICROBIOLOGY Food Microbiology MICR1010: INTRODUCTION TO MICROBIOLOGY AND MOLECULAR BIOLOGY Learning Outcomes 2  State the properties of useful industrial microorganism  Describe the steps involved in the making of Yogurt  Discuss the process of Cheese making  Describe the process of Bread making  Describe the Beer making process  Differentiate between the Red and White wine making process What characteristics should industrial microorganisms possess? Properties of a useful industrial 4 microorganism  Organism must be capable of growth and product formation in a large scale culture.  Should produce spores or some other reproductive cell form for ease of inoculation in large fermenters.  Should grow rapidly and produce the desired product in a relatively short period of time.  Reproducible production of correct levels of flavours, texture and aroma compounds. Properties of a useful industrial 5 microorganism  Should grow in relatively inexpensive liquid culture medium.  Should not be pathogenic especially to humans, animals and plants.  Should be amenable to genetic manipulation (must be genetically stable after manipulation).  Produce the product of interest in high yield. Properties of a useful industrial 6 microorganism  Should not produce end products that is undesirable or toxic.  Organism should be easily harvested at the end of product formation.  Limited or no need for vitamins and additional growth factors. Fermented Foods and Primary Fermentation Microorganism Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Fermented Foods and Primary Fermentation Microorganism Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Fermented Foods Figure 37.3 Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings  10 Microorganism in Dairy  FOOD AND BEVERAGE INDUSTRY 11 Some Microbially Fermented Dairy Products DAIRY PRODUCT PRODUCTION MICROORGANISM Yogurt Streptococcussp, Lactobacillus sp Cheddar Cheese Streptococcus, Lactococcus Cottage cheese Streptoccocus Sour cream Streptococcus Swiss cheese Propionibacterium Cultured buttermilk Streptococcus sp and Leuconostoc sp Yogurt 12  To make yogurt :  Milk is pasteurized to eliminate spoilage bacteria.  It is inoculated with a starter culture of Lactobacillus bulgaricus and Streptococcus thermophilus and incubated at 40ºC.  These lactic acid bacteria grow and ferment lactose to produce lactic acid and acetaldehyde.  The characteristic flavour of yogurt is due to the lactic acid produced. The lactic acid lower the pH coagulating proteins thereby changing the texture of the milk.  More than 3 billion pints of yogurt is sold/year in US.  Step 1: Heat milk up to 80-95°C Step 2: Cool milk down to 40-45°C. Step 4: Bacteria changes Step 3: Keep mixture at sugar into acid and milk 40-45°C for 3-6 hours. proteins form lumps  General Yogurt Processing Steps Pasteurize Milk: The milk mixture is pasteurized at 80°C for 30 minutes or 95°C for 10 minutes ( the time for pasteurization can be 15 seconds- 30 minutes depending on the pasteurization technique used). The blend is homogenized to mix all ingredients thoroughly and improve yogurt consistency. Cool Milk: The milk is cooled to between 40-45°C to bring the milk to the ideal growth temperature for the starter culture. Inoculatewith Starter Cultures: The starter cultures are mixed into the cooled milk. Hold: The milk is held at 40-45°C until a pH of 4.5 is reached. This allows the fermentation to progress to form a soft gel and the characteristic flavor of yogurt. This process can take several hours.  General Yogurt Processing Steps Cool: The yogurt is cooled to 7°C to stop the fermentation process. Add Fruit & Flavors: Fruit and flavors are added at different steps depending on the type of yogurt. For set style yogurt the fruit is added in the bottom of the cup and then the inoculated yogurt is poured on top and the yogurt is fermented in the cup. For swiss style yogurt the fruit is blended with the fermented, cooled yogurt prior to packaging. Package:The yogurt is pumped from the fermentation vat and packaged as desired. Cheese 16  Cheeses consist of milk curds that have been separated from the liquid portion of the milk (whey).  The curdling of the milk is accomplished by using the enzyme rennin (casein coagulase or chymosin) and lactic acid starter cultures. Cheese 18  The production of cheese involves lactic acid fermentation.  Various mixtures of Streptococcus and Lactobacillus species are used as starter cultures to initiate fermentation.  Cheese 20  The flavours of different cheeses is dependent on: o The use of different starter cultures. o Varying incubation times and conditions. o The inclusion and omission of a secondary microorganism in the late fermentation process. o After the formation of the curds, they are separated from the whey, washed, pressed, cooked and salted. Cheese 21  The cheese curd is then ripened - this is a process involving various transformations performed by proteolytic enzymes.  