Pro-Juice® Refractometer0 pages

Case study

Pro-Juice® Refractometer
ACHIEVING HIGHLY REPRODUCIBLE °BRIX MEASUREMENT OF
ORANGE JUICE USING A PRO-JUICE® REFRACTOMETER

For many years now, beverage manufacturers have adopted digital
refractometers as their primary instrument for measuring the final
dilution ratio (°Brix) of re-constituted fruit juice not only to assure
product quality but also in an attempt to reduce losses by tightly
controlling concentrate yields. For most fruit types this has been
successful but for one of the most commonly produced juices,
the high accuracy measurement achieved by the latest digital refractometers has unmasked an erratic behaviour within an orange
juice sample that prevents tighter dilution control. Consequentially,
this negates any opportunity of cost reduction by way of lowering
target values without the risk of compromising minimum specifications defined by regulation. As a functional food, it is therefore essential that the quality of orange juice is rigorously monitored.

Order date:t

2012

Completion:t

2012
Solution Provider

Product Code:

FPrevious reports into the phenomenon have cited varying deviations between sample, instrument and ambient temperatures
causing an irregular stabilization period between sample analysis
compounding the effects of solid particles settling on to the prism
surface as being the root cause. Others have discussed possible
electro-static affects or absorption as possible causes. However,
until now, no manufacturer has managed to provide an absolute,
or more importantly, practical solution to resolve the issue.

UK Major Fruit Juice Producert

Xylem’s role:t

(Figure 1 – Readings of Three Orange Juice applications on a
Digital Refractometer)

End user:t

22-10

Xylem scope:
Following extensive on-site trials, Xylem’s role was to
design, manufacture, deliver, install and commission a
number of Pro-Juice Refractometers so that the
customer could refine production line blend ratios to
an extent that losses were significantly reduced;
enabling the customer to maximize juice yield from
concentrate that in turn contributed to an increase in
profitability.

Recently, leading refractometer manufacturer Bellingham + Stanley, part of Xylem’s analytics businesses, has been
working alongside a major fruit juice producer in order to develop an instrument that can achieve the same high
accuracy results for orange juice samples as it can for other fruit based juices. By focusing on the practical handling
of the sample prior to high accuracy measurement, Bellingham + Stanley has designed an instrument based on its
leading RFM340+ refractometer that offers a measurement accuracy of 0.01 °Brix for sucrose solutions and more
importantly, a reproducibility of 0.02 °Brix between orange juice samples, regardless of temperature deviation or
operator skill level.
(Figure 2 – Comparison of Reading Deviation from Average on Different Refractometers)