apple cider

VIETNAM NATIONAL UNIVERSITY HO CHI MINH CITY

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY

FACULTY OF CHEMICAL ENGINEERING

DIVISION OF FOOD TECHNOLOGY

FERMENTATION REPORT

CIDER

Lecturer : Assoc. Prof., Dr. L Vn Vit Mn

Student : PHM L DIU HIN 61101147

L NGC MN 61102030

Year : 2014

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CONTENTS

I. INTRODUCTION .............................................................................................................. 4

1. Concept ................................................................................................................................ 4

2. Origin ................................................................................................................................... 5

3. Classification ....................................................................................................................... 5

II. RAW MATERIAL ............................................................................................................. 7

1. Apple .................................................................................................................................... 7

1.1 Classification ................................................................................................................. 7

1.2 Chemical compositions ................................................................................................. 8

1.3 Malic acid ...................................................................................................................... 9

1.4 Phenolic compounds ................................................................................................... 10

1.5 Tannin.......................................................................................................................... 11

2. Adjunct .............................................................................................................................. 12

2.1 Glucose syrup .............................................................................................................. 12

2.2 Malic acid .................................................................................................................... 13

2.4 SO2 ............................................................................................................................... 15

3. Inoculum : Saccharomyces cerevisiae ............................................................................... 16

III. PRODUCTION LINE ...................................................................................................... 19

1. Classifying ......................................................................................................................... 20

2. Cleaning ............................................................................................................................. 22

3. Milling ............................................................................................................................... 23

4. Enzyme treatment .............................................................................................................. 25

5. Pressing .............................................................................................................................. 26

6. Sulfitation .......................................................................................................................... 27

7. Adjustment ......................................................................................................................... 28

8. Primary fermentation ......................................................................................................... 30

9. Secondary fermentation ..................................................................................................... 32

10. Filtration ............................................................................................................................ 33

11. Pasteurization ..................................................................................................................... 35

12. Aseptic packaging .............................................................................................................. 37

IV. CIDER QUALITY ............................................................................................................ 38

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1. Nutritional value ................................................................................................................ 38

2. Physicochemical characteristics ........................................................................................ 39

3. Microorganism characteristics ........................................................................................... 39

4. Sensory characteristics ....................................................................................................... 40

V. REFERENCES ................................................................................................................. 41

LIST OF FIGURES

Figure 1: Apple cider ....................................................................................................................... 4

Figure 2: Still cider .......................................................................................................................... 5

Figure 3: Sparkling cider ................................................................................................................. 6

Figure 4: Type of ciders................................................................................................................... 7

Figure 5: Kreb cycle diagram .......................................................................................................... 9

Figure 6: Chemical structure of malic acid ................................................................................... 10

Figure 7: Polyphenol molecule concentration ranges in seed, peel and peel + flesh .................... 10

Figure 8: Typical phenolic components in cider apples ................................................................ 11

Figure 9: Glucose syrup ................................................................................................................. 12

Figure 10: Malic acid powder ........................................................................................................ 13

Figure 11: Chemical structure of potassium metabisulfite ............................................................ 15

Figure 12: Basic yeast morphology ............................................................................................... 16

Figure 13: Saccharomyces cerevisiae budding .............................................................................. 17

Figure 14: Alcoholic fermentation ................................................................................................ 18

Figure 15: The conversion from pyruvic acid to ethanol .............................................................. 18

Figure 16: Apples are classified by size on conveyor belt ............................................................ 20

Figure 17: Overripe apple and normal apple ................................................................................. 20

Figure 18: Workers are classifying apples .................................................................................... 21

Figure 19: Roller conveyor ............................................................................................................ 21

Figure 20: Conveyor washing combine spraying .......................................................................... 22

Figure 21: Spray nozzle with pressure .......................................................................................... 23

Figure 22: Perforated screen under the rolls..24

Figure 23 : Serrated rolls.......24

Figure 24 : Roller mill diagram ..................................................................................................... 24

Figure 25: Steel perforate cylinder ................................................................................................ 26

Figure 26: Structure of screw press ............................................................................................... 27

Figure 27: Screw pressing machine ............................................................................................... 27

Figure 28: Cut-away view of a stirred-tank with a cooling jacket ................................................ 30

Figure 29: Transformation from glucose to ethanol ...................................................................... 31

Figure 30: Diagram of fermenter ................................................................................................... 32

Figure 31: The mechanics of cross flow microfiltration ............................................................... 34

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Figure 32: Crossflow filtration system in industry ........................................................................ 35

Figure 33: Partly reflux model of retentate ................................................................................... 35

Figure 34: Holding tube.36

Figure 35: Structure of plates and arrangement of flows .............................................................. 36

Figure 36: Plate heat exchanging machine .................................................................................... 36

Figure 37: Cider packed in glass bottles. ....................................................................................... 37

Figure 38: Aseptic packaging chamber ......................................................................................... 37

Figure 39: Nutrition summary for 1 cup of Sparkling Cider ......................................................... 38

Figure 40: A sample of a simple nutritional label for gallon containers of cider .......................... 38

Figure 41: Cider flavor wheel ........................................................................................................ 40

LIST OF TABLES

Table 1: The Composition of Apple Juice( Figures in percent by weight ) .................................... 8

Table 2: Distribution of Nutrients (fresh apple fruit) ...................................................................... 8

Table 3: Basic composition of some apple fruits cultivars .............................................................. 9

Table 4: Standards for apple juice in cider production .................................................................. 12

Table 5: Required standards for glucose syrup ............................................................................. 13

Table 6: Physical and chemical properties .................................................................................... 13

Table 7: Solubility in water of malic acid ..................................................................................... 14

Table 8: Acid Strength, (defined as the % w/v of acid required to lower the pH of 0.005N NaOH

solution to a specific value*) ......................................................................................................... 14

Table 9: Technical requirements for DL-malic acid food additive ............................................... 14

Table 10: Characteristics of pectinase enzyme preparation. ......................................................... 15

Table 11: Required standards for Potassium metabisulfite powder .............................................. 16

Table 12 : Recommended concentration of sulphite in apple juice at various pH ........................ 28

Table 13: Proportions of juice used in cider .................................................................................. 29

Table 14: Content of apple juice used for cider making ............................................................... 29

Table 15: Relative initial quality and shelf life of cider ................................................................ 37

Table 16: General Composition of Cider ...................................................................................... 38

Table 17: Physicochemical characteristics of Argentina cider. ..................................................... 39

Table 18: Physicochemical criteria of some commercial ciders ................................................... 39

Table 19: Volatile compounds in cider ......................................................................................... 39

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I. INTRODUCTION

1. Concept

Cider can be defined as a fermented, alcoholic beverage made on apple juice. The term cider is

also used in England indicating very traditional production methods. A product similar to cider is

perry, which is made on pear juice.

