PLANTS AND PEOPLE 

 Beverages II

American contribution: Cocoa - Theobroma cacao (Sterculiaceae - related to 'kola' [Cola nitida]) - tropical family - first observied by Europeans in Nicaragua on Columbus's 1st trip, later Hernando Cortez was offered brew of ground cacao seeds, red pepper, other species and ground cornmeal (Molé) - Europeans deleted the spices and added sugar and later (Dutch and Swiss) modified processing to produce a unique product from an ancient beverage plant - monopoly first established by Spain, Dutch later established plantations in se asia - introduced into Africa in late 1800s - most now comes from Africa, although latin american close 2nd (history detail).  See overview and more on Candida krusei and theobromine.

Also Maté - Ilex paraguariensis - Aquifoliaceae (also Ilex vomitoria - Yaupon - Black Drink) - Inca drink now very popular in Argentina and Paraguay - leaves (whole) reduced to powder added to a gourd (Lagenaria) cup (Maté) and sucked out with a metal straw (Bombilla).

Asia - both cofffee and chocolate derived from embryo - mostly cotyledons, Asian contribution - Tea - Camellia sinensis (Camelliaceae or (more often) often placed in the Theaceae) - small, evergreen tree - plantations often started from seed - numerous prunings (after 3 years and thereafter every 12 years) to force the trees into a bush-like form - harvest only 2 or 3 of the youngest leaves on a terminal branch - can pick once a week - common black tea is first fermented, heated (stop enzyme activity) and packaged. Ancient - 1st published info dated 780 A.D. - originated in China, moved from China thorughout Asia - Japan by 593 A.D. Europeans 1st exposed in 1500s (Portuguese exploration of chinese coast) - by 18th century - important euopean trade item - British started plantations in India in early 1800s - india now #1 producer. 2nd largest produced is Sri Lanka - began growing only after coffee plantations fell to a fungal disease. Thus, Tea became a traditional British drink AFTER problems with the coffee supply from the colonies. 

Alcoholic Beverages

In the great ecological scheme of things - conversion of radiant energy to the biosphere - the system must be maintained by DECOMPOSITION. This brings in the fungal world and - from the point of view of Economic Botany - alcohol production

As is the case with grass/legume food complexes - all developing societies and racial groups developed a drug [usually ritual] of choice that is derived from a plant - SA - coca, Mexico - Peyote - Near East - Cannabis - Asia - opium. Ethanol is 'our' drug of choice [except 18th amendment [1920] to 21st amendment [1933]. Rationale probably goes to the roots of Anglo-European history.

Drunk robbins (Jim Beam Tree) - consumption of fermented fruit - probably initial contact between H. sapiens and beverage alcohol [ethanol]. Ethanol is the legal drug of modern civilization - it is toxic [base characteristic of a drug - 'intoxicated'] over both the short term (nonselective central nervous system depressant - affects all neurons of the brain and brainstem - can take a lethal dose - also harmful to health over the long term [brain damage, proliferation of fat in the liver [cirrhosis], numerous heart problems and - probably most significant with regard to application of national health care resources, trauma on the highway.

As is the case with soy sauce and blue cheese - ethanol production involves interaction between angiosperms and a fungus - in this case species of the yeast genus Saccharomyces. Why this particular yeast?

    1. single cells - no multicellular hyphae to mat together to form complex structures [mycelia or reproductive bodies].

    2. Very efficient at ethanol production [fermentation] and can tolerate high levels of ethanol in the substrate.

    3. Produce organic compounds other than ethanol during fermentation - these provide favored characteristics.

    4. Some strains will clump during later stages of fermentation - flocculation - that facilitates removal.

    5. Domesticated species [S. cerevisiae and S. uuvarum] function in anerobic conditions [in solution]. DOMESTICATED in that SELECTED strains [genomically (polyploid) genetically different from wild type] have been developed and are maintained as lineages by H. sapiens.

Saccharomyces - S. cerevisiae and S. uuvarum [bread and beer], S. bayanus [wine].

Yeast/Plant interaction: FERMENTATION - The plant produces sugars and nitrogenous compounds that are ingested by the yeast. The yeast produces - as metabolic waste products - ethanol and CO2 [ref. glutin and levening]. It requires simple, 6-carbon [HEXOSE] sugars (not di-or polysaccharides) for energy and amino acids to grow (protein) and reproduce. Since starch [a hexose polymer] is often present - enzymes are usually necessary to break down complex carbohydrates. [amylase - saliva - CHICHA]

With an unlimited hexose supply, about 47% of available sugar can be converted to ethanol by yeast [the rest is used in growth and reproduction] - CO2 is often released to the atmosphere and ethanol increases in the fermentation solution up to a concentration of 14-18% - this kills the yeast.