Different kinds of cheese are ripened at various temperatures to promote growth of specific microorganisms.  Sometimes a cheese is soaked in brine to encourage the growth of specific bacteria and fungal populations.  Cheese 22  During ripening the curds are softened by enzymes and the cheese acquires its characteristic taste and aroma.  Swiss cheese formation involves late propionic acid fermentation.  Various fungi may be used in the ripening process. The unripened cheese is normally inoculated with fungal spores and incubated in warm moist rooms to promote filamentous growth of fungi. Cheese 23  Various fungi may also be used in the ripening of cheese  Blue cheese: Penicillium sp  Roquefort cheese: P. roqueforti  Brie: P. candidum  Camembert : P. camamberti  Penicillium roqueforti is a common blue mold added to cheese Penicillium camemberti covers Brie and Camembert Lactobacillus helveticus often gives a sweet flavor to cheeses like aged Gouda Cheese 25  Cream cheese: ripened without additional microorganisms  Mozzarella: undergoes little or no ripening Cheese 26  Cheese is classified based on its texture and hardness:  The hardness of the cheese is dependent on the length of the ripening period and the amount of water removed from the curd.  Soft (Cottage, Cream and Brie)  Semi-soft (Monterey jack, Fontina)  Hard (Cheddar, Colby, Swiss)  Very hard (Parmesan, Asiago) Bread 27  Bread is made by using yeasts that carry out an alcoholic fermentation  Principal yeast used is Saccharomyces cerevisiae (baker’s yeast)  Yeast ferments sugar producing CO2 and ethanol Fermented Foods 28 Some Fermented Foods Produced by Microorganisms FOOD PRODUCTION MICROORGANISM Cocoa Removal of bean from pods by Candida krusei and lactic acid bacteria Green olives Leuconostoc mesenteroides, Lactobacillus plantarum Pickles (cucumber) Lactobacillus plantarum, Leuconostoc mesenteroides Sauerkraut (cabbage) Enterobacter cloacae, Leuconostoc mesenteroides and Lactobacillus plantarum Soy Sauce (soy bean) Aspergillus oryzae and lactic acid bacteria Vinegar Saccharomyces cerevisiae subsp. Ellipsoideus, Acetobacter sp., and Gluconobacter sp Tamari sauce Aspergillus tamarii Citron Saccharomyces citri medicae and Bacillus citri Microorganisms in the Beverage Industry Fermented Beverages 30  Yeasts in the genus Saccharomyces (brewers yeast) are used to produce various beverages  Alcoholic Beverages  Beer (fermentation of malted grains)  Wine (fermentation of fruit juice)  Distilled beverages (distillation of fermented products) - Whiskey, brandy, vodka, rum Wines and Alcoholic Beverages 31 Types of Wines  Dry wine: all sugar is fermented e.g. Chardonnay, Pinot Grigio  Sweet wine: some sugar left or added e.g Moscato, Zinfandels  Fortified wine: a wine to which distilled beverage is added e.g. Port, Sherry, Marsala  Sparkling wine: CO2 present from fermentation in closed bottle e.g. Champagne, Prosecco Steps in Wine Production 32  Most wine produced by fermentation of grapes  Grapes are chopped, squeezed, pressed to produce grape juice (must).  White wine can be made with white or red grapes, but fermentation is carried out without the grape skin.  Red wine is made from black or red grapes is fermented with their skin.  Yeast added S. ellipsoideus (fermentation)  Wine aged (remove tart compounds)  Filtered  Bottled  33 Steps in Wine Production Brewing 35  Brewing is the manufacture of alcohol beverage from malted grains e.g. beer, ale and stout.  Beer making can be divided 3 basic stages:  Wort making  Fermentation  Bottling and aging  Steps in Beer making 36  Water and barley mixed to produce malt (which is the dried germinated grain).  Malt is crushed in a mill, to break the kernels apart and increase surface area.  Resulting milled grain is mixed with heated water (process called mashing).  The strained mash known as wort used as substrate for growth of Saccharomyces sp (Brewers yeast).  Alcohol produced by fermentation of sugars present in wort.  Stored and then bottled. Producing Beer Distilled Alcoholic Beverages 40  Distilled alcoholic beverages is made by heating fermented liquids at high temperature (distillation). A product with high alcoholic content is produced.  Distillation of:  Malt brew → whiskey  Wine → brandy  Fermented molasses → rum  Fermented grains and potato → vodka  Fermented grain (juniper berries which is a botanical added for flavor) → gin Videos on the different Processes  Cheese making Process https://www.youtube.com/watch?v=y9wLhRrj5Ug https://www.youtube.com/watch?v=7-s2Kql0CHI  Yoghurt making Process https://www.youtube.com/watch?v=kecBi27dhjw  Beer making process https://www.youtube.com/watch?v=OH295LYOwxk &index=63&list=PLfCk374GUQIj46VRW- dydG0TsFdv3QgBr https://www.youtube.com/watch?v=DwD7SZ0PMrI Videos on the different Processes  Wine making Process https://www.youtube.com/watch?v=w2_w_JvRi5g  Rum making Process https://www.youtube.com/watch?v=eQ579KOOjAI