Figure 1: Apple cider

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2. Origin

The word cider has had quite an etymological journey. It originated in Hebrew and has been

translated many times prior to reaching its modern day American meaning and spelling. Cider

was produced over 2000 years ago and used to be a beverage that even more popular than beer in

11th

and 12nd

century.

Apple trees were growing in the UK well before the Romans came

but it was they who introduced organised cultivation. It is likely that

the wandering peoples, who travelled through the countries which we

now know as Spain and Northern France, introduced their shekar (a

word of Hebrew origin for strong drink) to the early Britons.

In the UK and France, cider apples tended to be grown towards the

western extremities because the climatic and soil conditions were

most suitable. Under the influence of the Gulf Stream, the weather

was relatively mild and the areas concerned had a fairly heavy annual

rainfall.

These combined factors of climate and history established the cider producing areas of England

as we know them today.

3. Classification

Styles of cider are very diverse, from traditional, with heavy complex flavour, to pale and light

fruity ciders. Cider alcohol content varies from 1.2% ABV to 8.5% or more in traditional English

ciders, and 3.5% to 12% in continental ciders.

Classify by carbon dioxide

Still cider : Still cider is cider unadorned by bubbles and does not contain carbon dioxide or with

low level.

Figure 2: Still cider

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Sparkling cider : contain carbon dioxide which is produced naturally from fermentation or force-

injected later. To have this effect, the wine is fermented twice.

Figure 3: Sparkling cider

Each different type of cider requires different techniques and raw materials to achieve the desired

flavour and aroma.

Classified by residual sugar from dry to sweet

It includes extra dry, dry, semi dry and semi sweet cider, depend on the residual sugar content,

the higher it is, the sweeter product is and their colour ranges from almost clear to amber to

brown.

Extra dry ciders have less than 0.5% residual sugar, they are often quite tannic, with a

pronounced acidity.

Dry cider usually has 1 to 2% residual sugar.

Semi-dry and semi-sweet are catch-all categories for ciders above 2% residual sugar.

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Figure 4: Type of ciders

In this report, we will introduce the production line for still semi dry cider that contain 7%

alcohol.

II. RAW MATERIAL

1. Apple

1.1 Classification

Cider apple varieties are divided into four categories according to the relative proportion of

acidity and tannin:

Sweet varieties are the blandest of the four categories, being low in both components. They are useful to blend with ciders from the more strongly flavoured varieties, which, by

themselves, would be too extreme in taste and aroma to be palatable. Typical examples of

sweet apples are Sweet Coppin, in use to a small extent, and Court Royal which was used

extensively at one time but rarely used nowadays. This group is low in tannins (

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Bittersharp is the fourth class of cider apple. These are fairly high in acid and tannin, although the latter component does not show the wide range of flavours exhibited by the

bittersweet. Stoke Red is a good example. This group is high in both acidity (>0.45%)

and tannin (>0.2%).

1.2 Chemical compositions

Normally, ciders are blended using juice from several apple cultivars to give the best results. To

decide what cider fruit to grow we need to know a little about fruit composition. About 80% of

the apple is water soluble in the form of juice, and the approximate composition of that juice in

different varieties is shown in the table below.

Table 1: The Composition of Apple Juice( Figures in percent by weight )

Component Bramley Cox Typical bittersweet Ideal cider apple

Sugar 10 12 15 15

Malic acid > 1 0.5 < 0.2 0.4

Tannin < 0.05 0.1 > 0.2 0.2

Amino nitrogen 0 - 300 parts per million depending on cultivation

Starch 0 - 2%, depending on fruit maturity

Pectin 0 - 1%, depending on fruit storage period

Table 2: Distribution of Nutrients (fresh apple fruit)

Nutrients: Content per 100 g Vitamins Val 12 mg

Energy 229 kJ (54 kcal) Carotene 45 g Carbohydrates

Water 85.3 g Vitamin E 490 g Glucose 2210 mg

Protein 0.3 g Vitamin K 0-5 g Fructose 6040 mg

Lipids 0.4 g Vitamin B1 35 g Sucrose 2470 mg

Carbohydrate 11.8 g Vitamin B2 30 g Starch 600 mg

Organic acids 0.6 g Nicotinamide 300 g Sorbit 510 mg

Fiber 2.3 g Pantothenic acid 100 g Lipids

Minerals 0.3 g Vitamin B6 45 g Palmitic acid 50 mg

Minerals Biotin 1-8 g Stearic acid 10 mg

Sodium 3 mg Folic acid 7 g Oleic acid 20 mg

Potassium 145 mg Vitamin C 12 mg Linolic acid 100 mg

Magnesium 6 mg Amino Acids Linoleic acid 20 mg

Calcium 7 mg Arg 8 mg Other

Manganese 65 g His 6 mg Malic acid 550 mg

Iron 480 g Ile 10 mg Citric acid 16 mg

Copper 100 g Leu 16 mg Oxalic acid 500 g

Zinc 120 g Lys 15 mg Salicylic acid 310 g

Phosphorus 12 mg Met 3 mg Purines 3 mg

Chloride 2 mg Phe 9 mg

Fluoride 7 g Thr 8 mg

Iodine 2 g Trp 2 mg

Selenium 1-6 g Tyr 5 mg

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Table 3: Basic composition of some apple fruits cultivars

1.3 Malic acid

Malic acid is found in a wide variety of fruits and vegetables, but the richest source is apples,

which is why malic acid is sometimes referred to as apple acid and contributes to the pleasantly

sour taste of fruits. This acid is also produced within the human body as a part of the citric acid

cycle. The salts of malic acid, known as maltates, are an important intermediary step in the cycle.

