New philosophy in DryingMangoesProblem

In a revolutionary approach towards drying mangoes, Munters andLandman Dried Produce embarked on a journey of research and proved anew drying method that is conceptually and thermodynamicallyground-breaking in the fruit-drying industry. Landman Dried Producehas been exporting fresh mangoes to Europe for many years prior toembarking on drying their mangoes for export. Munters and LandmanDried Produce got together with the mutual goal of setting a newstandard in quality dried mango.

Landman Dried Produce were contracted to produce a specific tonnage ofdried mango for export to Europe and worked together with Munters toensure this outcome. Two drying chambers were erected to accept 7500kg of wet fruit when fully packed. The chambers are designed to copewith the heavy drying-load of batch drying as an alternative to acontinual-flow “first in first out” method, which is a much lessproductive.

The batch drying approach was previously complicated due to theexponential change of the rate at which moisture is given off by theproduct. With Munters help the batch drying approach has now beenperfected. The most significant effect during the drying process to beavoided, is the formation of an outer skin on the product, as this willinhibit any further moisture loss from the fruit.

Quality Solution...

Munters supplied an enhanced MX7600 system to supply low humidityair through a tunnel holding wet mango layered out on trays. 7500kg ofwet mango were batch dried to 1500kg in 30 hours.

Drying tropical fruit

A Quality Solution

• Increased productivity

• No skin formed during drying

• Optimised air distribution

• Maximised evaporative effect

• Extremely good colour retention

• More natural taste and texture

• Lower risk of mould and yeastformation

• Optimised energy-efficiency

The Humidity Expert

Layers were created to maximise airdistribution over the mangoes formaximum evaporative effect. Muntersfound an optimised three-step humidityapproach suitable for the varyingconditions required during the process.Temperature and humidity is keptconstant in the re-circulated air and careis taken not to surface dry the product.The evaporative effect is extremelystrong in the first step of the dryingcycle, so Munters create the optimumhumidity level whilst maintaining thesupply air at 35oC.

This new drying process is revolutionarybecause at no stage is the fruit warmerthan 36oC. This has a major impact onquality, as too much heat affects bothcolour and taste. With this newMunters approach, colour retention isextremely good and taste more natural,with improvements in the driedproduct’s texture too.

Hygiene and Reliability

Hygiene is more easily controlled inMunters “enclosed-loop” system. If allcare is taken with hygiene from thebeginning of the process, there is a lowrisk of yeast formation in this type ofsystem. This is because the air isrecirculated and reconditioned without

the possibility of being contaminatedwith unnecessary fresh air.

Because Munters have a carefullycontrolled climate inside this“enclosed-loop” system, the producerdoes not feel the effects of varyingambient climate conditions which canresult in a reduction of output from thedrying chamber. Extended drying times

come with an increased risk of yeast andmould formation. With Munters system,a producer can control how much isdried and its quality. Continuity of flowthrough any drying facility is important,as the fresh fruit cannot be storedindefinitely without becoming spoiled.

Energy efficiency

Munters approach optimises theenergy-efficiency in two areas oftemperature and enthalpy. Because thedrying chamber removes moisture fromthe fruit, the air needs to be conditionedto create the right climate condition forthe fruit to relinquish its moistureefficiently and naturally. Muntersmethod utilises 40% less energyconsumption than envisaged by theproducer. Landman Dried Produce hashad very positive feedback from theirinternational clientele and the newapproach produces superlative quality.While the mango-drying season typicallyends mid-April, Landman DriedProduce can now continue throughoutthe year, drying other fruits such asbanana and papaya, where the resultshave also been more than satisfactory.

Tap into your local Munters HumidityExperts by contacting your local office orread more about our solutions atwww.munters.com/food

060926_09301404553200-06/11

Munters A/SRyttermarken 43520 FarumTel +45 4495 3355Fax +45 4495 3955Email: info@munters.dkwww.munters.dk