AIJN Technical Committee Meeting, 18 March 2008

AGD 3.1.2 Revised RG Blackcurrant

The current website version is dated Revision March 2007. The modifications proposed by the COP Expert Group are indicated in bold blue.

Reference Guideline for Blackcurrant Juice/Puree

Introduction

This reference guideline seeks to define various acceptability parameters for blackcurrant juice.

The parameters are listed under 2 sections:

·  Section A contains various parameters that characterise the absolute quality requirements. They are considered as being mandatory for all blackcurrant juices marketed in the EU.

·  Section B contains various criteria relevant to the evaluation of identity and authenticity. It also contains some less critical quality criteria. It is crucial for users of this guideline to understand that a valid conclusion, regarding the authenticity of a particular sample, can only be reached providing the whole analytical picture has been subject to expert interpretation. If some parameters do not fall within the values quoted in Section B this does not mean, automatically, that the sample is adulterated.

The values and comments in this guideline are based on pure, authentic juices, without permitted ingredients and / or additives, exhibiting the characteristic colour and flavour of the named fruit.

Blackcurrant juice/purée is obtained, by definition of the EC Directive from mature and sound fruit by mechanical processes and is treated by physical means.

It is understood that :

-  blackcurrant juice/purée is made from Ribes nigrum L.

-  blackcurrant juice can be cloudy or clear.

-  for the fruit juice industry mainly blackcurrant juice is processed. The indicated values are therefore referred to litres.

-  only the treatments and processes regulated by the Fruit Juice Directive (see annex 8.1) are permitted.

-  for the reconstitution of concentrated fruit juices water should have the appropriate characteristics. The definition of "appropriate" is given under the specific comments on the A.I.J.N. Reference Guidelines completed by further details in annex 8.2.

-  the use of additives is regulated by horizontal European additives directives. The details are listed in annex 8.3.

-  if in-line water extraction (diffusion) of the edible part of blackcurrant is used in the manufacture of concentrated juice the following conditions have to be met [1]:

° the water used for the extraction must conform with the requirements as set out in chapter 5.3.b.;

° the temperature of the water should be as low as possible and no higher than 30 C;

° during this in-line water extraction process, apart from separation and re-addition of the WESOS stream, no further processes (e.g. enzymation or debittering) are allowed.

Various types and origins of fruit of industrial significance were subject to comprehensive analysis to provide the values found in this guideline. To help in their interpretation please read carefully the associated Commentary Notes.

A.  Absolute quality requirements

1. Industrially agreed upon requirements /

Commentary Notes

DIRECT JUICE
Rel. density 20/20 for juice / min. / 1.042 / Although most single strength juices/purées will show a rel. density of 1.047 or higher, it has been acknowledged that single strength juices/purées from defined origins and/or varieties can show lower figures, but the lowest acceptable value is 1.042.
Corresponding Brix / min. / 10.5
JUICE FROM CONCENTRATE
Rel. density 20/20 for juice / min / 1.047
Corresponding Brix / min / 11.6
2. Hygiene requirements
Volatile acids as acetic acid / g/l / max. / 0.4
Ethanol / g/l / max. / 3.0
D/L Lactic acid / g/l / max. / 0.5
3. Environmental requirements
Arsenic and heavy metals
Arsenic (As) / mg/kg / max. / 0.1
Lead (Pb) / mg/kg / max. / 0.05
Copper (Cu) / mg/kg / max. / 5.0
Zinc (Zn) / mg/kg / max. / 5.0
Iron (Fe) / mg/kg / max. / 15.0 / In canned products higher values for iron and tin are possible but they should not exceed official limits.
Tin (Sn) / mg/kg / max. / 1.0
Mercury (Hg) / mg/kg / max. / 0.01
Cadmium (Cd) / mg/kg / max. / 0.05
4. Compositional requirements
L-ascorbic acid / mg/l / min. / 500 / The L-ascorbic acid content is subject to variations depending on variety, ripeness and processing. The average natural L-ascorbic acid content is over 1000 mg/l. The minimum value refers to products before bottling. In products from concentrate the minimum value can be even lower.
Hydroxymethylfurfural (HMF) / mg/l / max. / 20