Figure 5: Kreb cycle diagram

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Malic acid has:

A clean, mellow, smooth, persistent sourness.

Flavour enhancement and blending abilities.

A high solubility rate.

Lower hygroscopicity than Citric or Tartaric acids

Lower melting point than other acids for easier

incorporation into molten confections a nd good

chelating properties with metal ions.

It forms:

Economical acidulant blends with other acids.

More soluble calcium salts than Citric acid, and effective buffering mixtures

1.4 Phenolic compounds

Figure 7: Polyphenol molecule concentration ranges in seed, peel and peel + flesh

The famous sentence: An apple a day keeps the doctor away! is what is highly recommended

and heavily advertised nowadays to the general public to stay fit and healthy.

Evidence suggests that a diet rich in apples may reduce the risk of diseases. For polyphenols,

apples are fruits for which numerous data are available and each polyphenol molecule might have

specific health benefits.

Figure 6: Chemical

structure of malic acid

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For example, the non-glycosilated form of phlorizin, phloretin, has been shown to influence

epigenetic processes, heritable changes not encoded in the DNA sequence itself that play an

important role in gene expression regulation in breast cancer cells. Other polyphenols, such as

quercetin, are efficient inhibitors of sulfotransferases, and may change the activity of thyroid

hormones, steroids, and catecholamines

1.5 Tannin

Tannin is a loose term for a whole collection of non-volatile phenolic substances found in apples,

grapes and many other fruits, and which provide 'body' to fermented beverages. There are a

dozen or more of these in apples, such as chlorogenic acid, phloridzin, epicatechin and the

procyanidins.

Figure 8: Typical phenolic components in cider apples

a) Chlorogenic acid, b) phloridzin, c) (-)epicatechin, d) procyanidin B2

Many traditional ciders such as those from Germany, Switzerland and the East of England have

quite low levels of tannin. Most modern 'factory' ciders have rather little. But traditional ciders

France and England have noticeably higher levels, so the cider is markedly astringent to most

people's taste, especially if it's 'dry' (unsweetened). That's because these areas have always used

bittersweet apples which are characterised by high levels of tannin. The reasons for this are

historical and not entirely clear. Some tannin in a cider is highly desirable or it simply becomes

too insipid for anyone's taste.

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There are generally no significant differences between juice and fermented cider in the tannin

figures obtained by any one method. Although tannin is subject to oxidation and loss if the apple

pulp is greatly exposed to air between milling and pressing, the practical losses between fruit

extracted with no oxidation (sulphite during milling) and with normal oxidation during handling

amount to no more than around 20%

Table 4: Standards for apple juice in cider production

Density at 20C g/L 1050

pH 3,3 - 3,8

L-acid Malic g/L 3,45

Yeast count CFU/ml 3,1.105

Lactic acid bacteria count CFU/ml 3,8.106

Acetic acid bacteria count CFU/ml 1,4.105

Total acidity g/L Tartaric acid 2,66

Phloridzin mg/L 100 - 200

Epicatechin and procyanidins mg/L 1000 -1500

Fructose g/100ml 7-11

Glucose g/100ml 1,5 - 3

Pectin g/100ml 0,1 -1

2. Adjunct

2.1 Glucose syrup

Glucose syrup is a purified concentrated aqueous

solution of nutritive saccharides obtained from

starch .

Normally, juice before fermentation need to

reaches some requirements as pH value, sugar

content Since sugar and water are much cheaper

than apple juice, many commercial ciders company

made their product with 35% juice and 65%

glucose syrup. It will help to adjust sugar content

in juice and increase nutritional value for cider

apple.

Figure 9: Glucose syrup

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Table 5: Required standards for glucose syrup

Essential composition and quality factors

Total solid content Not less than 70% m/m

Reducing sugar content Not less than 20% m/m, expressed as D-glucose,

on a dry basic

Sulphated ash Not more than 1% m/m on a dry basic

Sulphur dioxide Max 40 mg/kg

Sulphur dioxide for manufacture of sugar

confectionary

Max 400 mg/kg

Contaminants

Arsenic (As) < 1mg/kg

Copper (Cu) < 5mg/kg

Lead (Pb) < 2mg/kg

2.2 Malic acid

Malic acid is use as a direct food additive to adjust pH. L-Malic acid is the naturally occurring

form, whereas a mixture of L- and D-malic acid is produced synthetically.

Table 6: Physical and chemical properties

Appearance: White crystals Specific Gravity (20C/4C ): 1.601

Odour: None Melting Point (oC): 130 - 132

Taste: Smooth, tart Degradation (oC):140 or above

Molecular Weight: 134.09 Molecular Formula: C4H6O5

Figure 10: Malic acid powder

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Table 7: Solubility in water of malic acid

Table 8: Acid Strength, (defined as the % w/v of acid required to lower the pH of 0.005N NaOH

solution to a specific value*)

Table 9: Technical requirements for DL-malic acid food additive

Sensory White or near white crystal powder or grains, with

special acidic taste

Water insoluble, w / % 0.1

DL-malic acidper C4H6O5, w /% 99.0 - 100.5

Arsenic (As/ (mg/kg) 2

Residue on ignition, w /% 0.10

Fumaric acid , w / % 1.0

Malic acid, w / % 0.05

2.3 Enzyme pectinase

The cell wall of a apple contains pectin (found in the middle lamella). Adding more pectinase can

speed up the process of breaking down the pectin molecules in the cell wall therefore releasing

more juice.

