AIJN Technical Committee Meeting, 18 March 2008

AGD 3.1.4 Revised RG Strawberry

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 Strawberry Juice/Puree

Introduction

This reference guideline seeks to define various acceptability parameters for Strawberry 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 strawberry 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

Strawberry 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 :

-  strawberry juice/purée is made from Fragaria x ananassa Dutch H.

-  strawberry juice can be cloudy or clear.

-  for the fruit juice industry mainly strawberry juice is mainly processed into juice and so values are expressed per litre.

-  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 strawberry 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. / 1.025 / Although most single strength juices/purées will show a relative density of 1.028 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 1.025.
Corresponding Brix / min. / 6.3
JUICE FROM CONCENTRATE
Rel. density 20/20 for juice / min / 1.028
Corresponding Brix / min / 7.0
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. / 5.0 / 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
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 / 80 / - / 180 / The acidity is dependent on variety. The values indicated correspond to 5.1 - 11.5 g/l calculated as anhydrous citric acid pH 8.1
Citric acid / g/l / 5 / - / 11 / Citric acid is always the main acid.
D-Isocitric acid / mg/l / 30 / - / 90 / Low values may indicate microbial degradation.
Citric acid : D-Isocitric acid / 100 / - / 230 / The range limits are rarely exceeded.
L-malic acid / g/l / 0.6 / - / 5.0 / There is no direct relation between the contents of citric acid and L-malic acids contents. cannot be recognised. The malic acid content can be as high as 70 % of the citric acid level content.
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 / 2.8 / - / 6.0 / Usually the ash content is between 3 and 5 g/l.
Sodium (Na) / mg/l / max. / 30 / In the case of properly produced juices the sodium content is as a rule under 10 mg/l. In the case of values over 20 mg/l the origin of the raw materials or the technology should be investigated.
Potassium (K) / mg/l / 1000 / - / 2300 / The potassium content in the ash is in the range of 30 to 50 %.
Magnesium (Mg) / mg/l / 70 / - / 170 / Only in rare cases is the lower limit is not reached.
Calcium (Ca) / mg/l / 80 / - / 300
Total phosphorus (P) / mg/l / 100 / - / 300 / Only in rare cases is the lower limit is not reached.
Nitrate (NO3) / mg/l / The nitrate concentration is influenced by the soil composition or fertilisation. There is no relation to the type of variety processed. Values up to 200 mg/l or even higher have been found.
Sulphate (SO4) / mg/l / max. / 150 / Higher sulphate concentrations indicate, amongst other things, unauthorised sulphur dioxide treatment.
Formol number ml 0.1 M NaOH/100 ml / ml / 5 / - / 26 / Due to its the broad range the formol number is not very significant.
Glucose / g/l / 15 / - / 35
Fructose / g/l / 18 / - / 40
Glucose : fructose / g/l / 0.75 / - / 1.0 / Lower values indicate microbial degradation damages.
Sucrose / g/l / max. / 10 / Sucrose is a natural constituent of strawberry but only even if it occurs at only in low concentrations. Only in rare cases is more than 10 g/l are found and values above this must be carefully examined.
Sugar-free extract / g/l / 15 / - / 35
Sorbitol / g/l / max. / - / 0.25 / Higher values indicate the use of fruits containing sorbitol or the processing of spoiled raw material.
Amino acids / mg/l / mmol/l* / The assessment of strawberry 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 strawberry and also the different crop years. It is also dependent on the processing technology.
Due to the generally low levels and the wide ranges seen for the amino acids the assessment of strawberry juices/purées by this method is of limited use. The concentrations are dependant on the variety, season and processing technology, e.g. The content varies within large limits. Tthe asparagine, for instance, will show the highest values in a purée and the lowest value in a clarified juice. In order to detect possible adulterations, it is suitable useful to combine different analytical data.
In the case of an increased proline content, it may be supposed that the juice/purée has been blended with other products with a high proline content.
Aspartic acid
Threonine
Serine
Asparagine
Glutamic acid
Glutamine
Proline
Glycine
Alanine
Valine
Methionine
Iso-leucine
Leucine
Tyrosine
Phenylalanine
delta gamma-Aminobutyric acid
Ornithine
Lysine
Histidine
Arginine
Ammonia
Ethanolamine / 15 - 250
5 - 70
10 - 150
150 - 1500
20 - 250
traces - 750
traces - 30
traces - 20
5 - 350
traces - 30
traces - 10
traces - 15
traces - 40
traces - 40
traces - 40
5 - 120
traces - 10
1 - 70
traces - 35
traces - 40
5 - 90
traces - 18 / 0.11 – 1.88
0.04 – 0.59
0.1 – 1.43
1.14 – 11.36
0.14 – 1.7
traces - 5.14
traces - 0.26
traces - 0,27
0.06 – 3.93
traces - 0.26
traces - 0.07
traces - 0.11
traces - 0.31
traces - 0.22
traces - 0.24
0.05 – 1.17
traces - 0.08
0.01 – 0.48
traces - 0.23
traces - 0.23
0.29 – 5.29
traces - 0.3
Remark : n.p. = not present

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

6.14 Reference Guide Strawberry Outcome Nantes COP Expert Group Revised May 2007