Digital Re-print - May | June 2012Mould control in grain and feed preservation Grain & Feed Milling Technology is publishe...
FEATUREMOULD                                                                                           in grain           ...
Siwertell grain ship unloader at Rizhao Port, ChinaGrain handling systemsthat you can truly rely onCargotec’s land-based S...
FEATURE                                                                                                  of propionic acid...
News         May - June 2012                                                                                              ...
This digital Re-print is part of the May | June 2012 edition of Grain & Feed Milling Technology magazine. 	 Content from t...
MOULD CONTROL in grain and feed preservation
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MOULD CONTROL in grain and feed preservation


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Moulds are ubiquitous and unavoidable contaminants in all animal feeds. Virtually all animal feeds contain moulds and viable mould spores which continue to pose a threat to grain quality.

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MOULD CONTROL in grain and feed preservation

  1. 1. Digital Re-print - May | June 2012Mould control in grain and feed preservation Grain & Feed Milling Technology is published six times a year by Perendale Publishers Ltd of the United Kingdom. All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies, the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of information published. ©Copyright 2010 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1466-3872
  2. 2. FEATUREMOULD in grain and feedCONTROL preservation by André Meeusen, application manager and Yvonne van der Horst, technical manager, Kemira ChemSolutions b.v., The NetherlandsM oulds are ubiquitous and unavoida- a widespread application, however, this is not shelf life, maintains nutritional value, and prevents ble contaminants in all animal feeds. an efficient way to tackle the problem as they formation of mycotoxins. Virtually all animal feeds contain damage the nutritional quality of feeds. Thesemoulds and viable mould spores which continue toxin binders, which usually contain different Mould and moistureto pose a threat to grain quality. types of clay minerals, are not that efficient and Development of moulds in feed depends on may even compromise nutrient digestibility. the interaction of several factors, including the Moulds are fungi which are distinguished Moreover, mycotoxin contaminated feeds can presence of spores, the availability of nutrients,by the formation of mycelium (a network impair the animals’ health and productivity duestorage time, temperature and moisture. Waterof filaments or threads), or by spore masses. to loss of appetite, feed refusal, allergic reactions, activity, i.e. the presence of free water, is theConditions that favour moulds include moisture reproductive failure, suppression of the immunemost important factor in the growth of moulds.levels higher than 12 percent, warm tempera- system and even mortality. Indeed, microbial spoilage of food and feedstures, the presence of oxygen, and prolonged Contamination by moulds and consequently, occurs at different levels of moisture and thestorage time. the production of mycotoxins, can be greatly water activity (aw) concept describes the water Many moulds are toxigenic and produce reduced by using organic acids as inhibitors. available for microbial growth.mycotoxins, a secondary metabolite created by Organic acids effectively inhibit the growth of Most feed mills optimise or maximise mois-moulds that is toxic to organisms other than the moulds, yeast and bacteria in different types of ture levels during feed production to com-mould itself. The growth of moulds and produc- feedstuffs and prevent recontamination after pensate for losses that occur during grinding,tion of mycotoxins by these moulds in feed production of the compound feed. This extends pelleting and cooling processes. Moreover, aingredients can cause significant eco- sufficient moisture level reduces thenomic losses. They consume valuable energy usage during the pelletingfeed nutrients such as vitamins and process and results in better pelletamino acids and they convert energy quality. The drawback of increasinginto water and CO2 and can cause moisture levels is that increasing levelstemperature increase as a result of of free water creates ideal condi-their carbohydrate metabolism (see tions for rapid mould growth and thebelow) development of mycotoxins. Moulds C6H12O6 + 6 O2 => 6 CO2 + 6 and yeast grow at aw > 0.75 and aw >H2O + Heat 0.85 respectively. Mould growth depletes the nutri- Products that protect feeds againstent density and affects feed palatabil- mould growth and at the same timeity and consequently decreases feed lower the aw are based on calciumintake. Moulds cause lipid oxidation or sodium propionate. Propionic acidand pigment deterioration and are is reacted with