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Pectinase is an enzyme that catalyzes the breakdown of pectin, is used commercially to aid in

extracting juice from fruit. Pectinase is also used for clarifying the extracted juice.

Pectinase enzyme solution was made by mixing dry pectinase enzyme and distilled water for

several minutes to assure the enzyme fully dissolved.

Table 10: Characteristics of pectinase enzyme preparation.

Appearance Liquid

Color Brown

Operative pH range 3.5 - 4,5

Operative Temperature range 30C - 55C

Solubility Soluble in water

2.4 SO2

Sulfur dioxide (SO2) also named the sterilizer is added to the freshly press juice before

fermentation to restrict and destroy harmful bacteria.

Potassium metabisulfite was used as the SO2 source (50 mg/L of total SO2). The treatment was

applied immediately after the main batch of juice was subdivided, after pressing.

When you dissolve potassium metabisulfite (K2S2O5) in water it forms three different

compounds, sulfur dioxide, bisulfite, and sulfite. Each of these is able to bond with free oxygen

floating around in wine. When this happens the free oxygen is no longer available to be

consumed by micro-organisms. The removal of oxygen chokes off most micro-organisms and

will prevent them from reproducing.

Figure 11: Chemical structure of potassium metabisulfite

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Table 11: Required standards for Potassium metabisulfite powder

Colour Colourless crystalline powder

Odour Sulfur dioxide

Thiosulfate Not more than 0.1%

Iron Not more than 10 mg/kg

Lead Not more than 2 mg/kg

Selenium Not more than 5 mg/kg

Arsenic Not more than 4ppm

3. Inoculum : Saccharomyces cerevisiae

Yeast physiology

Saccharomyces cerevisiae is a species of yeast, be commonly used as baker's yeast and for some

types of fermentation. Yeast is often taken as a vitamin supplement because it is 50 percent

protein and is a rich source of B vitamins, niacin, and folic acid.

S. cerevisiae cells are round to ovoid, 510 micrometres in diameter. Vegetative cell division of

yeast characteristically occurs by budding, in which a daughter is initiated as an out growth from

the mother cell, followed by nuclear division, cell-wall formation, and finally cell separation.

Figure 12: Basic yeast morphology

The cell is surrounded by a cell wall, followed by a space called the periplasmic space, a cell

membrane and the cytoplasma, or the inside of the yeast. In the inside of the yeast there are many

important organelles, of which the vacuole is the most mentioned in winemaking. The cell wall

consists of mainly mannoproteins and glucans and is responsible for giving form to the yeast cell

and providing a physical protection barrier for the inside of the cell. The cell wall is linked to the

cell membrane across the space by glucan and chitin chains. The space contain various enzymes

responsible for regulating yeast metabolism, one of them being invertase, which is responsible for

hydrolysing sucrose to glucose and fructose.

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Saccharomyces cerevisiae has both asexual and sexual reproduction. In asexual reproduction the

haploid of the yeast under goes mitosis and forms more haploid yeasts. There is an a and strain

of these haploids. Then these haploid yeasts, one from each strain, can fuse together and become

on cell. Then the nuclei of both cell fuses together and this cell is now the zygote. These diploid

cells can go through mitosis, which they call budding, and four more zygotes or they can under

go meiosis and from an ascus which will split into four ascospores. These haploids can then

under go germination and become haploid yeast again

S.cerevisiae can live in both aerobic as well as anaerobic conditions. In the presence of oxygen,

yeast can undergo aerobic respiration, where glucose is broken to CO2 and ATP is produced by

protons falling down their gradient to an ATPase. When oxygen is lacking, yeast only get their

energy from glycolysis and the sugar is instead converted into ethanol, a less efficient process

than aerobic respiration.

Figure 13: Saccharomyces cerevisiae budding

Saccharomyces cerevisiae gets its energy from glucose and fructose. Besides that, yeast can also

use other sugars as a carbon source. Sucrose can be converted into glucose and fructose by using

an enzyme called invertase, and maltose can be converted into two molecules of glucose by using

the enzyme mannose

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Fermentation pathway

Figure 14: Alcoholic fermentation

Figure 15: The conversion from pyruvic acid to ethanol

Alcoholic fermentation consists of pyruvate, product of glycolysis pathway, being first converted

into acetaldehyde by the enzyme pyruvate decarboxylase and releasing CO2. In the second step

acetaldehyde is converted into ethanol using alcohol dehydrogenase and producing NAD+ in the

process. It is this recycled NAD+ that can be used to continue on with glycolysis.

Criteria for strain selection

Insensitive to sulfur dioxide.

The strain can tolerate ethanol level from 7% in must.

Fermentable many type of sugar in apple juice.

Yeast with stable activity during fermentation process.

Synthesis specific aroma and flavor for product with reasonable concentration.

Working well at 25C

No or low foam formation

Flocculating potential

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III. PRODUCTION LINE

Our group chose production line for still cider with low alcohol content : 4% - 7%

K2S2O5 solution

Sucrose, malic acid

Enzyme Pectinase

Yeast biomass

Bottles

Filtration

Pasteurization

Package

Cider

Primary

fermentation

Secondary

fermentation

Water

Apple

Classifying

Cleaning

Milling

Enzyme treatment

Pomace

.

Pressing

Sulfitation

Adjustment

Activation

Yeast

prearation

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1. Classifying

a. Objective

Fresh cider fruit is traditionally stored for a few weeks after harvest so that all the starch converts

to suger (Although nowadays amylase added to the pulp can also achieve this). After post

harverst, apples usually have a different size and ripeness. To make the milling process easier, the

manufacturer need to classify apples by size. Those which are too big or too small will be

separated and will be treated in another mode.

Figure 16: Apples are classified by size on conveyor belt

Those which are unripe or overripe will reduce the quality of the juice and cider product. So that,

classification by ripeness is really nesscesary, just those which fully ripe or reached technical

maturity will be took part in production line. Apples should be sound. Defects such as rots or

insect damage will lower cider quality. Apples having these problems should be discarded.