B. Further criteria for evaluation of identity and authenticity

The B-criteria are not a set of standards. If the result of any analysis falls outside the given parameters, the conclusion should not automatically be drawn that the product is questionnable. For a balanced interpretation it is necessary to consult the General Comments and the Detailed Comments.
Commentary Notes
Titratable acidity at pH 8.1 / mval / 420 / - / 630 / The acidity is essentially determined by the proportion of indicated citric acid and is subject to variations. The values indicated correspond to 26.7 - 40.1 g/l, calculated as anhydrous citric acid pH 8.1.
Citric acid / g/l / 26 / - / 42 / Citric acid is the dominating acid. The lower range limit is usually reached. If it is not reached it may be supposed that water or other juices have been added. Values of more than 1.05 g/g titratable acid (calculated as anhydrous citric acid, pH 8.1) indicate the addition of citric acid or salts of citric acid..
D-Isocitric acid / mg/l / 125 / - / 500
Citric acid: D-Isocitric acid / 80 / 200 / The D-isocitric acid content and the citric acid-isocitric acid ratio are dependent on provenance and season. The range limits are seldom exceeded.
L-malic acid / g/l / 1 / - / 4 / A direct relation between the contents of citric acid and L-malic acid cannot be recognised. If the value of max. 0.11 g/g titratable acid (calculated as anhydrous citric acid, pH 8.1) is exceeded it may be supposed that malic acid or other juices (e.g. red currant juice, pome fruit juice) have been added.
D-malic acid / mg/l / n.p. / D-malic acid is not present in the fruit. Small amounts detected can be due to analytical methodology.
Ash / g/l / 5 / - / 10 / The ratio of the ash content to the acid content (calculated as anhydrous citric acid, pH 8.1), has only a small range (0.18 - 0.30).
Sodium (Na) / mg/l / max. / 30
Potassium (K) / mg/l / 2000 / - / 4100 / The average potassium content in the ash amounts to 45 %, but varies between 42 - 48 %.
Magnesium (Mg) / mg/l / 80 / - / 200 / The magnesium is normally less than 50% of the calcium content present in the juice
Calcium (Ca) / mg/l / 160 / - / 550 / .
Total phosphorus (P) / mg/l / 160 / - / 360
Nitrate (NO3) / mg/l / max. / 15
Sulphate (SO4) / mg/l / max. / 500 / In the case of juices with excess sulphate contents it may be supposed that a sulphurization treatment or a manipulation of the mineral substances has been performed..
Formol number ml 0.1 M NaOH/100 ml / ml / 7 / - / 30 / The formol number is heavily dependent on the ammonium content which is quite high as compared to the amino acid content. Because of the relatively large range of the formol number, an isolated formol number is not very useful without a knowledge of the amino acid composition.
Glucose / g/l / 20 / - / 50
Fructose / g/l / 25 / - / 65
Glucose : fructose / 0.6 / - / 0.9 / Glucose: Fructose ratios lower than 0.6 are a sign of microbiological degradation of the glucose.
Sucrose / The juice of blackcurrants contains almost no sucrose. Immediately after juice extraction, low sucrose contents up to 5 g/l have been observed in some cases
Values refer to 26.9 g/l titratable acid pH 8.1 calculated as anhydrous citric acid.
Sugar-free extract / g/l / 55 / - / 80 / Values refer to 20 g/l titratable acid pH 8.1 calculated as anhydrous citric acid
Sorbitol / mg/l / max. / 150 / To avoid false positive results, due to the method of analysis, a value up to 150 mg/l is acceptable. Higher values may indicate presence of other fruits or another sorbitol containing material.
Amino acids / mg/l / mmol/l* / The assessment of blackcurrant juices/purées on the basis of the amino acids spectrum is limited by the fact that most of the concentrations are too low and the range of the individual free amino acids too great both when comparing the varieties of blackcurrant and also the different crop years. It is also dependent on the processing technology.
Aspartic acid
Threonine
Serine
Asparagine
Glutamic acid
Glutamine
Proline
Glycine
Alanine
Valine
Methionine
Iso-leucine
Leucine
Tyrosine
Phenylalanine
gamma-Aminobutyric acid
Ornithine
Lysine
Histidine
Arginine
Ammonia / 20 - 100
10 - 80
15 - 115
30 - 400
40 - 220
max. 730
10 - 100
3 - 20
35 - 180
10 - 60
max. 30
6 - 40
3 - 40
max. 30
max. 30
70 - 340
max. 8
1 - 40
1 - 45
10 - 140
max. 150 / 0.15 – 0.75
0.08 – 0.67
0.14 – 1.1
0.23 – 3.03
0.27 – 1.5
max. 5
0.09 – 0.87
0.04 – 0.27
0.39 – 2.02
0.09 – 0.51
max. 0.2
0.05 – 0.31
0.02 – 0.31
max. 0.17
max. 0.18
0.68 – 3.3
max. 0.06
0.01 – 0.27
0.01 – 0.29
0.06 – 0.8
max. 8.82
Remark : n.p. = not present

* The range expressed in mmol/l is obtained from the range in mg/l by calculation

6.11 Reference Guide Blackcurrant Outcome Nantes COP Expert Group Revision March 2007