calcium or sodium todetrimental to animal health, perform- produce a salt with high propionic acidance and reproduction. The most level, 76-78 percent depending onfrequently found mycotoxins are afla- Fig 1: Assessing the activity of Kemira Mould Control the salt form. The acid is completelytoxins and ochratoxin produced by SP1 (calcium propionate) using a CO2 test on mash buffered, has a good solubility, is safeAspergillus, the latter are also produced feed. (Kemira ChemSolutions, Tiel, The Netherlands). to use and easy to handle. Theirby Penicillium and zearalenone and efficiency in shelf life extension whentrichothecenes produced by Fusarium used in feeds is dose related and canmoulds. be easily demonstrated by an in vitro accelerated method, increasing mois-Toxin binders vs. organic ture content and storage temperature,acids by measuring the CO2 production Animal feed is susceptible to mould over time. An efficient preservativegrowth. The microbiological quality of effect is obtained up to the momentfeed is a comparatively unexplored that CO2 production starts to increasearea but is receiving more attention (Figure 1).due to the recognition of mycotoxinsas a widespread economic threat. Fig 2: Aspergillus niger growth inhibition efficacies Grain preservation of organic acids on ground whole wheat grains. The use of toxin binders in feed is Animal feeds generally contain18 | may - June 2012 Grain &feed millinG technoloGy
  3. 3. Siwertell grain ship unloader at Rizhao Port, ChinaGrain handling systemsthat you can truly rely onCargotec’s land-based Siwertell ship unloaders and loaders are designed to suit each terminal’s specificrequirements. Siwertell systems use unique enclosed screw conveyor technology to ensure that dry bulk cargooperations are environment-friendly and efficient.Let the dry bulk handling experts design a custom-made answer to your particular • SIWERTELL IS A CARGOTEC BRAND
  4. 4. FEATURE of propionic acid Finland and compared to ammonium buff- Table 1: Mould inhibiting and killing-off effect of Propionic acid (Kemira Mould Control LP1) and formic – propionic (Kemira Mould Control LF1) to overcome the ered propionic acid (Kemira Mould Control buffered products in highly challenged conditions (Wessling 2011) odour and corro- LP1 NC). Figure 2 shows that the initial sion problems. inoculation with Aspergillus niger in grains TREATMENTS RESULTS To enter into without preservatives resulted in significant the mould cell, the growth during the first week. Both Kemira Name % Mould cfu/g Mould cfu/g Mould cfu/g acids have to pass a Mould Control LP1 NC and Kemira Mould double barrier, the Control LF1 at 0.2 w/w-%, inhibited growthPositive control: ASPERGILLUS inoculated 3.5∙104 4.7∙105 2.0∙107 cell membrane and of Aspergillus niger in grinded whole wheat the outer cell wall of grains over a 2 weeks period and total killKemira Mould Control LP1 nc 0,4 1.0∙103 <50 <50 these moulds. Inside off was obtained with both products at 0.4Kemira Mould Control LF1 0,4 8.5∙102 <50 <50 the moulds the w/w-%. Positive control: FUSARIUM inoculated 2.2∙105 3.6∙105 6.4∙106 organic acids dissoci- The same laboratory tests have been ate decreasing the repeated in Wessling Laboratories. AlsoKemira Mould Control LP1nc 0,4 2.0∙104 1.0∙102 <50 intracellular pH and here the inclusion of 0.4 percent with bothKemira Mould Control LF1 0,4 1.0∙102 <50 <50 compromising the products showed to be efficient in killing off Negative control <50 <50 <50 cell metabolism. The both types of moulds during a two weeks three-dimensional incubation period. The Fusarium moulds mould spores which originate from raw materials structure and the lipophilic character of propi- seemed somewhat more sensitive to the used. The three genera of moulds - Aspergillus, onic acid seems to play an important role for the formic acid based mould inhibitor with total Penicillium and Fusarium cause most cases of acids to pass through this double barrier. kill off at seven days already (Table 1). mycotoxin contamination in many grains and Kemira has developed several mould con- The efficacy of Kemira Mould Control LF1 their byproducts and in vegetable proteins. Their trol products containing appropriately buffered was further assessed in a simulated field trial at optimal growth is mostly influenced by tempera- acids avoiding the typical drawbacks of straight Wageningen UR, The Netherlands. The trial ture and this determines their global presence. acids. The organic acids in the liquid Kemira measured mould and temperature develop- Aspergillus and Penicillium species will grow Mould Control product range are buffered ment of fresh harvested grains during a four better in warmer-tropical climates whereas with ammonium or sodium, ensuring reduced month storage period at ambient temperature Fusarium moulds prefer cooler temperate cli- corrosivity and volatility and a long lasting pres- and results were compared to Kemira Mould mates. Moulds are obligate aerobe and their ervation effect. Control LP1nc. proliferation