Figure 17: Overripe apple and normal apple

Furthermore, in the classification process, we also need to eliminate the damaged fruit caused by

mechanical impacts or by microorganisms and insects.

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b. Transformations of material

There is no transformation occurring during this process.

c. Equipment

Figure 18: Workers are classifying apples

Many workers stand around a conveyor belt, picking out items that unsatisfactory. Not every

worker finds every low quality item, but there are enough workers standing at this belt that at the

end of the line almost all of the low quality items have been removed.

Roller conveyor can turn the apples from all sides, so that worker can easily detect unsatisfied

items.

Technical parameters

Velocity of conveyor is about 0,1 - 0,15 m/s and 60-80 cm in width.

Figure 19: Roller conveyor

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2. Cleaning

a. Objective

Preparation: Remove the impurities in material, prepare for the milling process.

Improvement : sensory, physic-chemiscal and biological qualities will be better due to

reduction of contaminants.


Physical: Remove dust, sand cling on peel of apples.

Chemical: Reduce pesticide level.

Biological: Reduce level of microorganism on the peel.

Affected factors

Quality of water (composition and temperature )

Soaking time

Intensity of nozzle spray

Amount of air blown

c. Equipment

Figure 20: Conveyor washing combine spraying

Equipment includes four parts:

1. Material chute

2. Conveyor belt transfer material under the water for rinsing

3. Air blown tube

4. Spray nozzle with pressure

Materials are put into equipment by trough and then follow the conveyor, moving under the

water. The air will be blown into the tube to soaking sink by fan and help mixing material. So

that, apples can impact each other and especially with water, make the dirt soften and dissolve

easily. Velocity of conveyor determine the soaking time of apples. Next, materials are led

through spray nozzle with pressure further aids in removing dirt and microorganisms.

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Figure 21: Spray nozzle with pressure

To improve efficiency of cleaning process and saving water, people usually supply water in the

opposite direction of fruit. Let the cleaning water flow continuously of rinsing step to washing

then re-use for soaking step and durty water will be poured out.


Cleaning time : 30 minutes

Pressure of spay nozzle : 2 - 3 atm

Temperature of water : 25C -30C

Hardness < 20mg/l

3. Milling

a. Objective

The purpose of milling process is reduced apples size to pulp by mechanical forces. The finer the

fruit is ground before pressing, the more cider will be collected. Grinding serves to break cell

walls and liquid inside will be easily extracted.

Preparation: Breaking appe to smaller size that help juice easily escape so that yield of

pressing process will be improved.


Physical: reduce material size, temperature rising due to friction.

Chemical: break the structure of fruit cells that easily make the oxidation-reduction

reactions happen and reduce the nutritional value of product.

Biological: after milling, surface area will increase, microorganism thrives and flavoring

constituents synthesized by them will negatively affect product quality.

- Biochemical: the more substrate expose to oxygen, the more oxidation-reduction reactions

catalyse by enzymes occur stronger.

The size of product after milling should not be too small because the suspened particles will

affect the sensory quality of final product.

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Affected factors

The size of material: the bigger the apple, the easier the breakage under the same

mechanical forces.

Hardness: the harder material is, the more the energy will be used.

The more speed of rotation, the greater the force, the more breakable material is and the

better effective milling process.

c. Equipment

Roller mill.

Structure of equipment include 2 horizontal serrated cylinders and be linked with a rotor.

When rotor turn around, 2 rolls rotate in opposite directions, collision between materials and

rotary serrated roll will break apples down and reduce the size of apple. There is a perforated

screen under the roll, milled apples which achieved size will pass through and released by

discharge chute.

Figure 22: Perforated screen under the rolls Figure 23 : Serrated rolls

Figure 24 : Roller mill diagram

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Pore size : 0,3cm - 1cm

Rotation speed of rolls : 750rpm

4. Enzyme treatment

a. Objective

Some time, to increase pressing yield, manufacturers add enzyme pectinase and enzyme cellulase

into the tank that contain apples after milling. It help to break cell walls made from cellulose

down and transform pectins which stabilises the cell walls of apple so that juice inside apple cells

can easily escape out. . In some cases, they clarify naturally cloudy juices.

The addition of pectinase following crushing significantly reduces the pectin content and their

effect on pressing or filtration.

Preparation : prepare for pressing operation, increase pressing yield.

Improvement: improve the transparecy of product.

b. Transformation of material

Physical : reduce viscosity of juice.

Biochemical: Enzyme pectinase catalyzes hydrolysis reaction and breaks -1,4 glycocidic

linkage in pectin compounds.

Affected factors :

Temperature and pH : Every enzyme has an optimized range temperature and pH which

will help to increase enzyme activity and shorten treatment time. If the temperature is too

high, enzyme will be irreversible inhibited. pH value too high or too low will reduce

enzyme activity, reaction rate and reaction yield.

Enzyme preparation concentration : High concentration of enzyme not only increase

reaction rate and yield, but also increase the cost for production line.

Substrate concentration : Every enzyme has an limited range of substrate concentration,

too high level may inhibit enzyme.

Treatment time need to be optimized, long time of treatment may reduce the level of

product and increase energy cost.

Activator and inhibitor in juice can accelerate or shorten time for treatment.

c. Equipment

Tank for enzyme treatment is a vertical cylindrical tank with convex bottom, made from stainless

steel, cooling jacket outside and a mixer inside to stir the pulp with enzyme thoroughly.

However, mixer will not work continuously during process to limit the exposed air and oxidation

reaction.

Apples after milling will be contained into tank, adjust till the optimal temperature and pH value

and then will be added in enzyme pectinase.

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Technical parameters :

Temperature : 50C

Time: 30 minutes

pH value: 3,5 - 4

Ratio of enzyme pectinase per pulp : 0,05ml/100g pulp.