Wine - fermented fruit juice - usually fruit from Vitis vinifera VITACEAE. - Simple process - although details of processing vary according to final production capacity [vintage vs. bulk processing]. Process:

    1. HARVEST, CRUSH GRAPES to express juice often add sulfur dioxide to kill bacteria, LEAVE SKINS FOR RED WINE, ADD PREFERRED STAINS OF YEAST, would work without this addition, yeast on skins, but would be using a 'wild type' strain of yeast

    2. allow to ferment for 8-10 days [hexose content high in fruit juice], draw off from skins [if present] and other material, more fermentation for about 1 month,

    3. series of RACKING [DRAWING SOLUTION AWAY FROM SEDIMENTATION LAYER, also 'fining' [application of 'fining' agents such as DIATOMACEOUS EARTH, to clear the wine of particles small enough to remain in suspension], then AGING [WHITE WINES CA. 1 YEAR, RED WINES UP TO 5 YEARS - BOTTLE. Can also age in the bottle.

    4. That's it for 'still' wines - sparkling wines contain extra CO2 - better types do this by adding a little extra sugar to wine that still has active yeast cells and cap the bottle. Final spate of fermentation produces excess of CO2. Cheaper types simply charge the bottles with CO2.

CORK - cellular product of a meristematic layer that develops OUTSIDE the vascular cambium of woody plants [CORK CAMBIUM] - air-filled cells - special properties - cannot be produced synthetically - stoppers for wine bottles is one of many modern applications. Quercus suber - Mediterranean basin - fire protection - chapperal vegetation - esp. Portugal and Spain.

Standard wine is a product of Vitis vinifera - domesticate grape of the near east and mediterraneau basin - VITRICULTURE - Columbus introduced V. vinifera to NW on 2nd trip - established in NW habitats similar to home area (Chile, California [spanish 1769], and the eastern slopes of the Andes - Argentina) - other species, esp. V. labrusca] of the genus provided wine for other areas of the NW - Concord]. North American insect [Phylloxera] invaded European vinyards in 1860 - had to used 'rootstock' of NA [genus of ca. 60 species - northern hemisphere - 14 species in texas] species [with grafting] to maintain Europen wine production. [reverse of typical story - Sunflower, Coffee, Pineapple, etc.]. Wines of Chile evidently among the few that are produced by original vinifera stock [un-grafted].

Wine also produced from many other fruits - all you need is a hexose and yeast for fermentation. Cider - Perry

Fortified Wines: - ethanol content exceeds killing concentration for yeast - added ethanol either from distilled wine (Brandy) or ethanol distilled from other souces

BEER: Possible connection between beer and bread making in that in Egypt barley was made digestiable by sprouting, drying the sprouted grains, and grinding into a flour - dough from this flour is a good habitat for yeast - early Egyptian wines were made from fermentation of this sprouted barley dough and water.

MALT: Any grain [usually Hordeum] that has been sprouted and dried.

HOPS: Humulus lupulus [Cannabaceae] - introduced to brewing process - about 1000 BP by the Dutch and Germans - not used by the english till 1524. Use bracts of the pistillate inflors.

'ADJUNCTS': unmalted grains or other starch sources.

BREWING:

1. MALTING: artificial germination to produce amylases.

2. MASHING: mixing the malt and adjunct starch source - starch is broken down, as are proteins [to amino acids]. Product - WORT - is filtered and boiled. ['lite' beer features either less starch added or more enzymes] Hops added.

3. FERMENTATION - filter off hops, add yeast, ferment for 7-12 days

4. Age (2-3 weeks) - pasturize, filter [removes natural CO2 - have to add CO2

SAKE: Made from fermented grain [thus a beer], but different in that no malting [partial germination] but conversion (saccharify) from rice endosperm starch to sugar by Aspergillus oryzae - produces amylases

Chicha [talked about earlier - native American - saliva/amylase], 'Pulque' exudate collected after cutting inflorescence stalk of large Agave [Century plant] [Liliaceae], allow to ferment. Spanish introduced DISTILLATION = the process where ethanol is removed in pure form from a fermented beverage (wine = brandy, mescal, tequila = whole Agave shoots, or grain (Bourbon - Z. mays, Scotch - Hordeum [malt], Rye - Secale) and other sources (Gin Juniperus for taste) and Vodka [grain, potatoes] - multiple sources of starch.  Check out a commercial mexcal/tequila site and an overview of the Maguey worm.

MEAD - mixture of honey with [pure honey is TOO rich in sugar] water and yeast. 


Return to Course syllabus
8 Mar 2011