can thus be controlled by oxygen Ammonium buffering has the advantage The treatment with the formic acid based free storage, such as silage. They consume of delivering a proton H+ supporting a more Kemira Mould Control LF1 at 0.7 percent carbohydrates and provoke fat hydrolysis leading effective mould inhibitory effect. The inclusion of showed the biggest effect in preventing the to nutritionally low quality grains. Organic acids a lipophilic compound assures a better surface temperature to increase. It was significantly contact with grains and an easier penetration (P<0.05) lower than both the positive control Table 2: Mould counts in freshly harvest rolled into meals and feeds. It will also improve the (propionic acid based) and negative control. wheat after three weeks storage with and water binding capacity of feed materials and Moreover, results showed that Kemira Mould without treatment (Aberystwyth University) lower the water activity of feeds. This extends Control LF1 at 0.4 percent is as effective in Mould count the shelf life, maintains the nutritional quality, and inhibiting mould growth and preventing tem- Treatment (cfu/g) prevents the formation of mycotoxins in feeds perature increase in freshly harvested grains with and feedstuffs. high moisture content (17.6%) as the propionic acid based Kemira Mould Control LP1nc. Mould Kemira Mould Control LP1 nc 227 Formic acid based mould inhibitor growth was reduced from 5 log platable fungal Kemira Mould Control LF1 40 Traditionally propionic acid is used against colonies per gram in the non-treated grains Untreated >1,500,000 mould and mycotoxin formation. The relative down to 1.34 log/gram and 1.15 log/gram shelf life depends to a great extent on the pro- respectively. are known in the feed industry as an effective pionic acid content. Indeed, the lowest survival This was also confirmed in a field trial in UK, and affordable tool to control mould growth rates for Fusarium spp. and Aspergillus niger were monitored by Aberystwyth University in which in grains and their byproducts during transport achieved with the highest actual propionic acid freshly harvested wheat with a moisture content and storage. contribution, irrespective of the type of mould of 17.9 percent was rolled and treated with Anaerobic preservation of grains usually inhibitors tested. different dosages of the ammonium-sodium applies when moisture is very high, from 25 – As the leading global producer of formic buffered formic-propionic acid based product 45 percent. Grains are crimped before ensiling acid-based products for the animal feed industry, or with the ammonium buffered propionic acid with formic acid based products. Kemira has developed a new liquid mould inhibi- only and stored for eight months in 10 ton bins. Aerobic preservation is usually done with tor for grain preservation based on formic and At nine litres per ton of grains, both products whole grains with moisture content between propionic acid with an excellent ammonium- allowed easy storage without any temperature 15 – 25 percent. Typically, blends of different sodium buffering system to minimise volatility increase in the bins during the eight months. acids or acids with other active compounds are and corrosivity and ensuring proper handling Initial mould counts at three weeks showed used, with propionic acid being the principle properties. It is activated by lipophilic com- both products to be effective, compared to an active component. The level of propionic acid pounds. Formic acid does not have this lipophilic untreated sample. needed under local conditions depends on characteristic but it contains the highest antimi- This makes Kemira Mould Control LF1, a for- kernel quality, initial mould counts, storage con- crobial properties as this is the smallest molecule mic acid based blend with a novel ammonium ditions and time. of all the organic acids and has a > 60 percent – sodium buffering and activated by lipophilic higher number of active organic radicals per compounds, an interesting alternative to the Straight vs. buffered acids kilogram of pure substance. traditional propionic acid based products, assur- The mechanism of inhibition of growth The efficacy of such a novel ammonium- ing the fast killing of any mould that appears on of moulds by organic acids is generally not sodium buffered formic acid based product grains and assuring a save and long preservation. considered a pH phenomenon. It is the propi- (Kemira Mould Control LF1) on reduction onate ion or radical (CH3CH3CO0-) that is the of Aspergillus niger in grinded whole wheat More inforMation: active mould inhibiting ingredient in propionic grains was assessed in a laboratory study Kemira ChemSolutions b.v. acid, so attempts have been made to use salts done in the Kemira R&D center in Espoo- Email: 20 | may - June 2012 Grain &feed millinG technoloGy
