食品专业英语课件lesson5

Lesson5 Alcoholic beverages
酒精饮料
一、Questions:
1 In the following contents, which belong to alcoholic beverages?
beer, wine, carbonated beverage , fruit juice, tea drink
2. Which types alcoholic beverages can you list?
The alcoholic beverages include:
non-distilled beverages :非蒸馏制取的酒精饮料(酿造酒)
Beers, wines, ciders苹果酒, sake日本米酒
distilled beverages : 蒸馏制取的酒精饮料
whisk 威士忌酒, rum 朗姆酒, brandy 白兰地酒, vodka 伏特加酒, gin 杜松子酒fortified wines 强化葡萄酒, 加度酒
sherries 雪利酒, Port 葡萄牙酒，Madeira wines马德拉酒.
Distilled beverages : 蒸馏制取的酒精饮料
whisk 威士忌酒Produced from fermented cereals
rum 朗姆酒Produced from fermented molasses
brandy 白兰地酒Produced by distillation of wine
vodka 伏特加酒Produced from neutral spirits obtained by distillation of fermented molasses, grain, potato or whey
gin 杜松子酒
Fortified wines 强化葡萄酒, 加度酒
sherries 雪利酒,
port 葡萄牙酒，
madeira wines马德拉酒.
produced by addition of distilled spirit to wines [to raise the alcohol content to 15-20% distilled spirit 精馏酒精
alcohol content 酒精含量(浓度)
3 Which materials can be used to produce alcoholic beverages?
Alcoholic beverages are produced from a range of raw materials but especially from cereals, fruits and sugar crops.
cereals 谷类(barley, rice, corn…)
fruits （wine, apple, berry, waxbe rry…）
sugar crops 糖类作物（cane, beet, potato…）
酒精饮料可以从一系列的原材料，尤其是谷物、水果及糖类作物中制取。

The alcoholic beverages include:
–Non-distilled beverages
–Distilled beverages
–Fortified wines : 15-20% alcohol
The raw materials of alcoholic beverages:
–cereals, fruits and sugar crops
Why alcoholic beverage can be produced from above materials?
Biology of yeast fermentation
•glucose+2ADP→2ethanol + 2CO2+2A TP
Sugar glucose
Starch
Why alcoholic beverage can be produced from cereals, fruits and sugar crops materials?
二、New Words
poly- "多的"
polysaccharide 多糖
polyacid 多元酸
polyphenol 多酚
polyatomic 多原子的；多酸的；多元的
glyco- 甜，糖原
glycine [Gly] 甘氨酸
glycogen 肝糖原动物淀粉
glycolysis 糖酵解
（acetone 丙酮）
pyruv- 丙酮……的
pyruvate 丙酮酸盐或酯
pyruvate oxidase 丙酮酸氧化酶
pyruvate decarboxylase 丙酮酸脱羧酶
-ose "糖"
sucrose 蔗糖
fructose 果糖
maltose 麦芽糖
maltotriose 麦芽三糖
glucose 葡萄糖
lactose 乳糖
galactose 半乳糖
enzyme 酶-ase "酶“
invertase 转化酶
permease 透性酶
glucosidase 葡糖糖苷酶
amylase 淀粉酶
glucoamylase 葡糖糖化酶
pullulanase 支链淀粉酶
hexokinase 己糖激酶
melibiase 密二糖酶
decarboxylase 脱羧酶
三、Biology of yeast fermentation
◆Strains :
Saccharomyces cerevisiae 啤酒酵母，酿酒酵母
Saccharomyces uvarum 葡萄汁酵母
◆Pathway:
Embden-Meyerhof-Parnas(EMP) pathway , Glycolysis 糖酵解途径
Glucose+2ADP→2ethanol + 2CO2 +2ATP
•Glucose+2ADP→2ethanol + 2CO2 +2ATP
Theoretical yields from 1g glucose are 0.51g ethanol and 0.49g CO2. However, in practice ,approximately 10% of the glucose is converted to biomass and yields of ethanol and CO2 reach 90% of theoretical.
biomass:生物量
The yeast-cell envelope contains a plasma membrane, a periplasmic space and a cell wall (consisting mainly of polysaccharides with a small amount of peptide material).
–envelope 外层
–plasma membrane 质膜
–Periplasmic 外周胞质, 周质空间
酵母细胞的外层包含质膜、周质空间及由多糖与少量多肽类物质组成的细胞壁构成。

The wall component is a semi-rigid but solute permeable structure （which provides considerably compressional and tensile strength to yeasts）.
细胞壁成份是一种半固体、可透性结构，使酵母可承受一定的压力与张力。