5. Pressing

a. Objective

Next the pulp must be crushed to extract the juice. This is done in a cider press. As pressure is

applied, the juice flows out. The effect of air on the juice is that gives cider a brown color. A fair

amount of sugar still remains in pomace so by adding a litre or two of water to each 5 kg of

broken-up pomace before re-pressing, a useful yield of slightly weaker juice may be obtained,

which is usually added to the first pressing.

The pressed pomace is also dried in hot air to 12% moisture and used for manufacture of pectin,

or it is directly sold on for cattle feed.

Exploitation: separate the juice from apples thoroughly.


There is no transformation in this process, except mechanical change. Under the pressing force,

volume and density will be changed. Friction is made by screw may increase the temperature of

juice.

Affected factors

Porosity of material : the higher the porosity, the more effective the pressing, against the

hardness.

c. Equipment

Screw press include :

Steel perforate cylinder for the juice or must escaping

Figure 25: Steel perforate cylinder

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Screw made from stainless steel with the diameter and height of thread screw increases

from the inlet to outlet. That screw can rotate by a motor, hollow structure inside for

cooling by water.

Trough under the screw contained the juice.

Figure 26: Structure of screw press

Apples after milling will be conveyed to screw pressing machine to extract the juice to pomace.

Material follow inlet trough and screw not only push material ahead but also made a force to

separate the juice from the pulp. Because of the steel perforated cylinder, pomace can be retained

and juice escape out with a residual pulp. At the end of the screw, pomace is pushed out.

Figure 27: Screw pressing machine


Screw speed : 150200rpm

Pressure : 138 150 N/m2

6. Sulfitation

a. Objective Preparation : inhibit bacteria and undesirable yeasts, prepare for fermentation. Improvement : prevent oxidation reaction which change aroma, flavor and color of cider.

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b. Transformation of material Chemical : Sulfur dioxide be able to bond with free oxygen, inhibit most microorganisms

and will prevent them from reproducing. SO combines with products of previous oxidation and prevents darkening of product.

Biological : microorganism will be inhibited and inactivated. Affected factors pH : The more low level of pH, the more free form of SO2 and more effective inhibition. Temperature: increase temperature to a limited range will help to raise SO2 content in

juice and improve ability to inhibit microbial.

Concentration of SO2 solution : should not exceed the limited level 350mg/L. c. Equipment

Potassium metabisulfite will be dissolved in water to make 10% SO2. To avoid the dilution of

juice, potassium metabisulfite may dissolved in apple juice first and then added directly into the

tank.

To distribute well SO2 solution into must, manufacturers can pump the solution into juice pipe,

adjust the flow rate and pumping process of both juice and SO2 solution will simultaneously

finish.

Technical parameters Sulphite concentration 100 ppm

Table 12 : Recommended concentration of sulphite in apple juice at various pH

7. Adjustment

Before fermentation, must need to blend, adjust and test some criterias.

a. Objective

The press juice then needs to be collected in another tanks and at this point it is convenient to

measure its sugar level, acidity and pH so that blending may be corrected with other batches of

juice pressed on the same day. Blending before fermentation can ensure good pH control < 3,8.

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Preparation: adjust concentration of sugar, pH prepare for fermentation process.

Improvement: complete flavours and taste for cider product.


Concentrations of chemical compounds are modified to make sure the quality of final product.

Blending is also necessary to produce ciders of different alcohol contents and additions of sugar

syrups are made to vary the degree of sweetness.

Table 13: Proportions of juice used in cider

Table 14: Content of apple juice used for cider making

Juice from Cider Apple Juice from Culinary Apples

Specific Gravity 1,045 1,061 1,047 1,057

Tannin 1.0 4.6 g/l 0.6 1.6 g/l

Total sugar 98 131 g/l 100 118 g/l

Total Nitrogen 76 267 mg/l 98 250 mg/l

Amino Nitrogen 13 106 mg/l 10 112 mg/l

Adjust pH and acidity

If the total acid is too low, the pH will be too high and the fermentation will be susceptible to

bacterial infections. If the total acid is too high, the pH will be low enough to safe guard against

infection but the final cider will be unacceptably sharp to the palate and may never be pleasant to

drink. A desirable juice pH range for cider making is say 3,2 - 3,8.

Adjust sugar content

Customize concentration of sugar by adding glucose syrup to ensure the final ethanol level.

Adjust nitrogen compounds

Customize nitrogen compound as a yeast nutrient in juice to help yeast can grow and maintain

metabolism like ammonium diphosphate or ammonium sulfate.

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c. Equipment

Must will be led into a stainless steel tank with mixer to blend all the additions and jacket to keep

the must cool. Sugar or additions will be brought into tank by a tube at lid of equipment and

sample will be drawn at sample door. After testing, if the must achieve those standards, it will be

drained out and fermented.

Figure 28: Cut-away view of a stirred-tank with a cooling jacket


Ammonium salt content : max 0,3g/L

Moisture content of malic acid powder 12 %.

Optimal pH range : 3,2 - 3,8

Sugar content : 10% -12%

8. Primary fermentation

a. Objective

Cider is made from apple juice as a result of fermentation carried out by yeasts added

deliberately, converts sugar to ethanol.

Processing : glucose and fructose in must will be convert to ethanol, highest metabolite concentration. In case of adding saccharose, yeast will use invertase enzyme to catalyze

them.

Inoculum preparation : Normally, to stabilize cider qualities, manufacturers prefer to use active

dry yeast at freeze drying form. These strains, in general, have good fermentation characteristics,

but, additionally, may also have some special features to meet the winemakers particular need.


Physical : destiny, temperature will be change

Physic-chemical : supply oxygen or use mixer will made partly oxygen in the air dissolve

into culture.

Biology : metabolism and growth of yeast.

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Chemical and bio-chemical : glucose and fructose in must will be convert to ethanol by

yeast.

Alcolholic fermentation can be described as a three-step process :

Glucose and fructose (six carbon molecules) are beaked down into phosphoglyceraldehyde (three carbon molecule) by phosphorylation

Phosphoglyceraldehyde (three carbon molecule) is transformed into carbon acetaldehyde and carbon dioxide (source of CO2 for fermentation) by decarboxylation.