  5. 5. News May - June 2012 NEWS Top-class grain cleaning within the smallest space Premiere of the new Bühler Vega High Performance Grain Classifier MTVA at Ipack-Ima 2012 in Milan, Italy F rom February 27 – March design and the high kinetic Perfectly THE GLOBAL LEADER 2, 2012, the new Bühler momentum acting upon the adaptable to INVALVES FOR Vega High Performance screen carrier. The outstanding specific needs DRY BULK SOLIDS Grain Classifier MTVA was separation of impurities ensures Depending on the presented to the specialist public optimal results for further specific design at Ipack-Ima in Milan, Italy. processing and storage of grain. version, the new Vega Per formance Grain Whether wheat, rye, oats, Amazing energy Classifier MTVA can be rice, corn/maize, or barley – savings applied for cleaning or the new Performance Grain T h e n e w B ü h l e r Ve g a grading grain. A total of Classif ier MT VA promises Performance Grain Classifier three different cleaner a n e xc e p t i o n a l l e v e l o f MTVA convinces by its high versions have been performance with minimized throughput capacities and designed to process energy consumption and a low energy consumption – up a wide range of grain very low space requirement. It to 50 percent energy savings varieties at throughput owes this performance over comparable machines are rates varying between 15 CARBON OR STAINLESS to its special screen possible. But Vega is also and 200 metric tons per distinguished in many hour. In the product inlet, other respects by its exemplary efficiency. an optional air-recycling aspirator separates low- UNIQUE FLOW DESIGN The use of high-grade components results in long maintenance density matter and fines from the accept material. The screens can be DUST TIGHT intervals. Even in continuous selected from the screen module to suit a wide CLEAN IN PLACE operation, this keeps range of requirements. maintenance cost s A total screen area as low. You can also save high as 28 square meters time and money when is available thanks to the changing its screens, horizontal staggering of with quick and easy the screens. screen changes being possible by one More inforMation : person. SKF launches new SE bearing housing series S KF has launched new SE The new design makes it Compared to SNL bearing housings. The unlikely for the housing to housings, the SE housing housings are an upgrade become distorted by over- improves heat transfer of the SNL housing series, which have been used in many tightening the attachment bolts A grease guiding system, from the bearing outer ring to the support surface, DUST TIGHT industries for many years. for relubrication from the side, applies grease directly reducing the temperature in the bearing. This makes WEAR COMPENSATING SEALS SKF claim the SE housing is a reliable, versatile solution for to the bearing during relubrication. This greases it possible to extend relubrication intervals ADJUSTABLE NYLON ROLLERS mounted bearing applications and is designed to meet the needs of customers across the bearing more reliably, making it possible to reduce gre ase quantities during w h i l e i n c re a s i n g t h e service life of the bearing and lubricant. STAINLESS MATERIAL CONTACT virtually all industrial and relubrication. These high quality processing sectors. housings provide improved The housings, which range from rust protection that is in size SE 507-606 to SE 532, are designed to exploit the accordance with the C3 corrosivity class ( ISO VORTEXVALVESEUROPE.COM full service life potential of 12944). the incorporated bearings, +44 (0) 870-770-9861 and significantly More inforMation: VORTEX.EU@VORTEXVALVES.COM reduce maintenance Website: costs and related downtime. Grain &feed millinG technoloGy may - June 2012 | 3
  6. 6. This digital Re-print is part of the May | June 2012 edition of Grain & Feed Milling Technology magazine. Content from the magazine is available to view free-of-charge, both as a full LINKS online magazine on our website, and as an archive of individual features on the docstoc website. Please click here to view our other publications on May - June 2012 • See the full issue • LC-MS/MS: The New Reference Method for Mycotoxin Analysis • Visit the GFMT website • Contact the GFMT Team • Mould control in grain and feed preservation In this issue: • NIR in practice • Rice and • Fast, reliable contract • Subscribe to GFMT and flexible: terms the world of modern bulk weighing • New weighing software for UK co-operative A subscription magazine for the global flour & feed milling industries - first published in 1891 GFMT12.03.indd 1 22/06/2012 08:48 To purchase a paper copy of the magazine, or to subscribe to the paper edi- tion please contact our Circulation and Subscriptions Manager on the link adove. INFORMATION FOR ADVERTISERS - CLICK HERE Article reprints All Grain & Feed Milling Tecchnology feature articles can be re-printed as a 4 or 8 page booklets (these have been used as point of sale materials, promotional materials for shows and exhibitions etc). If you are interested in getting this article re-printed please contact the GFMT team for more informa- tion on - Tel: +44 1242 267707 - Email: or visit