The cell wall structure
semi-rigid but solute permeable structure
ma
Carboxyl groups of cell-wall peptides confer important flocculating characteristics on brewing yeasts, facilitating post-fermentation solid-liquid separation.
–flocculating characteristics絮凝特性
–brewing yeasts 酿造酵母
–post-fermentation后发酵
位于酿造酵母细胞壁上的肽的羧基具有重要的絮凝特征，这有利于发酵后物质的固液分离
salt-bridge formation between calcium ions and these cell-wall carboxyl groups Fermentation conditions
Which factors can influence the yeast fermentation？
Beer brewing process
Which factors can influence the yeast fermentation ？
Strains
Oxygen
Ethanol concentrations
pH value
Temperature
1. Strains
Saccharomyce cerevisiae (S. cerevisiae ) : sucrose, fructose, maltose, maltotriose
Saccharomyces uvarum ( S. carlsbergensis ) : utilize melibiase
Kluyveromyces fragilis and Kluyvermyces lactis : can ’t ferment lactose
Saccharomyces diastaticus : not for brewing
S. cerevisiae utilization of sugars:
Order: sugars, sucrose, fructose, maltose, maltotriose
Sugars are transported across the cell membrane
by either active or passive transport 主动或被动运输
Mediated by inducible or constitutively-produced permeases
Utilization of sugars:
Sucrose : hydrolyzed by invertase , transported across the cell membrane , mediated by permeases.
Maltose and maltotriose : hydrolyzed by α-glucosidase
Kluyveromyces fragilis and Kluyvermyces lactis , which unlike S. cervisiae can ferment lactose, contain a lactose permease system for lactose transport into the cell (where it is hydrolyzed to glucose and galactose which enter glycolysis).
Kluyveromyces fragilis 和 Kluyvermyces lactis 与 S. cervisiae 不同，它们不能发酵乳糖，它们具有可以使乳糖运输到细胞内的乳糖透性酶系统，在细胞内，乳糖被水解成葡萄糖和半乳糖，进入糖酵解循环。

Brewer’s wort: 19 amino acids and a range of other nutrients m grou liquefact wat
filtrati boili ho sug depositi refrigerat fermentat filtrati aging packing distribution be
brewer 啤酒工人，酿造者
brewer’s barley 啤酒大麦
brewer’s malt啤酒麦芽
brewer’s wort 啤酒麦芽汁
2. Oxygen
✓anaerobic
✓need for the yeast to synthesize the membrane components
✓sub-optimal levels 未达最适宜水平
3、Ethanol concentrations:乙醇浓度
many strains attain ethanol concentrations: 12-14%
higy alcohol tolerant yeast: 18-20%：
osmophilic yeasts (耐高渗透性酵母) ferment very high sugar concentrations
Interest has developed in the use of high alcohol tolerant yeasts （in high-gravity brewing processes and in alcohol production for distillation）with a view to increasing plant productivity and decreasing distillation costs.
–high alcohol tolerant yeasts耐酒精能力强的酵母
–with a view to考虑到
考虑到降低蒸馏成本和提高产量，在高比重酿造过程和酒精蒸馏中，人们对耐酒精能力强的酵母的利用产生越来越强的兴趣。

Yeast glycolytic enzymes:
Hexokinase:己糖激酶
Glu→Glu-6-P
gluceraldehydes-3-phosphate dehydrogenase:磷酸甘油醛脱氢酶
GAP→1,3-biphosphoglycerate
pyruvate decarboxylase：丙酮酸脱羧酶
Pyruvate→ethanol
糖降解概况见下图
preparatory
payoff phase
Present only in those alcohol fermentative organisms Present in many
organisms including
human
丙酮酸脱羧酶
乙醇脱氢酶
4 pH values
pH values between : 3-6
Since most bacteria , with the exception of acetic acid and lactic acid bacteria, prefer more neutral pH values / the susceptibility of wine musts to infection is greatly reduced.
除了乙酸菌和乳酸菌外，大多数的细菌都喜欢较中性的pH，因而葡萄汁对细菌感染的敏感性大大降低。

5 Temperature :
temperature optima:
yeast fermentation, yeast respiration and cell growth
tartaric acid 酒石酸
malic acid 苹果酸
Starches and dextrins:
addition of exogenous enzymes外源酶
–α- and β-amylase of malt
–microbial enzymes: α- amylase , amyloglucosidase (glucoamylase), pullulanase amylase 直链淀粉酶
pullulanase支链淀粉酶
amyloglucosidase , glucoamylase葡糖淀粉酶。