Acetaldehyde is reduced to ethyl alcohol as an end product.

Figure 29: Transformation from glucose to ethanol

Affected fators :

Inoculum strain : use yeast preparation for ethanol fermentation will stabilize and shorten

fermentation time with suitable inoculum size.

Concentration of sugar : the more level of sugar in must, the more ethanol content in

product, but too high concentration of sugar will increase osmatic presser and inhibit the

yeast cell.

Nitrogen content and growth factor : ensure to maintain metabolism of yeast.

pH : low pH value will prolong fermentation time.

Sulfur dioxide content : high level of SO2 content may inhibite yeast cell.

Temperature and fermentation time : every yeast strain has an optimal limited range of

temperature and time. High temperature ( > 35C ) may inhibit the cell and short time can

affect badly to qualities of cider due to fermentation has not completed.

c. Equipment

Batch fermenter has cylinder with conical bottom, made from stainless steel that corrosion

protection with cooling unit due to jacket. Moreover, there was a mixer and sensor inside the

fermenter. These sensor will help measure pH, temperature, alcohol content , and all of them

will be linked with computer, controlled by specific program.

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Before use, active dry yeast will be rehydrated at 5 times its weight in clean water, initially at

40C and stand for 15 minutes then adjust to fermented temperature. The primary fermentation

will last for 48 hours at 25C when ethanol content in must achieve 5 - 7% then biomass and

death cells of yeast will be remove at the bottom of the tank and green cider will be cooled for

secondary fermentation.

Figure 30: Diagram of fermenter

Technical factors

Brix of medium : 12Bx

Inoculum size : 106 - 1,2.106cells/ml

pH : 3,2 - 3,8

Temperature : 22C - 25C

Time : 48 hours

9. Secondary fermentation

a. Objective

Improvement: Secondary fermentation help to increase aroma and flavor for cider product

especially reduction reaction of aldehyde and diacetyl, synthesize flavored ester.

b. Transformation of material

Biological : Residual yeast in must will continuously fermentated with slow rate and level

than primary fermentation due to low temperature, low substrate content and high

inhibitors content.

Chemical and biochemical: residual sugar will be convert by yeast into ethanol and CO2.

Aldehyde and keton will participate in reduction reactions to help improve flavor of

product. Specially reduction and autolysis of yeast cell.

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Affected factors

Oxygen : During secondary fermentation, presence of oxygen may oxidize phenolic

compounds and negatively affect to sensory quality of product.

Temperature : At low temperature, colloidal particle will easily to flocculate and improve

transparency for cider.

pH : changing pH value will change the ability to inhibit microorganism

c. Equipment

Cylinder tank made from stainless steel with conical bottom and jacket outside.

Secondary fermentation is the time for maturation. After primary fermentation,trub - the layer of

sediment that appears at the bottom of the fermenter, composed mainly of heavy fats, proteins

and dead cells of yeast - can leave bad flavors as they break down., the breakdown of yeast cells

is known as autolysis, so that cider need to be removed out of fermenter and making sure not to

splash and disturb the trub bed.

During the maturation stage the yeast begin to slow down and become inactive. They start to

absorb some of the minor byproducts in an attempt to store up important nutrients before falling

into a state of hibernation. Keep this process for a few weeks to ensure that those unwanted

byproducts are not detectable in the flavor profile of finished cider.



Time : 2 weeks

10. Filtration

a. Objective

After fermentation process, cider will be cloudy due to death cell of yeast, suspended particles

So that clarification of cider will not only improve sensory quality but also help pasteurization

process more easily with high level of heat conductor coefficient.

Improvement : improve transparecy of product.

Preservation : separate some suspended particles, microorganism and yeast cells, prolong

shelf life.


Micro filtration will separate inlet cider flow to two flows, permeate flow is a cider flow that pass

through filter and retentate flow is flow that can not pass through membrane.

Physical : separating fermented cider into permeate and retentate, change destiny and

increase clarity of product.

Chemical : changing in total solid content

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Dynamics of filter process is the different pressure between two side of membrane and be

generated by a inlet pump.

Affected factors :

Total solid content in cider liquid : the more concentration of total solid, the more osmatic

pressure and reduce the pressure that across the membrane.

Size of solid particles : membrane with 1,2m of pore size can practically separate yeast

cells from cider.

Temperature : High temperature may increase velocity of particles and improve

separation yield.

c. Equipment

In cross flow microfiltration, an incoming flow passes across, parallel with the surface of a

membrane, and two existing streams are generated. The permeate stream is the portion of the

fluid that passes through the membrane. This filtered fluid will contain some percentage of

soluble and/or insoluble components from the initial feed stream that are smaller than the

membrane removal rating. The remainder of the feed stream, which does not pass through the

membrane, is known as the retentate stream.

Figure 31: The mechanics of cross flow microfiltration

Equipment has horizontal cylindrical shape with many smaller diameter tube inside and be

perforated. Membrane grids will be curled up that formed tubular and be closely put into smaller

tube. Inlet flow will be pumped into smaller diameter tubes, retentate flow will be released at the

end, permeate will pass through the capillary membrane, escape out of small tube and follow the

way out path.

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Figure 32: Crossflow filtration system in industry

1. Tank

2. Pump

3. Reflux pump

4. Membrane filtration

Figure 33: Partly reflux model of retentate

Technical factors :

Pore size of cross-flow filter : 1,2m

Rate of inlet flow need to be stabled to limit the blockage

Pressure : 15bar

11. Pasteurization

a. Objective

Preservation : inactivated harmful bacteria and microorganisms like yeast, most in

fermentation, kill the vegetative cells of the common pathogenic bacteria and increase

storage time.


Chemical : high temperature may cause Maillard reaction and decompose some vitamin.

Biologycal and bio-chemical : inactivated harmful bacteria and microorganisms.

Physical : increase of temperature can affect to volatile particles.

