Cloudy apple juice is drunk all year round. But for the majority of consumers, shaking the dregs for distribution is not an option. We show what can be done.

Cloudy apple juice is drunk all year round in German-speaking countries. The special “naturally cloudy” appearance is valued in addition to the familiar taste and additional benefits of secondary botanicals in the sediment. For the majority of apple juice consumers, shaking sediment to distribute it is not an option. Mechanical engineering provides juice processors with sophisticated technologies for pulping and juicing. There is the right set-up for everyone, from the mobile packing press or belt press to fully programmable hydraulic presses and various continuous juicing systems. At first sight technical additives are unnecessary, but they can help to circumvent many of the daily struggles.

Use of enzymes in cloudy apple juice
The issue of the need to use enzymes can be answered with a clear No… but really yes because it almost always helps. As an apple contains increasing proportions of dissolved pectins (hydropectin) with greater ripeness, this greatly impairs juicing system performance. Naturally this has a very great impact on belt press users. The continuous process results in certain quality advantages, but reaches the limits of efficiency as soon as the apple’s pressability declines significantly due to ripeness. If in doubt, hydraulic presses can achieve the specified total yield as a result of longer pressing times. Yet every additional press stroke wastes time, an irritation that reduces income at the peak season. In continuous operation a belt press also relies on effective belt cleaning. Its effectiveness declines perceptibly during continuous operation due to sticky pomace. The use of enzymes prepares the mash for more efficient juicing. The tissues do not decompose. The aim of enzyme treatment is therefore not so much an economic optimum, but efficient safeguarding of achievable target parameters. Even at low doses of Fructozym^® APX (20 – 40 ml/t) the liquid phase viscosity is adequately reduced, without impairing the stability of the haze particles. The gel-like pectin is also quickly degraded on the pomace particles, which makes cleaning the press material much easier.

The particular case of pectin pomace
The pectin-rich pomace in a cloudy juice process is particularly suitable for pectin recovery. The purified pectin esterase Fructozym® Flot Fructozym® Flot is the first choice in these mashes. Preparations with a broader efficacy continue to act too long after pressing, as it is impossible to avoid a period that is difficult to monitor until the drying machinery is reached.

Control starch and lees
Initially the storage substance starch occurs in the form of crystals in apples, with arelatively small proportion being already hydrolysed. Overall, the starch content in apples decreases significantly with increasing ripeness. Starch crystals mainly present a problem as a component in the lees which do not remain stable in suspension. This fraction is separated off by means of (accelerated) sedimentation. This step is assisted by low dosing of pectinase -– as a transition from mash enzymation or as (sparing) dosing to the raw juice. Lees separation also makes sense in the event of the juice being stored with the subsequent option of clarification. As starch loses its natural structure through storage, this makes subsequent removal much more difficult. In principle, thism also applies to other coarse particles from cellulose fibres, polysaccharides, protein and polyphenol fractions. None of them are “improved” by a storage process, so should be promptly removed from play if possible.

Direct effects of enzyme application

• Stabilisation of juice yield at realistic optimum
• Good system capacity through improved pressability
• Fast cleaning of press materials (performance, hygiene)
• Management of turbidity reduction and starch content

Other options for cloudy juice production

• Mash heating to obtain darker juices
• Ditto for optimum enzyme use -> minimal reactivity at typical autumn temperatures
• Ercobin Ercobin (pure ascorbic acid) up to 1000 mg/L
• Deposition tank with use of amylase
• Addition of Klar-Sol 0 Klar-Sol 30 directly before the separator -> Stoppage of turbidity and optimum starch separation

System purification
Remaining fruit residues are a perfect feeding ground for harmful organisms. This is why effective periodic cleaning of the processing line is one of the most important quality assurance measures. The new e.Clean Tools is a high performance enzymatic cleaner. Botanical biofilms composed of pectins, cellulose, starch residues and so on can be removed in this way and subsequently easily cleaned. Press cloths, jigger screen, pumps and corner pipe strainers visibly benefit from use.

Tip:
Non-enzymated apple mash has a much-improved structure with suitable drainage for rapid pressing with the help of a specially prepared cellulose fibre, CelluMASH. Better total yield and rapid cleaning of press membranes or belts are the direct benefits of organic, easily compostable pressing aids. CelluMASH is added to the mash stream as continuously as possible.

Summary of benefits of kieselguhr-free variants of VarioFluxx PreCoat:

• Turbidity comparable with kieselguhr filtration
• Greater filter lifetimes possible (up to 30%)
• Improved safety at work (no cristobalite)
• No waste requiring special treatment (easy disposal via agriculture all year round)
• No investment costs (filtration using existing systems: frame filter, candle filter or centrifugal discharge filter)
• Familiar working method
• Reduce air/sea/land miles (CO2 footprint)
• Goods come from Europe and Germany