Affected factors :

Cider product has a low pH value, so that we do not need a strictly pasteurized mode.

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c. Equipment

Plate heat exchanger

Pasteurization include 3 steps : Heating, holding and cooling.

Firstly, cider will be heated indirectly to 70C by heating agent - hot water. Two flows be led into

plates alternately, hot water will transfer heat through the plates and heat the cider to required

temperature. Secondly, cider will move through a tube to hold that temperature in 15 seconds and

finally it will be cooled to 20C by water.

Figure 34: Holding tube Figure 35: Structure of plates and arrangement of flows

Figure 36: Plate heat exchanging machine

Technical factors :

Time : 15s


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Table 15: Relative initial quality and shelf life of cider

12. Aseptic packaging

This step included : filling, capping and labeling in sterile chamber. The entire packaging process

is assured absolute sterility and prevented reinfection from harmful bacteria. Cider product must

not have impurities and do not happen any transformation of material that affect to final product.

Cider products are usually packed in glass bottles. Packaging is sterilized by H2O2 and high

temperature.

Figure 37: Cider packed in glass bottles.

Figure 38: Aseptic packaging chamber

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IV. CIDER QUALITY

1. Nutritional value

Table 16: General Composition of Cider

CHEMICAL COMPOSITION NATURAL SUGARS

Water (86% To 88%) Fructose (4.5% To 8.5%)

Carbohydrates (11% To 12%) Sucrose, (1.5% To 4.5%)

Fat (0.25%) Glucose (1.2% To 2%)

Protein (0.25%) ACID COMPOSITION

Fiber (0.5%) Malic Acid (0.15% To 1.1%)

Ascorbic Acid Or Vitamin C (3 Mg To 30 Mg/100 Gm) Citric Acid (Trace Amounts)

Figure 39: Nutrition summary for 1 cup

of Sparkling Cider

Figure 40: A sample of a simple

nutritional label for gallon containers of

cider

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2. Physicochemical characteristics

As with any beverage, the flavour of cider is a combination of taste and aroma. Cider product has

a little bit bitter and astringent taste due to tannin content and sour taste due to acid content.

Table 17: Physicochemical characteristics of Argentina cider.

Alcohol 4 to 7 GL Total acidity 4,5 g/lts. of Tartaric

acid

Volatile acidity 1 g/lts of Acetic

acidity

Sorbic acid (as sorbate) 250 mg/lts

Sugar superior to 16 g/lts pH 3,1 - 3,9

Sulfur dioxide

total

up to 150 mg/lts Turbity less than 1 U.T.N

Sulfur dioxide

free

from 20 to 100 mg/lts Poliphenols total content > 1,5 gr. / l. expressed

as tanic

Table 18: Physicochemical criteria of some commercial ciders

Criteria

Sample

US cider -Farnum Hill

Farmhouse

Fresh VietNam

cider - Firi

Pasteurized Firi cider

VietNam

Ethanol ( %v/v) 6,5 6,5 6,48

Residual sugar (g/l) 26,5 25 24,32

Total acidity (g/l) of

lactic acid 3,62 3 2,88

Aldehyde (mg/l) 56 55 55

Acetate ethyl (mg/l) 25 23 24

Isobutanol (mg/l) 9,02 9 9

Propanol (mg/l) 14 12 11,2

Table 19: Volatile compounds in cider

3. Microorganism characteristics

Total Plate Count: < 100 cfu/ml

Yeast & Mold: Negative

Listeria monocytogenes : Negative

Alyciclobacillus acidoterrestris: Negative

Escherichia Coli : Negative

Salmonella : Negative

S. aureus : Negative

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4. Sensory characteristics

Finished cider has a range in color from a pale yellow to a dark amber rose, do not have

impurieties and specific flavor of apple.

The following attributes should be considered when evaluating cider:

Sight the color of cider will vary with the apples used; the effervescence

Smell the aroma of the apples

Touch cider should have the right balance of malic acid and tannin

Taste the degree of sweetness

Sound range of effervescence (bubbles, carbonation)

Cider Flavor Wheel is a handy visual, usually use to help evaluate the qualities of a beverage by

going from a general characteristic and narrowing down to the specific.

Figure 41: Cider flavor wheel

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V. REFERENCES

1. L Vn Vit Mn, Cng ngh sn xut ru vang, Nh xut bn i hc Quc Gia Thnh ph

H Ch Minh, Tp.HCM, 2011.

2. L Vn Vit Mn, Li Quc t, Nguyn Th Hin, Tn N Minh Nguyt, Trn Th Thu Tr,

Cng ngh ch bin thc phm, Nh xut bn i hc Quc Gia Thnh ph H Ch Minh,

Tp.HCM, 2011.

3. L Vit Nga, Hon thin cng ngh ln men nc qu c cn thp, Bo co tng kt khoa

hc v k thut,H Ni, 3/2004.

4. Dr Sian Thomas, Juice Content in Ciders, FSA project Q 01057A, London, 2004.

5. M. Duenas, A. Irastorza, C. Fernandez, A. Bilbao and G. Del Campo, Influence of apple juice

treatments on the cider making process, Institute of Brewing and Distilling, 1997.

6. Violeta Nour, Ion Trandafir, Mira Elena Ionica, Compositional characteristics of fruits of

several apple cultivars, University of Craiova, Faculty of Horticulture and Faculty of Chemistry,

Romania, 2010.

7. Boyer, J. and R. H. Liu., Apple phytochemicals and their health benefits, Nutrition Journal 3,

2004.

8. Kim Johansen, Cider Production in England and France and Denmark, BRYGMESTEREN

- NR., 6/2000.

9. Department for the Environment, Food and Rural Affairs, Traditional Welsh Cider, EU Food

Policy Team - Food and Policy Unit, United Kingdom.

10. Ronald S.Jackson, Wine Science Principle and Application, Third Edition, Elsevier Inc, 2008.

11. www.cideruk.com

http://www.cideruk.com/

apple cider

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